Premium
Phase velocities from seismic noise using beamforming and cross correlation in Costa Rica and Nicaragua
Author(s) -
Harmon Nicholas,
Gerstoft Peter,
Rychert Catherine A.,
Abers Geoffrey A.,
Salas de la Cruz Mariela,
Fischer Karen M.
Publication year - 2008
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2008gl035387
Subject(s) - seismic noise , beamforming , noise (video) , cross correlation , seismic array , geology , seismology , ambient noise level , acoustics , phase (matter) , physics , mathematics , statistics , computer science , sound (geography) , quantum mechanics , artificial intelligence , image (mathematics)
An expression for the cross correlation of noise between seismic stations and the 2D Green's function is derived assuming that noise travels as 2D surface waves. The phase velocity is obtained directly from the noise correlation function with a phase shift of + π /4. Mean phase velocity dispersion curves are calculated for the TUCAN seismic array in Costa Rica and Nicaragua from ambient seismic noise using two independent methods, noise cross correlation and beamforming. The noise cross correlation and beamforming methods are compared and contrasted by evaluating results from the TUCAN array. The results of the two methods as applied to the TUCAN array agree within 1%, giving good confidence in the phase velocities extracted from noise.