Infrasound travels thousands of kilometres and can be detected using the appropriate instrumentation. Several natural sources generate infrasound, including the hundreds of volcanoes surrounding Singapore.
EOS has developed three main volcano laboratories at Mayon (Southeast Luzon, Philippines), Gede and Salak (West Java, Indonesia), and Marapi (Sumatra, Indonesia), in collaboration with the Philippine Institute of Volcanology and Seismology (PHIVOLCS)1 and the Centre of Volcanology and Geological Hazards Mitigation (CVGHM). This collaboration started in 2011 and is part of a long-term effort to mitigate hazards in the region. A variety of monitoring instruments (consisting of seismometers, tiltmeters, GPS receivers, CO2 sensors and scanning DOAS) are installed and maintained on the flanks of Gede, Salak, Marapi and Mayon to collect continuous data. Weekly reports are then generated, presenting time series of data (gas, seismic, tilt and cGPS) at different timescales to track potential trends in changing activity.
Why these volcanos?
The laboratory volcanoes are a window into the magmatic processes underlying volcanoes. They range from open to closed systems, and are high-risk volcanoes in the region. Gede and Salak volcanoes have the ever growing capital of Indonesia, Jakarta, in their shade. Mayon and Marapi are respectively the most active volcanoes in the Philippines and Sumatra (Indonesia), and therefore offer a unique opportunity to record unrest and eruptive signals at open-vent volcanoes. Marapi is also the closest volcano from Singapore, with only 430 kilometres between the two.
Apart from weekly reports, more in-depth research is also on-going using the data collected.
A multi-parametric approach is used, involving measurements of seismicity, deformation, and gas. The goals are to recognise and properly interpret magmatic ascent as soon as possible. We would like to address questions such as:
• What is the volcano doing during repose?
• How is magma transported from the reservoir to the surface?
• How to interpret signals during an eruption?
This project is complemented by a range of other geological, petrological and geochemical studies that will be combined to provide a comprehensive understanding of each volcano. We hope to be able to incorporate this information into forecasting algorithms and give probabilistic estimates of eruptions.
[1 Note that part of the network at Mayon volcano is a collaboration between PHIVOLCS and the Japan International Cooperation Agency (JICA).]