IODP Expedition 334: An Investigation of the Sedimentary Record, Fluid Flow and State of Stress on Top of the Seismogenic Zone of an Erosive Subduction Margin

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 JOIDES Resolution 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−1 possibly caused by on-land uplift triggered by the subduction of the Cocos Ridge. The geochemical data as well as the in situ 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 in situ 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). doi:<a href="http://dx.doi.org/10.2204/iodp.sd.15.03.2013" target="_blank">10.2204/iodp.sd.15.03.2013</a>

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Modeling the Interaction between Slow Slip Events and Earthquake Ruptures in the Nicoya Peninsula, Costa Rica.

10.5194/egusphere-egu21-6324 ◽

2021 ◽

Author(s):

Lise Alalouf ◽

Yajing Liu

Keyword(s):

Costa Rica ◽

Subduction Zones ◽

Computation Time ◽

Seismogenic Zone ◽

Model Parameters ◽

Slow Slip ◽

Coseismic Slip ◽

Slow Slip Events ◽

Megathrust Earthquakes ◽

Earthquake Ruptures

Subduction zones are where the largest earthquakes occur. In the past few decades, scientists have also discovered the presence of episodic aseismic slip, including slow slip events (SSEs), along most of the subduction zones. However, it is still unclear how these SSEs can influence megathrust earthquake ruptures. The Costa Rica subduction zone is a particularly interesting area because a SSE was recorded 6 months before the 2012 Mw7.6 earthquake in the Nicoya Peninsula, suggesting a potential stress transfer from the SSE to the earthquake slip zone. SSEs beneath the Nicoya Peninsula were also recorded both updip and downdip the seismogenic zone, making it a unique area to study the complex interaction between SSEs and earthquakes.As most of the shallow SSEs were recorded around the Nicoya Peninsula, we chose to start using a 1D planar fault embedded in a homogeneous elastic half-space, with different dipping angles following several geometric profiles of the subduction fault beneath the Nicoya Peninsula section of the Costa Rica margin. This 1D modelling study allows us to better investigate the interaction between shallow and deep SSEs and megathrust earthquakes with high numerical resolution and relatively short computation time. The model provides information on the long-term seismic history by reproducing the different stages of the seismic cycle (interseismic slip, shallow and deep episodic slow slip, and coseismic slip).We study the influence of the variation of numerical parameters and frictional properties on the recurrence interval, maximum slip velocity and cumulative slip of SSEs (both shallow and deep) and earthquakes and their interaction with each other. We then compare our results with GPS and seismic observations (i.e. cumulative slip, characteristic duration, moment rate, depth and size of the rupture, equivalent magnitude) to identify an optimal set of model parameters to understand the interaction between various modes of subduction fault deformation.

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Compaction and dewatering processes of the oceanic sediments in the Costa Rica and Barbados subduction zones: estimates from in situ physical property measurements

Earth and Planetary Science Letters ◽

10.1016/s0012-821x(01)00403-4 ◽

2001 ◽

Vol 191 (3-4) ◽

pp. 283-293 ◽

Cited By ~ 26

Author(s):

Saneatsu Saito ◽

David Goldberg

Keyword(s):

Costa Rica ◽

Subduction Zones ◽

Physical Property ◽

Oceanic Sediments

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Geometría de la zona sismogénica interplacas en el Sureste de Costa Rica a la luz de la secuencia de Golfito del 2018

Geofísica Internacional ◽

10.22201/igeof.00167169p.2021.60.1.2026 ◽

2021 ◽

Vol 60 (1) ◽

pp. 51-75

Author(s):

Ivonne Gabriela Arroyo ◽

Lepolt Linkimer

Keyword(s):

Costa Rica ◽

Main Shock ◽

Seismogenic Zone ◽

Double Difference ◽

Cocos Plate ◽

Seismic Sequences ◽

Rupture Area ◽

Interplate Seismicity ◽

Seismic Records ◽

Dextral Strike Slip

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.

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IODP workshop: Core-Log Seismic Investigation at Sea – Integrating legacy data to address outstanding research questions in the Nankai Trough Seismogenic Zone Experiment

Scientific Drilling ◽

10.5194/sd-24-93-2018 ◽

2018 ◽

Vol 24 ◽

pp. 93-107

Author(s):

Anna Cerchiari ◽

Rina Fukuchi ◽

Baiyuan Gao ◽

Kan-Hsi Hsiung ◽

Dominik Jaeger ◽

...

Keyword(s):

