Use of satellite remote sensing to support crisis response to the 2010 eruption of Merapi Volcano, Indonesia
Abstract
The U.S. Geological Survey through the Volcano Disaster Assistance Program (VDAP) provided satellite remote sensing and other technical support to the Indonesian Center for Volcanic and Geologic Hazard Mitigation (CVGHM) during the October-November 2010 eruption of Merapi Volcano. A variety of satellite data were utilized including Synthetic Aperture Radar (SAR) from the TerraSAR-X and ERS-2 sensors, thermal infrared (TIR) from the ASTER sensor, and high resolution visible and near-infrared data from the GeoEye 1 and WorldView-2 sensors. Increased satellite tasking frequency and expedited product generation were supported by several pre-existing national and international hazard response protocols. Images were available for analysis by volcanologists at the USGS Alaska and Cascades Volcano Observatories typically within 2-6 hours of acquisition and critical data and analyses were provided to CVGHM within the same time periods. CVGHM scientists integrated the remote sensing data with real-time seismic data as their primary tools for monitoring the eruption, issued warnings and called for evacuations which saved many thousands of lives. Data from SAR sensors were especially useful in observing changing conditions in the summit crater as they were able to penetrate the frequent weather clouds, steam, volcanic gas, and ash emissions that obscured visible and thermal infrared observations of the summit for most of the main eruptive period. Data were collected with spatial resolutions that varied from 1 to 8 meters, allowing for detailed views of the summit crater, sequential observations of rapidly growing lava domes, vent features, and pyroclastic-flow deposits. Data from these satellite sources documented key morphological changes during eruptive events. Explosive eruptions on 26 and 30 October (local time) removed the 2006 lava dome, enlarged the summit crater, and deeply incised the headwall of the Kali Gendol drainage. Remote sensing data confirmed that the 2010 eruptive period with an explosive event rather than lava extrusion as in prior eruptions. This fact, along with documentation of rapid rates of dome growth, reinforced and validated CVGHM concerns that the 2010 eruption would be much larger and more hazardous than those of the past century. Reconfiguration of the summit crater over the course of the eruption resulted in the majority of pyroclastic-flows produced by dome collapse to follow the Gendol drainage. Rapid lava dome growth was indicated by repeat SAR observations prior to the largest explosive event on 5-6 November. This event produced pyroclastic flows and surges that traveled up to 15 km from the summit shortly after the evacuation zone was extended to 20 km. Rapid dome growth then resumed for less than a day on 6 November, and was followed by dome subsidence and ash emissions from several vents adjacent to or penetrating the newly-erupted lava dome. These small ash and gas emissions continued through mid-November as dome growth slowed and eventually ceased. Although lava, pyroclastic-flow, surge, and tephra-fall deposits were readily observed and their extent measured using SAR, infrared and visible wavelength satellite data, lahar deposits were not easily identifiable.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2011
- Bibcode:
- 2011AGUFMNH52A..02S
- Keywords:
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- 8485 VOLCANOLOGY / Remote sensing of volcanoes;
- 8488 VOLCANOLOGY / Volcanic hazards and risks;
- 4315 NATURAL HAZARDS / Monitoring;
- forecasting;
- prediction;
- 4337 NATURAL HAZARDS / Remote sensing and disasters