Images

Imagery shows topographic point clouds from photos, first from September 11, 2015 courtesy of California Coastal Records Project, second from March 8, 2017 (USGS photo), third from May 19, 2017 (USGS photo), and fourth from May 27, 2017 (USGS photo) 7 days following the catastrophic Highway 1 landslide.

Topographic “point clouds” (or 3D maps) created by computer processing of air photos show what the Mud Creek area looked like on March 8, 2017 (top), May 19 (center), and May 27 (bottom).

USGS air photo of the Mud Creek landslide, taken on May 27, 2017

View from an airplane looking at the Mud Creek landslide on the Big Sur coast that occurred May 20, 2017.

Still-image from video camera atop the Dream Inn looks eastward over Main Beach and boardwalk in Santa Cruz, CA.

Frame from video of Cowells Beach in Santa Cruz, California, showing “pixel instruments” measured continuously during the video and used to estimate different coastal processes. The blue dots represent an array of pixels used by a computer program called cBathy to estimate seafloor depths (bathymetry).

USGS ocean engineer Gerry Hatcher (left) and USGS postdoctoral oceanographer Shawn Harrison make adjustments to a computer controlling two video cameras on the roof of the Dream Inn, a 10-story hotel overlooking Monterey Bay in Santa Cruz, California. One camera looks eastward over Santa Cruz Main Beach and boardwalk, and the other southward over Cowells Beach.

Snapshot, or first frame of from a 10-minute video taken May 6, 2017, in Santa Cruz, California.

Time-averaged image, or “timex,” created by averaging the intensity of light recorded at each spot, or “pixel,” during a 10-minute video taken at Santa Cruz, California, on May 6, 2017. Blurred white zones show where waves are breaking. Line between wet and dry sand shows the maximum height on the beach reached by the waves (“runup”).

“Variance” image produced from video shot at Cowells Beach in Santa Cruz, California, on May 6, 2017. The more the light intensity changes at a given spot, or “pixel,” during the video, the brighter the value assigned to that pixel. Motion tends to produce changes in light intensity. Note bright areas along and beyond the shore where waves were breaking.

Provisional data subject to revision. From the USGS Remote Sensing Coastal Change Project, illustration describes how the USGS measures topographic change with 4D photogrammetry utilizing the techniques of Warrick et al., 2017. A digital terrain model of a coastal cliff is shown with its ground control points.

After mixing about 20 grams of a sediment sample with distilled water, we add strong hydrogen peroxide to break down or "digest" organic matter that may be in the sample. Organic matter makes clay particles stick together and we need them separate in order to calculate accurate particle size fractions of the sample.

Tips of Brazilian waterweed (Egeria densa) break the surface at low tide in Lindsey Slough in the northern Sacramento-San Joaquin River Delta. More commonly, this invasive plant is completely submerged.

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. 

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.

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

Each half of a split sediment core is wrapped in plastic to prevent drying and contamination. For long-term storage, we can shrink-wrap one half with a thick film that prevents moisture loss.

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.

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

Sediment cores may be subsampled for further processing and analysis in other labs, like the Sediment Lab which is across the hall from the Core Lab.