Introducing the Alaska Broadband Accessory Deployment for Geophysical Research (BADGER): A New Seismic Dataset for Investigating Slow Slip and Subduction Zone Structure
Description:
The Cook Inlet region of the Alaska-Aleutian subduction zone spans two areas of recurrent Slow Slip Events (SSEs). The northern zone, coincident with subduction of the Yakutat terrane, has been associated with seismic tremor, while the southern SSE zone has not. Both tremor and slow slip have been linked to physical properties of the subducting plate, including crustal fluid content and variations in lithology and/or metamorphic facies. Seismic observations are key to understanding how these properties vary spatially, and how they influence slip rate and seismicity style. Thus far, the northern Cook Inlet SSE zone has been more heavily instrumented. Therefore, we have deployed the Alaska Broadband Accessory Deployment for GEophysical Research (BADGER) experiment to enhance data coverage above the southern SSE zone. Eleven broadband seismometers were installed with dense (10-20 km) spacing on the western Kenai Peninsula in November 2022 for a planned two-year deployment. This campaign emphasized inclusive fieldwork practices by choosing accessible sites and involving community members and K-12 schools.
Scattered-wave imaging, including receiver functions and P wave coda autocorrelations, constrains seismic wavespeed contrasts across the subduction interface and the subducting plate Moho. Wavespeed can then be linked to variations in fluid content, lithology, and anisotropy of the subduction zone. Here we present synthetic tests demonstrating the ability of these imaging methods to distinguish between end-member models of fluid saturation conditions and metamorphic facies. Subsequently, we present preliminary results for teleseismic Ps receiver functions and P wave autocorrelations using the first year of Alaska BADGER data. High noise levels due to the Cook Inlet, basin reverberations, and near-surface natural and anthropogenic sources, present challenges. A concurrent Distributed Acoustic Sensing (DAS) experiment on fiber optic cables beneath the Cook Inlet provides exciting opportunities for augmenting the land-based dataset, and for exploring bridges between DAS and broadband seismic experiments.
Session: Structure and Behavior of the Alaska-Aleutian Subduction Zone [Poster Session]
Type: Poster
Date: 5/3/2024
Presentation Time: 08:00 AM (local time)
Presenting Author: Eva
Student Presenter: No
Invited Presentation:
Authors
Eva Golos Presenting Author Corresponding Author golos@wisc.edu University of Wisconsin-Madison |
Mustafa Aleid maleid@wisc.edu University of Wisconsin-Madison |
Neal Lord lord@geology.wisc.edu University of Wisconsin-Madison |
Peter Sobol psobol@wisc.edu University of Wisconsin-Madison |
Marine Denolle mdenolle@uw.edu University of Washington |
Bradley Lipovsky bpl7@uw.edu University of Washington |
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Introducing the Alaska Broadband Accessory Deployment for Geophysical Research (BADGER): A New Seismic Dataset for Investigating Slow Slip and Subduction Zone Structure
Category
Structure and Behavior of the Alaska-Aleutian Subduction Zone