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.