Report on Lopevi (Vanuatu) — June 2004
Bulletin of the Global Volcanism Network, vol. 29, no. 6 (June 2004)
Managing Editor: Richard Wunderman.
Lopevi (Vanuatu) MODVOLC thermal alerts of 4-6 pixels during 9-16 June 2003
Please cite this report as:
Global Volcanism Program, 2004. Report on Lopevi (Vanuatu). In: Wunderman, R. (ed.), Bulletin of the Global Volcanism Network, 29:6. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN200406-257050.
16.507°S, 168.346°E; summit elev. 1413 m
All times are local (unless otherwise noted)
Subsequent to the events of June 2001 (BGVN 28:01) only one further period of activity, between 9 and 16 June 2003, was indicated by MODVOLC. MODIS detected activity on 9 June 2003 first with Terra at 1135 UTC with six alert pixels, followed by Aqua at 1435 UTC, when the alert pixels had reduced in number to four. The highest alert ratio, +0.432 (unusually high ) was detected by the Aqua satellite on 13 June 2003. There were three days when the number of alert pixels reached six (on 9, 13, and 16 June 2003). These data suggested that a lava flow, previously noted as occurring on 14 June 2003 (BGVN 28:06), probably began effusion at least as early as 9 June.
Data acquisition and analysis. Reports from Diego Coppola and David A. Rothery provided analyses of MODIS thermal alerts during 2001 and 2002 (using the MODVOLC alert-detection algorithm) extracted from the MODIS Thermal Alerts website (http://modis.hgip.hawaii.edu/) maintained by the University of Hawaii HIGP MODIS Thermal Alerts team (BGVN 28:01). Rothery and Charlotte Saunders provided updates to 31 May 2004. MODVOLC data are now routinely available from the Aqua satellite (equator crossing times 0230 and 1430 local time) in addition to the original Terra satellite (equator crossing times 1030 and 2230 local time).
Geologic Background. The small 7-km-wide conical island of Lopevi, known locally as Vanei Vollohulu, is one of Vanuatu's most active volcanoes. A small summit crater containing a cinder cone is breached to the NW and tops an older cone that is rimmed by the remnant of a larger crater. The basaltic-to-andesitic volcano has been active during historical time at both summit and flank vents, primarily along a NW-SE-trending fissure that cuts across the island, producing moderate explosive eruptions and lava flows that reached the coast. Historical eruptions at the 1413-m-high volcano date back to the mid-19th century. The island was evacuated following major eruptions in 1939 and 1960. The latter eruption, from a NW-flank fissure vent, produced a pyroclastic flow that swept to the sea and a lava flow that formed a new peninsula on the western coast.
Information Contacts: David A. Rothery and Charlotte Saunders, Department of Earth Sciences, The Open University, Milton Keynes, MK7 6AA, United Kingdom.