JpGU-AGU Joint Meeting 2017

講演情報

[EE] 口頭発表

セッション記号 S (固体地球科学) » S-CG 固体地球科学複合領域・一般

[S-CG65] [EE] 混濁流:発生源から堆積物・地形形成まで

2017年5月25日(木) 10:45 〜 12:15 302 (国際会議場 3F)

コンビーナ:横川 美和(大阪工業大学情報科学部)、泉 典洋(北海道大学大学院工学研究院)、Svetlana Kostic(Computational Science Research Center, San Diego State University)、阪口 口(国立研究開発法人海洋研究開発機構)、座長:横川 美和(大阪工業大学情報科学部)、座長:阪口 秀(海洋研究開発機構、海洋研究開発機構)

10:45 〜 11:00

[SCG65-07] Direct observation of knick point acitivity in turbidity current channels

★招待講演

*Matthieu Cartigny1John Hughes Clarke2Cooper Stacey3Sophie Hage5Daniel Parsons4Peter Talling1Maria Azpiroz5Michael Clare6Joris Eggenhuisen 7Jenny Gales6Jamie Hizzett5James Hunt6Gwyn Lintern3Steve Simmons4Esther Sumner5Age Vellinga5Daniella Vendettuoli5Jon Wood8 (1.Department of Geography and Earth Sciences, Durham University, UK、2.Center for Coastal and Ocean Mapping, University of New Hampshire, USA、3.Natural Resources, Geological Survey of Canada, Canada、4.School of Environmental Sciences, Hull University, UK 、5.School of Ocean and Earth Science, University of Southampton, UK、6.Marine Geoscience, National Oceanography Centre, UK、7.Department of Geosciences, Utrecht University, The Netherlands、8.Ocean Data Technologies, Inc., Hyannis, USA)

キーワード:Turbidity currents, submarine channels, knick points

High-resolution bathymetric images of turbidity current channels reveal the existence of a wide range of bedforms within these systems. Knick points are the dominant bedform on a kilometre scale in most sandy systems. These knick points are thought to initiate and maintain submarine channels, and they would therefore play a key role the transport of sediment and nutrients to the deep sea. In contrast to their important role very little is known about knick points. What drives the formation of a knick point? Are they remnant headwalls of landslide, or are they related to turbidity currents? Are they a purely erosional feature? Do they have any preservation potential in the rock record?

Here we present data collected from knick points in an active turbidity current channel on a fjord floor in British Colombia, Canada. These data show how trains of knick points migrate several hundred metres upstream every year. We use repeat surveys to show how knick points are a combined erosional-depositional feature. Furthermore, we have deployed several instruments over the knick points to study how the knick points interact with the passing turbidity currents. Finally, we use repeat surveys and cores to explore the potential architecture and facies association associated to knick points.