Vol. 12/ Núm. 2 2025 pág. 2908
https://doi.org/10.69639/arandu.v12i2.1116
Historical seismicity of the province of Chimborazo
Sismicidad histórica de la provincia de Chimborazo
Diego Javier Barahona Rivadeneira
dbarahona@unach.edu.ec
https://orcid.org/0000-0002-6476-9690
Universidad Nacional de Chimborazo
Ecuador
Wilson Roberto Barahona Ribadeneira
wili_barahona@msn.com
https://orcid.org/0009-0006-9446-9767
Centro académico de ingeniería estructural
Ecuador
Artículo recibido: 10 marzo 2025 - Aceptado para publicación: 20 abril 2025
Conflictos de intereses: Ninguno que declarar
ABSTRACT
This study analyzes the impact of gamification as a methodological strategy in the teaching of
mathematics at the Basic General Education level. The research is based on the need to transform
traditional pedagogical practices through innovative approaches that promote meaningful
learning and the development of logical-mathematical skills. A qualitative approach with a
descriptive design was used, applying interviews and direct observation with teachers and
students from an educational institution in Ecuador. The results show that gamification enhances
student motivation, engagement, and active participation in the classroom. Additionally,
improvements were observed in the understanding of mathematical concepts, problem-solving,
and collaborative work. It is concluded that integrating playful elements into teaching activities
strengthens the teaching-learning process and contributes to a more dynamic, inclusive, and
student-centered education. The study recommends training teachers in the use of digital tools
and gamification strategies, as well as promoting educational policies that support active
methodologies within the school curriculum.
Keywords: Ecuador, earthquakes, history, testimonies and natural disasters
RESUMEN
El presente estudio analiza el impacto de la gamificación como estrategia metodológica en la
enseñanza de las matemáticas en el nivel de Educación General Básica. La investigación se
fundamenta en la necesidad de transformar las prácticas pedagógicas tradicionales mediante
enfoques innovadores que favorezcan el aprendizaje significativo y el desarrollo de habilidades
Vol. 12/ Núm. 2 2025 pág. 2909
lógico-matemáticas. Para ello, se empleó una metodología de enfoque cualitativo con diseño
descriptivo, aplicando entrevistas y observación directa a docentes y estudiantes de una institución
educativa en Ecuador. Los resultados muestran que la gamificación potencia la motivación, el
compromiso y la participación activa de los estudiantes en el aula. Asimismo, se evidencian
mejoras en la comprensión de conceptos matemáticos, la resolución de problemas y el trabajo
colaborativo. Se concluye que integrar elementos lúdicos en las actividades didácticas fortalece
el proceso de enseñanza-aprendizaje y contribuye a una educación más dinámica, inclusiva y
centrada en el estudiante. El estudio recomienda capacitar a los docentes en el uso de herramientas
digitales y estrategias de gamificación, así como fomentar políticas educativas que promuevan
metodologías activas en el currículo escolar.
Palabras clave: Ecuador, terremotos, historia, testimonios y desastres naturales
Todo el contenido de la Revista Científica Internacional Arandu UTIC publicado en este sitio está disponible bajo
licencia Creative Commons Atribution 4.0 International.
lógico-matemáticas. Para ello, se empleó una metodología de enfoque cualitativo con diseño
descriptivo, aplicando entrevistas y observación directa a docentes y estudiantes de una institución
educativa en Ecuador. Los resultados muestran que la gamificación potencia la motivación, el
compromiso y la participación activa de los estudiantes en el aula. Asimismo, se evidencian
mejoras en la comprensión de conceptos matemáticos, la resolución de problemas y el trabajo
colaborativo. Se concluye que integrar elementos lúdicos en las actividades didácticas fortalece
el proceso de enseñanza-aprendizaje y contribuye a una educación más dinámica, inclusiva y
centrada en el estudiante. El estudio recomienda capacitar a los docentes en el uso de herramientas
digitales y estrategias de gamificación, así como fomentar políticas educativas que promuevan
metodologías activas en el currículo escolar.
Palabras clave: Ecuador, terremotos, historia, testimonios y desastres naturales
Todo el contenido de la Revista Científica Internacional Arandu UTIC publicado en este sitio está disponible bajo
licencia Creative Commons Atribution 4.0 International.
Vol. 12/ Núm. 2 2025 pág. 2910
INTRODUCTION
In Seismic Risk Analysis, historical seismicity studies provide important information, as
they correspond to a long period of time (approximately 400 years for the province of
Chimborazo, more representative over time, than instrumented studies carried out over a shorter
period in relation to the slowness with which seismic events occur.
However, historical data presents some drawbacks, such as the fact that small earthquakes
are often overlooked; records are available only from inhabited areas, which means that epicenters
are often poorly located. Due to the uncertainty of the information available, in some cases, the
intensity is exaggerated, which is why: " It is essential to dedicate time and effort to first
understand the construction systems of the period... "
But despite its imprecision, its analysis and interpretation can provide scientific data
regarding seismic intensities and magnitudes, as well as their location, the periodicity of seismic
activity over time, etc. However, this activity has not been well received by researchers and has
been somewhat neglected in the conduct of seismic hazard studies based on instrumental
information.
This paper analyzes the main seismic movements that shook the province of Chimborazo,
attempting to provide a scientific explanation of the impact of the geological phenomenon on the
buildings of the time and its consequences on the mortality of the population based on historical
evidence.
Seismic intensity
It is defined as follows: " the effects produced by earthquakes on structures and people are
measured by means of seismic intensity ", it is a subjective description of the destructive potential
of earthquakes. there are several intensity scales, one of them is called "modified mercalli", which
is indicated in summary form in table 1, the same one that was developed by wood and newman
in 1931 and is a modification of the one developed by mercalli in 1902.
macroseismic intensity scales in a publication by goula, starting with the rossi-forel scale
that appeared in 1873 up to the i msk scale proposed by medvedev, sponheuer and karnik, which
is widely used and accepted worldwide. it is observed that there is a good approximation between
the i mm and i msk scales . 2
Table 1
Modified Mercalli Intensity Scale I MM
1 MM DEFINITION
Yo
II
III
IV
V
VI
Detected only by instruments.
Felt by people at rest.
Felt by people inside a building.
You feel outside the building.
It's noticed by everyone. Unstable objects fall.
INTRODUCTION
In Seismic Risk Analysis, historical seismicity studies provide important information, as
they correspond to a long period of time (approximately 400 years for the province of
Chimborazo, more representative over time, than instrumented studies carried out over a shorter
period in relation to the slowness with which seismic events occur.
However, historical data presents some drawbacks, such as the fact that small earthquakes
are often overlooked; records are available only from inhabited areas, which means that epicenters
are often poorly located. Due to the uncertainty of the information available, in some cases, the
intensity is exaggerated, which is why: " It is essential to dedicate time and effort to first
understand the construction systems of the period... "
But despite its imprecision, its analysis and interpretation can provide scientific data
regarding seismic intensities and magnitudes, as well as their location, the periodicity of seismic
activity over time, etc. However, this activity has not been well received by researchers and has
been somewhat neglected in the conduct of seismic hazard studies based on instrumental
information.
This paper analyzes the main seismic movements that shook the province of Chimborazo,
attempting to provide a scientific explanation of the impact of the geological phenomenon on the
buildings of the time and its consequences on the mortality of the population based on historical
evidence.
Seismic intensity
It is defined as follows: " the effects produced by earthquakes on structures and people are
measured by means of seismic intensity ", it is a subjective description of the destructive potential
of earthquakes. there are several intensity scales, one of them is called "modified mercalli", which
is indicated in summary form in table 1, the same one that was developed by wood and newman
in 1931 and is a modification of the one developed by mercalli in 1902.
macroseismic intensity scales in a publication by goula, starting with the rossi-forel scale
that appeared in 1873 up to the i msk scale proposed by medvedev, sponheuer and karnik, which
is widely used and accepted worldwide. it is observed that there is a good approximation between
the i mm and i msk scales . 2
Table 1
Modified Mercalli Intensity Scale I MM
1 MM DEFINITION
Yo
II
III
IV
V
VI
Detected only by instruments.
Felt by people at rest.
Felt by people inside a building.
You feel outside the building.
It's noticed by everyone. Unstable objects fall.
Vol. 12/ Núm. 2 2025 pág. 2911
VII
VIII
IX
X
XI
XII
People walk with difficulty. Windows and glass objects break.
Structures with weak masonry crack.
Moderate damage to well-designed structures, and
severe damage due to poor construction.
Light damage to well-designed structures, considerable
in regular and severe in poorly designed ones.
General panic. Structures with earthquake-resistant design
are seriously damaged. Damage to the foundations.
Major destruction to well-built buildings.
Large landslides.
Almost nothing remains standing. Cracks in the floor.
Underground pipes out of service.
Almost total destruction. Catastrophe.
Large masses of rock displaced.
Seismic intensity depends on the following factors 2 :
The distance from the site to the epicenter: the further the population is from the epicenter,
the lower the intensity will be, since the damage will be less.
The type of soil in the affected areas; soft soils amplify seismic waves, increasing their
effects, while firm soils can attenuate them, thereby reducing damage.
The topography of the site; buildings constructed on the edge of slopes are more likely to
be damaged than those located on completely flat terrain.
It depends on the strength of the structures; buildings designed with earthquake-resistant
criteria will experience less damage than others.
It depends on the level of people's preparedness and government campaigns to prevent
natural disasters.
