An 8–10 Ma tectonic event on the Cocos Plate offshore Costa Rica: Result of Cocos Ridge collision?

2004 ◽  
Vol 31 (18) ◽  
Author(s):  
Eli Silver
2001 ◽  
Vol 106 (B9) ◽  
pp. 19207-19220 ◽  
Author(s):  
Udo Barckhausen ◽  
Cesar R. Ranero ◽  
R. von Huene ◽  
Steven C. Cande ◽  
Hans A. Roeser

Author(s):  
Harm J. A. Van Avendonk ◽  
W. Steven Holbrook ◽  
Daniel Lizarralde ◽  
Mauricio M. Mora ◽  
Steven Harder ◽  
...  
Keyword(s):  

Lithos ◽  
2015 ◽  
Vol 212-215 ◽  
pp. 214-230 ◽  
Author(s):  
Antje Herbrich ◽  
Kaj Hoernle ◽  
Reinhard Werner ◽  
Folkmar Hauff ◽  
Paul v.d. Bogaard ◽  
...  

2013 ◽  
Vol 15 ◽  
pp. 23-30 ◽  
Author(s):  
P. Vannucchi ◽  
K. Ujiie ◽  
N. Stroncik ◽  

The Costa Rica Seismogenesis Project (CRISP) is an experiment to understand the processes that control nucleation and seismic rupture of large earthquakes at erosional subduction zones. Integrated Ocean Drililng Program (IODP) Expedition 334 by R/V <i>JOIDES Resolution</i> is the first step toward deep drilling through the aseismic and seismic plate boundary at the Costa Rica subduction zone offshore the Osa Peninsula where the Cocos Ridge is subducting beneath the Caribbean plate. Drilling operations included logging while drilling (LWD) at two slope sites (Sites U1378 and U1379) and coring at three slope sites (Sites U1378–1380) and at one site on the Cocos plate (Site U1381). For the first time the lithology, stratigraphy, and age of the slope and incoming sediments as well as the petrology of the subducting Cocos Ridge have been characterized at this margin. The slope sites recorded a high sediment accumulation rate of 160–1035m m y<sup>&minus;1</sup> possibly caused by on-land uplift triggered by the subduction of the Cocos Ridge. The geochemical data as well as the <i>in situ</i> temperature data obtained at the slope sites suggest that fluids are transported from greater depths. The geochemical profiles at Site U1381 reflect diffusional communication of a fluid with seawater-like chemistry and the igneous basement of the Cocos plate (Solomon et al., 2011; Vannucchi et al., 2012a). The present-day <i>in situ</i> stress orientation determined by borehole breakouts at Site U1378 in the middle slope and Site U1379 in the upper slope shows a marked change in stress state within ~12 km along the CRISP transect; that may correspond to a change from compression (middle slope) to extension (upper slope). <br><br> doi:<a href="http://dx.doi.org/10.2204/iodp.sd.15.03.2013" target="_blank">10.2204/iodp.sd.15.03.2013</a>


2011 ◽  
Vol 12 (6) ◽  
pp. n/a-n/a ◽  
Author(s):  
H. J. A. Van Avendonk ◽  
W. S. Holbrook ◽  
D. Lizarralde ◽  
P. Denyer
Keyword(s):  

2021 ◽  
Vol 60 (1) ◽  
pp. 51-75
Author(s):  
Ivonne Gabriela Arroyo ◽  
Lepolt Linkimer

Between August and November 2018, a seismic sequence took place in the vicinity of Golfito, a city in the Dulce Gulf in Southeastern Costa Rica. The main shock had a moment magnitude (Mw) of 6.1 and was widely felt in Costa Rica and Western Panama, with maximum Modified Mercalli intensities of VI. In this region, the oceanic Cocos Ridge, riding on top of the Cocos Plate, subducts beneath the Panama Microplate. Using the seismic records from the National Seismological Network of Costa Rica, in this work the seismicity is relocated using the double-difference technique, and an analysis of its temporal and geographic distribution together with the focal mechanism and intensities of the strongest events are presented. The results show that the sequence occurred at the interplate seismogenic zone, within the rupture area of the 1983 Golfito earthquake (7.4 Mw), between 12 and 27 km depth, in a cluster dipping 35º northeast underneath the Dulce Gulf. Based mainly on these results and on previous seismic sequences, it is here proposed that the seismogenic zone in Southeastern Costa Rica has an extension of ~160 x 45 km. Further, during the Golfito sequence, the rupture of an inverse fault (5.9 Mw) took place within the Cocos Plate beneath the Dulce Gulf, as well as of dextral strike-slip faults (4.6-5.6 Mw) in the Panama Microplate, 50 km away of the Dulce Gulf. The analysis of the interseismic interplate seismicity contributes to a better understating of the dynamics of the seismogenic zone. This is of particular relevance in Southeastern Costa Rica, where at least six damaging earthquakes of Mw > 7 have occurred since 1803, implying the impending risk of the next big earthquake in this region.


1996 ◽  
Vol 86 (1A) ◽  
pp. 19-31 ◽  
Author(s):  
Marino Protti ◽  
Susan Y. Schwartz ◽  
George Zandt

Abstract We have imaged the complex crustal and upper mantle structure beneath central Costa Rica using P-wave arrival times from locally recorded earthquakes. Thurber's (1983) iterative inversion method is used to simultaneously estimate velocities along a three-dimensional grid and hypocentral parameters of local earthquakes. Our data consist of over 12,000 arrival times from more than 1300 earthquakes recorded by stations of a permanent seismographic network in Costa Rica. Our resulting velocity model correlates well with mapped geologic units at very shallow depth and with tectonic features at greater depth. We find low velocities (4.0 to 4.8 km/sec) in the shallow crust (above 10 km) near the active volcanoes and associated with a NW-SE trending late Cretaceous to late Tertiary sedimentary basin southeast of Herradura peninsula. High velocities (5.4 to 5.7 km/sec) in the shallow crust correlate with outcrops of late Jurassic to early Tertiary ultramafic ophiolitic units and with basic Tertiary volcanic units. At depths between 20 and 30 km, high velocities (6.8 to 7.2 km/sec) are associated with the subducting Cocos plate under Costa Rica and two prominent low-velocity bodies (6.3 to 6.5 km/sec) are present about 30 km trenchward of the volcanic arc and along the projection of the aseismic Cocos Ridge as it subducts beneath Costa Rica. The thickened oceanic crust of the Cocos Ridge is most likely responsible for its low velocities. The deep low-velocity anomaly located trenchward of the axis of the volcanoes may indicate the presence of a low-density intrusive resulting from an earlier phase of magmatism, possibly the late Miocene episode that produced the Talamanca intrusive complex.


Tectonics ◽  
2000 ◽  
Vol 19 (2) ◽  
pp. 314-334 ◽  
Author(s):  
R. von Huene ◽  
C. R. Ranero ◽  
W. Weinrebe ◽  
K. Hinz

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