Submarine eruption and sedimentation processes in the rear Izu-Bonin-Mariana arc

This research will improve our knowledge on how underwater volcanoes erupt, how their products are transported under water, and what type of deposits are generated on the sea floor. The IODP Expedition 350 will drill/core hundreds of metres of volcaniclastic sediments in a submerged portion of the Izu-Bonin arc (south of Japan), where sediment accumulated over millions of years, giving an unprecedented record of submarine volcanism and evolution of the arc. Facies analysis of volcanic textures, detailed stratigraphy, and clast chemistry will be used in this project. This study will help determining whether the deposits where partly erupted subaerially, and whether they are linked to direct input from submarine eruptions, or if they are result of re-sedimentation of previous deposits. Such information is necessary for worldwide hazard assessment to vessels and coastal populations, and for a better understanding of submarine volcanoes in general.

This research will widen our understanding of submarine eruptions. It will help understand differences between subaerial vs. submarine eruptions, as well as giving applicable example on types of eruptions to expect in similar setting. Importantly, it will bring attention to possible hazards to oceanic traffic and coastal populations from submarine explosive eruptions, which are currently barely known. This dataset will permit a better risk assessment of these marine hazards, and will be made available for coastal guards, volcano observatories, volcanic ash advisory centres, civil defence, and shipping and insurance companies. Specifically, publication of this research will substantially increase the global awareness in the range of eruption dynamism to expect from submarine volcanism, thus will mitigate eruption hazards (tsunami, release of ash in the atmosphere, pumice raft) that can affect coastal populations, divert/block shipping and airline routes.
Certain types of ore deposits (e.g. volcanic hosted massive sulphides, manganese nodules) are closely linked to submarine volcanic vents. Depending on the type of recovered sediments, this study may give strong insights on the formation of economic-grade ore deposits and their link with submarine volcanism/venting, allowing more efficient exploration strategies to the mining industry. Similarly, hydrothermal vent life communities may be entrained by eruption-fed density currents and deposited away from vent, on the flank of submarine volcanoes, thus giving a geological record of life activity through various eruptive episodes, an important data for deep sea biologists.
Submarine telecommunication cables carry 95% of the global data traffic, commonly cross volcanic arcs, and can be broken by submarine density currents, leading to large-scale disruption of data transmission. Telecommunication companies will beneficiate from such hazard assessment on eruption-fed density currents.
There is large public interest to submarine volcanic eruptions, exemplified by large media coverage for each shoaling of a new volcanic island, or pumice raft sightings, for instance. Publication of this research in highly recognised journals will reach a large audience, as well as being transmitted to a wider public.
Finally, the models developed during this research may be exported to volcanism in the solar system, where atmosphere and hydrosphere compositions and density are different than on Earth.