It should be noted that the intensity assessment carried out later has the particularity of
being applied to buildings made of adobe, lime and stone, which do not withstand seismic actions
in the same way as concrete. Furthermore, it refers to periods in which adequate construction
techniques did not exist, so we will cite descriptions of the homes of the time in order to
adequately estimate the intensity value.
Analysis of the main historical earthquakes
The Earthquake of 1645
In order to correctly analyze and evaluate the impact caused by this seismic event, we must
try to have a clearer conception of the city and the buildings destroyed at the time, for which the
following description of the Villa de Riobamba dating from the year 1605 is stated:
“ The town belongs to Spain; it has four main streets in length and four in width, and a
plaza. The residents' houses are low, built from adobe and roofed with thatch, with only
three or four having tiled roofs. They use the lower ones because they are more comfortable
and safer from the strong winds and the cold climate .”
VII
VIII
IX
X
XI
XII
People walk with difficulty. Windows and glass objects break.
Structures with weak masonry crack.
Moderate damage to well-designed structures, and
severe damage due to poor construction.
Light damage to well-designed structures, considerable
in regular and severe in poorly designed ones.
General panic. Structures with earthquake-resistant design
are seriously damaged. Damage to the foundations.
Major destruction to well-built buildings.
Large landslides.
Almost nothing remains standing. Cracks in the floor.
Underground pipes out of service.
Almost total destruction. Catastrophe.
Large masses of rock displaced.
Seismic intensity depends on the following factors 2 :
The distance from the site to the epicenter: the further the population is from the epicenter,
the lower the intensity will be, since the damage will be less.
The type of soil in the affected areas; soft soils amplify seismic waves, increasing their
effects, while firm soils can attenuate them, thereby reducing damage.
The topography of the site; buildings constructed on the edge of slopes are more likely to
be damaged than those located on completely flat terrain.
It depends on the strength of the structures; buildings designed with earthquake-resistant
criteria will experience less damage than others.
It depends on the level of people's preparedness and government campaigns to prevent
natural disasters.
It should be noted that the intensity assessment carried out later has the particularity of
being applied to buildings made of adobe, lime and stone, which do not withstand seismic actions
in the same way as concrete. Furthermore, it refers to periods in which adequate construction
techniques did not exist, so we will cite descriptions of the homes of the time in order to
adequately estimate the intensity value.
Analysis of the main historical earthquakes
The Earthquake of 1645
In order to correctly analyze and evaluate the impact caused by this seismic event, we must
try to have a clearer conception of the city and the buildings destroyed at the time, for which the
following description of the Villa de Riobamba dating from the year 1605 is stated:
“ The town belongs to Spain; it has four main streets in length and four in width, and a
plaza. The residents' houses are low, built from adobe and roofed with thatch, with only
three or four having tiled roofs. They use the lower ones because they are more comfortable
and safer from the strong winds and the cold climate .”
Vol. 12/ Núm. 2 2025 pág. 2912
With this description, we have an idea of the buildings of the Villa before the earthquake
of 1645, the summaries given by eyewitnesses of the catastrophe refer to the poor soil on which
Riobamba had been founded:
“ ...this said town is founded on bad soil very close to a large swamp that borders it, and
many of the houses have collapsed due to the earthquakes that began last March of this
year, and the temples, like those that remained standing, are very dangerous to enter
because they are open and damaged, both in the main chapels and in their bodies. ”
It is also indicated that the monasteries of Santo Domingo, La Merced, San Francisco and
San Agustín were seriously damaged, of which the following is reported :
“... The church of the convent of San Agustín is falling down due to the said earthquake...
because it is all... cracked so much that no man or woman dares to enter it or pass by the
said church and some of the cells are fallen down and others are falling down and the walls
of the corals and orchards of the said convent have fallen down, due to which the religious
of the said convent live in huts... they moved the Blessed Sacrament to the royal street
where they made a ramada in which they have celebrated until now...”
Taking into account the material of the buildings, the poor quality of the soil on which the
town was founded, which resulted in the amplification of seismic waves and the damage caused
by soil moisture in the foundations, so much so that it is claimed that some buildings fell down
without the need for earthquakes, where a Modified Mercalli intensity with a value of I MM =
VI, would be enough for the earthquake to cause cracks in the houses and some to collapse as
stated in historical archives, according to the Ecuadorian Earthquake Catalogue, provided by the
Geophysical Institute of the National Polytechnic School, the epicenter was found at the
coordinates - 1.68S and - 78.55W , very close to the town.
The Earthquake of 1698
June 20, 1698, a massive earthquake shook the central region of Quito's Sierra de la
Audiencia. Historical documents agree that the cause was the collapse of the Carihuairazo snow-
capped mountain.
This earthquake caused the destruction of Ambato, and its effects extended to neighboring
towns. In the town of Riobamba, the consequences of this "terrible cataclysm," as history
describes it, affected both religious buildings and private homes. The following is literally
stated: "... although the buildings suffered significant damage and several collapsed, the
danger from the ruins was extremely rare ..."
Taking into account the poor soil on which the Villa de Riobamba was founded and the
construction materials, mainly adobe, lime and stone, when evaluating the damage, the intensity
is I MM. = VII in the area of the town of Riobamba, since according to historical accounts it is
specified that the greatest damage occurred in Ambato because the aforementioned population
was very close to the epicentral zone that according to the Ecuador Earthquake Catalogue is
With this description, we have an idea of the buildings of the Villa before the earthquake
of 1645, the summaries given by eyewitnesses of the catastrophe refer to the poor soil on which
Riobamba had been founded:
“ ...this said town is founded on bad soil very close to a large swamp that borders it, and
many of the houses have collapsed due to the earthquakes that began last March of this
year, and the temples, like those that remained standing, are very dangerous to enter
because they are open and damaged, both in the main chapels and in their bodies. ”
It is also indicated that the monasteries of Santo Domingo, La Merced, San Francisco and
San Agustín were seriously damaged, of which the following is reported :
“... The church of the convent of San Agustín is falling down due to the said earthquake...
because it is all... cracked so much that no man or woman dares to enter it or pass by the
said church and some of the cells are fallen down and others are falling down and the walls
of the corals and orchards of the said convent have fallen down, due to which the religious
of the said convent live in huts... they moved the Blessed Sacrament to the royal street
where they made a ramada in which they have celebrated until now...”
Taking into account the material of the buildings, the poor quality of the soil on which the
town was founded, which resulted in the amplification of seismic waves and the damage caused
by soil moisture in the foundations, so much so that it is claimed that some buildings fell down
without the need for earthquakes, where a Modified Mercalli intensity with a value of I MM =
VI, would be enough for the earthquake to cause cracks in the houses and some to collapse as
stated in historical archives, according to the Ecuadorian Earthquake Catalogue, provided by the
Geophysical Institute of the National Polytechnic School, the epicenter was found at the
coordinates - 1.68S and - 78.55W , very close to the town.
The Earthquake of 1698
June 20, 1698, a massive earthquake shook the central region of Quito's Sierra de la
Audiencia. Historical documents agree that the cause was the collapse of the Carihuairazo snow-
capped mountain.
This earthquake caused the destruction of Ambato, and its effects extended to neighboring
towns. In the town of Riobamba, the consequences of this "terrible cataclysm," as history
describes it, affected both religious buildings and private homes. The following is literally
stated: "... although the buildings suffered significant damage and several collapsed, the
danger from the ruins was extremely rare ..."
Taking into account the poor soil on which the Villa de Riobamba was founded and the
construction materials, mainly adobe, lime and stone, when evaluating the damage, the intensity
is I MM. = VII in the area of the town of Riobamba, since according to historical accounts it is
specified that the greatest damage occurred in Ambato because the aforementioned population
was very close to the epicentral zone that according to the Ecuador Earthquake Catalogue is
Vol. 12/ Núm. 2 2025 pág. 2913
located at coordinates - 1.45S and - 78.25W , supporting the greatest damage, of such magnitude
that after this event the most convenient solution was to relocate rather than rebuild Ambato.
The inhabitants of Riobamba also approved the relocation of the Villa to the Gatazo plain:
“... in order to build the new city they took materials from the old one ...”, but the
government of the Audience did not agree to this relocation and also: “...this left them with
bitter experiences when this sector was flooded...” so the inhabitants of Riobamba had to
return to take up positions on their old lots in the Villa.
1797 earthquake
As previously stated, it is important to devote time and effort to learning the construction
techniques of the period. To this end, we will cite testimonies that indicate what the Villa de
Riobamba looked like before this earthquake. Around 1736, the city's appearance still reflected
its former opulence, an impression captured as follows:
"The main square and streets of this town are very regular and spacious. The houses are
made of lime and stone; although the latter is light, it is not as light as the pumice used in
Latacunga. Some are high, and this is more regular in those facing the square and its
surroundings; but the rest are all low due to the fear of earthquakes ..."
There is another description closer to the earthquake, since the Italian Jesuit father, Mario
Cicala, wrote the following in 1767:
“... The entire city is certainly majestic, beautiful, ornate, and noble... the Governor's and
Magistrate's houses are truly beautiful and immaculate, and are located in the main
square, with magnificent and richly furnished halls... but there are many single-story
houses, almost all of which are made of lime and stone, and a few of adobe. The roofs of
the houses in the city center are tiled; but most of the houses in the suburbs, especially
those of the Indians, are covered with thatched straw ...”.
