Insights into fluid transport mechanisms at White Island from analysis of coupled very long-period (VLP), long-period (LP) and high-frequency (HF) earthquakes

摘要

The August 2012 to October 2013 White Island unrest sequence included 5 explosive volcanic eruptions and emplacement of a small dome. These events were linked to an overall increase in SO2 and H2S gas flux and RSAM seismic tremor which began in late 2011. Prior to this unrest, a small swarm of 25 events was observed on 19-21 August 2011 and captured on a temporary seismic array including 14 broadband sensors. Each event comprised coupled pulses having distinct high frequency (HF = 2-5 Hz), long-period (LP = 0.5-1.1 Hz) and very long period (VLP = 0.03-0.125 Hz or 8-30 s) earthquakes.