Pre- and post-eruptive deformation at the Rabaul Caldera, Papua New Guinea modelled using PALSAR time series

In this contribution we present interferometric time series analysis of ALOS PALSAR images acquired between 2007 and 2011 for the Rabaul Caldera, situated at the north-eastern point of New Britain Island in Papua New Guinea. During this time period, a broad subsidence signal is observed across the caldera, followed by a period of uplift. These signals are thought to originate from deflation and inflation (respectively) from a magma chamber situated at 4.258°S, 152.182°E and a depth of 4.5 km beneath Rabaul Harbor. Using a Mogi point source model, we infer the time series of volume change in this magma chamber and deduce a deflation rate of ~10×10⁶ m³ yr^-1 during 2008 and 2009 and an inflation rate of ~7×10⁶ m³ yr^-1 during 2010 and early 2011.