Analysis of the mentawai region fault field based on earthquake relocation data using the modified joint hypocenter determination (MJHD) method

Abstract The area of Sulawesi, especially along the Palu Koro Fault, is an area that is largely influenced by the confluence and movement of plates as well as regional fault activity pathways with high levels of seismicity. Determining the location of the hypocenter accurately through relocation is required in identifying the detailed tectonic structures in the area. Relocation of the hypocenter using the Modified Joint Hypocenter Determination (MJHD) method using the IASP91 velocity model in the period August to October 2018 with the arrival time data from BMKG catalog. The results of hypocenter relocation using the MJHD method show that from 132 earthquake distribution points to 63 earthquake hypocenter points after the relocation. The change in the location of the hypocenter was much denser along the Palu Koro Fault route than before the relocation as evidenced by the mean value of rms (root mean square) before relocation was 1.31 and after relocation it became smaller (0.61). Changes in parameter values after relocation using the MJHD method caused the distribution of the earthquake hypocenter to be tighter towards the Palu Koro fault than before the relocation, where the distribution had a random and scattered pattern.

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Seismicity and tectonics of western Venezuela

Bulletin of the Seismological Society of America ◽

10.1785/bssa0620061711 ◽

1972 ◽

Vol 62 (6) ◽

pp. 1711-1751 ◽

Cited By ~ 10

Author(s):

James W. Dewey

Keyword(s):

Fault Zone ◽

South American ◽

Seismic Zone ◽

South American Plate ◽

Intermediate Depth ◽

Hypocenter Determination ◽

Joint Hypocenter Determination ◽

Shallow Earthquakes ◽

Seismicity And Tectonics ◽

North And South

abstract New seismicity data on western Venezuela and northeastern Colombia are presented. Teleseismically recorded earthquakes from 1930 through 1970 have been relocated by Joint Hypocenter Determination (JHD) or with source-station adjustments calculated by JHD. Additionally, 540 days of recording have been obtained with local seismographs installed near the Boconó Fault. The most intense shallow activity occurred north and south of the Tachira Depression along the eastern flank of the Cordillera Oriental of Colombia. The Boconó Fault Zone is seismically active; small shallow shocks were recorded in it by the local stations. Shallow earthquakes also occur in the Cordillera de Mérida away from the Boconó Fault. The new hypocenters for the intermediate-depth Bucaramanga earthquakes define a smaller source volume than defined by previously computed hypocenters. A previously inferred southward-dipping seismic zone near Bucaramanga is probably spurious, a consequence of correlation between errors in latitude and errors in depth. If one assumes that these intermediate-depth earthquakes lie on a single lithospheric slab, that slab strikes approximately north and dips to the east. The distribution of hypocenters and focal mechanisms support the platetectonic hypothesis that the present tectonics of northwestern Venezuela are a result of eastward motion of the Caribbean plate with respect to the South American plate. The principal interface between these two plates may have changed within the last 5 m.y. from a zone of underthrusting west of the Sierra de Perija to the predominantly right-lateral Boconó Fault Zone.

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Seismicity of the Baffin Bay region

Bulletin of the Seismological Society of America ◽

10.1785/bssa0640010087 ◽

1974 ◽

Vol 64 (1) ◽

pp. 87-98

Author(s):

Anthony Qamar

Keyword(s):

Upper Mantle ◽

Baffin Island ◽

Sea Floor ◽

Baffin Bay ◽

Hypocenter Determination ◽

Joint Hypocenter Determination ◽

Glacial Rebound ◽

Sea Floor Spreading ◽

Linear Trends ◽

Northeast Coast

abstract Twenty-eight earthquakes in the Baffin Bay region have been relocated using the method of Joint Hypocenter Determination. The revised locations indicate two parallel, linear trends, one along the northeast coast of Baffin Island and the other in the western part of Baffin Bay. The seismicity does not appear to be controlled by glacial rebound but may be a remnant of sea-floor spreading which occurred 40 to 60 m.y. ago. Early P arrivals at near seismograph stations (Δ < 20°) can be explained by a high-velocity (8.5 km/sec) upper mantle in the Baffin region.

