Collaborative Research: FACET: Quantifying the topographic response to tectonic processes in southern Taiwan

Utah State University, Logan UT

Investigators

Abstract

The interaction of climate-driven erosion and tectonic processes shape and sculpt Earth?s topography through a range of processes. The processes can be gradual, such as the slow, continuous collision of tectonic plates lifting a landscape above sea-level, or they can be catastrophic such as rare, high magnitude earthquakes or large tropical cyclones that drive erosion by landslide processes. This project, a collaborative effort between U.S. and Taiwanese researchers, is aimed at understanding how such processes interact over a range of timescales using southern Taiwan as a natural laboratory. Specifically, this project will advance knowledge by elucidating the erosion processes responsible for shaping the landscape and how tectonics and climate influence these processes. The collaboration with Taiwanese and U.S. scientists will build international research capacity while understanding the topographic signature of hazardous tectonic, climate, and erosion processes, such as earthquakes, typhoons, and landslides. The project benefits society or advances desired societal outcomes in many ways. Graduate student training, U.S.-Taiwan graduate student workshop activities, and early career scientist support will develop a competitive STEM workforce. Additionally, the project will facilitate the interaction among Taiwanese scientists and graduate students with U.S. graduate students through a summer graduate student workshop tectonic geomorphology co-taught by the research team and forge new research collaborations between U.S. scientists and Taiwanese scientists. This project will explore the interaction of climate driven erosion, tectonics, and topography along the steep topographic gradient in southern Taiwan. The U.S. and Taiwan research team will test the ideas that (1) detachment-limited stream power erosion model predicts the fluvial response to tectonics in southern Taiwan; (2) catchment averaged erosion rates estimated from cosmogenic radionuclides provide reliable estimates for hillslope erosion in southern Taiwan; and (3) deformation and mountain building processes propagated towards the south in southern Taiwan at about 60-90 mm/yr. The team will quantify river incision and hillslope erosion through the Holocene to constrain the magnitude of landscape disequilibrium along strike of the steep topographic gradient. River incision will be estimated by dating strath terraces perched well above modern river high water marks. Hillslope erosion throughout the Holocene will be constrained by estimating paleo-erosion rates with cosmogenic nuclides in the sediments on the terraces. Additionally, the research team will quantify structural data and integrate these with geodetic and geophysical data to understand the kinematic evolution and tectonic processes along strike. The integrated geomorphic and tectonic picture of the study area will provide a rigorous test of the underlying physical controls of river incision in a tectonically active landscape and constrain the rate of orogenic processes using geomorphic, topographic, and kinematic information. This award is co-funded by the NSF Office of International Science and Engineering.