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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 Micromeritics Sedigraph III uses X-rays to automatically analyze settling times for sediment sizes between 300 microns and 0.1 microns (2 phi to 13 phi).

This Dionex ASE 350 accelerated solvent extractor automatically extracts hydrocarbons for further analysis. We also have a Zymark TurboVap II for sample preparation (not shown).

In the core lab, the Geotek core splitter cuts sediment cores in half lengthwise using oscillating saws and a wire cutter.

In the cold storage room at the USGS Pacific Coastal and Marine Science Center, we store cores on large racks that can hold about 4,500 full sized cores or D-tubes with split cores, up to 1.5 meters long.

These track-mounted racks pack together to save space. Cranking a handle moves the aisle between racks for core access.

We slip split cores into a labeled D-tube, and both are stored on specialized core racks in a walk-in sample refrigerator. USGS and non-USGS scientists often use our core and sample archives for new research. Contact the lab manager for access policies and other details.

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.

The Beckman Coulter LS 13 320 uses laser diffraction to automatically analyze sediment size fractions between 2 millimeters and 0.35 micron (-1 phi to 11.5 phi).

For some projects, scientists want to calculate sediment settling velocity and need to measure particle size using gravity. We use custom-built settling tubes filled with water – three at 2 meters tall (like the one shown here) and one 3 meters tall.

The settling tube is filled with water and a pre-weighed sediment sample of mixed particle sizes is poured onto this brass "gate" at the top of the tube. When the operator flips the switch, the gate opens quickly like a venetian blind, releasing the whole sediment sample into the water column at the same time.

After releasing sediment into the top of a settling tube filled with water, a pan and microbalance collects and weighs the sediment as it slowly reaches the bottom of the tube. A computer records the cumulative sediment weight over time, as well as how long it took each particle to reach the pan.

In the carbon analysis laboratory, these three instruments (the UIC CM250) automatically analyze the total carbon, total organic carbon, and total inorganic carbon content of multiple dried sediment samples. 

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

Our fume hood lab allows for sample preparation in safe conditions.

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, below the University of California, Santa Barbara.