Continental shelf sedimentology: scales of investigation define future research opportunities

Investigations of continental shelf sedimentology can be separated into small-scale sediment–fluid-interaction studies and large-scale sediment-survey techniques. Small-scale studies rely on time-series observations from benthic tripods using current meters, turbidity sensors, CTDs, cameras, and acoustic altimeters and sonars. Large-scale studies rely on repeated spatial surveys using side-scan sonar, acoustic profiling methods, and coring techniques. Over the past four decades these approaches have been very successful in describing the sediments on continental shelves and interpreting the physical forcing mechanisms and resulting sediment transport pathways, depositional sites, sediment budgets, and strata formation. Results from shelf studies carried out off the west coast of North America and the Amazon River are used to illustrate the many insights gained from small-scale and large-scale investigations. Recent developments of new sensors and observational techniques have greatly improved our ability to investigate the sedimentology of continental shelves. The time and spatial scales of resolution for both small-scale and large-scale investigative approaches have begun to overlap, and the possibility of concurrent investigations defines exciting new opportunities for future research.