Omar Flores

University of San Carlos of Guatemala

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Charles DeMets

University of Wisconsin–Madison

Beatriz Cosenza Muralles

University of Wisconsin–Madison

Basil Tikoff

University of Wisconsin–Madison

N. E. Lord

University of Wisconsin–Madison

Andria P. Ellis

United States Geological Survey

Bridget Garnier

University of Wisconsin–Madison

Enrique Molina

Universidad Mariano Galvez

Walter Hernández

Ministry of Health

C. Lasserre

Université Claude Bernard Lyon 1

H. Lyon‐Caen

Laboratoire de Physique de l'ENS

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University of Wisconsin–Madison

Ministerio de Medio Ambiente y Recursos Naturales

Ministry of Health

Universidad Politécnica de Madrid

Centre National de la Recherche Scientifique

University of Minnesota

Stanford University

Universidad de Costa Rica

Universidad Nacional Autónoma de México

Laboratoire de Physique de l'ENS

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Deformation in western Guatemala associated with the NAFCA (North America-Forearc-Caribbean) triple junction: Neotectonic strain localization into the Guatemala City graben

Bridget Garnier Basil Tikoff Omar Flores Brian R. Jicha Charles DeMets

Earth and Space Science Open Archive This preprint has been submitted to and is under consideration at Tectonics. ESSOAr is a venue for early communication or feedback before peer review. Data may be preliminary.Learn more about preprints preprintOpen AccessYou are viewing the latest version by default [v1]Deformation in western Guatemala associated with the NAFCA (North America-Forearc-Caribbean) triple junction: Neotectonic strain localization into the Guatemala City grabenAuthorsBridgetGarnieriDBasilTikoffOmarFloresBrian R.JichaCharlesDemetsBeatrizCosenza MurallesiDWalterHernándezDavid C.GreeneiDSee all authors Bridget GarnieriDCorresponding Author• Submitting AuthorUniversity of Wisconsin-MadisoniDhttps://orcid.org/0000-0001-9622-8269view email addressThe email was not providedcopy email addressBasil TikoffUniversity of Wisconsin-Madisonview email addressThe email was not providedcopy email addressOmar FloresUSACview email addressThe email was not providedcopy email addressBrian R. JichaDepartment of Geoscience, University of Wisconsin-Madisonview email addressThe email was not providedcopy email addressCharles DemetsUniversity of Wisconsin-Madisonview email addressThe email was not providedcopy email addressBeatriz Cosenza MurallesiDUniversity of Wisconsin-MadisonInstituto de Investigación en Ciencias Físicas y Matemáticas, Universidad de San Carlos de GuatemalaiDhttps://orcid.org/0000-0002-4626-2757view email addressThe email was not providedcopy email addressWalter HernándezObservatorio Ambiental, Ministerio de Medio Ambiente y Recursos Naturales (MARN)view email addressThe email was not providedcopy email addressDavid C. GreeneiDDenison UniversityiDhttps://orcid.org/0000-0002-6384-9752view email addressThe email was not providedcopy email address

Forearc

10.1002/essoar.10506010.1

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Geodetic slip solutions for the Mw = 7.4 Champerico (Guatemala) earthquake of 2012 November 7 and its postseismic deformation

Geophysical Journal International (2015)

Andria P. Ellis Charles DeMets Pierre Briole Enrique Molina Omar Flores

As the first large subduction thrust earthquake off the coast of western Guatemala in the past several decades, the 2012 November 7 Mw = 7.4 earthquake offers the first opportunity to study coseismic and postseismic behaviour along a segment of the Middle America trench where frictional coupling makes a transition from weak coupling off the coast of El Salvador to strong coupling in southern Mexico. We use measurements at 19 continuous GPS sites in Guatemala, El Salvador and Mexico to estimate the coseismic slip and postseismic deformation of the November 2012 Champerico (Guatemala) earthquake. An inversion of the coseismic offsets, which range up to ∼47 mm at the surface near the epicentre, indicates that up to ∼2 m of coseismic slip occurred on a ∼30 × 30 km rupture area between ∼10 and 30 km depth, which is near the global CMT centroid. The geodetic moment of 13 × 1019 N m and corresponding magnitude of 7.4 both agree well with independent seismological estimates. Transient postseismic deformation that was recorded at 11 GPS sites is attributable to a combination of fault afterslip and viscoelastic flow in the lower crust and/or mantle. Modelling of the viscoelastic deformation suggests that it constituted no more than ∼30 per cent of the short-term postseismic deformation. GPS observations that extend six months after the earthquake are well fit by a model in which most afterslip occurred at the same depth or directly downdip from the rupture zone and released energy equivalent to no more than ∼20 per cent of the coseismic moment. An independent seismological slip solution that features more highly concentrated coseismic slip than our own fits the GPS offsets well if its slip centroid is translated ∼50 km to the west to a position close to our slip centroid. The geodetic and seismologic slip solutions thus suggest bounds of 2–7 m for the peak slip along a region of the interface no larger than 30 × 30 km.