The two testimonies coincide in the fundamentals with which one has a more or less clear
vision of the situation, the form and distribution of the Villa, with respect to the popular
architecture of the period in question in a very objective way one can have an idea since many of
the houses that were built during the reconstruction of the city have lasted until the present day:
“The houses were generally one-story, and some two-story, with a hallway, a large main
courtyard, and often a backyard or orchard and stables. The rooms were arranged around
the porticoed courtyard. In two-story houses, the staircase, usually made of stone and
brick, was located at one of the corners. The pillars supporting the upper floor were made
of stone and were octagonal or circular. The houses of the wealthy had essentially the same
design, but were distinguished by their larger dimensions, better materials, and sumptuous
finishes.
The front structure of the house, facing the street, had a gabled roof, while the other
sections had a single slope, known as "half-pitched." Depending on the owner's economic
located at coordinates - 1.45S and - 78.25W , supporting the greatest damage, of such magnitude
that after this event the most convenient solution was to relocate rather than rebuild Ambato.
The inhabitants of Riobamba also approved the relocation of the Villa to the Gatazo plain:
“... in order to build the new city they took materials from the old one ...”, but the
government of the Audience did not agree to this relocation and also: “...this left them with
bitter experiences when this sector was flooded...” so the inhabitants of Riobamba had to
return to take up positions on their old lots in the Villa.
1797 earthquake
As previously stated, it is important to devote time and effort to learning the construction
techniques of the period. To this end, we will cite testimonies that indicate what the Villa de
Riobamba looked like before this earthquake. Around 1736, the city's appearance still reflected
its former opulence, an impression captured as follows:
"The main square and streets of this town are very regular and spacious. The houses are
made of lime and stone; although the latter is light, it is not as light as the pumice used in
Latacunga. Some are high, and this is more regular in those facing the square and its
surroundings; but the rest are all low due to the fear of earthquakes ..."
There is another description closer to the earthquake, since the Italian Jesuit father, Mario
Cicala, wrote the following in 1767:
“... The entire city is certainly majestic, beautiful, ornate, and noble... the Governor's and
Magistrate's houses are truly beautiful and immaculate, and are located in the main
square, with magnificent and richly furnished halls... but there are many single-story
houses, almost all of which are made of lime and stone, and a few of adobe. The roofs of
the houses in the city center are tiled; but most of the houses in the suburbs, especially
those of the Indians, are covered with thatched straw ...”.
The two testimonies coincide in the fundamentals with which one has a more or less clear
vision of the situation, the form and distribution of the Villa, with respect to the popular
architecture of the period in question in a very objective way one can have an idea since many of
the houses that were built during the reconstruction of the city have lasted until the present day:
“The houses were generally one-story, and some two-story, with a hallway, a large main
courtyard, and often a backyard or orchard and stables. The rooms were arranged around
the porticoed courtyard. In two-story houses, the staircase, usually made of stone and
brick, was located at one of the corners. The pillars supporting the upper floor were made
of stone and were octagonal or circular. The houses of the wealthy had essentially the same
design, but were distinguished by their larger dimensions, better materials, and sumptuous
finishes.
The front structure of the house, facing the street, had a gabled roof, while the other
sections had a single slope, known as "half-pitched." Depending on the owner's economic
Vol. 12/ Núm. 2 2025 pág. 2914
power, the walls were built of brick or sun-dried mud adobe mixed with chopped straw.
The main walls were quite wide, while the secondary walls, which bore less weight, were
thinner and sometimes made of wattle and daub. The walls were covered with a plaster of
mud with chopped straw and plastered with a layer of fine mud. The use of stone was rare
in popular houses, but not so in stately homes, public buildings, and especially in churches.
The two-slope roofs were built in the form of wooden scissors, the ends of which rested on
rib beams embedded in the main walls. The apexes of the scissors were joined to the ridge
beams, from which thin timbers and longitudinal strips were stretched for the tiles. The
room ceilings were made of reed cloth or matting lined with materials similar to those used
for plastering the walls.
In large churches, convents, and stately homes, the building materials were of higher
quality. They were generally constructed of bricks bound with mortar (lime, sand, and
water). Stone was widely used in the plinths of facades, doorways, and porches. The
thickness of the walls varied, but they were generally very wide, depending on the desired
consistency of the construction, reaching up to a meter thick and even more in large spaces.
Tile was the common roofing material. In rural areas, this type of construction could be
found on large estates and workshops. However, in many cases, buildings of this type also
had adobe walls with a unique mortar of stone (quarried or river stone), brick, or some
other type of material mixed into the fill.
The construction techniques for stately homes were obviously the best known at the time.
Each owner strove to demonstrate his financial means with the solidity, sumptuousness,
and ornamentation of his dwellings, just as religious orders did in churches and convents
as a demonstration of faith and to attract the faithful. It is also true that there was already
awareness of earthquakes, and efforts were made to ensure the solidity of buildings.
In the poor houses of cities and towns, or in rural areas, adobe, bahareque, and rammed
earth dominated the construction of dwellings, with tile or thatched roofs and brick floors.
As is logical to assume, if many important buildings were built by hand, this type of house
was even more so, and consequently, their construction techniques were extremely poor,
with no interlocking (confinement) between the walls, at the corners, or with the interior
walls, and a precarious connection with the beams of the roofs and floors.
The above gives us an idea of the materials used to construct the buildings and their size,
as well as the construction techniques of the time, allowing us to understand the structures that
withstood the earthquake and analyze the reasons for their collapse.
Between seven and eight in the morning of February 4, 1797, the earthquake occurred on
such a large scale that, as historical documents report, there was total desolation and devastation
of the town of Riobamba and some other nearby towns. To get an idea of the catastrophe, we will
power, the walls were built of brick or sun-dried mud adobe mixed with chopped straw.
The main walls were quite wide, while the secondary walls, which bore less weight, were
thinner and sometimes made of wattle and daub. The walls were covered with a plaster of
mud with chopped straw and plastered with a layer of fine mud. The use of stone was rare
in popular houses, but not so in stately homes, public buildings, and especially in churches.
The two-slope roofs were built in the form of wooden scissors, the ends of which rested on
rib beams embedded in the main walls. The apexes of the scissors were joined to the ridge
beams, from which thin timbers and longitudinal strips were stretched for the tiles. The
room ceilings were made of reed cloth or matting lined with materials similar to those used
for plastering the walls.
In large churches, convents, and stately homes, the building materials were of higher
quality. They were generally constructed of bricks bound with mortar (lime, sand, and
water). Stone was widely used in the plinths of facades, doorways, and porches. The
thickness of the walls varied, but they were generally very wide, depending on the desired
consistency of the construction, reaching up to a meter thick and even more in large spaces.
Tile was the common roofing material. In rural areas, this type of construction could be
found on large estates and workshops. However, in many cases, buildings of this type also
had adobe walls with a unique mortar of stone (quarried or river stone), brick, or some
other type of material mixed into the fill.
The construction techniques for stately homes were obviously the best known at the time.
Each owner strove to demonstrate his financial means with the solidity, sumptuousness,
and ornamentation of his dwellings, just as religious orders did in churches and convents
as a demonstration of faith and to attract the faithful. It is also true that there was already
awareness of earthquakes, and efforts were made to ensure the solidity of buildings.
In the poor houses of cities and towns, or in rural areas, adobe, bahareque, and rammed
earth dominated the construction of dwellings, with tile or thatched roofs and brick floors.
As is logical to assume, if many important buildings were built by hand, this type of house
was even more so, and consequently, their construction techniques were extremely poor,
with no interlocking (confinement) between the walls, at the corners, or with the interior
walls, and a precarious connection with the beams of the roofs and floors.
The above gives us an idea of the materials used to construct the buildings and their size,
as well as the construction techniques of the time, allowing us to understand the structures that
withstood the earthquake and analyze the reasons for their collapse.
Between seven and eight in the morning of February 4, 1797, the earthquake occurred on
such a large scale that, as historical documents report, there was total desolation and devastation
of the town of Riobamba and some other nearby towns. To get an idea of the catastrophe, we will
Vol. 12/ Núm. 2 2025 pág. 2915
mention the following testimonies, which fundamentally coincide with the other accounts of the
witnesses:
Don Ignacio Lizarzaburu on February 22, 1797 declares the following:
" That he has seen the town ruined, its streets and squares covered by fallen buildings with
no traffic on them except for the destroyed roofs, without finding a house or church
standing due to all the destruction caused by the collapse of the Cullca hill , with whose
mass a third or more of the town was buried, without any houses or living people being
saved in the three neighborhoods of Sigcho Guayco , Barrionuevo and La Merced.
That its ground is entirely open, its streets, as has been said, covered with ruins and the
entire floor gushing water, in addition to the lakes that have been formed both by the torrent
named Quilloyaco , and by the river that was dammed by the landslide and that has taken
its course through half the town...”.
Don Luis Nájera's story says the following
“ ...He found Riobamba in such a pitiful state that he could not recognize the parts that
previously comprised it, nor the houses that adorned it because they were overturned from their
foundations and so joined together in what were previously streets, nothing was noticeable but
destroyed roofs, and he also saw the mountain named Cullca overthrown from its foundations ,
taking under its collapse a large part of the population ...”.
But this must be analyzed in a very objective way so as not to overvalue the intensity, since
there were already references about the poor soil on which the Villa de Riobamba was founded,
and in some accounts it is understood that although they were seriously damaged, not all the
buildings collapsed as stated in other testimonies such as the following account of the
investigation by González Suárez that points out 19:
“The scene of the greatest devastation was the city of Riobamba and its province, where
not a single church remained standing, not a single house that wasn't reduced to rubble or cracked
and threatening ruin....”
