In situ seafloor images were acquired at four sites (SKM, SLG, LDB, WLW) in the lower Columbia River, Washington and Oregon, with an underwater camera system between June 5 and June 8, 2021. Between 248 and 427 digital images of the sediment surface were collected at each site with an underwater camera system that was repeatedly lowered to the seabed along a series of 1 km-long transects oriented along the main navigation channel and spaced about 60 m apart. The camera consisted of a FLIR Blackfly BFS-PGE ...

This dataset contains surface sediment grain diameter measurements from in situ seafloor images collected in the lower Columbia River, Washington and Oregon, in 2021. Surface sediment grain diameters were derived from manual measurements (or "point counts") in a subset of images used to calibrate and validate an automated image processing algorithm to determine surface sediment grain size distributions. For each calibration and validation image that was selected, the long and short axis of 100 grains were ...

This dataset contains surface sediment grain size distributions derived from manual point counts of in situ seafloor images obtained with an underwater camera system in the lower Columbia River, Washington and Oregon, in 2021. The distributions derived from manual point counts were compared with results from an automated image processing technique to calibrate and validate the automated method used to quantify surface sediment grain size distributions in objective images. The surface sediment grain size ...

This dataset contains water velocity data derived from spatial surveys performed with a vessel-mounted acoustic Doppler current profiler at four sites (SKM, SLG, LDB, WLW) in the lower Columbia River, Washington and Oregon, in 2021. The data are provided in netCDF (.nc) format and compressed into .zip archives for each site.

In summer 2018, the U.S. Geological Survey partnered with the U.S Department of Energy and the Bureau of Ocean Energy Management to conduct the Mid-Atlantic Resources Imaging Experiment (MATRIX) as part of the U.S. Geological Survey Gas Hydrates Project. The field program objectives were to acquire high-resolution 2-dimensional multichannel seismic-reflection and split-beam echosounder data along the U.S Atlantic margin between North Carolina and New Jersey to determine the distribution of methane gas ...

In summer 2018, the U.S. Geological Survey partnered with the U.S Department of Energy and the Bureau of Ocean Energy Management to conduct the Mid-Atlantic Resources Imaging Experiment (MATRIX) as part of the U.S. Geological Survey Gas Hydrates Project. The field program objectives were to acquire high-resolution 2-dimensional multichannel seismic-reflection and split-beam echo sounder data along the U.S Atlantic margin between North Carolina and New Jersey to determine the distribution of methane gas ...

This text file (2021-607-FA_Image_Locations.txt) provides the GNSS antenna location for underwater images collected near Dollar Point, Lake Tahoe, CA, using a recently developed towed-surface vehicle with multiple downward-looking underwater cameras. The GNSS antenna location for the time of each image capture is presented with greater precision than is stored in the individual image’s EXIF header due to decimal place limitations of the EXIF format.

Underwater images were collected near Dollar Point, Lake Tahoe, CA, using a recently developed towed-surface vehicle with multiple downward-looking underwater cameras. The images are organized in zipped files grouped by survey line. The SQUID-5 system records images as TIFF (.tif) format to maintain the highest resolution and bit depth. Each image includes EXIF metadata, containing GNSS date, time, and latitude and longitude of the GNSS antenna mounted on the towed surface vehicle, copyright, keywords, and ...

Bathymetry and seafloor acoustic backscatter data were collected at four sites (SKM, SLG, LDB, WLW) using a SWATHPlus interferometric sonar (234 kHz) pole mounted to the R/V Parke Snavely during a June 2021 survey of the lower Columbia River, Washington and Oregon. Each site was surveyed repeatedly between June 5 and June 9, 2021 to quantify bathymetric changes resulting from migration of subaqueous sand dunes. The bathymetry and seafloor acoustic backscatter data from each site are provided as GeoTIFF ...

This dataset contains surface sediment grain size distributions derived from automated image processing of in situ seafloor images obtained with an underwater camera system at four sites (SKM, SLG, LDB, WLW) in the lower Columbia River, Washington and Oregon, in 2021. The surface sediment grain size distribution data are provided in comma-separated text (.csv) format for each site and for data used in calibration and validation of the automated image processing technique.

These metadata describe high-resolution chirp sub-bottom data collected in May 2019 in Whiskeytown Lake, California. Data were collected and processed by the the U.S. Geological Survey (USGS), Pacific Coastal and Marine Science Center (PCMSC) with fieldwork activity number 2018-686-FA. The chirp sub-bottom data are provided in SEG-Y format.

Chirp sub-bottom data were collected by the U.S. Geological Survey in August of 2019 in Lake Crescent, Washington.

This dataset presents core information such as core IDs, section numbers, lengths, depth intervals, and locations from sediment cores collected in southern Cascadia (offshore northern California) aboard the M/V Bold Horizon in September-October 2019. An inventory of core section CT, MSCL, and photograph scan files available in this data release are listed here.

This dataset includes computed tomography (CT) scan imagery of sediment cores collected in southern Cascadia (offshore northern California) aboard the M/V Bold Horizon in September-October 2019.

This dataset includes multi-sensor core logger (MSCL) data of sediment cores collected in southern Cascadia (offshore northern California) aboard the M/V Bold Horizon in September-October 2019.

This dataset includes photographs (linescan images) of sediment cores collected in southern Cascadia (offshore northern California) aboard the MV Bold Horizon in September-October 2019.

This dataset presents radiocarbon data from 87 samples from sediment cores collected in southern Cascadia (offshore northern California) aboard the M/V Bold Horizon in September-October 2019. Sample ages were determined by the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) facility and the W.M. Keck Carbon Cycle Accelerator Mass Spectrometry (KCCAMS) facility at the University of California, Irvine (UCI).