Broadband ambient noise surface wave tomography across the United States
| Autor: | Michael H. Ritzwoller, Nikolai M. Shapiro, G. D. Bensen |
|---|---|
| Přispěvatelé: | Center for Imaging the Earth's Interior [Boulder], Department of Physics [Boulder], University of Colorado [Boulder]-University of Colorado [Boulder], Institut de Physique du Globe de Paris (IPGP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), University of Colorado [Boulder], Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP) |
| Jazyk: | angličtina |
| Rok vydání: | 2008 |
| Předmět: |
Atmospheric Science
010504 meteorology & atmospheric sciences [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph] Ambient noise level Soil Science tomography Aquatic Science 010502 geochemistry & geophysics Oceanography 01 natural sciences Physics::Geophysics symbols.namesake Geochemistry and Petrology Earth and Planetary Sciences (miscellaneous) Rayleigh wave Rayleigh scattering Dispersion (water waves) 0105 earth and related environmental sciences Earth-Surface Processes Water Science and Technology Ecology Paleontology Forestry Surface waves Love wave Geophysics 13. Climate action Space and Planetary Science Surface wave [SDU]Sciences of the Universe [physics] symbols Group velocity Phase velocity seismic noise Seismology Geology |
| Zdroj: | Journal of Geophysical Research : Solid Earth Journal of Geophysical Research : Solid Earth, American Geophysical Union, 2008, ⟨10.1029/2007JB005248⟩ Journal of Geophysical Research : Solid Earth, American Geophysical Union, 2008, 113 (B5), pp.B05306. ⟨10.1029/2007JB005248⟩ |
| ISSN: | 2169-9313 2169-9356 |
| Popis: | International audience; This study presents surface wave dispersion maps across the contiguous United States determined using seismic ambient noise. Two years of ambient noise data are used from March 2003 through February 2005 observed at 203 broadband seismic stations in the US, southern Canada, and northern Mexico. Cross-correlations are computed between all station-pairs to produce empirical Green functions. At most azimuths across the US, coherent Rayleigh wave signals exist in the empirical Green functions implying that ambient noise in the frequency band of this study (5–100 s period) is sufficiently isotropically distributed in azimuth to yield largely unbiased dispersion measurements. Rayleigh and Love wave group and phase velocity curves are measured together with associated uncertainties determined from the temporal variability of the measurements. A sufficient number of measurements (>2000) is obtained between 8 and 25 s period for Love waves and 8 and 70 s period for Rayleigh waves to produce tomographic dispersion maps. Both phase and group velocity maps are presented in these period bands. Resolution is estimated to be better than 100 km across much of the US from 8–40 s period for Rayleigh waves and 8–20 s period for Love waves, which is unprecedented in a study at this spatial scale. At longer and shorter periods, resolution degrades as the number of coherent signals diminishes. The dispersion maps agree well with each other and with known geological and tectonic features and, in addition, provide new information about structures in the crust and uppermost mantle beneath much of the US. Citation: Bensen, G. D., M. H. Ritzwoller, and N. M. Shapiro (2008), Broadband ambient noise surface wave tomography across the United States |
| Databáze: | OpenAIRE |
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