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Seismicity of the Middle America arc-trench system near Managua, Nicaragua

Bulletin of the Seismological Society of America ◽

10.1785/bssa0640041033 ◽

1974 ◽

Vol 64 (4) ◽

pp. 1033-1048 ◽

Cited By ~ 5

Author(s):

James W. Dewey ◽

S. T. Algermissen

Keyword(s):

Surface Expression ◽

Benioff Zone ◽

Hypocenter Determination ◽

Joint Hypocenter Determination ◽

Volcanic Chain ◽

Middle America ◽

Master Event ◽

Shallow Focus ◽

Principal Chain ◽

East West

Abstract Hypocenters of earthquakes occurring during the period 1950 through 1972 in the Middle America arc-trench system near Managua, Nicaragua, have been relocated by the method of joint hypocenter determination (JHD) or the master event method with the Managua earthquake of December 23, 1972 as the calibration event. The relocated hypocenters show a considerably narrower Benioff zone than previous hypocenters of the same earthquakes and clearly separate shallow-focus volcanic terrane earthquakes of the type which struck Managua from the Benioff zone earthquakes. The shallow-focus volcanic terrane earthquakes are probably caused by tectonic conditions associated with the formation of the Nicaraguan depression or the principal chain of Quaternary volcanoes. The Managua earthquake of December 23, 1972 may have occurred as a consequence of slippage along a transform fault zone which connects offset segments of the chain of Quaternary volcanoes; the volcanic chain is then taken to be the surface expression of a secondary spreading zone which lies above the Benioff zone of the Middle America arc-trench system. Alternatively, the recent Managua earthquake may have occurred as a consequence of regional east-west tension in the Nicaraguan depression.

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Aysén seismic swarm (January 2007) in southern Chile: analysis using Joint Hypocenter Determination

Journal of Seismology ◽

10.1007/s10950-010-9190-y ◽

2010 ◽

Vol 14 (4) ◽

pp. 683-691 ◽

Cited By ~ 13

Author(s):

Cindy Mora ◽

Diana Comte ◽

Ray Russo ◽

Alejandro Gallego ◽

Victor Mocanu

Keyword(s):

Southern Chile ◽

Hypocenter Determination ◽

Seismic Swarm ◽

Joint Hypocenter Determination

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Earthquake relocations, fault zone geometry and constraints on lateral velocity variations using the joint hypocenter determination method in the Taiwan area

Earth Planets and Space ◽

10.1186/bf03351860 ◽

2005 ◽

Vol 57 (9) ◽

pp. 809-823 ◽

Cited By ~ 3

Author(s):

Kwang-Hee Kim ◽

Jer-Ming Chiu ◽

Jose Pujol ◽

Kou-Cheng Chen

Keyword(s):

Fault Zone ◽

Determination Method ◽

Lateral Velocity ◽

Hypocenter Determination ◽

Joint Hypocenter Determination ◽

Velocity Variations ◽

Taiwan Area

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Earthquake Relocation Using Double Difference Method for 2D Modelling of Subducting Slab and Back Arc Thrust in West Nusa Tenggara

Jurnal Penelitian Fisika dan Aplikasinya (JPFA) ◽

10.26740/jpfa.v8n2.p132-143 ◽

2018 ◽

Vol 8 (2) ◽

pp. 132

Author(s):

Rian Mahendra Taruna ◽

Vrieslend Haris Banyunegoro

Keyword(s):

Difference Method ◽

Strong Motion ◽

Seismic Hazard Assessment ◽

Source Zone ◽

Double Difference ◽

Earthquake Relocation ◽

Hypocenter Determination ◽

2D Modelling ◽

Earthquake Sources ◽

Back Arc

West Nusa Tenggara is classified into earthquake prone zone as it is located between subduction and back arc thrust earthquake sources. Accurate hypocenter determination in this area is necessary for strong motion calculation and earthquake source zone modelling. Earthquake relocation in the region is needed to produce a more accurate hypocenter location and 2D modelling of subduction slab and back arc thrust. A double difference method was employed with earthquake data from 2009-2017. The results show better accuracy in the distribution of the travel-time residual. Subduction slab modelling shows a dip value of about 7-13° from a trench to an arc, 49-55° from an arc to a transition zone, and 60-64° dip at a depth of 300 km. Back arc thrust modelling shows a dip value of about 19-28° at a depth of 15-30 km. The results provide a reliable 2D model for subduction slab and back arc thrust in West Nusa Tenggara. Therefore, the developed models can be used as reference for earthquake zones and seismic hazard assessment in West Nusa Tenggara.

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