Data

Eelgrass (Zostera marina) characteristics, sediment grain size distributions, sediment total organic carbon contents (TOC), carbon isotope ratios of sediment organic matter, and total carbon to total nitrogen ratios were measured at four lower intertidal sites in Bellingham Bay, Washington, July 2-5, 2019, and three subtidal sites (grain-size and TOC only) on July 11, 2019.

Sediment samples were collected on and adjacent to the Whale's Tail South marsh. Short push-cores of bed sediment were collected in South San Francisco Bay adjacent to Whales Tail South marsh on five days from June through August 2021 and 3 days from November 2021 to January 2022. Additional samples were taken from ceramic tiles placed on the marsh to measure sediment deposition and from rip-up cl

High-resolution multichannel sparker seismic (MCS) data and chirp sub-bottom data were collected by the U.S. Geological Survey in collaboration with the University of Washington (UW) in the summer of 2019 along the Cascadia submarine forearc offshore Oregon and Washington. Data were acquired to characterize quaternary deformation and sediment dynamics along the central and northern Cascadia margin

Multichannel seismic (MCS) data were collected by the U.S. Geological Survey (USGS) in 1990 in the California Continental Borderland (USGS field activity L490SC). In 2021, these data were reprocessed to improve accuracy and resolvability of geologic structures and fault systems of California's continental margin. MCS data were acquired to support the Southern California Earthquake Hazards project

This data release contains processed high-resolution multichannel sparker seismic-reflection (MCS) data and chirp sub-bottom data that were collected aboard Humboldt State University's R/V Coral Sea in October of 2018 on U.S. Geological Survey cruise 2018-658-FA on the shelf and slope between Cape Blanco, Oregon, and Cape Mendocino, California. MCS data were collected to characterize quaternary de

Growth of subaqueous sand dunes commonly causes shoaling in engineered river channels that necessitates costly dredging to maintain adequate depths for navigation. The factors that result in sand wave growth are theoretically understood from laboratory experiments, but the capacity to predict sand wave geometries in field settings is limited due to temporal and spatial variability in hydrodynamics

Between 2018-2021, the U.S. Geological Survey cooperated with NOAA to conduct multibeam echo-sounding surveys to map the seafloor along the Cascadia convergent margin, collecting acoustic bathymetry, backscatter and water column data. Rising bubbles emitted from methane cold seeps on the seafloor can be detected acoustically with this multibeam echo-sounding sonar, and this dataset contains the lo

Geochemical analysis of authigenic carbonates from the Cascadia Subduction Zone. Powdered carbonate samples for stable carbon (delta-C-13) and oxygen (delta-O-18) isotopes and carbonate phase were analyzed as a proxy for potential fluid sources, and to better understand how process, such as mixing, and oxidation, can alter the initial fluid isotopic composition and the archived fluid-source signat

Elemental chemistry and weight percent of the less than 0.063 mm fine sediment fraction are reported for surface sediments from shoals, the ebb tide delta, local tributaries, and inland rivers that carry sediment to San Francisco Bay, California.

This data release supersedes version 1.0, published in October 2021 at https://doi.org/10.5066/F74F1NW7. Versioning details are documented in the accompanying VersionHistory_P9DZ321R.txt file.  This data release presents sediment grain-size data from samples collected from core S3-15G, a 4.72-m long gravity core collected at a depth of 3,491 meters on the western levy of the Monterey Fan on May 3

High-resoulution multichannel seismic-reflection (MCS) and Chirp sub-bottom data were collected by the U.S. Geological Survey in 2019 offshore Humboldt County of northern California to expand data coverage along the southern Cascadia Margin. Data were acquired to characterize offshore faults and to study sediment distribution. MCS and Chirp data were collected coincidentally and were used to deter

Sediment samples were collected from Los Padres reservoir in the Carmel River watershed, central California coast, between July 11 and 17, 2017, using a CME-45 barge-mounted drill rig, to characterize sedimentary properties in the reservoir deposits following the Soberanes Fire of 2016 and high river flows in winter 2017. Borehole samples were recovered using direct push coring with an Osterberg p