Landslides triggered by the 2015 Mw 6.0 Sabah (Malaysia) earthquake: inventory and ESI-07 intensity assignment

Abstract. On 4 June 2015, a Mw 6.0 earthquake occurred in the Sabah region (Malaysia), triggering widespread landslides along the slopes of Mt. Kinabalu. Despite the moderate magnitude, the Sabah earthquake was very efficient in triggering landslides: here I provide an inventory containing 5198 slope movements, mapped in an 810 km²-wide area. I investigate earthquake intensity using the Environmental Seismic Intensity (ESI-07) scale, which is a macroseismic scale based exclusively on earthquake environmental effects. The epicentral ESI-07 intensity is assessed at IX, considering the dimension of the area affected by secondary effects; such figure agrees well with a dataset of global earthquakes.

I estimate the volume of individual landslides using area-volume scaling laws, then I assigned an ESI-07 intensity to each mapped landslide. I document that the selection of a given area-volume relation has a minor influence on the ESI-07 assignment. Then, I compare ESI-07 values to landslide density and areal percentage on a 1-km² grid; such parameters are widely adopted in the description of earthquake-triggered landslide inventories. I argue that their integration with the ESI-07 scale may provide an effective way to compare earthquake damage on a variety of spatial and temporal scales. The methodological workflow here illustrated is useful in joining the scientific communities dealing with the realization of earthquake-triggered landslide inventories and with ESI-07 assignment; I believe this effort is beneficial for both the communities.