V044-02 - The August 2019 eruption of Volcano 0403-091: pumice-raft formation and dispersion eruption

Description

Without warning, a new eruption of Volcano 0403-091 (30 km NW of Vava’u, northern Tonga) occurred on the 7th August 2019 producing a >200 km2 pumice raft. Pumice raft formation and evolution is poorly understood, yet rafts pose a range of potential hazards for marine traffic and infrastructure. The 7th August raft was imaged by satellites almost daily, so its source and path are well-constrained. This eruption therefore provides a unique opportunity to sample both rafted pumice with known float times and sunken pumice at the vent, as well as a rare chance to study vent structure, hydrothermal activity and marine life interactions immediately following an explosive, shallow eruption. Here we present the first results from a rapid response survey of the submarine vent site, conducted 6 months post eruption. We discuss the textural and geochemical charcateristics of the samples collected at the vent and compare them with floating pumice collected by a boat that intersected the raft (floated for 1 week), and from the shores of two Fijian Islands (floated for > 1 month). Physical, geochemical and textural (including high resolution X-ray computed tomography) analyses of these different pumice types from a single well-constrained eruption help to determine the controls on pumice raft formation and their potential hazards for marine shipping and infrastructure.

Period	16 Dec 2020
Event title	American Geophysical Union Fall Meeting 2010
Event type	Conference
Location	San Francisco, United StatesShow on map
Degree of Recognition	International