Deep-sea water displacement from a turbidity current induced by the Super Typhoon Hagibis

PeerJ

article

Shinsuke Kawagucci¹  Tetsuya Miwa²  Dhugal J. Lindsay⁴  Eri Ogura⁴  Hiroyuki Yamamoto²  Kenichiro Nishibayashi⁷  Hiroyuki Yokooka⁷  Shotaro Nishi⁷  Ayu Takahashi⁸  Sangkyun Lee⁸ 

[1] Super-cutting-edge Grand and Advanced Research ,(SUGAR) Program, Institute for Extra-cutting-edge Science and Technology Avant-garde Research ,(X-star), Japan Agency for Marine-Earth Science and Technology;Project Team for Developing Innovative Technologies for Exploration of Deep-Sea Resources, Japan Agency for Marine-Earth Science and Technology;Institute for Marine-Earth Exploration and Engineering ,(MarE3), Japan Agency for Marine-Earth Science and Technology;Institute for Extra-cutting-edge Science and Technology Avant-garde Research ,(X-star), Advanced Science-Technology Research ,(ASTER) Program, Japan Agency for Marine-Earth Science and Technology;Graduate School of Nanobioscience, Yokohama City University;Research Institute for Global Change ,(RIGC), Marine Biodiversity and Environmental Assessment Research Center ,(BioEnv), Japan Agency for Marine-Earth Science and Technology;Research and Development Partnership for Next Generation Technology of Marine Resources Survey;Research and Development Partnership for Next Generation Technology of Marine Resources Survey ,(J-MARES) / JGI, Inc.

关键词: Deep sea;    In situ observation;    Video image;    Oceanography;   

DOI  :  10.7717/peerj.10429

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Turbidity currents are the main drivers behind the transportation of terrestrial sediments to the deep sea, and turbidite deposits from such currents have been widely used in geological studies. Nevertheless, the contribution of turbidity currents to vertical displacement of seawater has rarely been discussed. This is partly because until recently, deep-sea turbidity currents have rarely been observed due to their unpredictable nature, being usually triggered by meteorological or geological events such as typhoons and earthquakes. Here, we report a direct observation of a deep-sea turbidity current using the recently developed Edokko Mark 1 monitoring system deployed in 2019 at a depth of 1,370 m in Suruga Bay, central Japan. A turbidity current occurred two days after its probable cause, the Super Typhoon Hagibis (2019), passed through Suruga Bay causing devastating damage. Over aperiod of 40 hours, we observed increased turbidity with turbulent conditions confirmed by a video camera. The turbidity exhibited two sharp peaks around 3:00 and 11:00 on October 14 (Japan Standard Time). The temperature and salinity characteristics during these high turbidity events agreed with independent measurements for shallow water layers in Suruga Bay at the same time, strongly suggesting that the turbidity current caused vertical displacement in the bay’s water column by transporting warmer and shallower waters downslope of the canyon. Our results add to the previous few examples that show meteorological and geological events may have significant contributions in the transportation of shallower seawater to the deep sea. Recent technological developments pertaining to the Edokko Mark 1 and similar devices enable straightforward, long-term monitoring of the deep-seafloor and will contribute to the understanding of similar spontaneous events in the deep ocean.

【 授权许可】

CC BY