Report on Dempo (Indonesia) — June 2022
Bulletin of the Global Volcanism Network, vol. 47, no. 6 (June 2022)
Managing Editor: Edward Venzke. Research and preparation by Paul Berger.
Dempo (Indonesia) Phreatic explosion on 31 May 2022
Please cite this report as:
Global Volcanism Program, 2022. Report on Dempo (Indonesia) (Venzke, E., ed.). Bulletin of the Global Volcanism Network, 47:6. Smithsonian Institution.
4.016°S, 103.121°E; summit elev. 3142 m
All times are local (unless otherwise noted)
The Dempo stratovolcano in SE Sumatra, Indonesia, has had many small explosive eruptions reported since 1817. The active Marapi crater (750 x 1,100 m) in the summit area contains a 400-m-wide crater lake (figure 7). Recent activity has consisted of single-day phreatic explosions in September 2006, January 2009, and November 2017. Indonesian’s Center of Volcanology and Geological Hazard Mitigation (CVGHM), also known as Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG), is the monitoring agency.
|Figure 7. Satellite image of Dempo on 30 May 2022, showing the 400-m-wide crater lake within the Marapi summit crater. Sentinel-2 image with natural color rendering (bands 4, 3, 2). Courtesy of Sentinel Hub Playground.|
PVMBG reported phreatic explosion similar to those of recent years at 0154 on 31 May 2022. This event lasted 239 seconds and produced ashfall in areas within 5 km, including Pagar Alam Utara district (E) and North Dempo District; ash deposits were as thick as 1 mm. The Alert Level remained at 2 (on a scale of 1-4), and the public were reminded to stay 1 km away from the crater and as far as 2 km on the N flank.
Geological Summary. Dempo is a stratovolcano that rises above the Pasumah Plain of SE Sumatra. The andesitic complex has two main peaks, Gunung Dempo and Gunung Marapi, constructed near the SE rim of a 3-km-wide amphitheater open to the north. The high point of the older Gunung Dempo crater rim is slightly lower, and lies at the SE end of the summit complex. The taller Marapi cone was constructed within the older crater. Remnants of seven craters are found at or near the summit, with volcanism migrating WNW over time. The active 750 x 1,100 m active crater cuts the NW side of the Marapi cone and contains a 400-m-wide lake at the far NW end. Eruptions recorded since 1817 have been small-to-moderate explosions that produced local ashfall.
Information Contacts: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as Indonesian Center for Volcanology and Geological Hazard Mitigation, CVGHM), Jalan Diponegoro 57, Bandung 40122, Indonesia (URL: http://www.vsi.esdm.go.id/); Sentinel Hub Playground (URL: https://www.sentinel-hub.com/explore/sentinel-playground).