Images

We add about 20 grams of sediment from a sample to distilled water for particle size analysis. Then we add strong hydrogen peroxide to break down organic matter that makes clay particles stick together. Digestion takes place overnight.

At the USGS Pacific Coastal and Marine Science Center, we have 3 WS Tyler RX-29 Ro-Taps that can dry-sieve coarser samples. This machine automatically rotates and taps the stack of sieves, so that smaller sediment falls through to the next sieve. Weighing the sediment trapped in each sieve gives us sediment size fractions.

The UIC CM5230/CM5015 analyzes total inorganic carbon content. It's less automated than other analyzers, but often easier to use.

The refrigerated sample repository of the USGS Pacific Coastal and Marine Science Center in Santa Cruz, CA includes easily accessible shelving space which can store thousands of samples.

High-resolution (10-meter per pixel) digital elevation model (DEM) of the Sacramento-San Joaquin Delta, using both bathymetry and topography data relative to current modern datum of North American Vertical Datum of 1988 (NAVD88). This DEM is the result of collaborative efforts of the U.S.

University of Washington's research vessel R/V Barnes is loaded with the USGS multichannel seismic system components GeoEel, Chirp, and boom plates.

Exposed bedrock on the beach during very low (negative) tide at Isla Vista, California.

Installing large boulders as rip rap to armor the shore against further erosion at Goleta Beach in Southern California. The tide is very low (negative).

Exposed bedrock on the beach during very low (negative) tide at Isla Vista, California

Beach loss and armoring at Goleta Beach, very low (negative) tide

Bedrock exposed at low tide along the beach at Isla Vista, California

Exposed bedrock on the beach, below the University of California, Santa Barbara.

USGS oceanographer Dan Hoover uses a GPS-equipped backpack to measure sand elevations near the mouth of the San Lorenzo River in Santa Cruz, California, January 12, 2017. Surveys like this make long-term studies of coastal change possible.

USGS scientists readying a sonar-equipped boat to map the ocean bottom near Santa Cruz, Calif.

USGS scientist Daniel Hoover mapping the beach at Santa Cruz with a GPS-equipped backpack unit.

 USGS scientists setting up a lidar scanner on the pier to map the beach near Capitola, California.

A sonar-equipped personal watercraft mapping the bathymetry underwater near Santa Cruz, Calif.

USGS research geologist Jon Warrick explains how his team applied structure-from-motion analysis to photos from the California Coastal Records Project to measure coastal change. Jon Warrick explains a “difference map” constructed from structure-in-motion data. Red areas indicate loss of material (erosion); blue areas show addition of material (deposition).

Photograph from pole-mounted camera, looking west across the Skagit River delta and one of several large sediment fans that are moving 1-2 meters per day across the tidal flats. These fans threaten to bury the last intact stands of eelgrass in Skagit Bay, an important rearing habitat for juvenile salmon, crab, and other marine wildlife.

Three-dimensional view of the Hosgri fault 45 meters below the seafloor, revealing fault strands (black), and potential paths along the fault that fluid could follow (green/blue). The other colors represent different geologic layers.

The USGS strives to put coastal change data and information at the fingertips of users such as planners and emergency managers. The explicit goal is to enable users to integrate and apply USGS data and tools to address their specific needs. Online resources such as the Coastal Change Hazards (CCH) portal are designed with applied use of data in mind.