Images

The large white radar dome is a former Distant Early Warning Line site, which sits atop a permafrost bluff on Barter Island, Alaska.

Location of earthquakes as a function of depth and size in the northeastern Caribbean.

Comparison of observed near-bed velocities and modeled near-bed velocities using several bottom-roughness formulations. Velocity vectors are overlaid on map of backscatter from the sea floor showing regions with coarse sand (light color) and fine sand (dark colors). White lines are bathymetry contours.

Simulation results for geomorphic change in Suisun Bay, CA (Ganju and Schoellhamer, 2010)

The Instrumented Pressure Testing Chamber (IPTC). A device for measuring the physical properties of naturally-occurring, hydrate-bearing sediment at nearly in situ pressure conditions

Shaded relief image of Northern Cape Cod Bay, MA

Map of the island of Hispaniola that include the countries of Haiti and the Dominican Republic. Fault traces are shown as lines with the following descriptions: barbed=thrust fault; solid=strike-slip fault with arrows showing relative direction of motion; black and white=normal fault.

Water molecules (1 red oxygen and 2 white hydrogens) form a pentagonal dodecahedron around a methane molecule (1 gray carbon and 4 green hydrogens). This represents 2 of the 8 parts of the typical Structure I gas hydrate molecule.

Map of the Northeastern Caribbean: topography is in shades of green and bathymetry in shades of blue. Fault traces are shown as lines with the following descriptions: barbed=thrust fault; solid=strike-slip fault with arrows showing relative direction of motion; black and white=normal fault. Faults outlined in red have a potential to generate a large earthquake.

Methane seeping on the Virginia margin just shallower than the limit for gas hydrate stability. 

The R/V Rafael performs nearshore geophysical surveys, and includes high resolution sub-bottom profiling, sidescan sonar, and multibeam echosounding in its arsenal of survey capabilities.

Sandra Brosnahan (USGS) collecting water samples (Long Island, NY).

John Pohlman (USGS, left) and colleagues from the University of Alaska Fairbanks examine a sediment core retrieved through winter ice from the bottom of a lake in northern Alaska. Such cores are used to reconstruct methane emissions and climate history over the past 20,000 years.

Map of the North American - Caribbean tectonic plate boundary. Colors denote depth below sea level and elevation on land. Bold numbers are the years of moderately large (larger than about M7) historical earthquakes written next to their approximate location. Asterisk - Location of the January 12, 2010 earthquake.

A methane seep in shallow Lake Qalluuraq on the Alaskan North Slope near the Native Village of Atqasuk breaks the water's surface during 2009 geophysical surveys

Canadian Coast Guard Ship Louis S. St. Laurent alongside U.S. Coast Guard Cutter Healy in the Arctic Ocean. The United States and Canada are mapping the Arctic seafloor and gathering data to help define the outer limits of the continental shelf in this region. 

 U.S. Coast Guard Cutter Healy breaks ice ahead of the Canadian Coast Guard Ship Louis S. St-Laurent on September 1, 2009. The two ships were part of a multi-year, multi-agency Arctic survey that will help define the North American continental shelf.

A sub-bottom profile of CHIRP seismic data is draped over swath bathymetry showing the Gulf of Maine pockmark field stratigraphy common to the area. Seafloor mapping combined with sub-bottom geologic profiles shows that Holocene mud ranges in thickness between 5 and 10 meters but pockmarks in Belfast Bay do not penetrate below the geologic unconformity. Th

The Native communities’ in-ground food storage facilities are being lost as a result of eroding bluffs and thawing permafrost.

Fire Island, NY sand dunes with protective sand fencing