| Description |
Following marine oil spills, weathered oil can mix with sediment in the surf zone and settle to the seafloor to form mats up to hundreds of meters long. Wave action fragments these mats into 1- to 10-centimeter (cm) diameter sand and oil agglomerates (SOAs). SOAs can persist for years, becoming buried in or exhumed from the seafloor and/or transported cross-shore and alongshore (Dalyander and others, 2015). These fragments are angular near the source mat and become increasingly rounded as they are transported. To quantify SOA motion, the USGS conducted experiments in November 2016 (field activity number (FAN) 2016-364-DD) and June 2017 (FAN 2017-329-FA) using various size, shape, and density artificial sand and oil agglomerates (aSOAs). Video and velocity data were collected under a range of hydrodynamic forcing scenarios in the Small-Oscillatory Flow Tunnel at the U.S. Naval Research Laboratory (NRL) located in Stennis, Mississippi. Between November 14 and 18, 2016, laboratory studies were conducted on spherical- and patty-shaped particles on a roughened flatbed. Two types of particles were used, one consisting of paraffin wax and sand, while the other was machine-fabricated out of aluminum and coated in sand. Between June 5 and 8, 2017, laboratory studies were conducted on spherical, patty, ellipsoidal, and angular-ellipsoidal particles using paraffin wax and sand, aluminum, and three-dimensional (3D) printed plastic particles. [More]
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