Channel inception through bottom-current erosion of pockmarks revealed by numerical simulation

Yu, Kaiqi1,2,3,4,5; Lefebvre, Alice3; Li, Wei1,2; Zhan, Wenhuan1,2; Miramontes, Elda3,4

2023-05-01

10.1002/esp.5610

EARTH SURFACE PROCESSES AND LANDFORMS   影响因子和分区

0197-9337

1096-9837

In deep-marine environments, the inception of channels can be induced by the interaction between bottom currents and rough topography. However, it is still unclear under which conditions such features can form and what happens in the earliest phase of channel development. In this study, based on the morphological, sedimentary and oceanographic settings of a pockmark field in the NW South China Sea, we reveal the process of channel inception through the erosion of pockmarks by bottom currents. Using numerical simulations, we show that an appropriate current velocity can induce the erosion of pockmark trains in cohesive sediments, leading to the coalescence of discrete pockmarks and the formation of a channel with a rough thalweg. The interaction of bottom currents with the pockmarks induces a significant erosion along the pockmarks axis. Bottom-current erosion is strongest at the downstream edges of pockmarks, where the horizontal velocity reaches a maximum and an upwelling forms. Erosion increases as the distance between pockmarks reduces. In our simulation results, a channel is only formed by the coalescence of pockmarks if the distance between pockmarks is <6 times the diameter of the pockmark. This study provides evidence of the formation of channels by bottom currents, which helps reconstruct palaeoceanographic conditions based on sediment architecture. It also shows the complex hydrodynamics at these structures that strongly control sedimentary processes and may affect distribution of benthic ecosystems in marine environments.

bottom-current erosion channel inception morphological evolution numerical simulation pockmark

SCI

英语

其他

Guangdong Basic and Applied Basic Research Foundation[2020B1515020016] ; National Natural Science Foundation of China[41876054] ; CAS Pioneer Hundred Talents Program[Y8SL011001]

Physical Geography ; Geology

Geography, Physical ; Geosciences, Multidisciplinary

WOS:000981009500001

WILEY

GEOSCIENCES

Web of Science

1.Chinese Acad Sci, South China Sea Inst Oceanol, Innovat Acad South China Sea Ecol & Environm Engn, Key Lab Ocean & Marginal Sea Geol, Guangzhou, Peoples R China
2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
3.Univ Bremen, MARUM Ctr Marine Environm Sci, Bremen, Germany
4.Univ Bremen, Fac Geosci, Bremen, Germany
5.Southern Univ Sci & Technol, Dept Ocean Sci & Engn, Shenzhen, Peoples R China

Yu, Kaiqi,Lefebvre, Alice,Li, Wei,et al. Channel inception through bottom-current erosion of pockmarks revealed by numerical simulation[J]. EARTH SURFACE PROCESSES AND LANDFORMS,2023,48(11).

Yu, Kaiqi,Lefebvre, Alice,Li, Wei,Zhan, Wenhuan,&Miramontes, Elda.(2023).Channel inception through bottom-current erosion of pockmarks revealed by numerical simulation.EARTH SURFACE PROCESSES AND LANDFORMS,48(11).

Yu, Kaiqi,et al."Channel inception through bottom-current erosion of pockmarks revealed by numerical simulation".EARTH SURFACE PROCESSES AND LANDFORMS 48.11(2023).