Hunt for slow slip events along the Sumatran subduction zone in a decade of continuous GPS data
Monday, 22 February 2016
Lujia Feng1, Emma Hill1, Pedro Elosegui2,3, Qiang Qiu1, Iwan Hermawan1, Paramesh Banerjee1 and Kerry Sieh1, (1)Nanyang Technological University, Earth Observatory of Singapore, Singapore, Singapore, (2)CSIC, Barcelona, Spain, (3)Massachusetts Institute of Technology, Haystack Observatory, Westford, MA, United States
Abstract:
Slow slip events (SSEs) have been observed in GPS time series for many subduction zones worldwide, but not in decade-long data from the Sumatran GPS Array (SuGAr). An outstanding question has been whether SSEs have simply not occurred on the Sunda megathrust, or whether they have been obscured by many earthquakes and large postseismic deformation in the last decade. We remove all known tectonic signals from the time series to search for evidence of SSEs. The residuals are essentially flat at the centimeter scale. At the millimeter scale, SSEs might exist but cannot be confirmed using the current data. The lack of evidence for events may reflect SSEs occurring at a magnitude, location, or time scale that renders them undetectable with the current resolution of SuGAr, that the properties of this megathrust are not conducive to SSEs, or because the megathrust is in an active period of the earthquake cycle.
