Controls of seismogenic zone width and subduction velocity on interplate seismicity: Insights from analog and numerical models

2017 ◽  
Vol 44 (12) ◽  
pp. 6082-6091 ◽  
Author(s):  
Fabio Corbi ◽  
Robert Herrendörfer ◽  
Francesca Funiciello ◽  
Ylona van Dinther
Keyword(s):  
Numerical Models ◽  
Seismogenic Zone ◽  
Zone Width ◽  
Interplate Seismicity

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

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.

A Significant Increase in Interplate Seismicity near Major Historical Earthquakes Offshore Martinique (FWI)

2021 ◽  
Author(s):  
Jordane Corbeau ◽  
O’Leary Gonzalez ◽  
Nathalie Feuillet ◽  
Anne-Marie Lejeune ◽  
Fabrice R. Fontaine ◽  
...  
Keyword(s):  
Subduction Zone ◽  
Subduction Zones ◽  
Plate Boundary ◽  
Historical Earthquakes ◽  
Seismogenic Zone ◽  
Plate Interface ◽  
Seismicity Rate ◽  
Rupture Area ◽  
Interplate Seismicity ◽  
Statistical Studies

ABSTRACT Understanding the processes that may be at the origin of major earthquakes in subduction zones is highly challenging, especially in the case of slowly converging areas such as the Lesser Antilles subduction zone. Our study reveals a recorded increase in seismicity rate and cumulative seismic moment over the last two decades offshore Martinique island and, particularly, in the presumed rupture area of the major historical 1839 earthquake. This sustained seismicity is shared between extensive intermediate depth activity since the 2007 Mw 7.4 earthquake that occurred about 20 km north of Martinique and a compressive seismic cluster located in the seismogenic zone of the subduction zone. We also observe a downward migration of the seismicity along the plate interface up to a 60–65 km depth and a recorded increase in the magnitudes of the earthquakes. All these observations may indicate ongoing changes along the plate boundary interface near the area of the historical major rupture of 1839, although more detailed statistical studies and additional data are necessary to confirm this trend.

scholarly journals How wide is the seismogenic zone of the Lesser Antilles forearc?

2013 ◽  
Vol 184 (1-2) ◽  
pp. 47-59 ◽  
Author(s):  
Marc-André Gutscher ◽  
Graham K. Westbrook ◽  
Boris Marcaillou ◽  
David Graindorge ◽  
Audrey Gailler ◽  
...  
Keyword(s):  
Heat Flow ◽  
Numerical Models ◽  
Thermal Structure ◽  
Lesser Antilles ◽  
Seismogenic Zone ◽  
Segment Length ◽  
Accretionary Wedge ◽  
The South ◽  
Maximum Width ◽  
Minimum Width

Abstract The Lesser Antilles subduction zone has produced no recent strong thrust earthquakes, making it difficult to quantify the seismic hazard from such events. The Lesser Antilles arc has a low subduction rate and an accretionary wedge that is very wide at its southern end. To investigate the effect of the wedge on seismogenesis, numerical models of forearc thermal structure were constructed along six transects perpendicular to the arc in order to determine the thermally predicted width of the seismogenic zone. The geometry of each section is constrained by published seismic profiles and crustal models derived from gravity and seismic data and by earthquake hypocenters at depth. A major constraint on the deep part of the model is that mantle temperature beneath the volcanic arc should achieve a temperature of 1,100°C to generate partial melts. Predicted surface heat flow is compared to the available heat flow observations. Thermal modeling results indicate a systematic southward increase in the width of the seismogenic zone, more than doubling in width from north to south and corresponding to a dramatic southward increase in forearc width (distance from the arc to the deformation front of the accretionary wedge). The minimum width of the seismogenic zone (distance between the intersections of the subduction interface with the 150°C and 350°C isotherms) increases from about 80 km, north of 16°N, to 230 km, at 13°N. The maximum width (between the 100°C and 450°C isotherms) ranges from about 150 km in the north to up to 320 km in the south. This large variation in the width of the seismogenic zone is a consequence of the increasing width of the accretionary wedge to the south, caused by the increased thickness of sediment on the subducting plate. There is good agreement between the thermally predicted seismogenic limits and the sparse distribution of recorded thrust earthquakes, which are observed only in the northern portion of the arc. Possible scenarios for mega-thrust earthquakes are discussed. Depending on the segment length (along-strike) of the rupture plane, the occurrence of an event of magnitude 8–9 cannot be excluded.

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

2019 ◽  
Author(s):  
Marino Protti ◽  
◽  
Nathan Bangs ◽  
Peter Baumgartner ◽  
Donald Fisher ◽  
...  
Keyword(s):  
Costa Rica ◽  
Seismogenic Zone ◽  
Osa Peninsula ◽  
Megathrust Earthquakes

Stochastic simulation of the spatio-temporal field of the average daily heat index in Southern Russia

2020 ◽  
Vol 82 ◽  
pp. 149-160
Author(s):  
N Kargapolova
Keyword(s):  
Heat Waves ◽  
Numerical Models ◽  
Heat Index ◽  
Real Field ◽  
Gaussian Field ◽  
The Real ◽  
Southern Russia ◽  
Weather Stations ◽  
Spatio Temporal ◽  
Temporal Field

Numerical models of the heat index time series and spatio-temporal fields can be used for a variety of purposes, from the study of the dynamics of heat waves to projections of the influence of future climate on humans. To conduct these studies one must have efficient numerical models that successfully reproduce key features of the real weather processes. In this study, 2 numerical stochastic models of the spatio-temporal non-Gaussian field of the average daily heat index (ADHI) are considered. The field is simulated on an irregular grid determined by the location of weather stations. The first model is based on the method of the inverse distribution function. The second model is constructed using the normalization method. Real data collected at weather stations located in southern Russia are used to both determine the input parameters and to verify the proposed models. It is shown that the first model reproduces the properties of the real field of the ADHI more precisely compared to the second one, but the numerical implementation of the first model is significantly more time consuming. In the future, it is intended to transform the models presented to a numerical model of the conditional spatio-temporal field of the ADHI defined on a dense spatio-temporal grid and to use the model constructed for the stochastic forecasting of the heat index.

Application of cave-scale rock degradation models in the imaging of the seismogenic zone

CIM Journal ◽  
2016 ◽  
Vol 7 (2) ◽  
pp. 87-92 ◽  
Author(s):  
J. M. Reyes-Montes ◽  
B. L. Sainsbury ◽  
J. R. Andrews ◽  
R. P. Young
Keyword(s):  
Seismogenic Zone ◽  
Degradation Models

Extending "the Shorted Port Method" for Calculation of S-Matrices, Using Reduced Numerical Models

2003 ◽  
Vol 59 (3-4) ◽  
pp. 10
Author(s):  
D. Yu. Kulik ◽  
S. L. Senkevich ◽  
Victor Ivanovich Tkachenko
Keyword(s):  
Numerical Models
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