NSF East Asia and Pacific Summer Institute (EAPSI) for FY 2013 in Taiwan

Lamont Ellen A, Willington CT

Investigators

Abstract

This action funds Ellen A. Lamont of the University of Connecticut, Center for Integrative Geosciences to conduct a research project in Geosciences during the summer of 2013 at National Cheng-Kung University, Department of Earth Sciences Tainan, Taiwan. The project title is "Using Earthquake-Generated 3-D Imagery and GPS-Based Deformation Models to Understand a Plate Collision Zone in Taiwan." The host scientist is Dr. Ruey-Juin Rau. This grant funds an integrative study of the geologically young Taiwan collisional zone that utilizes seismic, tomographic, and geodetic datasets (previously collected by a series of NSF supported instrumentation arrays). The anomalously high convergence rate (82mm/yr toward 330°) (Lee and Chan, 2007) has created spectacular topography (~3km) adjacent to large coastal planes and has caused a complicated crustal architecture to develop. The study area occurs at one of the youngest portions of the developing orogen and allows us to study these fundamental processes as they occur. Preliminary investigations of the area reveal a suite of earthquakes beneath the deforming orogenic material (i.e. beneath the decollément) and a conspicuous, high-velocity zone at 40km depth in tomographic imagery that may be controlling how the orogen deforms. From such findings, the Fellow hypothesizes two possible scenarios: 1) the primary decollément is stepping down into deeper continental basement possibly creating a new detachment over which the orogen is growing; 2) the deep seismicity and high velocity zone represent a change in the chemical composition of the lower crust. A different type of crust would behave differently under stress and may well be the source of the deep seismicity. Broader impacts of an EAPSI fellowship include providing the Fellow a first-hand research experience outside the U.S.; an introduction to the science, science policy, and scientific infrastructure of the respective location; and an orientation to the society, culture and language. These activities meet the NSF goal to educate for international collaborations early in the career of its scientists, engineers, and educators, thus ensuring a globally aware U.S. scientific workforce. Further knowledge about the fundamental processes occurring in collisional systems is applicable to the study of other collisional systems, modern and historical. A protocol could also be developed pertaining to acceptable ways to integrate non-related datasets effectively. More directly, active collision zones are sources for great earthquakes (i.e. the 1999 Chi-Chi Earthquake in Taiwan, the Chilean Earthquake, the 2011 Japan Earthquake, etc.) that cause millions of dollars in damage and the loss of countless innocent lives. Advancing our knowledge of the way in which the crust deforms during collision would move us one step closer to developing more accurate models of fault locations, hazard identification and early warning systems, affectively reducing costs, both economic and human. Furthermore, Components of this project will also be used to supplement classroom lectures/activities and will enhance the research experience of early-career students in the United States and abroad. The results of this project will be made available to the wider tectonics and structural geology community through presentations at scientific conferences and the publication of the Fellow's master's thesis.