The Role of the Ocean in Modulating the Dynamics of Silicic Submarine Volcanic Eruptions
Rebecca CAREY1#+, Adam SOULE2, Michael MANGA3, Richard FISKE4, Kenichiro TANI5, Kristen
FAURIA6, Raymond CAS7, Jocelyn MCPHIE1, Christina LIN6, Sam MITCHELL8, Meghan JONES9, Chris
CONWAY10, Wim DEGRUYTER11, Behnaz HOSSEINI6, Ryan CAHALAN12, James WHITE13, Martin
JUTZELER1, Richard WYSOCZANSKI14, Bruce HOUGHTON8, Yoshihiko TAMURA15, Iona MCINTOSH16
1 University of Tasmania, Australia, 2 Woods Hole Oceanographic Institute, Australia, 3 University of California
Berkeley, United States, 4 Smithsonian Organisation, United States, 5 National Museum of Nature and Science,Japan, 6 University of California at Berkeley, United States, 7 Monash University, Australia, 8 University ofHawaii, United States, 9 Woods Hole OCeanographic Institute, United States, 10 (5)National Museum of Natureand Science, Japan, 11 Cardiff university, United Kingdom, 12 Georgia Tech, United States, 13 University ofOtago, New Zealand, 14 New Zealand Institute for Water and Atmospheric Research, New Zealand, 15 Japan
Agency for Marine-Earth Science and Technology, Japan, 16 Jamstec, Japan#Corresponding author: rebecca.carey@utas.edu.au +Presenter
Submarine volcanoes can produce silicic magmas that can erupt variably from small-volume lava domes todevastating large-volume caldera-forming eruptions. However, eruption into water instead of air can give rise toeruption styles distinct from those on land due to: 1) higher confining pressures, and (2) the seawater medium,
which has a higher heat capacity, density and viscosity than air.
Only two examples of high volume silicic submarine eruptions are historically recorded: The eruption of
Kolumbo submarine volcano in 1650 (Mediterranean), and Havre volcano in 2012 (Kermadec Arc, NZ). The
Havre event provides observational, stratigraphic, vent depth, timing and magma flux constraints that elucidate
magma ascent, eruption into seawater, and particle transport processes.
Seafloor and satellite observations reveal that the ~1km3 Havre pumice raft was erupted from a vent depth of
900m at magma fluxes of ~9 x 106 kgs-1. 1D conduit models using Havre magma chemistry and melt inclusion
water contents of 5.8wt.% show that at ~9MPa of pressure buoyant magma was extruded into the ocean where itrose, quenched and fragmented to produce meter-sized clasts – this eruption was therefore a clast-generating
effusive event. Subsequent to this style of eruption, the fate of clasts is driven by their ability to ingest water. AtHavre, 70% of the erupted pumice was dispersed off the volcanic edifice.
A well constrained sample suite of submarine pumice deposits erupted from modern seafloor volcanoes exists.
This sample suite spans a spectrum of eruption intensities: 1) powerful explosive caldera-forming, 2) conebuilding, 3) effusive dome spalling, 4) passive dome effusion. The modeling and experimental constraints from
Havre provide a framework to begin to infer the style and intensity of other less-constrained silicic eruptions,
possibly leading to the start of an intensity-based classification for submarine silicic volcanic eruptions
comparable to that already available for subaerial eruptions.