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Revealing fine layering within cratonic upper mantle using H-κ-φ anisotropic stacking with crust-corrections.
- Source :
-
Geophysical Research Abstracts . 2019, Vol. 21, p1-1. 1p. - Publication Year :
- 2019
-
Abstract
- Seismic imaging with converted body waves has been used to infer layering within the globallithosphere leading to observations of a globally ubiquitous boundary known as themid-Lithosphere discontinuity (MLD). Explanatory models include partial melt/chemicalstratification, anisotropy, and elastically-accommodated grain-boundary sliding; each withunique implications for the geological evolution of continents. We present a new method forinvestigating these hypotheses, using a parametric approach which involves stacking ofthree-component earthquake-source deconvolved- receiver function traces.We conduct a statistical parameter search to determine the lithospheric discontinuity depth(H), the wave-speed ratio (κ), and order,φ, of harmonic back-azimuth variations, whichcan distinguish conversions from sub-crustal layers with anisotropic media. We demonstratethe procedure with a pilot study of synthetic waveforms and long-running seismic stationslocated in the Precambrian region of the US. We target sub-crustal depths, and distinguishbetween free surface reverberations, using a suite of high-resolution crustal 1D (PREM,IASP91, AK135) and 3D models (Crust1.0, LITHO1.0, and EMC-US.2016) velocity models.The results have important implications for the origin of the MLD and the approach can beused to study other cratonic regions globally. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 10297006
- Volume :
- 21
- Database :
- Academic Search Index
- Journal :
- Geophysical Research Abstracts
- Publication Type :
- Academic Journal
- Accession number :
- 140485075