Fig. 1

a (inset) Regional tectonic map of Southeast Asia. Red lines are primary plate boundary faults. Black dashed line is the active fold-and-thrust belt offshore Sabah. Color dot shows the M > 5 earthquakes from 1900 to 2015 from NEIC/USGS catalog. Red Arrow shows the general Sabah-Sunda motion extracted from the Global Strain Rate Model, with rate (mm/year) labeled in front of the arrow (Simons et al. 2007). b Topography of Sabah and details of instrumentally recorded earthquakes and geomorphologically evident active faults in the region. Colored squares indicate seismic intensities from the mainshock, based on the USGS “Did You Feel It” (DYFI) dataset and our own field interviews. Red lines denote features interpreted as normal faults mapped from 30-m SRTM data. Transparent colored lines show the approximate boundaries of major geological units, after (Hutchison 2005). G—granitic pluton of Mt. Kinabalu; U—ophiolitic basement