Constraints from finite element modeling on the active tectonics of northern Central America and the Middle America Trench

Álvarez‐Gómez, José A.; Meijer, Paul; Martínez‐Díaz, J. J.; Capote, Ramón

doi:10.1029/2007tc002162

Cited by 49 publications

(66 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Average shear stresses due to frictional forces at the Cocos trench are 5 MPa, at the Lesser Antilles trench they are around 2 MPa, and at transform boundaries they are 8 MPa. Plate boundaries of the Caribbean plate are thus weak, in agreement with the studies of Lyon ‐ Caen et al [2006], Álvarez ‐ Gómez et al [2008], Manaker et al [2008] and Correa ‐ Mora et al [2009].…”

Section: Torque Balance Resultssupporting

confidence: 87%

“…We computed the average difference in direction of the principal axes (obtained from focal mechanisms and borehole breakouts) with the World Stress map (WSM) [ Heidbach et al , 2008]: nobs is the number of observations, α wsm and α mod are the directions of maximum compression from the WSM and our models, respectively. We also calculated slip directions on existing fault planes of earthquakes (taken from the Centroid Moment Tensor (CMT) catalog and computed the average difference with the original direction of slip: Δ [ Meijer , 1995; Álvarez ‐ Gómez et al , 2008]. …”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

The Caribbean plate: Pulled, pushed, or dragged?

Benthem

Govers

2010

J. Geophys. Res.

View full text Add to dashboard Cite

[1] Mechanical coupling between the lithosphere and the asthenosphere remains a controversial topic in the geosciences. Beneath the Caribbean plate, shear wave splitting measurements indicate EW strain in the asthenosphere, which can be interpreted as mantle flow driving or resisting motion of the overlying lithosphere. Here, we constrain the average shear traction on the base of the Caribbean plate by balancing all torques. These torques result from body forces that act on the Caribbean (slab pull, ridge push, lateral density variations), from plate boundary friction and from basal shear tractions. We obtain a range of physically realistic torque solutions, which we examine further by computing the corresponding stresses and rotations within the Caribbean plate for comparison with observations. The deformation field for the Caribbean is particularly sensitive to the amount of friction on intraplate faults. Representative models have a good fit with observations and are characterized by (1) a near-zero basal shear traction (≤0.3 MPa), (2) (lithosphereaveraged) plate boundary friction ≤ 10 MPa, (3) local forces due to indenters and trench pull, (4) a net pull by the Caribbean slab and (5) intraplate fault shear stresses on the order of tens of megapascals. We conclude that the mechanical coupling of the Caribbean plate to the underlying asthenosphere is small.

show abstract

Section: Torque Balance Resultssupporting

confidence: 87%

Section: Resultsmentioning

confidence: 99%

The Caribbean plate: Pulled, pushed, or dragged?

Benthem

Govers

2010

J. Geophys. Res.

View full text Add to dashboard Cite

show abstract

“…The absence of a significant trench-normal component of station motion in the velocities of GPS sites in Nicaragua and El Salvador imply weak or no coupling across the Cocos plate subduction interface (Cáceres et al, 2005;Guzmán-Speziale, 2001;Lyon-Caen et al, 2006). The dextral strike-slip movement in El Salvador is caused by the Caribbean drift forces that produce the relative displacement of the Chortis Block to the east, owing to the required low coupling of the subducted plate (Cáceres et al, 2005;Guzmán-Speziale et al, 2005;Álvarez-Gómez et al, 2008;Correa-Mora et al, 2009;Franco et al, 2012). The complexity of the ESFZ structure and the kinematics variations along strike is associated with the incipient character of the shallow fault zone structure and the lateral variation of the angle between the principal displacement zone and the Caribbean drift forces (transtension).…”

Section: Discussionmentioning

confidence: 99%

Structural evolution of the El Salvador Fault Zone: an evolving fault system within a volcanic arc.