Subduction Zone ◽

Seismic Data ◽

Subduction Zones ◽

Nankai Trough ◽

Early Career ◽

Seismogenic Zone ◽

Geochemical Data ◽

Deformation Front ◽

Subduction Zone Processes ◽

Research Questions

Abstract. The first International Ocean Discovery Program (IODP) Core-Log-Seismic Integration at Sea (CLSI@Sea) workshop, held in January–February 2018, brought together an international, multidisciplinary team of 14 early-career scientists and a group of scientific mentors specialized in subduction zone processes at the Nankai Trough, one of the Earth's most active plate-subduction zones located off the southwestern coast of Japan. The goal of the workshop was to leverage existing core, log, and seismic data previously acquired during the IODP's Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE), to address the role of the deformation front of the Nankai accretionary prism in tsunamigenic earthquakes and slow slip in the shallow portion of the subduction interface. The CLSI@Sea workshop was organized onboard the D/V Chikyu concurrently with IODP Expedition 380, allowing workshop participants to interact with expedition scientists installing a long-term borehole monitoring system (LTBMS) at a site where the workshop's research was focused. Sedimentary cores from across the deformation front were brought onboard Chikyu, where they were made available for new description, sampling, and analysis. Logging data, drilling parameters, and seismic data were also available for investigation by workshop participants, who were granted access to Chikyu laboratory facilities and software to perform analyses at sea. Multi-thematic presentations facilitated knowledge transfer between the participants across field areas, and highlighted the value of multi-disciplinary collaboration that integrates processes across different spatiotemporal scales. The workshop resulted in the synthesis of existing geophysical, geologic, and geochemical data spanning IODP Sites C0006, C0007, C0011 and C0012 in the NanTroSEIZE area, the identification of key outstanding research questions in the field of shallow subduction zone seismogenesis, and fostered collaborative and individual research plans integrating new data analysis techniques and multidisciplinary approaches.

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Osa Peninsula, Costa Rica: A unique opportunity to drill and instrument the seismogenic zone of large megathrust earthquakes

10.32858/temblor.026 ◽

2019 ◽

Author(s):

Marino Protti ◽

◽

Nathan Bangs ◽

Peter Baumgartner ◽

Donald Fisher ◽

...

Keyword(s):

Costa Rica ◽

Seismogenic Zone ◽

Osa Peninsula ◽

Megathrust Earthquakes

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Magmatic flare-up causes crustal thickening at the transition from subduction to continental collision

Communications Earth & Environment ◽

10.1038/s43247-021-00103-z ◽

2021 ◽

Vol 2 (1) ◽

Author(s):

Carlos E. Ganade ◽

Pierre Lanari ◽

Daniela Rubatto ◽

Joerg Hermann ◽

Roberto F. Weinberg ◽

...

Keyword(s):

Production Rate ◽

Continental Margin ◽

Subduction Zones ◽

Continental Collision ◽

Crustal Thickening ◽

Time Intervals ◽

West Gondwana ◽

Continental Arc ◽

Order Of Magnitude

AbstractAbove subduction zones, magma production rate and crustal generation can increase by an order of magnitude during narrow time intervals known as magmatic flare-ups. However, the consequences of these events in the deep arc environment remain poorly understood. Here we use petrological and in-situ zircon dating techniques to investigate the root of a continental arc within the collisional West Gondwana Orogen that is now exposed in the Kabyé Massif, Togo. We show that gabbros intruded 670 million years ago at 20–25 km depth were transformed to eclogites by 620 million years ago at 65–70 km depth. This was coeval with extensive magmatism at 20–40 km depth, indicative of a flare-up event which peaked just prior to the subduction of the continental margin. We propose that increased H2O flux from subduction of serpentinized mantle in the hyper-extended margin of the approaching continent was responsible for the increased magma productivity and crustal thickening.

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The effect of temperature-dependent thermal parameters in thermal models of subduction zones

10.5194/egusphere-egu21-120 ◽

2021 ◽

Author(s):

Iris van Zelst ◽

Timothy J. Craig ◽

Cedric Thieulot

Keyword(s):

Subduction Zones ◽

Thermal Parameters ◽

Dislocation Creep ◽

Seismogenic Zone ◽

Effect Of Temperature ◽

Temperature Dependent ◽

Thermal Models ◽

Intermediate Depth ◽

Dehydration Reactions ◽

Model Setup

The thermal structure of subduction zones plays an important role in the seismicity that occurs there with e.g., the downdip limit of the seismogenic zone associated with particular isotherms (350 &#176;C - 450 &#176;C) and intermediate-depth seismicity linked to dehydration reactions that occur at specific temperatures and pressures. Therefore, accurate thermal models of subduction zones that include the complexities found in laboratory studies are necessary. One of the often-ignored effects in models is the temperature-dependence of the thermal parameters such as the thermal conductivity, heat capacity, and density.&#160;Here, we build upon the model setup presented by Van Keken et al., 2008 by including temperature-dependent thermal parameters to an otherwise clearly constrained, simple model setup of a subducting plate. We consider a fixed kinematic slab dipping at 45&#176; and a stationary overriding plate with a dynamic mantle wedge. Such a simple setup allows us to isolate the effect of temperature-dependent thermal parameters. We add a more complex plate cooling model for the oceanic plate for consistency with the thermal parameters.&#160;We test the effect of temperature-dependent thermal parameters on models with different rheologies, such as an isoviscous wedge, diffusion and dislocation creep. We find that slab temperatures can change by up to 65 &#176;C which affects the location of isotherm depths. The downdip limit of the seismogenic zone defined by e.g., the 350 &#176;C isotherm shifts by approximately 4 km, thereby increasing the maximum possible rupture area of the seismogenic zone. Similarly, the 600 &#176;C isotherm is shifted approximately 30 km deeper, affecting the depth at which dehydration reactions and hence intermediate-depth seismicity occurs. Our results therefore show that temperature-dependent thermal parameters in thermal models of subduction zones cannot be ignored when studying subduction-related seismicity.&#160;

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