Report on Lascar (Chile) — 14 December-20 December 2022
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 14 December-20 December 2022
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2022. Report on Lascar (Chile) (Sennert, S, ed.). Weekly Volcanic Activity Report, 14 December-20 December 2022. Smithsonian Institution and US Geological Survey.
23.37°S, 67.73°W; summit elev. 5592 m
All times are local (unless otherwise noted)
SERNAGEOMIN reported that seismic signals characterized as moderate were recorded on 19 December and located near Láscar’s main crater at shallow depths. The seismicity was the most notable recorded since the eruption on 10 December. The Alert Level remained at Yellow (the second lowest level on a four-color scale) and the public were warned to stay at least 5 km away from the crater. ONEMI maintained the Alert Level Yellow (the middle level on a three-color scale) for San Pedro de Atacama (70 km NW).
Geological Summary. Láscar is the most active volcano of the northern Chilean Andes. The andesitic-to-dacitic stratovolcano contains six overlapping summit craters. Prominent lava flows descend its NW flanks. An older, higher stratovolcano 5 km E, Volcán Aguas Calientes, displays a well-developed summit crater and a probable Holocene lava flow near its summit (de Silva and Francis, 1991). Láscar consists of two major edifices; activity began at the eastern volcano and then shifted to the western cone. The largest eruption took place about 26,500 years ago, and following the eruption of the Tumbres scoria flow about 9000 years ago, activity shifted back to the eastern edifice, where three overlapping craters were formed. Frequent small-to-moderate explosive eruptions have been recorded since the mid-19th century, along with periodic larger eruptions that produced ashfall hundreds of kilometers away. The largest historical eruption took place in 1993, producing pyroclastic flows to 8.5 km NW of the summit and ashfall in Buenos Aires.