Furthermore, it is difficult to establish the magnitude of what is described as "precipitous
landslides" and "landslides of all the surrounding hills," as reported in most affected towns, since
it can be interpreted as a genuine catastrophe or as small landslides that obstructed communication
routes. We must also take into account that the main accounts recorded in history are those of the
authorities of the Audiencia and the towns, informing the Spanish authorities, in most cases
requesting financial aid and tax exemptions due to the catastrophe, perhaps making it seem larger
than it actually was. Thus, after evaluating the testimonies not only from Riobamba but also from
the other affected towns, an average intensity of 1 MM = IX was established, which, given the
materials used to build the houses and the swampy soil of the town, would define the great
destruction described in the story.
mention the following testimonies, which fundamentally coincide with the other accounts of the
witnesses:
Don Ignacio Lizarzaburu on February 22, 1797 declares the following:
" That he has seen the town ruined, its streets and squares covered by fallen buildings with
no traffic on them except for the destroyed roofs, without finding a house or church
standing due to all the destruction caused by the collapse of the Cullca hill , with whose
mass a third or more of the town was buried, without any houses or living people being
saved in the three neighborhoods of Sigcho Guayco , Barrionuevo and La Merced.
That its ground is entirely open, its streets, as has been said, covered with ruins and the
entire floor gushing water, in addition to the lakes that have been formed both by the torrent
named Quilloyaco , and by the river that was dammed by the landslide and that has taken
its course through half the town...”.
Don Luis Nájera's story says the following
“ ...He found Riobamba in such a pitiful state that he could not recognize the parts that
previously comprised it, nor the houses that adorned it because they were overturned from their
foundations and so joined together in what were previously streets, nothing was noticeable but
destroyed roofs, and he also saw the mountain named Cullca overthrown from its foundations ,
taking under its collapse a large part of the population ...”.
But this must be analyzed in a very objective way so as not to overvalue the intensity, since
there were already references about the poor soil on which the Villa de Riobamba was founded,
and in some accounts it is understood that although they were seriously damaged, not all the
buildings collapsed as stated in other testimonies such as the following account of the
investigation by González Suárez that points out 19:
“The scene of the greatest devastation was the city of Riobamba and its province, where
not a single church remained standing, not a single house that wasn't reduced to rubble or cracked
and threatening ruin....”
Furthermore, it is difficult to establish the magnitude of what is described as "precipitous
landslides" and "landslides of all the surrounding hills," as reported in most affected towns, since
it can be interpreted as a genuine catastrophe or as small landslides that obstructed communication
routes. We must also take into account that the main accounts recorded in history are those of the
authorities of the Audiencia and the towns, informing the Spanish authorities, in most cases
requesting financial aid and tax exemptions due to the catastrophe, perhaps making it seem larger
than it actually was. Thus, after evaluating the testimonies not only from Riobamba but also from
the other affected towns, an average intensity of 1 MM = IX was established, which, given the
materials used to build the houses and the swampy soil of the town, would define the great
destruction described in the story.
Vol. 12/ Núm. 2 2025 pág. 2916
Due to the devastating effects suffered by the town of Riobamba with the earthquake, the
survivors were forced to take refuge in the neighboring parish of Cajabamba:
“After the earthquake...they built miserable huts out of wood and straw...in which they
spent the day weeping and wailing. A few days after the earthquake, the rains began; the lack of
shelter, the dampness, and above all the putrefaction of the hundreds of corpses lying under the
rubble caused malignant fevers, and the plague was added to the misery, finishing off the remnants
that had survived the catastrophe.”
The migration of the survivors to other regions of the Audiencia such as Guayaquil and
Cuenca then began, which led the corregidor of the Villa to call a Public Assembly or Open
Council that took place on March 21, 1797 in order to establish a suitable site for the relocation
and construction of the Villa since it was not possible to build it on the same site since according
to reports the ground was: " swampy, broken and threatened by landslides from the nearby hills .
"Two possible sites were finally proposed for the relocation of the city: Tapi and Gatazo. To
analyze the advantages and disadvantages of each of the sites, the town's mayor appointed a
commission made up of Dr. Andrés Falconí, Don José Antonio Lizarzaburu, Don Vicente Antonio
de León and Don José Larrea y Villavicencio, who were to present a report indicating the most
favorable site. The report was presented on March 30, 1797, in which the Tapi plain was indicated
as the most suitable for the construction of the town. However, in response to this report, the
town's attorney, Don Ignacio Velasco y Unda , pointed out that the information presented by the
commission lacked objectivity since the inspection carried out in the presence of the mayor on
the Tapi plain demonstrated otherwise.
The decision between Tapi and Gatazo was influenced by the interests of wealthy
landowners, who even steered the decisions of the open town council in their favor. Gatazo was
not a place that benefited their interests; rather, they were threatened, since building the town
there would entail selling their land to a population mired in an acute economic depression, which,
at best, could only offset a portion of the land's real value. For their part, the religious communities
that owned large estates in the area did not welcome the move, but they did not speak out either.
The Tapi plain, on the other hand, was uninhabited and largely royal land; that is, it belonged to
the king, and acquiring the plots for the construction of the new town would cost them nothing.
Ignacio Velasco y Unda stated that only twenty wealthy people would be interested in moving to
Tapi and not to Gatazo because their estates would be closer to the city. Based on these arguments,
a new meeting was called for the town to express its decision on July 12, 1797:
“Having gathered a considerable or majority of the people, at approximately four in the
afternoon, as a result of what was ordered in the order that was published regarding the positions
convenient for their benefit, they said resolutely and openly where they wanted to be transferred,
whether to Tapi or Gatazo, to which they unanimously expressed that they wanted to go to
Gatazo.”
Due to the devastating effects suffered by the town of Riobamba with the earthquake, the
survivors were forced to take refuge in the neighboring parish of Cajabamba:
“After the earthquake...they built miserable huts out of wood and straw...in which they
spent the day weeping and wailing. A few days after the earthquake, the rains began; the lack of
shelter, the dampness, and above all the putrefaction of the hundreds of corpses lying under the
rubble caused malignant fevers, and the plague was added to the misery, finishing off the remnants
that had survived the catastrophe.”
The migration of the survivors to other regions of the Audiencia such as Guayaquil and
Cuenca then began, which led the corregidor of the Villa to call a Public Assembly or Open
Council that took place on March 21, 1797 in order to establish a suitable site for the relocation
and construction of the Villa since it was not possible to build it on the same site since according
to reports the ground was: " swampy, broken and threatened by landslides from the nearby hills .
"Two possible sites were finally proposed for the relocation of the city: Tapi and Gatazo. To
analyze the advantages and disadvantages of each of the sites, the town's mayor appointed a
commission made up of Dr. Andrés Falconí, Don José Antonio Lizarzaburu, Don Vicente Antonio
de León and Don José Larrea y Villavicencio, who were to present a report indicating the most
favorable site. The report was presented on March 30, 1797, in which the Tapi plain was indicated
as the most suitable for the construction of the town. However, in response to this report, the
town's attorney, Don Ignacio Velasco y Unda , pointed out that the information presented by the
commission lacked objectivity since the inspection carried out in the presence of the mayor on
the Tapi plain demonstrated otherwise.
The decision between Tapi and Gatazo was influenced by the interests of wealthy
landowners, who even steered the decisions of the open town council in their favor. Gatazo was
not a place that benefited their interests; rather, they were threatened, since building the town
there would entail selling their land to a population mired in an acute economic depression, which,
at best, could only offset a portion of the land's real value. For their part, the religious communities
that owned large estates in the area did not welcome the move, but they did not speak out either.
The Tapi plain, on the other hand, was uninhabited and largely royal land; that is, it belonged to
the king, and acquiring the plots for the construction of the new town would cost them nothing.
Ignacio Velasco y Unda stated that only twenty wealthy people would be interested in moving to
Tapi and not to Gatazo because their estates would be closer to the city. Based on these arguments,
a new meeting was called for the town to express its decision on July 12, 1797:
“Having gathered a considerable or majority of the people, at approximately four in the
afternoon, as a result of what was ordered in the order that was published regarding the positions
convenient for their benefit, they said resolutely and openly where they wanted to be transferred,
whether to Tapi or Gatazo, to which they unanimously expressed that they wanted to go to
Gatazo.”
Vol. 12/ Núm. 2 2025 pág. 2917
With the unanimous opinion of the people to move the city to Gatazo, Velasco y Unda
asked that the decree issued by the president of the Court on June 17, 1797, by which the transfer
of the town to Tapi was established, be revoked.
The president of the Court, Luis Muños de Guzmán, appointed an impartial and proven
person to inspect the two sites of Tapi and Gatazo. Don Bernardo Darquea, mayor of Ambato,
was assigned. After inspecting the area, he decided that Tapi was the area that presented the best
conditions for the relocation of the village. He drew a plan for the new settlement, delineated it,
and laid out a regular layout. Despite this confirmation, disputes among the village residents
continued, with no consensus being reached.
To calm the town's residents, the Court appointed a new delegate to carry out the inspection.
This responsibility fell to Don Antonio Pastor, the Royal Administrator of the Town's Taxes. The
new survey was carried out on August 6, 1798, with the participation of the Town Council
authorities, the town's principal residents, and the prelates of the religious orders. It was concluded
that the definitive location for the town's relocation was the place called San Martín de Tapi. This
site was close to the Chibanca River creek and had sufficient water, stones, and other materials
needed to build the houses. Furthermore, the San Juan irrigation ditch, which supplied water to
the town, was being worked by Antonio Lizarzaburu, who stated that the water could be
introduced within a maximum of two months.
