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EPS Seminar: Dr. Tushar Mittal "Hunga Tonga eruption as an exemplar for shallow submarine volcanism : Analyzing the plume dynamics & radiative effects"

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Event Details:

The talk will cover the combination of recent observational work analyzing the eruption plume dynamics with satellite imagery, followed by new work on the plume dynamics side and analyzing the joint radiative effect of stratospheric water vapor, aerosols, and ozone (it turns out that the eruption would likely cool the planet once all three species are accounted for).

About Dr. Tushar Mittal:

On 15 January 2022, Hunga Tonga Volcano erupted from a shallow (~200 m deep) submarine vent, injecting unprecedented amounts of water vapor (~ 120-150 Tg) into the stratosphere as well as a more moderate amount of sulfur dioxide (~ 0.4-0.5 Tg) into the stratosphere. These two components have opposite climate effects -  Water vapor is a greenhouse gas while aerosols cool the surface . Consequently, several studies have hypothesized that the large amount of stratospheric water vapor injected by the Hunga eruption produced a net climate warming. If this is true, it would illustrate that shallow submarine eruptions have distinctly different climate effects than subaerial eruptions and has important implications for Earth system response of submarine volcanism - the most common but least observed mode of volcanism over Earth's history. We use a combination of satellite remote sensing datasets (Himawari, SAGE III) along with radiative transfer models to analyze eruption dynamics, as well the net effect of the Hunga eruption on the Earth's stratospheric composition and radiative forcing, accounting for the perturbation of three radiatively important constituents in the stratosphere: water vapor, ozone, and sulfate aerosols.

My research focuses on understanding isolated solid-Earth subsystems in detail, with the goal of integrating them to investigate how the environment and ecosystems on Earth evolve on various spatial and temporal scales. My active research encompasses three primary topics: (a) Volcano science (Magmatic processes in the sub-surface, lava flows, submarine volcanism, and fluid-rock interaction in geothermal and hydrothermal systems - this involves a combination of theory, fieldwork, and textural analysis), (b) Geofluids & Geomechanics (Understanding rock rheology and fluid-rock reactions on a micro-scale using seismic information in the lab & field to investigate processes in real-time for detailed process understanding

& control - this involves a combination of theory and lab experiments as well as field data from geothermal sites), and (c) Developing new geophysical and geochemical characterization methods (hyperspectral imaging for cost-effective and rapid use in field settings - both for science applications as well as various carbon dioxide removal strategies e.g., enhanced rock weathering.


For the Zoom information, please get in touch with Jannis Simões-Seymens (