Report on Iliwerung (Indonesia) — 31 October-6 November 2001
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 31 October-6 November 2001
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2001. Report on Iliwerung (Indonesia). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 31 October-6 November 2001. Smithsonian Institution and US Geological Survey.
8.53°S, 123.57°E; summit elev. 1018 m
All times are local (unless otherwise noted)
An increase in tectonic earthquakes around Iliwerung during 17-26 October led VSI to raise the Alert Level from 1 to 2 (on a scale of 1-4). From 2 to 11 earthquakes were felt per day with Modified Mercalli intensities of I-II. Visual and instrumental monitoring did not show a significant change in volcanic activity.
Geologic Background. Constructed on the southern rim of the Lerek caldera, Iliwerung forms a prominent south-facing peninsula on Lembata (formerly Lomblen) Island. Craters and lava domes have formed along N-S and NW-SE lines on the complex volcano; during historical time vents from the summit to the submarine SE flank have been active. The summit lava dome was formed during an eruption in 1870. In 1948 the Iligripe lava dome grew on the E flank at 120 m elevation. Beginning in 1973-74, when three ephemeral islands were formed, submarine eruptions began on the lower SE flank at a vent named Hobal; several other eruptions took place from this vent before the end of the century.