Although the townspeople were not entirely in agreement with the decision to build the
new town on the site of San Martín de Tapi, the authorities established it as the permanent
location. However, a new alternative for the relocation emerged, presented by Don José de León
y Otalora, Senior Councilor of the Riobamba Town Council. In a communication addressed to
the president of the Audiencia on September 13, 1798, this official indicated the site of Chambo
as a possible location for the town.
Although the president of the Court was aware of the new proposal, he reaffirmed the
decision to promptly relocate the prison to the San Martín de Tapi plain. His latest statement on
the matter was:
“ ...that, although there are opinions in favor of Chambo, San Andrés, Cajabamba itself, the
main interest is that no town in the Correguimiento loses its identity by being annexed to the New
Town and that the chosen site where the waters have already been conducted will be respected...”.
The streets were laid out. The nobility and religious communities were in possession of
their lands, and the transfer of water under the direction of Antonio de Lizarzaburu had been
completed. Despite this, a large part of the population remained in Cajabamba and in the old city.
“The Riobamba people, so attached to the land where they were born, preferred to live in
poor straw huts amid the rubble of their beloved city, rather than move their homes to the Tapi
plateau, even though the huts burned easily and they were left exposed to the elements.”
With the unanimous opinion of the people to move the city to Gatazo, Velasco y Unda
asked that the decree issued by the president of the Court on June 17, 1797, by which the transfer
of the town to Tapi was established, be revoked.
The president of the Court, Luis Muños de Guzmán, appointed an impartial and proven
person to inspect the two sites of Tapi and Gatazo. Don Bernardo Darquea, mayor of Ambato,
was assigned. After inspecting the area, he decided that Tapi was the area that presented the best
conditions for the relocation of the village. He drew a plan for the new settlement, delineated it,
and laid out a regular layout. Despite this confirmation, disputes among the village residents
continued, with no consensus being reached.
To calm the town's residents, the Court appointed a new delegate to carry out the inspection.
This responsibility fell to Don Antonio Pastor, the Royal Administrator of the Town's Taxes. The
new survey was carried out on August 6, 1798, with the participation of the Town Council
authorities, the town's principal residents, and the prelates of the religious orders. It was concluded
that the definitive location for the town's relocation was the place called San Martín de Tapi. This
site was close to the Chibanca River creek and had sufficient water, stones, and other materials
needed to build the houses. Furthermore, the San Juan irrigation ditch, which supplied water to
the town, was being worked by Antonio Lizarzaburu, who stated that the water could be
introduced within a maximum of two months.
Although the townspeople were not entirely in agreement with the decision to build the
new town on the site of San Martín de Tapi, the authorities established it as the permanent
location. However, a new alternative for the relocation emerged, presented by Don José de León
y Otalora, Senior Councilor of the Riobamba Town Council. In a communication addressed to
the president of the Audiencia on September 13, 1798, this official indicated the site of Chambo
as a possible location for the town.
Although the president of the Court was aware of the new proposal, he reaffirmed the
decision to promptly relocate the prison to the San Martín de Tapi plain. His latest statement on
the matter was:
“ ...that, although there are opinions in favor of Chambo, San Andrés, Cajabamba itself, the
main interest is that no town in the Correguimiento loses its identity by being annexed to the New
Town and that the chosen site where the waters have already been conducted will be respected...”.
The streets were laid out. The nobility and religious communities were in possession of
their lands, and the transfer of water under the direction of Antonio de Lizarzaburu had been
completed. Despite this, a large part of the population remained in Cajabamba and in the old city.
“The Riobamba people, so attached to the land where they were born, preferred to live in
poor straw huts amid the rubble of their beloved city, rather than move their homes to the Tapi
plateau, even though the huts burned easily and they were left exposed to the elements.”
Vol. 12/ Núm. 2 2025 pág. 2918
Faced with this delay, and upon Luis Francisco Barón de Carondelet assuming the
Presidency of the Quito Audience, he established April 1, 1799, as the deadline for the final
relocation and took measures to ensure the mobilization of the population. Troops were sent from
Latacunga to demolish the houses of the inhabitants who refused to move to the Tapi plain. Public
deeds were prohibited outside the new settlement, and carpenters were prohibited from rebuilding
in the destroyed city. Furthermore, the authorities prevented the introduction of food into
Cajabamba. Faced with these pressure measures, the residents who remained in Cajabamba, along
with the parish priest, petitioned the Audience to limit this provision on relocation, granting
freedom of action to residents who did not decide to part with their ancestral lands. This request
received no response from the authorities.
The population gradually settled in Tapi. Initially, religious and public buildings, such as
the Mother Church, convents, administration house, town hall, and prison, were constructed on a
temporary basis. The lasting stone structures were built later and took a considerable amount of
time during the following century. The remains of "Old Riobamba" lie beneath the settlement
now called Sicalpa.
Isosists map
After obtaining all possible information on the seismic event, in this case from the accounts
recovered from historical archives, the maps are drawn using isoseismic or isoseismal lines, i.e.,
imaginary curves that connect points on the map of the area where the earthquake occurred, where
the seismic intensity has the same value. Table 3 is presented below, containing a summary of the
intensities of the different sites where the effects of the February 4, 1797, earthquake were
reported, along with the respective justification for the intensity assessment, also indicating the
location and reference.
Table 2
Summary of Intensities of the 1797 Earthquake
Number
Observation Site
Effects of the Earthquake Ref. 1 MM
Locality Province
1 Quito Pichincha Clear falls from the corridors iv VI
2 Quito Pichincha Image of the Virgin falls into chapel. 23 VI
3 Quito Pichincha The towers of the Cathedrals of St.
Domingo, St. Augustine, and La
Merced were broken.
iv V
4 Ambato Tungurahua He blew down all the buildings 23 IX
5 Ambato Tungurahua He left no stone unturned 23 X
6 Ambato Tungurahua Large landslide that dammed the river. 24 X
7 Ambato Tungurahua There was no man able to stand up 23 VI
Faced with this delay, and upon Luis Francisco Barón de Carondelet assuming the
Presidency of the Quito Audience, he established April 1, 1799, as the deadline for the final
relocation and took measures to ensure the mobilization of the population. Troops were sent from
Latacunga to demolish the houses of the inhabitants who refused to move to the Tapi plain. Public
deeds were prohibited outside the new settlement, and carpenters were prohibited from rebuilding
in the destroyed city. Furthermore, the authorities prevented the introduction of food into
Cajabamba. Faced with these pressure measures, the residents who remained in Cajabamba, along
with the parish priest, petitioned the Audience to limit this provision on relocation, granting
freedom of action to residents who did not decide to part with their ancestral lands. This request
received no response from the authorities.
The population gradually settled in Tapi. Initially, religious and public buildings, such as
the Mother Church, convents, administration house, town hall, and prison, were constructed on a
temporary basis. The lasting stone structures were built later and took a considerable amount of
time during the following century. The remains of "Old Riobamba" lie beneath the settlement
now called Sicalpa.
Isosists map
After obtaining all possible information on the seismic event, in this case from the accounts
recovered from historical archives, the maps are drawn using isoseismic or isoseismal lines, i.e.,
imaginary curves that connect points on the map of the area where the earthquake occurred, where
the seismic intensity has the same value. Table 3 is presented below, containing a summary of the
intensities of the different sites where the effects of the February 4, 1797, earthquake were
reported, along with the respective justification for the intensity assessment, also indicating the
location and reference.
Table 2
Summary of Intensities of the 1797 Earthquake
Number
Observation Site
Effects of the Earthquake Ref. 1 MM
Locality Province
1 Quito Pichincha Clear falls from the corridors iv VI
2 Quito Pichincha Image of the Virgin falls into chapel. 23 VI
3 Quito Pichincha The towers of the Cathedrals of St.
Domingo, St. Augustine, and La
Merced were broken.
iv V
4 Ambato Tungurahua He blew down all the buildings 23 IX
5 Ambato Tungurahua He left no stone unturned 23 X
6 Ambato Tungurahua Large landslide that dammed the river. 24 X
7 Ambato Tungurahua There was no man able to stand up 23 VI
Vol. 12/ Núm. 2 2025 pág. 2919
8 Ambato Tungurahua All the hills and mounds suffered
collapses and divisions
23 X
9 Riobamba Chimborazo The houses turned over on their
foundations
23 X
10 Riobamba Chimborazo Big cracks everywhere. 24 VIII
11 Riobamba Chimborazo There is no way to distinguish streets
or houses
23 IX
12 Riobamba Chimborazo Cracks in the streets 23 VIII
13 Riobamba Chimborazo Landslide of Cullca Hill from its
foundations
23 X
14 Guaranda Bolivar Few buildings standing and unusable 23 VII
15 Guaranda Bolivar Cliffs and landslides on the road to
Guayaquil and Cuenca.
23 X
16 Pallatanga Chimborazo Landslides from the hills made the
access road impassable
23 IX
17 Pallatanga Chimborazo The Church fell 23 VIII
18 Chillanes Bolivar Landslides in nearby hills 23 IX
19 Chillanes Bolivar The Church fell 23 VIII
20 Latacunga Cotopaxi Houses and temples with severe
damage
23 VII
21 Latacunga Cotopaxi The gunpowder mill is close to
collapse
23 VII
22 Latacunga Cotopaxi Major landslides of mountains and
slopes, especially in the Pachanlica
River , which was dammed.
24 X
23 Saquisilí Cotopaxi Cracks so large that they make
construction difficult
24 IX
24 Saquisilí Cotopaxi Damage to the church tower 23 VI
25 Saquisilí Cotopaxi Cracks in the streets 23 VIII
26 Angamarca Cotopaxi Houses with cracks in the walls 23 VI
27 Angamarca Cotopaxi The earth opened up 23 VIII
28 Alausí Chimborazo Most of the houses are still standing
but are of no use.
