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Application of teleseismic receiver function in investigation of crustal thickness and Poisson's ratio
Published in Rajib Biswas, Recent Developments in Using Seismic Waves as a Probe for Subsurface Investigations, 2023
Monika Wadhawan, Devajit Hazarika, Sowrav Saikia
Passive seismological experiments are widely accepted for the investigation of the crustal composition and layered structure of the crust. The receiver functions (RFs) technique, a handy and robust technique, is widely used to probe primarily the crustal thickness, seismogenic depth, shear-wave velocity structure, and Poisson's ratio (or equivalently VP/VS). The RFs are time series computed from three-component seismograms that contain the relative response of the Earth near the receiver site. The incoming teleseismic wave bears the information of the earthquake source, the path travelled by the seismic wave, and the response of the local Earth's structure beneath the receiver site. It is obtained by removing the effects of source, the travel path, and instrument response by deconvolving vertical component seismogram with the radial and tangential components resulting in radial receiver function (RRF) and tangential receiver function (TRF), respectively. Whenever any teleseismic P wave travels a longer distance, it encounters with discontinuity, a part of this P wave gets reflected and converted into P-to-S phase (PmS) that causes reverberated phases or crustal multiples (e.g. PpPs, PsSs + PsPs) (Figures 7.1a, b).
Characteristics of Ground Vibrations Induced by Teleseismic Earthquakes and Their Impact on Vibration-Sensitive Facilities
Published in Journal of Earthquake Engineering, 2022
Teleseismic earthquakes denote those with sources very far away, at distances greater than 1,000 km from the measurement site according to the definition of United States Geological Survey (USGS 2021). Teleseismic waves can be used to identify the internal structure of the Earth, that is, teleseismic tomography, e.g. Rawlinson et al. (2016) and Estève et al. (2020), because they propagate deep inside the Earth. In addition, teleseismic wave propagation in deeper parts of the Earth is more regular than in the crust and can thus be described sufficiently well by 1-D velocity and attenuation models, which permits derivation of globally applicable teleseismic magnitude scales (Bormann et al. 2013) such as surface-wave magnitude (Ms) (Gutenberg 1945a) and body-wave magnitude (mb) (Gutenberg 1945b, 1945c).