Deep Sea Reveals Linkage Between Earthquake and Carbon Cycle

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An international team led by the Innsbruck geologists Arata Kioka, Tobias Schwestermann, Jasper Moernaut, and Michael Strasser could quantify for the first time the entire trench-wide volume of marine sediments that were remobilized by the magnitude 9 Tohoku-oki earthquake in 2011 and transported into the up to 8 km deep Japan Trench.

An international team led by the Innsbruck geologists Arata Kioka, Tobias Schwestermann, Jasper Moernaut, and Michael Strasser could quantify for the first time the entire trench-wide volume of marine sediments that were remobilized by the magnitude 9 Tohoku-oki earthquake in 2011 and transported into the up to 8 km deep Japan Trench.

This was facilitated within a project funded by the Austrian Science Fund (FWF) and in collaboration with researchers from Geological Survey of Japan of the National Institute of Advanced Industrial Science and Technology (AIST), JAMSTEC (Japan Agency for Marine-Earth Science and Technology), The City University of New York, MARUM (Centre for Marine Environmental Sciences, University of Bremen) and ETH Zurich, through integrating analyses of samples and data collected during several offshore research expeditions conducted between 2012 and 2016.

The results have now been published in Scientific Reports. Along with carbon content measurements, they could estimate the total carbon mass of more than 1 Tg (1 teragram = 1 million tons), triggered by one single tectonic event and transported to these water depths. "The results surprised us and our colleagues," said Tobias Schwestermann, PhD candidate at the Department of Geology at the University of Innsbruck. "This is much higher than expected from carbon fluxes observed in other deep-sea trench systems worldwide," continues Schwestermann.

Read more at University of Innsbruck

Image: The German Sonne is one of the best technically equipped research vessels currently available. (Credit: Universit├Ąt Hamburg/LDF/V M.Hartig/Meyer Werft)