23 VI
29 Alausí Chimborazo Collapse of the hills 23 X
30 Alausí Chimborazo Part of the brandy factory collapsed 23 VII
8 Ambato Tungurahua All the hills and mounds suffered
collapses and divisions
23 X
9 Riobamba Chimborazo The houses turned over on their
foundations
23 X
10 Riobamba Chimborazo Big cracks everywhere. 24 VIII
11 Riobamba Chimborazo There is no way to distinguish streets
or houses
23 IX
12 Riobamba Chimborazo Cracks in the streets 23 VIII
13 Riobamba Chimborazo Landslide of Cullca Hill from its
foundations
23 X
14 Guaranda Bolivar Few buildings standing and unusable 23 VII
15 Guaranda Bolivar Cliffs and landslides on the road to
Guayaquil and Cuenca.
23 X
16 Pallatanga Chimborazo Landslides from the hills made the
access road impassable
23 IX
17 Pallatanga Chimborazo The Church fell 23 VIII
18 Chillanes Bolivar Landslides in nearby hills 23 IX
19 Chillanes Bolivar The Church fell 23 VIII
20 Latacunga Cotopaxi Houses and temples with severe
damage
23 VII
21 Latacunga Cotopaxi The gunpowder mill is close to
collapse
23 VII
22 Latacunga Cotopaxi Major landslides of mountains and
slopes, especially in the Pachanlica
River , which was dammed.
24 X
23 Saquisilí Cotopaxi Cracks so large that they make
construction difficult
24 IX
24 Saquisilí Cotopaxi Damage to the church tower 23 VI
25 Saquisilí Cotopaxi Cracks in the streets 23 VIII
26 Angamarca Cotopaxi Houses with cracks in the walls 23 VI
27 Angamarca Cotopaxi The earth opened up 23 VIII
28 Alausí Chimborazo Most of the houses are still standing
but are of no use.
23 VI
29 Alausí Chimborazo Collapse of the hills 23 X
30 Alausí Chimborazo Part of the brandy factory collapsed 23 VII
Vol. 12/ Núm. 2 2025 pág. 2920
31 Alausí Chimborazo Cracks in walls of Church and houses 23 VI
32 Tixán Chimborazo The greatest ruin and death toll it has
ever had.
24 VIII
33 Tixán Chimborazo Completely destroyed 23 VIII
34 Chunchi Chimborazo Major landslides 23 X
35 Chunchi Chimborazo The Church fell 23 V
It is important to note that, in the analysis of historical earthquakes, it is found that cracks
in the ground appear around intensities VIII and IX 22.
To define the Isoseist map, it is necessary to obtain the average intensities of each location,
values that are summarized in the following table:
Table 3
Average intensities of the 1797 earthquake
Number Locality Province Intensity
Average
1 Quito Pichincha 5.7
2 Ambato Tungurahua 9.0
3 Riobamba (Sicalpa) Chimborazo 9.0
4 Guaranda Bolivar 8.5
5 Pallatanga Chimborazo 8.5
6 Chillanes Bolivar 8.5
7 Latacunga Cotopaxi 8.0
8 Saquisilí Cotopaxi 7.7
9 Angamarca Cotopaxi 7.0
10 Alausí Chimborazo 7.5
11 Tixán Chimborazo 7.5
12 Chunchi Chimborazo 7.5
By joining the points of the same seismic intensity, the different isoseismic lines will be
obtained , defined for each intensity value, it is remembered that for the interpretation of these
lines, continuous lines are used in places where data is available, and cut lines in places where
there is no data, the curves are defined as follows25 : “the shape of the curves is more or less
elliptical with its major axis in a north-south direction, following the direction of the branches of
the Andes mountain range, this tendency has been verified along the Inter-Andean Valley with
earthquakes before and after that of 1797, which can be interpreted by assuming that this effect is
a consequence of an attenuation of the seismic waves when crossing the mountain ranges, in the
31 Alausí Chimborazo Cracks in walls of Church and houses 23 VI
32 Tixán Chimborazo The greatest ruin and death toll it has
ever had.
24 VIII
33 Tixán Chimborazo Completely destroyed 23 VIII
34 Chunchi Chimborazo Major landslides 23 X
35 Chunchi Chimborazo The Church fell 23 V
It is important to note that, in the analysis of historical earthquakes, it is found that cracks
in the ground appear around intensities VIII and IX 22.
To define the Isoseist map, it is necessary to obtain the average intensities of each location,
values that are summarized in the following table:
Table 3
Average intensities of the 1797 earthquake
Number Locality Province Intensity
Average
1 Quito Pichincha 5.7
2 Ambato Tungurahua 9.0
3 Riobamba (Sicalpa) Chimborazo 9.0
4 Guaranda Bolivar 8.5
5 Pallatanga Chimborazo 8.5
6 Chillanes Bolivar 8.5
7 Latacunga Cotopaxi 8.0
8 Saquisilí Cotopaxi 7.7
9 Angamarca Cotopaxi 7.0
10 Alausí Chimborazo 7.5
11 Tixán Chimborazo 7.5
12 Chunchi Chimborazo 7.5
By joining the points of the same seismic intensity, the different isoseismic lines will be
obtained , defined for each intensity value, it is remembered that for the interpretation of these
lines, continuous lines are used in places where data is available, and cut lines in places where
there is no data, the curves are defined as follows25 : “the shape of the curves is more or less
elliptical with its major axis in a north-south direction, following the direction of the branches of
the Andes mountain range, this tendency has been verified along the Inter-Andean Valley with
earthquakes before and after that of 1797, which can be interpreted by assuming that this effect is
a consequence of an attenuation of the seismic waves when crossing the mountain ranges, in the
Vol. 12/ Núm. 2 2025 pág. 2921
east and west directions” . Taking into account the above, we define the Isoseist Map of the
Earthquake of February 4, 1797, which is indicated in figure 2.
The following can be deduced from similar earthquakes that have occurred in the same
epicentral zone: "the greatest effects are expected to occur to the north and south of the epicenter,
and to a lesser extent in directions perpendicular to the former, which is equivalent to saying that
the destruction will occur on a larger scale in the inter-Andean alley, with lesser effects in the
coastal and eastern regions from the foothills of the Andean mountain ranges that delimit them.
Subsequent earthquakes have confirmed the previous deductions."
The Isoseist Map is based on the work of Jose Egred , from the Geophysical Institute of the
National Polytechnic School, as regards the shape and direction of the isoseismic lines , the
intensities on the Modified Mercalli scale ( I MM ) are evaluated in table 3 and 4 indicated above.
Figure 1
Isoseist Map of the Earthquake of February 4, 1797
RESULTED
Summary of seismic activity in the province of Chimborazo
Table 4 indicates the year, location, and intensity of each seismic event. It is important to
clarify that most historical earthquakes occurred in "Antigua Riobamba" (Old Riobamba), and
that the town is designated by its current name, Sicalpa. Furthermore, the earthquakes indicated
are those known for the damage they caused to the populations, since these are the ones recorded
in historical documents. Only the main events of maximum intensity are included, leaving aside
premonitors and aftershocks. The Modified Mercalli scale, indicated in section 1.2, is used to
assess intensity.
east and west directions” . Taking into account the above, we define the Isoseist Map of the
Earthquake of February 4, 1797, which is indicated in figure 2.
The following can be deduced from similar earthquakes that have occurred in the same
epicentral zone: "the greatest effects are expected to occur to the north and south of the epicenter,
and to a lesser extent in directions perpendicular to the former, which is equivalent to saying that
the destruction will occur on a larger scale in the inter-Andean alley, with lesser effects in the
coastal and eastern regions from the foothills of the Andean mountain ranges that delimit them.
Subsequent earthquakes have confirmed the previous deductions."
The Isoseist Map is based on the work of Jose Egred , from the Geophysical Institute of the
National Polytechnic School, as regards the shape and direction of the isoseismic lines , the
intensities on the Modified Mercalli scale ( I MM ) are evaluated in table 3 and 4 indicated above.
Figure 1
Isoseist Map of the Earthquake of February 4, 1797
RESULTED
Summary of seismic activity in the province of Chimborazo
Table 4 indicates the year, location, and intensity of each seismic event. It is important to
clarify that most historical earthquakes occurred in "Antigua Riobamba" (Old Riobamba), and
that the town is designated by its current name, Sicalpa. Furthermore, the earthquakes indicated
are those known for the damage they caused to the populations, since these are the ones recorded
in historical documents. Only the main events of maximum intensity are included, leaving aside
premonitors and aftershocks. The Modified Mercalli scale, indicated in section 1.2, is used to
assess intensity.
Vol. 12/ Núm. 2 2025 pág. 2922
The seismic events indicated in Table 2 have been illustrated in Figure 1 to better appreciate
the location of the epicenters with their respective intensities. It is worth clarifying that if the
epicenter of an event coincides with another, the one with the greatest intensity has been graphed.
Table 4
Historical Seismicity of the Province of Chimborazo
DATE EPICENTER
REF. 1 MM
YEAR MONTH DAY HOUR LAT. LON.
