USAP-DC

Intellectual Merit:
Numerous candidate models for the geologic processes that have shaped the Antarctic continent have been proposed. To discriminate between them, detailed images of the upper mantle structure are required; however, the only existing continental-scale images of seismic structure beneath Antarctica lack sufficient resolution to delineate important, diagnostic features. Using newly available data from various Antarctic seismic networks, the PI will employ the adaptively parameterized tomography method to develop a high-resolution, continental-scale seismic velocity model for all of Antarctica. The proposed tomography method combines regional seismic travel-time datasets in the context of a global model to create a composite continental-scale model of upper mantle structure. The proposed method allows for imaging of finer structure in areas with better seismic ray coverage while simultaneously limiting the resolution of features in regions with less coverage. This research will help advance understanding of important global processes, such as craton formation, mountain building, continental rifting and associated magmatism. Additionally, the proposed research will have important impacts on other fields of Antarctic science. Constraints provided by tomographic results can be used to develop thermal models of the lithosphere needed to characterize the history and dynamics of ice sheets. Also, further constraints on lithospheric structure are required by climate-ice models, which are focused on understanding the cooling history of the Antarctic continent.

Broader impacts:
The PI is a new faculty member at the University of Alabama after having been funded as a National Science Foundation Postdoctoral Fellow in Polar Regions Research. The graduate student supported by this project is new to polar research. Through the UA-Tuscaloosa Magnet School partnership program, the PI will educate K-12 students about the Antarctic environment and associated career opportunities through various online and hands-on activities. University of Alabama dedicates a significant percentage of its enrollment space to underrepresented groups.

Person	Role
Hansen, Samantha	Investigator

Antarctic Earth Sciences

Award # 1139739

NSF-ANT11-39739_1

None in the Database

Repository	Title (link)	Format(s)	Status
USAP-DC	A New Approach to Investigate the Seismic Velocity Structure beneath Antarctica	None	exist

1. Hansen, S. E., Graw, J. H., Kenyon, L. M., Nyblade, A. A., Wiens, D. A., Aster, R. C., … Wilson, T. (2014). Imaging the Antarctic mantle using adaptively parameterized P-wave tomography: Evidence for heterogeneous structure beneath West Antarctica. Earth and Planetary Science Letters, 408, 66–78. (doi:10.1016/j.epsl.2014.09.043)
2. Hansen, S. E., Garnero, E. J., & Rost, S. (2021). Historical Interstation Pattern Referencing (HIPR): An Application to PcP Waves Recorded in the Antarctic for ULVZ Imaging. Journal of Geophysical Research: Solid Earth, 126(10). (doi:10.1029/2021jb022741)