Submarine channels deliver globally important volumes of sediments, nutrients, contaminants and organic carbon into the deep sea. Knickpoints are significant topographic features found within numerous submarine channels, which most likely play an role in channel evolution behaviour sediment-laden flows (turbidity currents) that traverse them. Although prior research has linked supercritical tur...

To develop empirical bases for the numerical treatment, I have: 1) conducted fieldwork (described below) involving eolian bedforms, with Philippe Claudin, Bruno Andreotti, Olivier Pouliquen, and Rebecca Hoyle; 2) begun a collaboration involving separate observations of subaqueous ripple evolution and sorted-bedform changes with Giovanni Coco and Malcolm Green; and 3) begun a collaboration to me...

Microbial biofilms are the prime site of nutrient and contaminant removal in streams. It is therefore essential to understand how biofilms affect hydrodynamic exchange, solute transport, and retention in systems where geomorphology end induced hydrodynamics shape their growth and structure. We experimented with large-scale streamside flumes with streambed landscapes constructed from graded bedf...

It can be shown from bedform stability diagrams, that each turbidity current, regardless of whether its density is low or high, or whether its history is simple (e.g., surging flow) or complex (e.g., sustained flow), should pass through a final waning phase in which flow conditions are prone to bedform development. Yet, many thick deep-marine sandstones of supposed turbidity-current origin are ...

For grain sizes finer than coarse sand, the first flow-transverse bedforms to develop are current ripples. Although numerous studies have analysed different aspects of bedform morphodynamics, to date no comprehensive physical explanation for the formation of ripples has been given. We offer such an explanation based on a virtual boundary layer concept, and present a model predicting ripple heig...