Moment magnitude scale

Epicenter

Seismic moment

Tsunami earthquake

Thrust fault

10.1093/gji/ggu484

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Citations (7)

MEASURING OFFSETS OF THE MOTAGUA FAULT USING LIDAR DRONE SURVEYING NEAR RIO EL TAMBOR, GUATEMALA

Abstracts with programs - Geological Society of America (2023)

Jarely Mendez Kenny Alvarez Luciano Lopez Leon Tina M. Niemi Omar Flores

Drone

10.1130/abs/2023am-392274

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An integrated structural and GPS study of the Jalpatagua fault, southeastern Guatemala

Geosphere (2020)

Bridget Garnier Basil Tikoff Omar Flores Brian R. Jicha Charles DeMets

Abstract The Jalpatagua fault in Guatemala accommodates dextral movement of the Central America forearc. We present new global positioning system (GPS) data, minor fault analysis, geochronological analyses, and analysis of lineaments to characterize deformation along the fault and near its terminations. Our data indicate that the Jalpatagua fault terminates at both ends into extensional regions. The western termination occurs near the Amatitlan caldera and the southern extension of the Guatemala City graben, as no through-going structures were observed to continue west into the active volcanic arc. Along the Jalpatagua fault, new and updated GPS site velocities are consistent with a slip rate of 7.1 ± 1.8 mm yr−1. Minor faulting along the central section of the fault includes: (1) N-S–striking normal faults accommodating E-W elongation; and (2) four sets of strike-slip faults (oriented 330°, 020°, 055°, and 295°, parallel to the Jalpatagua fault trace). Minor fault arrays support dextral movement along a major fault in the orientation of the Jalpatagua fault. GPS and fault data indicate that the Jalpatagua fault terminates to the east near the Guatemala–El Salvador border. Data delineate a pull-apart basin southeast of the fault termination, which is undergoing transtension as the Jalpatagua fault transitions into the El Salvador fault system to the east. Within the basin, minor faulting and lineations trend to the NW and accommodate NE-directed elongation. This faulting differs from E-W elongation observed along the Jalpatagua fault and is more similar to minor faults within the El Salvador fault system.

Transtension

Lineament

Transform fault

10.1130/ges02243.1

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Citations (10)

Deformation in Western Guatemala Associated With the NAFCA (North America‐Central American Forearc‐Caribbean) Triple Junction: Neotectonic Strain Localization Into the Guatemala City Graben

Tectonics (2022)

Bridget Garnier Basil Tikoff Omar Flores Brian R. Jicha Charles DeMets

Abstract Recent structural and geodetic data define the Guatemala City graben region as the continental triple junction between the North American plate, Caribbean plate, and the Central American Forearc sliver. We present minor fault analysis, geochronological and geochemical analyses, and newly updated GPS velocities in western Guatemala, west of the Guatemala City graben, to characterize the magnitude and timing of extensional deformation in this poorly understood area. Elongations estimated from fault data are parallel (∼east‐west) and perpendicular to the Polochic‐Motagua fault system to the north, similar to geodetically measured active deformation observed east of the Guatemala City graben. Four new 40 Ar/ 39 Ar dates and correlation of tephra deposits suggest that faulting was active during the Pliocene, but ceased eastward toward the Guatemala City graben over time. From west to east, fault cessation occurred before the deposition of the Los Chocoyos ash (75 ka) and E tephra (51 ka). Faulting just west of the Guatemala City graben appears to be active, where a major fault cuts the most recent Amatitlán tephras. Based on this data, we propose a time‐progressive strain model for deformation related to North America‐Caribbean plate interactions, whereby distributed elongation of the westernmost Caribbean plate occurred during the Pliocene but localized mostly within the Guatemala City graben and nearby faults during the Pleistocene. Our model supports that: (a) The Guatemala City graben is effectively the western limit of the Caribbean plate; and (b) Western Guatemala, which was the trailing edge of the Caribbean plate, has been transferred to the forearc region.