Catalán

Díaz

Pérez

et al. 2014

Journal of Iberian Geology

Self Cite

View full text Add to dashboard Cite

The El Salvador Fault Zone, firstly identified after the 13th February 2001 Mw 6.6 El Salvador earthquake, is a 150 km long, 20 km wide right-lateral strike-slip fault system. Ruptures along the ESFZ are thought to be responsible for most of the historical destructive earthquakes along the El Salvador Volcanic Arc, as well as for most of the current seismicity of the area. In this work, we focus on the geological setting of the fault zone by describing its geomorphology and structure, using field-based observations, digital terrain modelling, and aerial photograph interpretation with the aim at contributing to the understanding of the ESFZ slip behaviour. In particular, we address the ESFZ structure, kinematics and evolution with time.The ESFZ is a complex set of traces divided in major rupture segments characterized by different geometry, kinematics and geomorphic expressions. Natural fault exposures and paleoseismic trenches excavated along the fault show that the strike-slip deformation is distributed in several planes. Both geometry and kinematics of the fault zone are consistent with a transtensional strain regime.The estimated geological slip rate for the main fault segments by paleoseismic trenches and displaced geomorphic features implies a deficit in velocity of the fault compared to the available GPS velocities data. The high vertical scarps of some fault segments would require Quaternary slip rates not coherent neither with measured GPS velocities nor with slip rates obtained from paleoseismic analysis. This mismatch suggests a pre-existing graben structure that would be inherited from the previous regional roll back related extensional stage. We consider that the ESFZ is using this relict structure to grow up along it. As a result, we propose a model for ESFZ development consistent with all these observations. Keywords: El Salvador Fault Zone, active strike-slip fault, 13 February 2001 earthquake, geomorphology, Volcanic arc Resumen La Zona de Falla de El Salvador (ZFES) es un sistema de falla de desgarre dextral de 150 km de longitud y 20 de anchura, que fue identificada por primera vez después del terremoto de Mw 6.6 de El Salvador de febrero de 2001. La mayoría de la sismicidad y de los terremotos históricos destructivos producidos en el arco volcánico salvadoreño han sido producidos por la ruptura de la ZFES. Este trabajo se centra en el marco geológico de la zona de falla describiendo su geomorfología y su estructura a través de observaciones de campo, del estudio de los modelos digitales del terreno y de la interpretación de las fotografías aéreas, con el objetivo de avanzar en el conocimiento del comportamiento de la ZFES. En concreto trataremos del estudio de la estructura, la cinemática y la evolución de la ZFES.La ZFES es un complejo sistema de fallas divididas en varios segmentos que se diferencian en la geometría, la cinemática y la expresión geomorfológica. En los afloramientos de la falla, así como en las trincheras paleosismicas excavadas se ha observado que la deformación de d...

show abstract

“…These events are particularly common in low coupled subduction zones, as is the case of the Central American subduction (Pacheco et al, 1993;Guzmán-Speziale and Gómez-González, 2006;Lyon-Caen et al, 2006;Álvarez-Gómez et al, 2008), and have been recently studied in the area by Álvarez-Gómez et al (2012). To simulate these normal outer-rise events we used tsunamigenic sources proposed by Álvarez-Gómez et al (2012).…”

Section: Local Sourcesmentioning

confidence: 99%

Tsunami hazard assessment in El Salvador, Central America, from seismic sources through flooding numerical models.

Álvarez‐Gómez

Aniel-Quiroga

Gutiérrez

et al. 2013

Nat. Hazards Earth Syst. Sci.

View full text Add to dashboard Cite

Abstract. El Salvador is the smallest and most densely populated country in Central America; its coast has an approximate length of 320 km, 29 municipalities and more than 700 000 inhabitants. In El Salvador there were 15 recorded tsunamis between 1859 and 2012, 3 of them causing damages and resulting in hundreds of victims. Hazard assessment is commonly based on propagation numerical models for earthquake-generated tsunamis and can be approached through both probabilistic and deterministic methods. A deterministic approximation has been applied in this study as it provides essential information for coastal planning and management. The objective of the research was twofold: on the one hand the characterization of the threat over the entire coast of El Salvador, and on the other the computation of flooding maps for the three main localities of the Salvadorian coast. For the latter we developed high-resolution flooding models. For the former, due to the extension of the coastal area, we computed maximum elevation maps, and from the elevation in the near shore we computed an estimation of the run-up and the flooded area using empirical relations. We have considered local sources located in the Middle America Trench, characterized seismotectonically, and distant sources in the rest of Pacific Basin, using historical and recent earthquakes and tsunamis. We used a hybrid finite differencesfinite volumes numerical model in this work, based on the linear and non-linear shallow water equations, to simulate a total of 24 earthquake-generated tsunami scenarios. Our results show that at the western Salvadorian coast, run-up values higher than 5 m are common, while in the eastern area, approximately from La Libertad to the Gulf of Fonseca, the run-up values are lower. The more exposed areas to flooding are the lowlands in the Lempa River delta and the Barra de Santiago Western Plains. The results of the empirical approximation used for the whole country are similar to the results obtained with the high-resolution numerical modelling, being a good and fast approximation to obtain preliminary tsunami hazard estimations. In Acajutla and La Libertad, both important tourism centres being actively developed, flooding depths between 2 and 4 m are frequent, accompanied with high and very high person instability hazard. Inside the Gulf of Fonseca the impact of the waves is almost negligible.

show abstract

Constraints from finite element modeling on the active tectonics of northern Central America and the Middle America Trench

Cited by 49 publications

References 51 publications

The Caribbean plate: Pulled, pushed, or dragged?

The Caribbean plate: Pulled, pushed, or dragged?

Structural evolution of the El Salvador Fault Zone: an evolving fault system within a volcanic arc.

Tsunami hazard assessment in El Salvador, Central America, from seismic sources through flooding numerical models.

Contact Info

Product

Resources

About