Images

Sampling for microplastics on Lake Mead, March 21, 2017

On March 21, 2017, the sediment trap from this instrument package (deployed the previous October into Monterey Canyon) is gone and the mounting frame is mangled, having been exposed to several significant turbidity currents in one deployment. 

This 3D model of the lava lake at Kīlauea's summit was constructed from a series of thermal images acquired during an overflight on Thursday, March 16. For scale, the lava lake is about 250 meters (820 ft) across. The lake is within the Overlook crater, which is within Halema‘uma‘u Crater.

Map of U.S. showing karst areas, which are prone to land subsidence and sinkholes.

Mohawk River at Lock 8 near Schenectady, New York (01354330)

Processing a sample for detection of N. fowleri 

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 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. 

We spin down a sample of sediment that's mixed with distilled water in a centrifuge. This separates the sediment from the water at the bottom of the sample bottle, and we pour off most of the water. This process removes dissolved salts.

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.

The back door of the refrigerator connects to our core and sample processing labs.

Flowing groundwater site in Indiana

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

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

Ice Jam Webcam image of Mohawk River at Stockade bridge, Schenectady

Sunset view of the Kīlauea summit lava lake showing an active area of spattering at the right margin. Jagged openings between cooler crustal plates reveal molten lava. HVO is faintly visible on the Kīlauea Caldera rim at upper left. USGS photo February 13, 2017.

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).

The first stop for many sediment cores is the Geotek MSCL or multi-sensor core logger. The logger automatically measures P-wave velocity, magnetic susceptibility, electrical resistivity, and gamma density at intervals from 1 millimeter to 1 centimeter along cores up to 1.5 meters long.

Lab technicians create written descriptions of sediment cores, referencing Munsell chart colors and standard phrases.

This is the Pacific Coastal and Marine Science Center's Sediment Prep Lab, where sediment samples and core subsamples are prepared for analyses.

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.