Lara S. Wagner
Broadband seismology; field seismology; seismic tomography; seismic anisotropy; scattered wave imaging; tectonics of convergent margins; evolution of continents and the effects of tectonic inheritance
B.A., Columbia College of Columbia University, 1996 Ph. D., Geophysics, University of Arizona, 2005
Lara Wagner's research uses seismology to study the formation and evolution of the continental lithosphere. Unlike oceanic crust which is seldom over 200 million years old, continental crust records a history of up to billions of years of plate tectonic activity. Much of this history lies buried or has been overprinted by later events. Seismology cannot look back in time, but it has the unique ability to look deep into the Earth to investigate structures that are either being developed by modern tectonic processes today or that played a role in shaping the continents in the past.
The scientific motivation behind her research is twofold. First, Wagner is interested in how tectonic processes at modern convergent plate boundaries affect the composition and deformation of the continental crust. Convergent plate boundaries are where new continental crust is formed, and where existing continental crust is refined, accreted, and deformed. Understanding how these processes work today is crucial to understanding the role these processes played in the past. Secondly, she has been studying the effects of tectonic inheritance on intraplate continental settings. Most of her research on this subject has been focused on the southeastern United States where tectonic inheritance may have important implications for improved hazard assessment and natural resource development.
Being a field seismologist allows Wagner to study interesting tectonic structures anywhere on Earth using portable broadband seismic stations. These stations record ground motion continuously, typically for two or more years at a given location. The data are analyzed to determine variations in temperature, composition, rheology, and flow patterns at depth. A single data set from a broadband deployment can be analyzed using a range of methodologies, each of which provides unique insights into the tectonic processes in play.
Wagner's past field sites include central Chile and Argentina, southern Peru and northern Bolivia, central and eastern Oregon, and the southeastern United States. She plans to continue working in a number of these areas, while also expanding her research into other related tectonic settings.