Forearc

Triple junction

North American Plate

African Plate

Extensional tectonics

Transform fault

10.1029/2021tc006739

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Citations (7)

Seismicity in Central America (1520–2020) and Earthquake catalog compilation for seismic hazard assessments

Bulletin of Earthquake Engineering (2024)

Carlos Gamboa-Canté Mario Arroyo-Solórzano B. Benito J. P. Aguilar Ivonne G. Arroyo

10.1007/s10518-024-02059-9

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GPS constraints on deformation in northern Central America from 1999 to 2017, Part 2: Block rotations and fault slip rates, fault locking and distributed deformation

Geophysical Journal International (2019)

Andria P. Ellis Charles DeMets Robert J. McCaffrey Pierre Briole Beatriz Cosenza Muralles

We describe a new elastic-kinematic model for the present tectonics of northern Central America and southern Mexico, where the Motagua-Polochic fault zone, Middle America subduction zone and faults in the Central America volcanic arc pose significant seismic hazards. The new model, which consists of the angular velocities for eight plates and blocks, interseismic locking solutions for some of the block-bounding faults and strain-rate tensors for three blocks with significant internal deformation, optimizes the fit to regional fault azimuths and earthquake slip directions and a new 200+ station GPS velocity field that has been corrected for the coseismic and post-seismic effects of three large regional earthquakes in 2009 and 2012. From our new observations and modelling thereof, we find evidence for the following: (1) 13±1 mm yr−1 of ≈E-W stretching between undeformed Caribbean plate in central Honduras and a location ≈50 km west of the Guatemala City graben; (2) accommodation of the above extension via slow W-to-WNW motions of newly defined Chortis and Ipala blocks and distributed ENE-WSW stretching within both blocks; (3) 80 per cent of Chortis-North America plate motion in eastern Guatemala occurs on the Motagua fault versus only 20 per cent on the Polochic fault; (4) Motagua fault slip rates that decrease westwards from 14 ± 1.5 mm yr−1 to 9–10 ± 2 mm yr−1 to less than 2 mm yr−1 in eastern Guatemala, central Guatemala and west of the Guatemala City graben, respectively; (5) Slip rates along Central America volcanic arc faults that decrease from 12.5 ± 1.0 mm yr−1 in Nicaragua to 10 ± 1.3 mm yr−1 in central El Salvador to 7.6 ± 2.1 mm yr−1 on the Jalpatagua fault of southern Guatemala to 2-3 mm yr−1 or less across the volcanic arc west of Guatemala City; (6) a transition near the Mexico–Guatemala border from moderate-to-high locking of the subduction interface offshore from southern Mexico to low locking below the Central America forearc sliver; (7) Subduction of the Cocos plate beneath the Central America forearc sliver up to 10 mm yr−1 faster than and 7–8° clockwise from all previous estimates; (8) 12 ± 6 mm yr−1 of E–W extension across the newly defined Fonseca block. A pattern of misfits to the velocities of sites in northern Guatemala and southern Mexico may be caused by distributed deformation in this region or shortcomings with our model and/or assumptions. The primary factors that control the regional deformation appear to include the arcuate geometry of the Motagua fault, low locking of the Middle America subduction interface, slow-to-no motion between the leading edge of the Central America forearc sliver and North America plate and a rheologically weak volcanic arc.

