Geologic Background:
The Apaneca Range (also known as the Cayunausol
Range) consists of an elongated group of roughly
E-W-trending Pleistocene and Holocene stratovolcanoes in
western El Salvador between the Santa Ana complex and the
Guatemala border. The 6-km-wide Pleistocene Concepcion de
Ataco caldera lies at the western end of the complex. The
post-caldera cones of Cerro El Aguila (at 2,036 m the
highest peak of the complex) and Cerro Los Naranjos
volcano at the eastern end of the chain were mapped as
Holocene by Weber and Weisemann (1978). Young craters on
Laguna Verde stratovolcano may also have been active
during the Holocene. Numerous fumarole fields are located
on the northern flank of the range, and the Ahuachapan
geothermal field has been producing since 1975.
Historic Activity:
- Only solfataric and fumarolic activity has been
reported.
- Small hydrothermal explosions have occurred in
historical time.
Recent Activity:
- On Oct. 13, 1990 a small phreatic blast occurred in
the SW portion of the Ahuachapan geothermal field. Agua
Shuca (an area 2-3 m in diameter of fumaroles, mud pots,
and altered ground at 13.90° N, 89.82° W)
erupted violently, producing a blast the destroyed
several small dwellings and affected an area with a 100-m
radius. Fourteen people were reported killed and 21
injured. Additional people died in the hospital rasing
the death toll to 26. The blast of steam and mud roared
for 10-20 minutes and produced a 30-m-diameter crater
15-m-deep.
Data Sources:
- Global Volcanism Network (V. 15, No. 9 and V. 15, No.
11).
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