Assessing Non-Volcanic Tremor (NVT) in Sumatra Subduction Zone Triggered by Large Distance Earthquakes

Abstract:

Non-Volcanic Tremor (NVT) can be triggered instantaneously during the surface waves of teleseismic events. We expected that remote triggering of tremor could help to better understand possible interactions of large distant earthquakes. We examined tremors triggered by large distance earthquakes in northern Sumatra subduction zone. We focused for distant earthquake that have epicentral distances larger than 1000 km and predicted dynamic stresses larger than 20 kPa. We found two large earthquakes i.e. 2011 Tohoku Mw 9.1 and 2000 South Sumatra Mw 7.9 potentially triggered locally tremors in beneath Nias region in the fore arc of Sumatra. To identify the local sources, we applied high pass filter to remove long-period signal from distant regions. The dynamically triggered seismicity was detected using waveform matched filter technique.