Images

Skilak Lake, Alaska. A team of USGS scientists, in collaboration with partners from the Woods Hole Oceanographic Institution Ocean Bottom Seismic Instrument Center, are aiming to create a record of past earthquakes from Skilak Lake on the Kenai Peninsula of Alaska.

Brian Andrews (USGS) digs a hole for installing a seismometer. This is part of a USGS effort, in collaboration with partners from the Woods Hole Oceanographic Institution Ocean Bottom Seismic Instrument Center, to create a record of past earthquakes from Skilak Lake on the Kenai Peninsula of Alaska.

Peter Haeussler (USGS) marks the location of the seismometer sensor. The station box containing electronics and batteries can be seen in the foreground.

Rob Witter (USGS) on the R/V Lutris on Skilak Lake, Alaska. This is part of a USGS effort, in collaboration with partners from the Woods Hole Oceanographic Institution Ocean Bottom Seismic Instrument Center, to create a record of past earthquakes from Skilak Lake on the Kenai Peninsula of Alaska.

Nathan Miller (USGS) and Brian Andrews (USGS) on the R/V Lutris on Skilak Lake, Alaska as part of a USGS effort, in collaboration with partners from the Woods Hole Oceanographic Institution Ocean Bottom Seismic Instrument Center, to create a record of past earthquakes from Skilak Lake on the Kenai Peninsula of Alaska.

Tim Kane (WHOI) on Skilak Lake, Alaska during field work with USGS to create a record of past earthquakes from Skilak Lake on the Kenai Peninsula of Alaska. In May 2024, they deployed two seismographs on the bottom of the lake and eight seismographs on land around the lake. Each instrument will collect data there for about 1 year. 

Nathan Miller (USGS) with the OBS equipment at the Upper Skilak Campground parking lot. This is part of a USGS effort, in collaboration with partners from the Woods Hole Oceanographic Institution Ocean Bottom Seismic Instrument Center, to create a record of past earthquakes from Skilak Lake on the Kenai Peninsula of Alaska.

Rob Witter (USGS), Nathan Miller (USGS), and Brian Andrews (USGS) on Skilak Lake, Alaska as part of a USGS effort, in collaboration with partners from the Woods Hole Oceanographic Institution Ocean Bottom Seismic Instrument Center, to create a record of past earthquakes from Skilak Lake on the Kenai Peninsula of Alaska.

Study region with GTSM-ERA5 output locations marked as black circles and tide gauge locations marked as blue squares. Gray labels denote NOAA designated tide gauge station IDs. Information on tide gauges, including ID number, latitude, longitude, and the date when observations start, are listed in the table to the right of the map.

Component contributions to extreme water levels. Panel (a) shows GTSM-ERA5 stations (in black) with highlighted “multi-POT” node locations marked in red and numbered to correspond with panel (c).

Cover image for the geonarrative "Paleoclimate: Lessons from the past, roadmap for the future". In this interactive geonarrative, viewers can explore the different applications of USGS paleoclimate research.

Map showing location of radar network for the Advanced Quantitative Precipitation Information system in the San Francisco Bay Area.

Animation of a computed tomography scan of a coral core.

Scan of coral core, showing yearly growth rates and the density of the coral, which can in turn be used to determine the calcification, or constructive process responsible for reef growth. 

Animation of a computed tomography scan of a coral core.

The newly developed USGS Coral Core Archive, housed at the Santa Cruz and St. Petersburg Coastal and Marine Science Centers, contains approximately 500 coral reef cores from U.S. jurisdictions worldwide.

Photo of coral carbonate standards, arranged from high to low density. To convert CT values to real-world densities and quantify the uncertainty in reconstructed density as a result of offsets, a set of carbonate standards are included in every CT scan that represent a range of coral species with different densities.

Coral sample in aluminum tube being prepared for scanning. The use of a secondary aluminum filter reduces beam hardening artifacts (rings) while also avoiding attenuating the x-ray beam.

Example of the relationship between CT intensities and measured density of the coral standards used to calibrate data. The measured density of the coral standards are compared to the mean intensities of each standard. Linear regressions calculated from the standard values are then used to calibrate data.

Orbicella spp. coral sample with no packing material. Center of image is darker than edges. Transect across image shows intensity values lower in the center creating a cupping effect.

Bare-earth lidar image of the Nisqually River Delta. Lidar has been used to study and restore the delta, where levees have been removed to reconnect tidal lands.