Block model

Earthquake rupture

10.1093/gji/ggz173

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Citations (26)

Planning for the Lake Izabal Basin Research Endeavor (LIBRE) continental scientific drilling project in eastern Guatemala

Scientific Drilling (2023)

Jonathan Obrist‐Farner Andreas Eckert Peter Douglas Liseth Pérez Alexander Correa‐Metrio

Abstract. As Earth's atmospheric temperatures and human populations increase, more people are becoming vulnerable to natural and human-induced disasters. This is particularly true in Central America, where the growing human population is experiencing climate extremes (droughts and floods), and the region is susceptible to geological hazards, such as earthquakes and volcanic eruptions, and environmental deterioration in many forms (soil erosion, lake eutrophication, heavy metal contamination, etc.). Instrumental and historical data from the region are insufficient to understand and document past hazards, a necessary first step for mitigating future risks. Long, continuous, well-resolved geological records can, however, provide a window into past climate and environmental changes that can be used to better predict future conditions in the region. The Lake Izabal Basin (LIB), in eastern Guatemala, contains the longest known continental records of tectonics, climate, and environmental change in the northern Neotropics. The basin is a pull-apart depression that developed along the North American and Caribbean plate boundary ∼ 12 Myr ago and contains > 4 km of sediment. The sedimentological archive in the LIB records the interplay among several Earth System processes. Consequently, exploration of sediments in the basin can provide key information concerning: (1) tectonic deformation and earthquake history along the plate boundary; (2) the timing and causes of volcanism from the Central American Volcanic Arc; and (3) hydroclimatic, ecologic, and geomicrobiological responses to different climate and environmental states. To evaluate the LIB as a potential site for scientific drilling, 65 scientists from 13 countries and 33 institutions met in Antigua, Guatemala, in August 2022 under the auspices of the International Continental Scientific Drilling Program (ICDP) and the US National Science Foundation (NSF). Several working groups developed scientific questions and overarching hypotheses that could be addressed by drilling the LIB and identified optimal coring sites and instrumentation needed to achieve the project goals. The group also discussed logistical challenges and outreach opportunities. The project is not only an outstanding opportunity to improve our scientific understanding of seismotectonic, volcanic, paleoclimatic, paleoecologic, and paleobiologic processes that operate in the tropics of Central America, but it is also an opportunity to improve understanding of multiple geological hazards and communicate that knowledge to help increase the resilience of at-risk Central American communities.

Geologic record

Environmental change

10.5194/sd-32-85-2023

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Citations (1)

GPS constraints on deformation in northern Central America from 1999 to 2017, Part 1 – Time-dependent modelling of large regional earthquakes and their post-seismic effects

Geophysical Journal International (2018)

Andria P. Ellis Charles DeMets Pierre Briole Beatriz Cosenza Omar Flores

We use continuous and campaign measurements from 215 GPS sites in northern Central America and southern Mexico to estimate coseismic and afterslip solutions for the 2009 Mw = 7.3 Swan Islands fault strike-slip earthquake and the 2012 Mw = 7.3 El Salvador and Mw = 7.4 Guatemala thrust-faulting earthquakes on the Middle America trench. Our simultaneous, time-dependent inversion of more than 350 000 daily GPS site positions gives the first jointly consistent estimates of the coseismic slips for all three earthquakes, their combined time-dependent post-seismic effects and secular station velocities corrected for both the coseismic and post-seismic deformation. Our geodetic slip solutions for all three earthquakes agree with previous estimates that were derived via static coseismic-offset modelling. Our time-dependent model, which attributes all transient post-seismic deformation to earthquake afterslip, fits nearly all of the continuous GPS site position time-series within their several-millimetre position noise. Afterslip moments for the three earthquakes range from 35 to 140 per cent of the geodetic coseismic moments, with the largest afterslip estimated for the 2012 El Salvador earthquake along the weakly coupled El Salvador trench segment. Forward modelling of viscoelastic deformation triggered by all three earthquakes for a range of assumed mantle and lower crustal viscosities suggests that it accounts for under 20 per cent of the observed post-seismic deformation and possibly under 10 per cent. Our results thus point to afterslip as the primary and perhaps dominant mode of post-seismic deformation for these three earthquakes. Forward modelling of post-seismic deformation associated with the larger Mw = 7.6 September 2012 Costa Rica thrust earthquake suggests that afterslip, viscoelastic flow, or some combination thereof was responsible for a significant change in motion observed at a GPS site on San Andres Island in the Caribbean Sea more than 500 km from all four earthquakes. The measurable effects of the 2009 and 2012 earthquakes on the motions of GPS sites in nearly all of northern Central America underline the importance of time-dependent calibrations for transient, earthquake-related effects for studies of steady-state deformation processes.

Seismic moment

Moment magnitude scale

10.1093/gji/ggy249

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Citations (19)