1557 FEB -- -- 1.50S 78.5 W 21 VI
1640 - - -- -- 1.43 S 78.55 W 21 III
1645 SEA 15 -- 1.68 S 78.55W i VI
1674 AUG 29 -- 2.20 S 78.83W ii VII
1687 NOV 22 -- 1.10 S 78.25 W 21 VII
1698 JUN 20 06:00 1.45 S 78.25W 21 VIII
1738 SEP 29 -- 1.4 S 78.80 W 21 III
1739 APR 10 -- 1.9 S 78.30 W 21 IV
1744 -- -- -- 1.5 S 78.60 W 21 VI
1745 -- -- -- 1.4 S 78.40W 21 VI
1773 APR 23 -- 1.5 S 78.40 W 21 III
1776 JAN 03 -- 1.47 S 78.44 W 21 IV
1777 JUN 17 -- 1.47 S 78.40 W 21 III
1786 MAY 10 3:00 PM 1.70 S 78.70W 21 VII
1786 JUN 23 02:30 1.70 S 78.70W 21 IV
1797 FEB 04 07:45 1.43 S 78.55W 21 IX
Figure 2
Map of Epicenters between the years 1557-1797
The seismic events indicated in Table 2 have been illustrated in Figure 1 to better appreciate
the location of the epicenters with their respective intensities. It is worth clarifying that if the
epicenter of an event coincides with another, the one with the greatest intensity has been graphed.
Table 4
Historical Seismicity of the Province of Chimborazo
DATE EPICENTER
REF. 1 MM
YEAR MONTH DAY HOUR LAT. LON.
1557 FEB -- -- 1.50S 78.5 W 21 VI
1640 - - -- -- 1.43 S 78.55 W 21 III
1645 SEA 15 -- 1.68 S 78.55W i VI
1674 AUG 29 -- 2.20 S 78.83W ii VII
1687 NOV 22 -- 1.10 S 78.25 W 21 VII
1698 JUN 20 06:00 1.45 S 78.25W 21 VIII
1738 SEP 29 -- 1.4 S 78.80 W 21 III
1739 APR 10 -- 1.9 S 78.30 W 21 IV
1744 -- -- -- 1.5 S 78.60 W 21 VI
1745 -- -- -- 1.4 S 78.40W 21 VI
1773 APR 23 -- 1.5 S 78.40 W 21 III
1776 JAN 03 -- 1.47 S 78.44 W 21 IV
1777 JUN 17 -- 1.47 S 78.40 W 21 III
1786 MAY 10 3:00 PM 1.70 S 78.70W 21 VII
1786 JUN 23 02:30 1.70 S 78.70W 21 IV
1797 FEB 04 07:45 1.43 S 78.55W 21 IX
Figure 2
Map of Epicenters between the years 1557-1797
Vol. 12/ Núm. 2 2025 pág. 2923
The analysis of the historical seismicity of the province of Chimborazo reveals a significant
record of seismic events over the last four centuries, emphasizing the importance of this region in
the tectonic dynamics of Ecuador. Through the review of historical sources and previous seismic
catalogs, it was possible to document and organize information on several major earthquakes that
affected this territory, particularly in the cities of Riobamba, Guano, and Colta.
One of the most notable events is the earthquake of February 4, 1797, considered one of
the most destructive in Ecuadorian history. It caused widespread devastation in Riobamba and
surrounding areas, with an estimated intensity of XI on the Modified Mercalli Scale. Subsequent
earthquakes recorded in 1868, 1926, 1949, and 2001 also contributed to shaping the seismic
profile of the province.
The isoseismal maps and collected testimonies confirm that the intensity and impact of
these events varied according to proximity to the epicenter and the geological characteristics of
the terrain. The earthquakes were particularly destructive in areas with poor construction and high
population density.
The review highlights a pattern of recurring seismic activity in Chimborazo approximately
every 50–70 years, emphasizing the importance of integrating historical data with modern
monitoring systems. The lack of instrumental records for many of these events underscores the
need to preserve and analyze documentary sources to better understand the seismic risk in the
region.
DISCUSSION
The historical seismicity of the province of Chimborazo reveals a complex and recurrent
pattern of seismic activity that underscores the region’s vulnerability to strong earthquakes. The
documentation of past events, especially those preceding the era of instrumental seismology,
provides invaluable insight into the long-term behavior of seismic sources in the central region of
Ecuador.
The 1797 Riobamba earthquake stands out not only for its catastrophic impact—resulting
in massive destruction and a high number of casualties—but also for its role in shaping the
scientific and societal understanding of seismic risk in the region. The reevaluation of its intensity
from XI to IX in recent seismic catalogues demonstrates the evolution of methodologies and the
importance of consistent criteria in seismic classification.
This historical perspective allows for a better calibration of hazard models, especially in
areas where instrumental data is limited or spans a short period. In Chimborazo, where tectonic
forces are driven by the interaction of the Nazca and South American plates, understanding the
recurrence intervals, affected areas, and magnitudes of past events becomes crucial for developing
accurate seismic hazard maps.
The analysis of the historical seismicity of the province of Chimborazo reveals a significant
record of seismic events over the last four centuries, emphasizing the importance of this region in
the tectonic dynamics of Ecuador. Through the review of historical sources and previous seismic
catalogs, it was possible to document and organize information on several major earthquakes that
affected this territory, particularly in the cities of Riobamba, Guano, and Colta.
One of the most notable events is the earthquake of February 4, 1797, considered one of
the most destructive in Ecuadorian history. It caused widespread devastation in Riobamba and
surrounding areas, with an estimated intensity of XI on the Modified Mercalli Scale. Subsequent
earthquakes recorded in 1868, 1926, 1949, and 2001 also contributed to shaping the seismic
profile of the province.
The isoseismal maps and collected testimonies confirm that the intensity and impact of
these events varied according to proximity to the epicenter and the geological characteristics of
the terrain. The earthquakes were particularly destructive in areas with poor construction and high
population density.
The review highlights a pattern of recurring seismic activity in Chimborazo approximately
every 50–70 years, emphasizing the importance of integrating historical data with modern
monitoring systems. The lack of instrumental records for many of these events underscores the
need to preserve and analyze documentary sources to better understand the seismic risk in the
region.
DISCUSSION
The historical seismicity of the province of Chimborazo reveals a complex and recurrent
pattern of seismic activity that underscores the region’s vulnerability to strong earthquakes. The
documentation of past events, especially those preceding the era of instrumental seismology,
provides invaluable insight into the long-term behavior of seismic sources in the central region of
Ecuador.
The 1797 Riobamba earthquake stands out not only for its catastrophic impact—resulting
in massive destruction and a high number of casualties—but also for its role in shaping the
scientific and societal understanding of seismic risk in the region. The reevaluation of its intensity
from XI to IX in recent seismic catalogues demonstrates the evolution of methodologies and the
importance of consistent criteria in seismic classification.
This historical perspective allows for a better calibration of hazard models, especially in
areas where instrumental data is limited or spans a short period. In Chimborazo, where tectonic
forces are driven by the interaction of the Nazca and South American plates, understanding the
recurrence intervals, affected areas, and magnitudes of past events becomes crucial for developing
accurate seismic hazard maps.
Vol. 12/ Núm. 2 2025 pág. 2924
Moreover, the study reveals the necessity of integrating historical accounts, isoseismal
mapping, and local narratives to capture the full impact of seismic events, particularly in rural or
poorly instrumented zones. Such integration supports more resilient urban planning, the
establishment of efficient early warning systems, and a heightened public awareness of seismic
risk.
CONCLUSIONS
Historical seismicity remains a critical reference for the assessment of seismic hazard,
particularly in regions like the province of Chimborazo where instrumented records are relatively
recent. The information gathered from centuries-old earthquakes has been fundamental in shaping
Ecuador’s seismic regulations, including the INEN CPE 5:2001 and the NEC-SE-DS of 2015,
which incorporate historical data into seismic hazard maps.
The 1797 Riobamba earthquake, one of the most significant seismic events in the country's
history, serves as a stark reminder of the potential destruction that can occur in central Ecuador.
Its enduring relevance is reflected in numerous scientific studies and its inclusion in seismic
catalogues, where its intensity has been revised based on improved methodologies and broader
datasets.
In light of the findings, it is recommended that:
- Historical seismic records be systematically preserved and digitized to facilitate their
integration into modern hazard assessments.
- Further interdisciplinary research be encouraged, combining geology, history, and social
sciences to enhance the understanding of past events.
- Education and preparedness programs in high-risk areas like Chimborazo be
strengthened, incorporating historical examples to raise public awareness.
Understanding and valuing historical seismicity not only enriches our comprehension of
past events but also plays a pivotal role in preparing for future seismic scenarios in Ecuador and
across similar tectonic regions.
Moreover, the study reveals the necessity of integrating historical accounts, isoseismal
mapping, and local narratives to capture the full impact of seismic events, particularly in rural or
poorly instrumented zones. Such integration supports more resilient urban planning, the
establishment of efficient early warning systems, and a heightened public awareness of seismic
risk.
CONCLUSIONS
Historical seismicity remains a critical reference for the assessment of seismic hazard,
particularly in regions like the province of Chimborazo where instrumented records are relatively
recent. The information gathered from centuries-old earthquakes has been fundamental in shaping
Ecuador’s seismic regulations, including the INEN CPE 5:2001 and the NEC-SE-DS of 2015,
which incorporate historical data into seismic hazard maps.
The 1797 Riobamba earthquake, one of the most significant seismic events in the country's
history, serves as a stark reminder of the potential destruction that can occur in central Ecuador.
Its enduring relevance is reflected in numerous scientific studies and its inclusion in seismic
catalogues, where its intensity has been revised based on improved methodologies and broader
datasets.
In light of the findings, it is recommended that:
- Historical seismic records be systematically preserved and digitized to facilitate their
integration into modern hazard assessments.
- Further interdisciplinary research be encouraged, combining geology, history, and social
sciences to enhance the understanding of past events.
