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Investigating Controls on Submarine Channel Evolution Through Morphometric Scaling Relationships

Abstract

Submarine channels are major elements of deep-marine depositional systems, capable of transporting sediment hundreds of kilometers over extremely low-gradient slopes. Although submarine channels share morphological similarities with fluvial channels, observations from modern and ancient systems indicate they are formed under processes and controls unique to submarine settings. As demonstrated in fluvial geomorphology, morphologic characteristics of channels can constrain the mechanisms and context of their formation and evolution. This study takes advantage of well-established principles and workflows of fluvial geomorphology to advance understanding of submarine channels. A combination of publically available and industry-provided high-resolution seafloor bathymetry data showcases submarine channel systems in a variety of geographic, climatic, and tectonic settings. By measuring basic submarine channel morphometrics (e.g., width, depth, planform characteristics, and longitudinal profiles), this study builds a globally-distributed dataset of submarine channel morphometrics that constrains scaling relationships and possible correlations with external factors (e.g., slope gradient and sediment source characteristics). In conjunction with contextual information about each associated sediment transport system, these data document the spatiotemporal variability of submarine channels, helping constrain key controls on channel morphologies and providing a basis for predicting channel metrics in exploration scenarios, in which data may be sparse or discontinuous. Furthermore, linking synoptic channel morphology to preserved deposit architectures remains a significant challenge for translating understanding of channel evolution to prediction of the geometries and characteristics of channel deposits. This compilation of morphometric data from a diverse suite of channels captures the range of scales and variability exhibited by submarine channel systems, providing context for interpreting outcropping and subsurface channelized stratigraphy.