Esther Sumner on Turbidity Currents
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Though turbidity currents are massive and frequent underwater events, we have rarely observed them directly. Esther Sumner is one of the few researchers who has. In the podcast, she describes what it's like to instrument an active submarine canyon, what these flows have revealed about the way sediment moves across the seafloor — and the day her team accidentally flew an underwater robot into a live turbidity current. She is an Associate Professor of geology and geophysics at the University of Southampton.
In the image, Sumner is running a wave tank experiment to simulate a turbidity current.
Podcast Illustrations
Images courtesy of Esther Sumner unless otherwise indicated.
Diagram of a turbidity current showing two main components: a fast, short-lived destructive base flow and a long-lived, dilute cloud that rides above the base flow. The base flow can sweep boulders and experimental equipment along with it.
Study of Turbidity Currents in Monterey Canyon, California
Sumner has conducted several studies of turbidity currents in the Monterey Canyon off the west coast of California.
In the cross sections at left, the vertical scales are greatly exaggerated, but the same in both sections, showing that the Monterey Canyon is similar in scale to the Grand Canyon.
Is this slide showing the feeding of sediment into the canyon from a river, which can trigger at turbidity current?
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Acoustic doppler current profilers were used to measure the velocity profile of the water flow in Monterey Canyon. As indicated in the inset at bottom left, the instrument directs beams of high-frequency sound toward the