Reconstructing the sediment concentration of a giant submarine gravity flow.

ABSTRACT: Submarine gravity flows are responsible for the largest sediment accumulations on the planet, but are notoriously difficult to measure in action. Giant flows transport 100s of km³ of sediment with run-out distances over 2000 km. Sediment concentration is a first order control on flow dynamics and deposit character. It has never been measured directly nor convincingly estimated in large submarine flows. Here we reconstruct the sediment concentration of a historic giant submarine flow, the 1929 "Grand Banks" event, using two independent approaches, each validated by estimates of flow speed from cable breaks. The calculated average bulk sediment concentration of the flow was 2.7-5.4% by volume. This is orders of magnitude higher than directly-measured smaller-volume flows in river

SUBMITTER: Stevenson CJ 

PROVIDER: S-EPMC6033887 | biostudies-literature | 2018 Jul

REPOSITORIES: biostudies-literature