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has
one of the world's largest volcanic caldera with an average base diameter of 8
km. The crater is breached on the NW side and in the middle a
huge lava dome formed with a height of 500m and a base
diameter of 3 km. It is also one of two in the entire world,
which is populated and is primarily
used by indigenous people for
agricultural
purposes. Its exact location is 0°04´N
and 78°46´W, which locates itself
almost right on the equator and some 20 km NW of Quito.
The highest peak in the caldera rim is Sincholagua, rising to
3356m above sea level. |
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It is hard to get a proper perspective of
this huge volcanic caldera (unless you fly overhead by
plane). In this composite picture (taken by author) you might
get an idea of its huge dimension. The hill in the
middle is the lava dome and to the left you can see the
breach in the crater walls. |
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This huge
caldera
was probably created by
continous huge and cataclysmic
eruptions of
a high stratovolcano (at least 6000m)
with a subsequent cave-in of the
emptied magma chamber.
After this event, the volcanic activities continued in the crater, forming huge
lava domes, with 3 important eruptions in the last 13000 years.
The last significant eruption took place around 2500 years ago, spewing
pyroclastic materials, ashes and forming lahars. From then on, the volcano
entered in a period of dormancy with vegetation establishing
itself and covering the crater walls and the lava dome in the middle
of the crater with a cloudforest vegetation
and allowing indigenous people to settle there and use the
crater bottom for farming. |
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In middle you can observe the huge lava dome which is called now Pondoņa and has a base of
3 km and rises 500m from the bottom of the crater
floor. Just in front runs a crater rim, created by the
last big eruption 2500 years ago in the lava dome.
Here you can also appreciate the cultivated fields and
small farm houses of this inhabited volcano, unique in
the world. |
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The last eruption in 500 BC had a volume of approximately 5 km2 with
an column reaching a height of 30 km. It is the
99th largest eruption registered in the world (approximately 4800 eruptions listed) and was twice
as large as the
recent Pinatubo eruption in the Philippines. At the time of this eruption a highly developed Indian culture, called
the Cotacolloa, was located SE of the crater. Excavations showed that
entire villages were abandoned by the natives after the event and that
they had to resettle. This enormous eruption disrupted also agriculture
for several years and new trade routes from the coast had to be found.
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To my knowledge there are only two volcanoes in the world where
people live and work. One is in Malaysia where
mining is going on and the other one Pululahua, where people
live at the bottom of the crater, dedicating themselves to
agriculture. It is known that it is
inhabited at least since 500
years and probably even before the time
of the Incas. In the colonial times all the land of the
crater belonged to the Catholic church, to the religious order
of Dominicans, which administered it (to the right you a
photo of the old hacienda building, presently in ruins). Apart
from agriculture, also mining went on, reaching its
height between the two world wars. Chalk was taken from the
lower parts of the crater and after being burnt there in situ transported to Quito. |
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For more information and pictures of Pululahua crater and the geo-botanical reserve created there, check out our section
Pululahua. |
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Latest Update: |
Danger alert:
none
No activities reported in the last few hundred years. |
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