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Flexible Array experiment researchers brave alligators in the name of seismology!


The alligator photographed guards SESAME's station E22.  Locals report the alligator likely made a short traverse through the forest from a nearby river, where alligators are commonly spotted, to call the pond home.

The alligator pictured resides in a pond about 50 meters south of SESAME station E22, near Glennville, Georgia.  Station E22 is part of the Southeastern Suture of the Appalachian Margin Experiment or SESAME, an Earthscope USArray (Flexible Array) Experiment.

During the month of May, SESAME project principal investigators Karen Fischer (Brown University), Rob Hawman (University of Georgia) and Lara Wagner (University of North Carolina, Chapel Hill), along with graduate and undergraduate students and PASSCAL staff, neared completion of the last phase of seismic station installations.  Stations have been installed in Georgia, northern Florida, western North Carolina and eastern Tennessee to collect broadband seismic data.

This particular area of the southeast United States offers geoscientists the opportunity to study lithospheric deformation related to continental collision and later rifting.  During the Paleozoic the supercontinents Laurentia and Gondwana collided; later, during the Mesozoic, the supercontinents rifted apart.  The evidence of this collision and the subsequent rifting in what is now present day Georgia are being studied by the principal investigators and graduate students.

The goal of this experiment is to image crust and mantle seismic structure across a suture between the ancient lithospheres of Laurentia (proto-North America) and Gondwana (proto-Africa/South America).  The seismic waves from tele-seisms (distant earthquakes) traversing the mantle and crust immediately beneath the area are recorded by the experiment's seismic stations.  These data will be valuable for testing the models presently being debated as offering the most plausible explanations for the deformation observed.

The SESAME experiment began in 2010, with the majority of stations being installed in 2011 and 2012.  It is presently the only Flexible Array project imaging the Appalachians.