Swarms of small earthquakes on Marapi Volcano, West Sumatra, Indonesia: are these precursors to explosion event?
Abstract
Marapi Volcano's activity is characterized by Strombolian to small Vulcanian explosions with occasional VEI 2 producing tephra and pyroclastic flows. Currently in collaboration between Earth Observatory of Singapore (EOS) and Centre for Volcanology and Geological Hazard Mitigation (CVGHM) the volcano is seismically monitored with 7 broadband stations, and 2 short-period stations. In addition, we deployed 2 tiltmeters and an experimental soil CO2 sensor. These stations are telemetered by 5.8GHz radio to Marapi Observatory Post where data are archived and displayed for Marapi observers for their daily volcano activity monitoring work. We also archive the data in the EOS and CVGHM main offices. Data are being utilized by volcano scientists of CVGHM and researchers in both institutes as well as university students in and around them. We presented seismic earthquake sequences (swarm) prior to small explosion on Marapi in July 2016. These earthquakes are small, better identified after the deployment of seismic stations at summit, and located at depths < 1km near the volcano active vents. Similar swarms occurred prior to small explosions of Marapi. We also presented VLP-LP signals associated with an explosion which can be explained as volumetric change of sub-vertical crack at depth similar to the occurrence of small earthquake swarms. Our study attempt to understand the state of the volcano based on monitoring data and enable us to better estimate the hazards associated with future small explosions or eruptions.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.V43A3138H
- Keywords:
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- 7280 Volcano seismology;
- SEISMOLOGYDE: 8419 Volcano monitoring;
- VOLCANOLOGYDE: 8485 Remote sensing of volcanoes;
- VOLCANOLOGYDE: 8494 Instruments and techniques;
- VOLCANOLOGY