JpGU-AGU Joint Meeting 2017

Presentation information

[JJ] Poster

A (Atmospheric and Hydrospheric Sciences) » A-OS Ocean Sciences & Ocean Environment

[A-OS31] [JJ] Linkage between oceanography and paleoceanography in marginal, shelf and coastal oceans

Sat. May 20, 2017 5:15 PM - 6:30 PM Poster Hall (International Exhibition Hall HALL7)

[AOS31-P04] Capturing extreme river runoff events from oceanic sediment distribution

*Shinichiro Kida1, Yusuke Okazaki2, Jon Woodruff3 (1.Research Institute for Applied Mechanics, Kyushu University, 2.Department of Earth and Planetary Sciences, Kyushu University, 3.Department of Geosciences, University of Massachusetts - Amherst)

Keywords:river runoff, sediment, earthquake

A significant amount of the freshwater discharges around Japan occurs through extreme weather events. Capturing the event in the ocean, however, has been observationally difficult because of the strong currents and its random occurrence. Moreover, the low salinity signal often disappears after a few days since the majority of the rivers in Japan are directly connected to the open ocean and thus is strongly affected by its circulation. Regional-scale numerical oceanic models are becoming capable of resolving the dynamics of freshwater discharges but we have so far lacked a tool to test them from observations. We will introduce an observational project based on the Ariake Sea that aims to investigate the dynamics of the extreme freshwater discharges from oceanic sediments. The discharge following the Kumamoto Earthquake is likely associated with sediments that entered the rivers through the various landslides and thus contain a detectable record compared to previous years. The Ariake Sea is one of the few estuaries that is large to capture the discharge signal and not directed altered by the open oceanic circulation.