Nature of crustal terranes and the Moho in northern Costa Rica from receiver function analysis
Article first published online: 27 JAN 2010
Copyright 2010 by the American Geophysical Union.
Geochemistry, Geophysics, Geosystems
Volume 11, Issue 1, January 2010
How to Cite
2010), Nature of crustal terranes and the Moho in northern Costa Rica from receiver function analysis, Geochem. Geophys. Geosyst., 11, Q01S19, doi:10.1029/2009GC002795., , , , and (
- Issue published online: 27 JAN 2010
- Article first published online: 27 JAN 2010
- Manuscript Accepted: 19 NOV 2009
- Manuscript Revised: 12 NOV 2009
- Manuscript Received: 24 AUG 2009
- receiver functions;
- Costa Rica
 The Central American subduction zone in northern Costa Rica shows along-strike variations in both the incoming and overriding plates. By analyzing the subducting oceanic Moho (M1) and the upper plate Moho (M2) with receiver functions, we investigate the variability in the hydration state of the subducting Cocos Plate and the nature of crustal terranes within the overriding Caribbean Plate. We calculate high-quality P and PP wave receiver functions using broadband data of the Global Seismology Network; Geoscope Project; and the CRSEIZE, Pocosol, and Corisubmod experiments. In addition, we estimate the depth (H) and vertically averaged Vp/Vs (κ) to Moho and present a sensitivity study to explore the effects of a dipping interface on receiver functions and the H and κ estimates. Our results are consistent with a drier oceanic mantle subducting beneath the southernmost part of the Nicoya Peninsula, as compared to a serpentinized oceanic mantle subducting beneath the northern part. In the Caribbean Plate, we describe the nature of the Mesquito, Nicoya, and Chorotega terranes by integrating new and published Vp/Vs estimates. Both the Nicoya and Chorotega terranes display high Vp/Vs (1.80–1.92) consistent with their oceanic character. In contrast, the oceanic Mesquito Terrane mostly displays lower Vp/Vs (1.62–1.80) more compatible with continental crust, which may indicate that subduction zone magmatism is modifying the crust to display continental character. Our estimates show that the deepest M2 (∼42 km) is observed in the volcanic arc region whereas the shallowest M2 (∼27–33 km) is observed in parts of the fore-arc and back-arc regions.