44 D10. Geomorpholgy, Quaternary Geology, and Soils (Posters)

Sunday, 19 March 2023
8:00 AM - 12:00 PM
Grand Ballroom A–D

A MULTI-TEMPORAL LANDSLIDE INVENTORY FOR WETAR ISLAND, INDONESIA

Paper number: 44-7
Program: Technical Sessions
Time: 8:00 AM – 12:00 PM

Authors

Abstract

Wetar is a ~2652 km2 island in the Inner Banda Arc in Eastern Indonesia. The Inner Banda Arc consists of volcanic islands, of which many, including Wetar, are being rapidly uplifted by arc-continent collision between Australia and the Banda Arc. Volcanic activity on Wetar has shut off due to the cessation of subduction, but there is volcanic activity on neighboring islands, and rates of tectonic uplift are rapid. Furthermore, a gap in seismicity beneath the island hints at active reorganization of regional tectonics, making the Banda Arc a fascinating yet understudied region. To examine controls on mass wasting and landscape evolution in this complex environment, we assembled a multitemporal landslide inventory consisting of 6000 landslides for Wetar from Google Earth imagery between 2002 and 2021. Of particular note is a concentration of flow-type landslides in a mining area on the north coast of Wetar that appeared in 2004 imagery as well as a large cluster of landslides during summer 2010. The combination of Wetar’s relatively high topographic relief, complex tectonic setting, and small population (~7,000) and accompanying relative lack of development, with the exception of some mining along the north coast, make the island uniquely situated to provide information on the interplay between tectonics, climate, land-use, and mass-wasting events on tropical islands. Here, we explore potential landslide triggers including rainfall and seismicity, alongside topography, geology, and land cover. We also examine trends of regrowth and recovery of landslides.

Geological Society of America Abstracts with Programs. Vol. 55, No. 2

doi: 10.1130/abs/2023SE-385593

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