Slope Break and Avulsion Locations Scale Consistently in Global Deltas

Abstract

AbstractUnderstanding how deltas respond to changing sea level is crucial as deltas provide important ecosystems, are inhabited by ∼500 million people, and are nexuses of food, energy and economic activity. The response of delta distributary channels to sea‐level rise depends on the geomorphic controls on delta morphology and their scaling relationships. Our data from 105 deltas globally show strong scaling between the upstream distances to slope breaks and to avulsion nodes, and confirm the previously known scaling between backwater and avulsion lengths. The break in slope is proposed to be the principal control on delta development, along with other proposed secondary controls. We identify and discuss the implications of this slope break‐avulsion length scaling, leading to a conceptual model of delta morphology and sedimentology. This model suggests how deltas may respond to future sea level rise and guides interpretation of deltaic deposits in the rock record.