@article {Arroyo2014, title = {{Interplate seismicity at the CRISP drilling site: The 2002 Mw 6.4 Osa Earthquake at the southeastern end of the Middle America Trench}}, journal = {Geochemistry, Geophysics, Geosystems}, volume = {15}, number = {7}, year = {2014}, pages = {3035{\textendash}3050}, publisher = {Blackwell Publishing Ltd}, abstract = {We investigate potential relations between variations in seafloor relief and age of the incoming plate and interplate seismicity. Westward from Osa Peninsula in Costa Rica, a major change in the character of the incoming Cocos Plate is displayed by abrupt lateral variations in seafloor depth and thermal structure. Here a Mw 6.4 thrust earthquake was followed by three aftershock clusters in June 2002. Initial relocations indicate that the main shock occurred fairly trenchward of most large earthquakes along the Middle America Trench off central Costa Rica. The earthquake sequence occurred while a temporary network of OBH and land stations \~{}80 km to the northwest were deployed. By adding readings from permanent local stations, we obtain uncommon P wave coverage of a large subduction zone earthquake. We relocate this catalog using a nonlinear probabilistic approach within both, a 1-D and a 3-D P wave velocity models. The main shock occurred \~{}25 km from the trench and probably along the plate interface at 5-10 km depth. We analyze teleseismic data to further constrain the rupture process of the main shock. The best depth estimates indicate that most of the seismic energy was radiated at shallow depth below the continental slope, supporting the nucleation of the Osa earthquake at \~{}6 km depth. The location and depth coincide with the plate boundary imaged in prestack depth-migrated reflection lines shot near the nucleation area. Aftershocks propagated downdip to the area of a 1999 Mw 6.9 sequence and partially overlapped it. The results indicate that underthrusting of the young and buoyant Cocos Ridge has created conditions for interplate seismogenesis shallower and closer to the trench axis than elsewhere along the central Costa Rica margin. {\textcopyright} 2014. American Geophysical Union. All Rights Reserved.}, keywords = {earthquake relocation, erosional margin, interplate drilling}, issn = {15252027}, doi = {10.1002/2014GC005359}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84906266765\&partnerID=tZOtx3y1}, author = {Arroyo, Ivonne G. and Grevemeyer, Ingo and Ranero, Cesar R. and von Huene, Roland} } @article {Kluesner2013, title = {{High density of structurally controlled, shallow to deep water fluid seep indicators imaged offshore Costa Rica}}, journal = {Geochemistry, Geophysics, Geosystems}, volume = {14}, number = {3}, year = {2013}, month = {mar}, pages = {519{\textendash}539}, abstract = {We used high-resolution mapping to document 161 sites of potential fluid seepage on the shelf and slope regions where no geophysical seep indicators had been reported. Identified potential seabed seepage sites show both high-backscatter anomalies and bathymetric expressions, such as pockmarks, mounds, and ridges. Almost all identified seabed features are associated with bright spots and flat spots beneath, as mapped within the 3-D seismic grid. We obtained EM122 multi-beam data using closely spaced receiver beams and 4-5 times overlapping multi-beam swaths, which greatly improved the sounding density and geologic resolvability of the data. At least one location shows an acoustic plume in the water column on a 3.5 kHz profile, and this plume is located along a fault trace and above surface and subsurface seepage indicators. Fluid indicators are largely associated with folds and faults within the sediment section, and many of the faults continue into and offset the reflective basement. A dense pattern of normal faults is seen on the outer shelf in the multi-beam bathymetry, backscatter, and 3-D seismic data, and the majority of fluid seepage indicators lie along mapped fault traces. Furthermore, linear mounds, ridges, and pockmark chains are found on the upper, middle, and lower slope regions. The arcuate shape of the shelf edge, projection of the Quepos Ridge, and high density of potential seep sites suggest that this area may be a zone of former seamount/ridge subduction. These results demonstrate a much greater potential seep density and distribution than previously reported across the Costa Rican margin. {\textcopyright}2013. American Geophysical Union. All Rights Reserved.}, keywords = {Costa Rica, fluid flow, fluid seepage, Marine Geology and Geophysics, subduction zones}, issn = {15252027}, doi = {10.1002/ggge.20058}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84879641763\&partnerID=tZOtx3y1}, author = {Kluesner, Jared W. and Silver, Eli A. and Bangs, Nathan L. and McIntosh, Kirk D. and Gibson, James and Orange, Daniel and Ranero, Cesar R. and von Huene, Roland} } @book {VonHuene2009a, title = {{Subduction Zone Geodynamics}}, series = {Frontiers in Earth Sciences}, year = {2009}, month = {oct}, publisher = {Springer Berlin Heidelberg}, organization = {Springer Berlin Heidelberg}, address = {Berlin, Heidelberg}, abstract = {21 pages, 8 figures, 1 table}, keywords = {Accretion, Convergent margins, Subduction erosion}, isbn = {978-3-540-87971-8}, doi = {10.1007/978-3-540-87974-9}, url = {http://digital.csic.es/handle/10261/83778 http://hdl.handle.net/10261/83778}, author = {von Huene, Roland and Ranero, Cesar R. and Scholl, Dave W.}, editor = {Lallemand, Serge and Funiciello, Francesca} } @article {Ranero2007, title = {{Drilling the Seismogenic Zone of an Erosinal Convergent Margin: IODP Costa Rica Seismogenesis Project CRISP}}, journal = {Scientific Drilling}, number = {Special, No. 1}, year = {2007}, month = {nov}, pages = {51{\textendash}54}, issn = {1816-3459}, doi = {10.2204/iodp.sd.s01.29.2007}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-72749124634\&partnerID=tZOtx3y1}, author = {Ranero, Cesar R. and Vannucchi, Paola and von Huene, Roland} }