Hydrodynamic response of subduction zones to seismic activity: A case study for the Costa Rica margin

Cutillo, P. A.; Ge, Shemin; Screaton, E.

doi:10.1016/j.tecto.2006.02.017

Cited by 9 publications

(5 citation statements)

References 63 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Slip magnitudes required to reproduce observed flow rates are likely overestimates; in particular, they are similar to the 4.25 m slip suggested by Cutillo et al [2006] for a great earthquake based on the plate convergence rate of 8.5 cm a −1 and a 50‐year recurrence interval. It is highly improbable that the slow slip events occur every 50 years, especially since three of these events are observed in the 6‐month observation period.…”

Section: Resultssupporting

confidence: 55%

Hydrologic detection and finite element modeling of a slow slip event in the Costa Rica prism toe

2009

View full text Add to dashboard Cite

[1] We investigate transient fluid flux through the seafloor recorded near the Costa Rica trench during the 2000 Costa Rica Seismogenic Zone Experiment using a 2-D fully coupled poroelastic finite element model. We demonstrate that the observed hydrologic anomalies are consistent with a model of propagating slow slip at the subduction interface between the frontal prism and downgoing plate. There are two sources of volumetric strain that drive fluid flux at the seafloor in response to fault slip at depth: (1) compression and dilation in the vicinity of the tips of a slipping patch and (2) extension and compression due to flexure of the seafloor. The superposition of these two effects results in distinctive spatial and temporal patterns of fluid flow through the seafloor. In a forward modeling approach, time series from shear ruptures with a range of fault length-to-depth ratios in a heterogeneous crust are generated and compared with flow rate observations. Assuming a constant propagation rate and an elliptical profile for the distribution of slip along the decollement, the set of model predictions enables us to infer the probable rupture location, extent, propagation velocity, and duration from a single flow rate time series. The best fit model suggests that the slow slip event initiated within the toe at a depth of less than 4 km and propagated bilaterally at an average rate of 0.5 km dÀ1 . This interpretation implies that stress in the shallow subduction zone is relieved episodically. Furthermore, the Costa Rica data suggest that episodic slow slip events may initiate in the prism toe without being triggered by a seismic event further downdip.

show abstract

Section: Resultssupporting

confidence: 55%

Hydrologic detection and finite element modeling of a slow slip event in the Costa Rica prism toe

2009

View full text Add to dashboard Cite

show abstract

“…Strain from slip events produces significant excess fluid pressures and initiates postseismic fluid‐flow (Ge & Stover 2000; Masterlark & Wang 2002; Cutillo et al , in press). A cross‐section of computed coseismic changes in hydraulic head for the Little Skull Mountain fault slip shows that changes in hydraulic head varied with depth (Fig.…”

Section: Resultsmentioning

confidence: 99%

Analysis of strain‐induced ground‐water fluctuations at Devils Hole, Nevada

Cutillo

2006

Geofluids

View full text Add to dashboard Cite

The pool in Devils Hole is a sensitive indicator of crustal strain and fluctuates in response to changes in atmospheric pressure, earth tides, earthquakes, large-scale tectonic activity and ground-water development. Short-term and cyclic water-level fluctuations caused by atmospheric pressure and earth tides were found to be on the order of millimeters to centimeters. The 1992 Landers/Little Skull Mountain earthquake sequence and the 1999 Hector Mine earthquake induced water-level offsets of greater than )12 and )3.6 cm, respectively. The results of a dislocation model used to compute volumetric strain for each earthquake indicates that the coseismic water-level offsets are consistent in magnitude and sense with poroelastic responses to earthquake-induced strain. Theoretical postseismic fluid-flow modeling indicates that the diffusivity of the system is on the order of 0.03 m 2 sec )1 , and identified areas of anomalous water-level fluctuations. Interpretation of model results suggests that while the persistent post-Landers rise in water-level can be attributed to deformation-induced channeling of fluid to the Devils Hole fault zone, the cause of the pre-Hector Mine water-level rise may be related to postseismic excess fluid pressures or preseismic strain accumulation.

show abstract

“…This effect, though not systematic and requiring validation from further measurements, appears to suggest that variations in the stress field play a role in controlling groundwater chemistry. We suggest that this cause and effect relationship probably results from local permeability changes (i.e., opening or closing of microcracks and fractures) triggered by the variations of the stress field that also cause the earthquakes [ Rojstaczer et al , 1995; Miller et al , 1996; Miller and Nur , 2000; Claesson et al , 2004; Cutillo et al , 2006]. The permeability changes would favor the inflow of shallower waters into tapped wells, whereas the deeper water would remain partially separate.…”

Section: Discussionmentioning

confidence: 99%

“…Fluids circulating in volcanic areas (gas, vapor, or liquid water) result from the mixing of volcanic, hydrothermal, and shallow meteoric components [ Pilipenko , 1989; Giggenbach et al , 1990; Fischer et al , 1997; Lewicki et al , 2000; Brusca et al , 2001; Capasso et al , 2001]. Geochemical anomalies are hence attributable to three possible causes: (1) variations of the deep source (i.e., the volcanic system), whose detection is the main challenge of any monitoring activity; (2) changes in soil permeability due to the dynamics of the stress field (both at local and regional/subregional scales) acting on the volcanic edifice that may influence the mixing ratio between the different end‐members [ Rojstaczer and Wolf , 1992; Rojstaczer et al , 1995; Toutain et al , 1997; Poitrasson et al , 1999; Johnson et al , 2000; Claesson et al , 2004; Cutillo et al , 2006]; and (3) modifications to the hydrological regime that may change the dilution of the deep components with variable amounts of meteoric waters.…”

Section: Introductionmentioning

confidence: 99%

Crustal dynamics of Mount Vesuvius from 1998 to 2005: Effects on seismicity and fluid circulation

et al. 2008

View full text Add to dashboard Cite

[1] This paper presents the results of hydrogeochemical and seismological studies carried out at Mount Vesuvius during the period June 1998 to December 2005. Hydrogeochemical data show the occurrence of slowly varying long-term variations in the total dissolved salts and bicarbonate contents of the groundwaters, accompanied by a general decline in water temperatures. The temporal distributions of air temperature and rainfall in the Vesuvius area suggest that these variations do not depend on changes in the hydrological regime. The changes in the geochemical parameters are accompanied by slight variations in both the seismicity rate and energy release. A further relationship between seismic activity and fluid discharge rate is highlighted by a particular episode that occurred in August 2005, when a soil thermal anomaly was observed a few weeks before the occurrence of a very shallow earthquake. Moment tensor analysis of this earthquake suggests that the most plausible source mechanism is a shear faulting combined with the opening of tensile crack. This feature is often observed in volcanic areas and it is usually related to fluid-and/or gas-driven rock fracturing. The observed seismological, hydrological, and geochemical temporal changes are interpreted not as changes of the volcanic system but in terms of an external forcing as identified in the variation of the regional and local stress field acting on the volcano. This study has inferences onto the evaluation of the state of activity of volcanic systems and the eventual detection of unrest phenomena.

show abstract

Hydrodynamic response of subduction zones to seismic activity: A case study for the Costa Rica margin

Cited by 9 publications

References 63 publications

Hydrologic detection and finite element modeling of a slow slip event in the Costa Rica prism toe

Hydrologic detection and finite element modeling of a slow slip event in the Costa Rica prism toe

Analysis of strain‐induced ground‐water fluctuations at Devils Hole, Nevada

Crustal dynamics of Mount Vesuvius from 1998 to 2005: Effects on seismicity and fluid circulation

Contact Info

Product

Resources

About