EARTHSCOPE’S USARRAY IN THE EASTERN UNITED STATES: PAST, PRESENT, AND FUTURE

EarthScope’s USArray observatory provides unprecedented observations of geophysical targets across the contiguous United States through the systematic deployment of seismic, magnetotelluric, and atmospheric sensors.

The USArray Transportable Array (TA) has now occupied ~1700 sites spanning the entire contiguous 48 states, at 70 km inter-station spacing. These stations have provided broadband seismic, barometric pressure and atmospheric infrasound observations. The final footprint of approximately 400 TA stations is now fully deployed along the Atlantic coast, stretching from Maine to Florida, with the last of these sites not scheduled for removal until late 2015. The pool of instruments that comprise the Flexible Array (FA) have been deployed by numerous individual investigators in dense arrays to investigate local and regional features over time periods ranging from days to years. In the past several years multiple FA experiments have targeted the eastern US. The magnetotelluric (MT) component of USArray has provided both fixed and campaign-style long-period magnetotelluric observations at hundreds of locations across the US.

We will provide a brief overview of the past and present deployments of the TA, FA, and MT components of USArray. We will discuss plans for a set of approximately 160 TA stations to be left in place in the central and eastern US for the purpose of long-term monitoring. This set of stations, referred to as the Central and Eastern United States Network (CEUSN), will address the need for enhanced seismic observing capability in the eastern US and will provide a significant asset for both research and operational objectives. We will also present plans for MT campaign observations in the next five years, which include a major deployment in the eastern US. All USArray data and data products are open and unrestricted and we will provide an overview of relevant products, including seismic wave visualizations, low-magnitude-threshold earthquake hypocenters and phase readings, receiver functions, and tools for inter-comparison of Earth models.