- Education and preparedness programs in high-risk areas like Chimborazo be
strengthened, incorporating historical examples to raise public awareness.
Understanding and valuing historical seismicity not only enriches our comprehension of
past events but also plays a pivotal role in preparing for future seismic scenarios in Ecuador and
across similar tectonic regions.
Vol. 12/ Núm. 2 2025 pág. 2925
REFERENCES
Aguiar F. Roberto. (1994). “Eighth National Course on Structures: Seismic Threat”. Chapter 6.
Army Polytechnic School . Quito.
Aguiar F. Roberto. (2000). “Earthquake-Resistant Design of Reinforced Concrete Buildings”.
Army Polytechnic School . Quito.
X. Goula. (1993). “Seismic Risk Assessment: III Seismic Energy Propagation”. Master's Course
in Earthquake Engineering and Structural Dynamics . Barcelona. Polytechnic University
of Catalonia.
A.Medvedev and W. Sponheuer. (1969). “Scale os Seismic intensity. Proccedings”. World
Conference . Santiago de Chile. Earthquake Eng. 4th
CF Richter. (1958). “Elementary Seismology”. San Francisco. Freeman.
Torres de Mendoza Luis. (1868). “Description of the towns within the jurisdiction of the
Correguimiento de la Villa Don Pardo, in the Province of Puruguayes”. Collection of
Unpublished Documents Relating to the Discovery, Conquest, and Organization of the
Former Spanish Possessions in America and Oceania . Madrid, Spain
Report on the consequences of the 1645 earthquake. (9-VI-1645). Riobamba. Historical Archives
. Chimborazo House of Culture.
Juan de Velasco (1960). “History of the Kingdom of Quito”. Ecuadorian Library. J.M. Cajica Jr.
S.A. Mexico. pp. 545
Juan de Velasco (1960). “History of the Kingdom of Quito”. Part Two. Ecuadorian Library. J.M.
Cajica Jr. S.A. Mexico. pp. 546
Morales Mejía Juan Carlos. (1998). “Riobamba from the Lutheran to the Earthquake”. Collection:
Chimborazo, Yesterday, Today and Forever . Freire Pedagogical Publishing House .
Riobamba.
Jorge Juan and Antonio de Ulloa. (1978). “Historical Account of the Journey to South America.”
Volume I. Spanish University Foundation. Facsimile . Madrid.
Costales Cevallos Alfredo. (1972). “History of Riobamba and its Province”. Ecuadorian House
of Culture . Riobamba.
Egred A. José. (2001). “Characteristics of the Macroseismic Zone of the 1797 Earthquake”.
Geophysical Institute. National Polytechnic School . Quito.
Pazmiño Rocío, Gómez Nidia, Rueda Rocío. (2000). “Ancient Riobamba: The Hidden History of
a Colonial City.” Abya-Yala Editing . Quito. Ibid., 22-III-1797, [f. 7v –8v. Lizarzaburu].
Pazmiño Rocío, Gómez Nidia, Rueda Rocío. (2000). “Ancient Riobamba: The Hidden History of
a Colonial City.” Abya-Yala Editing . Quito. Ibid. , [f. 9v-10 Najera].
González Suárez Federico. (1970). “General History of the Republic of Ecuador.” Ecuadorian
House of Culture Publishing House . Quito.
REFERENCES
Aguiar F. Roberto. (1994). “Eighth National Course on Structures: Seismic Threat”. Chapter 6.
Army Polytechnic School . Quito.
Aguiar F. Roberto. (2000). “Earthquake-Resistant Design of Reinforced Concrete Buildings”.
Army Polytechnic School . Quito.
X. Goula. (1993). “Seismic Risk Assessment: III Seismic Energy Propagation”. Master's Course
in Earthquake Engineering and Structural Dynamics . Barcelona. Polytechnic University
of Catalonia.
A.Medvedev and W. Sponheuer. (1969). “Scale os Seismic intensity. Proccedings”. World
Conference . Santiago de Chile. Earthquake Eng. 4th
CF Richter. (1958). “Elementary Seismology”. San Francisco. Freeman.
Torres de Mendoza Luis. (1868). “Description of the towns within the jurisdiction of the
Correguimiento de la Villa Don Pardo, in the Province of Puruguayes”. Collection of
Unpublished Documents Relating to the Discovery, Conquest, and Organization of the
Former Spanish Possessions in America and Oceania . Madrid, Spain
Report on the consequences of the 1645 earthquake. (9-VI-1645). Riobamba. Historical Archives
. Chimborazo House of Culture.
Juan de Velasco (1960). “History of the Kingdom of Quito”. Ecuadorian Library. J.M. Cajica Jr.
S.A. Mexico. pp. 545
Juan de Velasco (1960). “History of the Kingdom of Quito”. Part Two. Ecuadorian Library. J.M.
Cajica Jr. S.A. Mexico. pp. 546
Morales Mejía Juan Carlos. (1998). “Riobamba from the Lutheran to the Earthquake”. Collection:
Chimborazo, Yesterday, Today and Forever . Freire Pedagogical Publishing House .
Riobamba.
Jorge Juan and Antonio de Ulloa. (1978). “Historical Account of the Journey to South America.”
Volume I. Spanish University Foundation. Facsimile . Madrid.
Costales Cevallos Alfredo. (1972). “History of Riobamba and its Province”. Ecuadorian House
of Culture . Riobamba.
Egred A. José. (2001). “Characteristics of the Macroseismic Zone of the 1797 Earthquake”.
Geophysical Institute. National Polytechnic School . Quito.
Pazmiño Rocío, Gómez Nidia, Rueda Rocío. (2000). “Ancient Riobamba: The Hidden History of
a Colonial City.” Abya-Yala Editing . Quito. Ibid., 22-III-1797, [f. 7v –8v. Lizarzaburu].
Pazmiño Rocío, Gómez Nidia, Rueda Rocío. (2000). “Ancient Riobamba: The Hidden History of
a Colonial City.” Abya-Yala Editing . Quito. Ibid. , [f. 9v-10 Najera].
González Suárez Federico. (1970). “General History of the Republic of Ecuador.” Ecuadorian
House of Culture Publishing House . Quito.
Vol. 12/ Núm. 2 2025 pág. 2926
Pazmiño Rocío, Gómez Nidia, Rueda Rocío. (2000). “Ancient Riobamba: The Hidden History of
a Colonial City.” Abya-Yala Editing . Quito. pp. 109
Pazmiño Rocío, Gómez Nidia, Rueda Rocío. (2000). “Old Riobamba: The Hidden History of a
Colonial City.” Abya-Yala Editing . Quito. Document Certification: [Order by which
Mayor Vicente Molina orders the residents to meet and express their opinion on the
relocation site] f.14
González Suárez Federico. (1970). “General History of the Republic of Ecuador”. Volume II.
Ecuadorian House of Culture Publishing House . Quito. pp. 1289-1300-1301.
Pazmiño Rocío, Gómez Nidia, Rueda Rocío. (2000). “Old Riobamba. The Hidden History of a
Colonial City.” Abya-Yala Editing . Quito. Document verification: [Communication from
President Luis Muños de Guzmán to the ordinary mayors of Riobamba, regarding
respecting the chosen site where the waters have already been channeled], pages 39-40
CERESIS. (1985). “Destructive earthquakes in South America (1530-1890)”. Volume 10.
Regional Seismology Center for South America .
Egred A. José. (2001). “1797 Riobamba Earthquake. Summary of effects, associated phenomena
and other consequences”. Geophysical Institute. National Polytechnic School . Quito.
Egred A. José. (2001). “1797 Riobamba Earthquake. Seismic Study”. Geophysical Institute.
National Polytechnic School . Quito.
Egred A. José. (2001). “Earthquake Catalogue of Ecuador”. Geophysical Institute. National
Polytechnic School . Quito.
Mica Tambo Project. (1988). “Historical Seismicity”. Municipal Drinking Water Company .
Pazmiño Rocío, Gómez Nidia, Rueda Rocío. (2000). “Ancient Riobamba: The Hidden History of
a Colonial City.” Abya-Yala Editing . Quito. pp. 109
Pazmiño Rocío, Gómez Nidia, Rueda Rocío. (2000). “Old Riobamba: The Hidden History of a
Colonial City.” Abya-Yala Editing . Quito. Document Certification: [Order by which
Mayor Vicente Molina orders the residents to meet and express their opinion on the
relocation site] f.14
González Suárez Federico. (1970). “General History of the Republic of Ecuador”. Volume II.
Ecuadorian House of Culture Publishing House . Quito. pp. 1289-1300-1301.
Pazmiño Rocío, Gómez Nidia, Rueda Rocío. (2000). “Old Riobamba. The Hidden History of a
Colonial City.” Abya-Yala Editing . Quito. Document verification: [Communication from
President Luis Muños de Guzmán to the ordinary mayors of Riobamba, regarding
respecting the chosen site where the waters have already been channeled], pages 39-40
CERESIS. (1985). “Destructive earthquakes in South America (1530-1890)”. Volume 10.
Regional Seismology Center for South America .
Egred A. José. (2001). “1797 Riobamba Earthquake. Summary of effects, associated phenomena
and other consequences”. Geophysical Institute. National Polytechnic School . Quito.
Egred A. José. (2001). “1797 Riobamba Earthquake. Seismic Study”. Geophysical Institute.
National Polytechnic School . Quito.
Egred A. José. (2001). “Earthquake Catalogue of Ecuador”. Geophysical Institute. National
Polytechnic School . Quito.
Mica Tambo Project. (1988). “Historical Seismicity”. Municipal Drinking Water Company .