The marine geophysical data collected during the 2015 MEGA-TERA expedition provide a unique window into the near-trench structure of the Sumatran accretionary wedge.
This webinar was part of the preparations for the Subduction Zone Observatory workshop held on 29 September to 1 October 2016 at the Boise Centre in Boise, Idaho, USA.
The highly active Sumatran Subduction Zone has produced more than four great earthquakes in the last decade. The first of these was the giant Mw 9.2 Sumatra-Andaman earthquake that ruptured on 26 December 2004. This devastating event was followed by three others – the Mw 8.6 Nias-Simeulue quake in 2005, the Mw 8.4 Bengkulu earthquakes in 2007, and the Mw 7.7 Mentawai tsunami-earthquake in 2010.
After over one month of intense seismic activity, during which the alert level at Agung was 4 (the highest), on 29 October 2017, at 4:00pm local time, the alert level was lowered to 3 (eruption imminent). This was due to a strong decrease in the number of earthquakes surrounding Agung, as well as a reduction in the seismic energy and amplitude of these quakes.
Petrological studies can inform of the processes and time scales of magma movement and ascent, and thus allow associating them with monitoring unrest signals, and thus better mitigate volcano hazar
