The 2012 Kilauea Volcano, Hawai’i, Slow-Slip Event Captured by cGPS and Satellite Radar Interferometry

Abstract

Slow-slip events (SSEs) have been detected to occur along the southern flank of Kilauea volcano (Hawaii, USA). SSEs have been recorded using continuous Global Positioning System (GPS) and tiltmeters stations. Until now, differential radar interferometry results have not been conclusive about the spatial pattern of associated vertical motion, although GPS time series show subsidence signals. In late May 2012, the most recent SSE began and it lasted for approximately 3 days. SSE was accompanied by earthquakes at the decollement ( ∼7--9km ), and an unusual swarm across the Koa’e fault system (June 5th). Here, we use a dense GPS network and Radarsat-2 satellite data to map the associated ground deformation. A SSE fault-slip map is inferred using elastic modeling and compared with the fault-slip map due to long-term volcano flank motion. Inferred long- and short-term fault-slip distributions allow observing a complementary pattern, likely related to different fault properties.