OMG学术报告2024013

报告题目：First direct observations of a submarine landslide (Homathko Delta,BC,Canada)

报告摘要：Every year ~19 billion tones of river-derived sediment arrive at the world’s deltas, where the sediment either remains parts of the delta, or is later remobilised and transported further toward the ocean floor. Understanding the processes that control remobilisation is therefore key to quantify the sedimentary fluxes of organic carbon, nutrients and pollutants to the ocean basins. One of the processes that remobilises deltaic sediment are submarine landslides. Although the resulting landslide scars of such landslides on the sea floor are well-known, such landslides had never been observed in action. Direct observations of submarine landslides are key as they enable the testing these different landslide models. In August/September 2022, we setup a sensor network on the delta front of the Homathko Delta (BC, Canada) to monitor a submarine landslide. We kept the boat moored for a full spring-neap tide cycle above the delta-lip where we knew submarine landslides would occur regularly. We also mapped the delta front every day to check for the occurrence of any delta-lip failures. We observe how over a 30-min period a series of smaller retrograding landslides eventually build a large landslide scare. The daily sea floor maps showed that the submarine channel downstream of the submarine landslides had been activated. Additionally, a turbidity sensor deployed 2km further down the submarine channel also detected a sediment density flow just after the submarine landslide. These first observations of a submarine landslide provide proof-of-concept that submarine landslides can be measured. Hopefully, these observations also provide valuable insight in the failure mechanisms that link terrestrial and oceanographic sediment transport processes.

报告人简介：Matthieu Cartigny是英国杜伦大学副教授(Royal Society Dorothy Hodgkin Fellow)。2012年获荷兰乌得勒支大学博士学位，先后任职于乌得勒支大学(2012-2013)、英国国家海洋研究中心(2013-2016)和英国杜伦大学(2016至今)。现任国际沉积学会巡回讲座(IAS Special Lecture Tours)主讲人和The Depositional Record期刊副主编(2017至今)。Matthieu Cartigny副教授主要从事海底浊流现代观测、沉积构造物理模拟等的教学和科研工作，曾担任多个科学考察航次的首席科学家，在浊流触发机制、超临界浊流搬运规律等方面取得了重要的科学发现，曾获国际沉积学会青年科学家奖、英国沉积学会Harold Reading奖。在Nature Geoscience、Science advances、Sedimentology等期刊发表论文70余篇，总被引4000+。

报告时间：2024年7月23日 14:00-17:30  

报告地点：南海海洋所南沙新园区604会议室  

主持人：李伟 研究员