EarthScope’s Transportable Array Reaches the East Coast

On land owned by the county near Yulee in northeast Florida, not far from the state line with Georgia and within miles of the Atlantic Ocean, a seismic station has been installed to record ground motion from earthquakes. Part of EarthScope, a project funded by the National Science Foundation, this is one of about 400 stations collectively called the Transportable Array that has been slowly traversing the country since 2004. Transportable Array Station 457A (right) is the first installation in this array to reach the East Coast.

By the end of FY13, the array will occupy 400 sites from Florida in the south to Michigan and Maine in the north, including sites in the southernmost regions of Ontario and Quebec, Canada. Stations are placed in a grid approximately 70 km (~43 miles) apart and operate for about two years. The Transportable Array began its eastward migration from the West Coast and, to date, has occupied more than 1350 locations across the US. With the installation of Station 457A, the Transportable Array has stations operating on all four coasts of the contiguous US: Pacific, Atlantic, Great Lakes and Gulf of Mexico.

Data recorded by the seismometers is helping scientists develop a better understanding of the structure beneath the North American continent. These data are used to generate 3D images of the Earth's interior from the surface to the core with greater detail than previously possible.

Each station in the array is self-contained, using solar panels to recharge the batteries that provide power to the seismometer and the other sensors and electronic systems that are placed in a vault that is buried about six feet below the surface. The seismometer is extremely sensitive and can detect earthquakes of magnitude 5.0 or greater occurring on the opposite side of the planet and smaller earthquakes that occur regionally and locally. Additionally, the station includes a high-performance barometer and an infrasound microphone, as well as sensors to record temperature and pressure. Data collected by the station's instruments are transmitted in real-time to the Array Network Facility at the University of California, San Diego, and then archived at the IRIS Data Management Center in Seattle for retrieval and use by researchers around the world.

View the National Science Foundation press release here.

The station's seismometer is aligned at the bottom of the vault and is wrapped in insulating material to help maintain a constant temperature.

The station's electronic components and communications system are housed in the upper section of the vault.

The vault with the seismometer and other equipment inside is closed and secured before a mound of dirt is piled on top for additional insulation.

The atmospheric acoustic sensor package, housing the ports for the barometer and infrasound microphone, is placed on the surface next to the dirt-covered vault.