Premium
Crust‐mantle coupling in the Gulf of Cadiz (SW‐Iberia)
Author(s) -
Stich Daniel,
Mancilla Flor de Lis,
Morales Jose
Publication year - 2005
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 - 10.1029/2005gl023098
Subject(s) - geology , seismology , mantle (geology) , subduction , induced seismicity , crust , focal mechanism , moment tensor , geophysics , tectonics , deformation (meteorology) , oceanography
In the Gulf of Cadiz and Cape St. Vincent region at the SW‐Iberian margin, seismic catalogues report seismicity down to ∼100 km depth. According to structural models for the region, this includes earthquakes that occur in the uppermost continental mantle. We invert regional waveforms to estimate moment tensors and centroid depths for moderate earthquakes, obtaining eight solutions (Mw 3.8 to 5.3) between 6 and 60 km depth. Moment tensor solutions and previous source estimates show predominately reverse and strike‐slip faulting style with ∼NNW‐SSE oriented P‐axes, close to plate convergence between Africa and Eurasia. We obtain similar stress tensor estimates from crustal and upper mantle earthquakes, both with sub‐horizontal, ∼NNW σ 1 ‐axes. This indicates analogous deformation in both domains, and that earthquakes are unrelated to any subduction process.