Neighbourhood inversion of teleseismic Ps conversions for anisotropy and layer dip

AW Frederiksen, H Folsom… - Geophysical Journal …, 2003 - academic.oup.com
AW Frederiksen, H Folsom, G Zandt
Geophysical Journal International, 2003academic.oup.com
The inversion of teleseismic receiver functions for lithospheric structure is difficult due to the
non-linearity of the problem, which is greatly increased in the presence of dipping interfaces
and layer anisotropy. Given an efficient ray-theoretical tool for forward-modelling teleseismic
seismograms, we perform a directed Monte Carlo search technique using the
neighbourhood algorithm of Sambridge, enabling us to search 20–30 parameters in a
reasonable amount of computer time. Tests on synthetic data reveal inherent velocity–depth …
Summary
The inversion of teleseismic receiver functions for lithospheric structure is difficult due to the non-linearity of the problem, which is greatly increased in the presence of dipping interfaces and layer anisotropy. Given an efficient ray-theoretical tool for forward-modelling teleseismic seismograms, we perform a directed Monte Carlo search technique using the neighbourhood algorithm of Sambridge, enabling us to search 20–30 parameters in a reasonable amount of computer time. Tests on synthetic data reveal inherent velocity–depth trade-offs in typical data sets, due to the limited moveout present in teleseismic Ps; the azimuth of the anisotropic symmetry axis and the strike of a dipping interface prove to be well-resolved given adequate backazimuthal coverage. We apply this technique to two single-station data sets. The first, from permanent station PGC, Vancouver Island, British Columbia, displays dipping low-velocity sediment layers in the mid-crust. The second, from a station at the northern end of the Tibetan plateau operating in 1991 and 1992, requires a sequence of thick crustal anisotropic layers to explain the observed pattern of receiver-function arrivals.
Oxford University Press
以上显示的是最相近的搜索结果。 查看全部搜索结果