Multi-Scale Lithospheric Architecture of Alaska Inferred From Receiver Functions

Date: 4/26/2019

Time: 06:00 PM

Room: Grand Ballroom

We present receiver function images of crustal and lithospheric architecture based on broadband seismic data across the region that are now constrained by new data from the EarthScope Transportable Array (TA). The resulting receiver functions (Ps and Sp) reproduce many of the Moho depth variations previously modeled by both more concentrated arrays, primarily in south-central Alaska, using receiver functions and tomographic imaging. However, these new results provide significantly more detailed images of the entire state that illustrate the accretionary tectonic history of the continental lithosphere in the region. The geologic mosaic of terranes, adjacent multi-phase plate boundary in the south, rapid lateral topographic variations, and heterogeneous distribution of strain throughout Alaska are reflected in complex tectonic history and geology of the region. The variable thickness of the crust and lithosphere reflects inherited structure from Mesozoic to early Cenozoic convergent and extension events that in some regions is being extensively modified by ongoing convergence and collision, particularly along the active southern margin. Combining three different receiver function methodologies for both Ps and Sp – Common Conversion Point (CCP) stacking, receiver function stacks, and receiver gathers - for viewing and imaging P receiver functions allows for an interpretation of Alaskan crustal structure that spans multiple scales.

Presenting Author: Meghan S. Miller

Authors