Earthscope and GeoPRISMS represents research communities of geologists, geophysicists, and geodynamicists who study the processes that build continents, open ocean basins, erode, transport and deposit sediment, and the associated natural hazards of earthquakes, tsunamis, sea level rise, and landslides both on land and under water. Earthscope science is done primarily, but not exclusively on land and involves a large transportable array of seismometers that are able to look down into the crust and mantle in assembling an image of the geologic foundation of the United States. GeoPRISMS research is done primarily, but not exclusively in the ocean, specifically in the coastal regions surrounding the country. It includes facilities and instruments able to image and sample the sedimentary packages preserved beneath coastal waters. Collectively, Earthscope and GeoPRISMS research spans the coastline and in doing so, provides an integrated framework for understanding not only natural hazards, but also the nation's natural resources including traditional and alternative sources of energy.
Our project is to convene two workshops open to the broader Earthscope and GeoPRISMS research communities interested in the processes of lithospheric formation, rift initiation, passive margin evolution, and interactions with dynamic mantle and surface processes for the east coast of the United States. The eastern United States encompasses the Appalachian Mountains and the archetype Atlantic passive margin and as a result is a source of formative thinking related to continental assembly, mountain building, continental rifting, and post-rift passive margin evolution. Key paradigms such as the Wilson cycle and global sea level change are based on data and research in this geographic area. A small planning workshop is to be held in Austin, TX in concert with the May, 2011 EarthScope meeting. The science workshop is to be held at Lehigh University in the Fall, 2011. Our goal is to focus community effort on cross-discipline learning and approaches, targeting a national and international forum of scientists from universities, national labs, federal, and state agencies including early-career scientists and graduate students. The transportable array of EarthScope arrives in the eastern United States in 2012-13 and GeoPRISMS has identified the same region as a key place to understand the processes of continental rift-initiation and evolution. Therefore, the timing is now perfect to organize both communities and identify the crucial science targets. We envision the workshops to serve as a forum for self-organization in the subsequent science proposal submission process.
On 23 August, 2011 the east coast of the United States was rocked by a M 5.8 earthquake centered in Louisa County, Virginia. Whereas this earthquake was moderate in size compared to those regularly experienced in places like California, the ground-shaking of the Virginia quake was felt over a wider range of distances than anyother previously recorded due to the efficient propagation of elastic energy through the hard rocks of the eastern US. Damage to homes, schools, historic buildings, and critical infrastructure was heavy in the region directly above the earthquake. Several schools remain closed. The nearby South Anna nuclear power plant was closed for several months for safety checks and precautions. Farther north the Washington Monument and National Cathedral were damaged and as of the summer of 2012, the Washington Monument remains closed. Had this earthquake occurred closer to Richmond, Washington D.C., Philadelphia, New York, or Boston, the potential for damage would have been greater. Given the major population centers and critical infrastructure located in the northeast corridor of the U.S., better understanding of east coast geology and geophysics has significant economic and societal benefits. It is in this context, long before the Louisa County earthquake occurred, that several communities of geologists and geophysicists self-organized with the goal being to conduct integrated geoscience research in the eastern United States. One of these communities is represented by mostly land-based scientists who map the distributions of rocks and faults capable of generating earthquakes, geodesists who use GPS technology to measure real-time movements of the land surface, and geophysicists who are able to instrument the landscape with seismometers that both record earthquakes and allow for a reconstruction of the Earth's crust below the surface. This community of scientists have constructed and are in the midst of a nation-wide effort to image the subsurface of the entire United States with a fleet of seismometers that is slowly moving from the west to the east coast. That fleet of instruments will be in place in the eastern United States from 2012-2015. The overall community science effort is called EarthScope and details about this program can be found here: www.earthscope.org/ Another community is represented primarily by marine-based scientists who use ship-born technology and drilling capabilities to map the distribution of sediments on the sea floor and acquire a 3-dimensional picture of the basins that contain these sediments, as well as the bedrock basement that makes up the floor of the basins. These data are critical for many purposes, not the least of which is better understanding opportunities and impacts of offshore energy and environment. This community of scientists have identified eastern North America as a primary site for investigating the initiation and formation of these basins as part of the geologic processes that rifted eastern North America from Africa and Europe 200 million years ago, an event the lead to the formation of the Atlantic ocean. This overall community science effort is called GeoPRISMS and details about the program can be found here: www.geoprisms.org/ The goal of our NSF-sponsored project was to organize and conduct a workshop where these two communities could assemble to discuss over-arching science goals and discover how they could leverage resources, equipment, and time so that the impact of the resulting science would greatly transcend it component efforts. The scientific workshop was held at Lehigh University from 26-29 October, 2011. The meeting was attended by a wide range of academic, early career, and State, Federal and industry geoscientists. It featured presentations, breakouts, discussions, and decision-making. Early career scientists were involved in every part of the process including a pre-workshop research seminar and field trip to the Appalachian foreland in eastern Pennsylvania. Broader impacts related to natural hazards, including the timely 23 August Louisa County, VA earthquake, and access to public geoscience education in the most densely populated part of the nation permeated presentations, breakouts, and discussions. The main outcome of the workshop was the identification of parallel synoptic, process-based studies, and more focused and geographic-specific research corridors, all of which leverage EarthScope and GeoPRISMS resources and community expertise. Among the synoptic studies, workshop participants noted particular opportunities to better understand lithospheric structure, tectonic and magmatic inheritance, geodynamic modeling of rift, breakup, and segmentation, post-rift eperiogeny, active tectonics, and active processes on the shelf-slope. These broad research targets also figured large in spirited and in-depth discussions of research corridors where research efforts and resources could be focused and coordinated. Workshop participants identified six such corridors, spaced from the southern U.S. to Newfoundland, all spanning and generally oriented orthogonal to the coastline. Of these, the largest enthusiasm centered on corridors that cross the coastline at Charleston, SC, Richmond, VA, and Nova Scotia, Canada. Existing data sets, data gaps, and EarthScope-GeoPRISMS synergy were identified by the working groups who championed a particular research corridor.
