Multi-Mode 3D Kirchhoff Migration of Receiver Functions in Southern Alaska using Permanent and Temporary Array Data
Abstract
The teleseismic scattered seismic wavefield contains valuable information about heterogeneities and discontinuities inside the Earth. By using fast Receiver Function (RF) migration techniques such as classic Common Conversion Point (CCP) stacks, one can easily interpret structural features down to a few hundred kilometers in the mantle. However, strong simplifying 1D assumptions limit the scope of these methods. Other more robust 2D and 2.5D methods rely on fewer assumptions but require considerable, sometime prohibitive, computation time. Following the ideas of Cheng (2017), we have implemented a simple fully 3D Prestack Kirchhoff RF migration scheme which uses the FM3D fast Eikonal solver to compute travel times and scattering angles. The method accounts for 3D elastic point scattering and includes free surface multiples, resulting in enhanced images of laterally varying dipping structures, such as subducted slabs. The method is tested on synthetic waveforms simulating realistic subduction zone environments and is then applied to field data from southern Alaska. For the latter, we use data from a dense composite array combining stations from TA/USArray and the Alaska Volcano Observatory with stations from the BEAAR, MOOS and SALMON temporary deployments.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.S31C0517M
- Keywords:
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- 7230 Seismicity and tectonics;
- SEISMOLOGYDE: 7240 Subduction zones;
- SEISMOLOGYDE: 7294 Seismic instruments and networks;
- SEISMOLOGY