Receiver Function Analysis of the Nicoya Peninsula, Costa Rica - fig. 2
Receiver Function Analysis of the Nicoya Peninsula, Costa Rica - fig. 2
Credit:
Claudia Flores, Susan Schwartz • University of California, Santa Cruz/IRIS Consortium
Description
Plot of receiver functions with respective distance from trench increasing going down. Receiver functions are shown in black for one event at recording stations and red for stacked receiver functions at respective stations (note: stations COND and PAPA are combined).
CRSEIZE (Costa Rica Seismogenic Zone Experiment) was a collaborative effort to identify and describe subduction zone processes occurring on the southern section of the Middle American Trench. This experiment consisted of deployed standard IRIS/PASSCAL three-component broadband and short period instruments on land as well as three-component broadband ocean bottom seismometers and hydrophones, and geodetic surveying throughout Costa Rica.
Receiver function analysis using time-domain deconvolution techniques (Ammon,1991; Ligorría and Ammon,1999) is applied to broadband data collected during CRSEIZE to constrain the depths to major boundaries such as the top of the subducting slab, the oceanic crust-mantle interface of the slab, and the base of continental crust in the overlying plate. Previous tomography studies using CRSEIZE data (Deshon, 2004; Deshon and Schwartz, 2004) suggest the existence of a serpentinized forearc mantle wedge and a change in the location and depth of the seismogenic zone from north to south beneath Nicoya Peninsula. With receiver function analysis, we hope to verify the depth and range of this mantle wedge and find other characteristics of the slab-plate interface where interplate earthquakes occur. Current work suggests that the velocity contrast resulting from the slab-continental crust interface seems to be reduced as you move away from the trench. Other arrival phases, such as PKP(AB), and statistical analysis of all receiver functions will be used to improve the quality and reduce the uncertainty of our final results.
Ammon, C. J., The isolation of receiver effects from teleseismic P waveforms, Bull. Seismol. Soc. Am, 81, 2504-2510, 1991.
Deshon, H. R., Seismogenic zone structure along the Middle America subduction zone, Costa Rica, Ph.D. thesis, 356, pp., Univ. of Calif. Santa Cruz, 2004.
Deshon, H. R., and S. Y. Schwartz, Evidence for serpentinization of the forearc mantle wedge along the Nicoya Peninsula, Costa Rica, Geophys. Res. Lett., 31, doi:10.1029/2004GL021179, 2004.
Ligorría, J. P. and Ammon, Iterative deconvolution and receiver-function estimation, Bull. Seismol. Soc. Am, 89, 1395-1400, 1999.
Photographer / Contributor: Claudia Flores, Susan Schwartz • University of California, Santa Cruz
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