b'Carnegie Science|Summer 2019 19New NSF Grant to Study Earths Flat SlabsThis is exactly the type of project that would benefit greatly from support for the newer rapid deploy seismic systems, like the Quick Deploy Boxes developed at Carnegie. Unlike standard subduction, in which a 0 Thick-skinnedtectonic plate descends beneath anotherEarlier Arc Migration Arc Cessation deformation RapidForelandplate into Earth, flat slab subduction is aOceanic Eclogite? Eclogite? SubsidenceHydrated CML?process in which a tectonic plate descends50 Plateau 2to depths of about 30 to 60 miles (~50-100HO Migr./Dehyration? Eclogitization?km), then flattens and travels horizontally100 Flat slab subduction,arc advance, forelandfor hundreds of miles before descendingdeformation.farther into Earths mantle. The process150affects enormous regions of a continentUnlike standard subduction, in which a tectonic plate descends beneath another plate into Earth, flat slab subduction is a including extensive geochemical, structural,process in which a tectonic plate descends to depths of about 30 to 60 miles (~50-100 kilometers) (light blue, green, and beige), then flattens and travels horizontally for hundreds of miles before descending farther into Earths mantle. and dynamic changes of the overridingImage courtesy Lara Wagner, Carnegie Institution for Scienceplate.Furthermore, large earthquakeswill be able to image and study the initial within flat slabs, such as the magnitude 8migration and cessation of volcanism, the earthquake in Peru that occurred this pastdevelopment of analogues to the Rocky May, can cause extensive damage far fromMountains called basement-cored uplifts, plate boundaries, where earthquakes arethe formation of ore deposits, and the uncommon and local communities are lessreturn to normal arc volcanismthe prepared.complete flat slab cycle. A new $2.7 million multidisciplinary,Lara Wagner (bottom photo, on the ground) assembles multi-institutional National ScienceThe coordinated multidisciplinarya standard seismic station in Peru in 2012. These approach, with coprincipal investigators atstations have been successful seismology workhorses Foundation-Frontiers of Earth Sciencefor years. She and her team have recently developed grant has been awarded to a team led bythe University of Texas at Austin andmore compact, lightweight equipment, the Quick Arizona State University, includes fundingDeploy Boxes, for more efficient deployment (above). Carnegies Lara Wagner to study an activeImages courtesy Lara Wagner and Roberto Molar Candanosa, flat slab in Colombia. Unlike previouslyfor a 70-station, two-year seismicCarnegie Institution for Sciencestudied flat slabs, the Colombian flat slabdeployment across much of central has broken into two parts, one of whichColombia. The grant has a major educationSeismic Studies of the Continental has recently sunk back down into theand outreach component led by theLithosphere (PASSCAL). However, Wagner mantle to resume normal subductionCarnegie Academy for Science Educationsees that this project could be an ideal geometry.(CASE). Teachers from Washington, D.C.,proving ground for new rapidly deployable By comparing the still-existingAustin, and Phoenix will go into the field toseismic systems like the one developed at flat slab region to the recentlyprepare bilingual educational lesson plans,Carnegie. Wagner says, This is exactly the failed flat slab region, researchersmultimedia, and web materials on thetype of project that would benefit greatly Earth sciences.from support for the newer rapid deploy Most of the equipment will be providedseismic systems, like the Quick Deploy from the national seismic lending pool runBoxes developed at Carnegie. It would by the Incorporated Research Institutionsenable three times the number of stations for Seismology (IRIS) Program for Arrayfor the same expense, time, and effort, and would ensure higher rates of data return because these systems are designed to work under the difficult remote field conditions we expect in Colombia. '