Quantitative analysis of Antarctic channel distribution and the role played by continental geomorphology in channel evolution

The submarine channel, also known as submarine canyon, is a narrow and long negative terrain 
that cuts to the shelf or slope and widely developed on the global continental margins. There are 
numerous factors in forming channels, including climate change, topography, sediment sources and 
grain size, and sea level change. However, for high latitudes, especially in the Antarctic region, the 
controlling factors of the formation and evolution of the channel are still poorly understood. In this 
study, we conduct a systematic analysis of the channels in various regions of the Antarctic 
continental margin with the aim of identifying the differences of the channels between the East and 
West Antarctic continental margins and associated controlling factors. We identified 2126 channels 
on the Antarctic continental margin based on IBCSO V2 data (International Bathymetric Chart of 
the Southern Ocean Version 2). The submarine channels and their possible factors in six regions 
(Weddell Sea, Amundsen Sea, Ross Sea, Wilkes Land, Prydz Bay and Dronning Maud Land) are 
statistically analyzed. Quantitative analysis shows that there are obvious differences in the 
geomorphology of submarine channels between the East and West Antarctic continental margin. 
First, consider the differences in the landscape. The shelf is narrower on the east and wider on the 
west. There are prominent troughs running across the broad shelf. West Antarctica has a gentler 
slope gradient than the East Antarctic continental margin, and the ice velocity is much faster. Second, 
submarine channels on the West Antarctica continental margin are longer and wider in cross section, 
with most large-scale channels extending beyond the slope foot, whereas submarine channels on the 
East Antarctica continental margin are deeper but shorter, with fewer channels. We consider that 
shelf width, slope gradient, trough and ice velocity can control sediment transportation and thus 
affect the size of channels. Channels are longer and wider on the margin with wide shelf, prominent 
trough and fast ice velocity, while they are shorter and deeper on the margin with steep slope.