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would be an acceptable term to describe
Ecuador as those natural phenomena
always played a big part in Ecuadorian
life and still continue to do so, as experienced by recent eruptions
of three of its volcanoes on the mainland and
continous volcanic activities on the western islands of Galapagos. |
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Guagua Pichincha, apart from displaying natural beauty (click for
photo) covered Quito twice with ashes at the end of 1999 with consequences like the
closure of the international airport and disruption in the daily life of 1.5
million citizens. The increased eruptions of
Tungurahua
near Baņos in the same year led to the
evacuation of over 25 000 people for 3 months and major losses to agricultural production due to heavy ash cover of crops.
Then, without warning
El
Reventador, a volcano located in the Amazon rainforest
erupted at the beginning of November 2002 and covered a large part of
Ecuador with ashes
and produced interruptions in the oil
transportation by damaging the Trans-Ecuadorian
pipeline. |
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Since 1534, when the Spaniards arrived in Ecuador and written records are available,
nine volcanoes in the country
experienced eruptions.
A huge eruption of the same
Pichincha occurred in 1660 and covered the city with
40 cm of ash, according to Spanish chroniclers.
They witnessed and recorded also eruptions of
Cotopaxi
and
Tungurahua in that period. |
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During the last 13 000 years, since humans settled in this
country, at least 15 volcanoes had bigger to cataclysmic eruptions,
affecting the indigenous population at that time and having an
great impact on their life, changing often their living and farming areas and trading
routes. For instance, a huge eruption like that of
Pululahua,
2500
years ago, led to a complete abandonment of a settlement
by the Cotocolloa Indians.
Apart from Pululahua volcano,
Cuicocha,
Guagua Pichincha, Atacazo and
Quilotoa
in the Western Cordilleras and Imbabura, Cayambe,
Cotopaxi and
Tungurahua in the Eastern Cordillera had all consequential eruptions.
Sangay,
located in a remote region, has continuous eruptions in the last few
decades and is considered one of the most active
in South America. |
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There are thousands of volcanoes worldwide (click
for map), which are found always grouped together, mostly
along edges of tectonic plates. One of the most
important one is the so-called Ring of Fire, which encircles the Pacific
ocean with its many active volcanoes. Ecuador, being an Andean country
is part of that ring and all its major peaks in the Andes mountains
are of volcanic origins
(click
for map). The Andes mountains began to form at the
end of the Mesozoic Era and are the result of
two major colliding
tectonic plates (click
for map). The lighter Nazca plate in the Pacific
ocean converges under the heavier American Plate. This process called
subduction, folded over millions of years the Andes up. The type of
volcanoes found are high and steep-sided stratovolcanoes,
which are known to have sudden and violent eruptions with longer periods of
dormancy. The more dangerous part of those eruptions are the combined flow of
lava, mud and
ice, called lahars (click
for explanations). One of those lahars killed
around 25 000
people in Colombia in 1985 and could happen anytime in Ecuador, like in the case
of
Cotopaxi ,
the country's highest active volcano. A large eruption would
create a 8 m deep lahar, which would bury large populated areas around suburban Quito
and the town of Latacunga. |
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Galapagos are a group of islands,
which are actually the top of huge underwater volcanoes (for
Galapagos volcanoes click to galapagos.geography.volcano). They are not part of the Ring of
Fire and never were connected to the mainland. The volcanic
origins of the islands are recent in geological time, 4-5 millions years ago, having risen from the
underwater seabed by the spreading or moving away of 2 major tectonic plates
and hot spot action (click
for explanations). The type of
volcanoes are shield volcanoes
and all
islands are marked by their past or recent volcanic
activities. Large lava fields of dark basalt cover some islands and others
are marked by huge calderas. Continous eruptions
occur on the western islands, Isabela and Fernandina,
which are also the youngest land masses
having arisen in the last million year.
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Recommended Book:
ACTIVIDAD VOLCANICA Patricia Mothes & others |
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