Geologic Background:
Lonquimay is a small, flat-topped, symmetrical
stratovolcano. Voluminous historical lava flows have been
issued from NE flank vents that are aligned along a SW-NE
trend.
Historic Activity:
- Was last active in 1933, when it ejected scoria. A
larger eruption, in 1989, produced lava and tephra.
Recent Activity:
- Eruption began on Dec. 25, 1988 after two weeks of
increasing seismicity. Vigorous tephra emission followed
several days later by substantial lava production feeding
a block lava flow to the NNE.
- Moderate ash emission and lava production were
continuing in mid-September 1989 from Navidad cone, at
the NE foot of the volcano. Strong fluorine emission
associated with the eruption is causing the death of many
animals and much illness amoung the human population.
Decrease in activity of cone began in Sept. and continued
until late Nov. when activity increased. Continued ash
and lava production in Dec. 1989, but lava production
slowed in Jan. 1990 and eruption ended late in Jan.
Data Sources:
- Smithsonian's SEAN Bulletin (V. 13, No. 12 to V. 14,
No. 12)
- Global Volcanism Network (V. 15, No. 1 to V. 22, No.
3).
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