Publications

Vaughan, RG; Webley, PW (2010). Satellite observations of a surtseyan eruption Hunga Ha'apai, Tonga. JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH, 198(2-Jan), 177-186.

Abstract
On March 17 2009 a surtseyan eruption occurred around Hunga Ha apai Island Tonga A series of observations from the high spatial resolution Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and the high temporal resolution Moderate Resolution Imaging Spectroradiometer (MODIS) was used to estimate the magnitude location start time and duration of the eruption and measure the evolving charactenstics of the new Hunga Ha apai Island The eruption start time was estimated to be between 01 50 and 11 10 local time on March 17 2009 (i e between 12 50 and 22 10 UTC March 16) The initial explosive phase lasted 3-5 days and consisted of multiple steam and tephra explosions from two distinct vent sources one on the northwest side and another about 100 m off the south shore of the pre-existing island The eruption plume reached 4 0 to 7 6 km altitude above sea level and tephra added new land around each of the vents initially tripling the area of the pre existing Island The next phase of steaming from newly formed crater lakes around the vents lasted a few days Three warm crater lakes formed initially but disappeared with time as the shoreline eroded After similar to 2 months vegetation that was initially buried by tephra was recovering after similar to 10 months the size of the island had eroded down to twice that of the pre-existing island and the one remaining crater lake had a temperature of similar to 68 +/- 17 degrees C The volume of erupted material was estimated to be similar to 0 0176 km(3) and the volcanic explosivity index (VEI) was estimated to be VEI=2 Published by Elsevier B V

DOI:
10.1016/j.jvolgeores.2010.08.017

ISSN:
0377-0273