The Islas Marias Archipelago is located south of the Gulf of California. This study presents a structural geologic analysis of Maria Madre Island, coupled with a detailed bathymetric survey of the surrounding area. Our goal is to delineate the deformation geometry and identify new morphostructural features in the region. Bedding tilting coincided with normal faulting of the lower member of the Ojo de Buey sequence, likely at the end of the Pliocene or the beginning of the Pleistocene, associated with the early stage of the Gulf of California rifting. Seismic reflection profiles from previous studies indicate that the West Ranges are within a thinned continental crust, structurally controlled by the Maria, Magdalena, and South Magdalena faults. Furthermore, a detailed bathymetric survey and orthoimages from the islands revealed structural lineaments in both oceanic and continental crust. In the continental crust, these lineaments have a preferred orientation between 050 degrees to 090 degrees, similar to the faulting trend on Maria Madre Island. However, they are oblique to those in the oceanic crust and mainland Mexico. We propose that Maria Madre Island may have undergone a 50 degrees clockwise rotation. If we apply a counterclockwise rotation of this magnitude to the faults and lineaments in the continental crust of the archipelago and the region west of it, their preferred orientation becomes parallel to the Tamayo Fracture Zone in the oceanic crust, the San Blas fault within the continental shield and, the Tepic-Zacolaco rift extending eastward into mainland Mexico. This suggests that rotation affected the continental crust, either west of Puerto Vallarta, in the archipelago, or the West Ranges, while the oceanic crust remained relatively unaffected. We propose the term "Islas Marias Block" to designate a fragment of continental crust encompassing the archipelago and the West Ranges, which share a common deformation style.

The oblique convergence between the Caribbean and North American plates produces the tectonic complexity of Hispaniola Island. The western region is characterized by high topography bounded by dominantly reverse and oblique-slip faults along the edges of the uplifted mountain ranges, while the eastern part is lower in elevation and no important active faults are identified. This work analyzes the seismic data (Profiles A and D) obtained during the CARIBE NORTE project (2009) in the frame of the current MICROSIS-I (2020-2021-1A4-043) and GEOCIBAO-RS (2023-1-1A4-0627) projects. A seismic array of vertical and three-component land stations registered both profiles along N-S and W-E seismic transects of 425 and 450 km, respectively. The seismic sources used in these lines corresponded to three marine shooting lines (LM1N, LM1S for Profile A and LM4, for Profile D), land borehole explosions 1 Ton (S1, S2, and S3), and one earthquake that occurred during the registering period.We constrained the seismic structure of the Dominican Republic by the inversion of wide-angle seismic travel-time data for the previous 2D P-wave velocity model of both profiles. The results show marked differences between the western and eastern regions of the island. In the eastern zone, the Moho discontinuity rises to 24 km deep, increasing towards the island's interior with a maximum depth value of approximately 30 km in the west and central part of the transect. A structure dipping 18º towards the eastern interior of Hispaniola Island was identified up to 120 km deep from the analysis and relocation of an earthquake that occurred on April 11, 2009, using the CARIBE NORTE temporary seismic network.

The first morphotectonic model of the Greater Antilles is presented. The model is adjusted to the current dynamics between the Caribbean and North American plates. It is mainly elaborated by Rantsmans methodology. We determined 2 megablocks, 7 macroblocks, 42 mesoblocks, 653 microblocks and 1264 nanoblocks. They constitute a set of active blocks under rotation, uplifting and tilting movements. A total of 11 active knots of faults and 8 cells are the main articulation areas. The largest seismogenetic structures in the Northern Caribbean are an array of the active fault segments. The majority of them are in the Caribbean-North American Plate Boundary Zone, the Hispaniola has the most complex neotectonic structure associated with the central axis of the morphotectonic deformations in the region.

Teaching innovation in Geophysics has driven a significant change in the way Earth Sciences are taught and applied (Lay and Wallace, 1995; Lowrie and Fichtner, 2020), especially in the investigation of the Earth's cortical structure.The Dominican Republic has a complex tectonic and geological situation that generates high seismic activity (Nunez, 2014), which constitutes an excellent natural laboratory for the integration of new educational methodologies essential to train future generations of geophysicists capable of facing these challenges.This paper presents a series of innovative approaches implemented in geophysical training programs, with special attention to the use of advanced technologies in applied mathematical modeling, geophysical data analysis, and 3D interpretation based on the different research projects that for more than 20 years researchers from the Complutense University of Madrid, as well as other Spanish institutions, and public and private institutions in the Dominican Republic have developed.This network involves students applying modern techniques to investigate the cortical structure in different island regions. This hands-on approach allows students to acquire technical knowledge and develop critical skills in solving real problems. In addition, it promotes interdisciplinary collaboration by linking geophysics with areas such as engineering and civil protection, strengthening students' ability to address complex issues, actively preparing them for natural hazard mitigation (Benito, et al., 2010), a fundamental aspect of the resilient and sustainable development of the Dominican Republic.

The crustal structure around the Islas Marías Archipelago has been debated for a long time. An important unresolved question is where the Rivera-North American plate subduction ends and the Tamayo fracture zone begins, from SE to NW. Results from the TsuJal project have shed light on the northwesternmost part of the Jalisco block structure. It is now clear that Sierra de Cleofas and the Islas Marías Escarpment comprise the northwestern continuation of the Middle America trench. However, other questions remain. In this paper, we present the structure of the shallow and deep crust and the upper mantle of the Islas Marías western region through the integration of multichannel seismic reflection, wide-angle seismic bathymetric and seismicity data, including records of an amphibious seismic network, OBS, and portable seismic stations, purposely deployed for this project, providing an onshore-offshore transect of 310 km length. Our findings disclose new evidence of the complex structure of the Rivera plate that dips 8°–9° underneath the NW Jalisco block as revealed by two seismic profiles parallel to the Islas Marías Escarpment. Moreover, we find five sedimentary basins and active normal faults at the edges of tectonic structures of the E-W oriented West Ranges and the N-S trending Sierra de Cleofas. Furthermore, the Sierra de Cleofas is the beginning of the active subduction of the Rivera plate beneath North America. The oceanic crust thickens and submerges towards the south while is coupled with the continental crust, from 6 km at the northern ends of the seismic profiles to 15 km in the contact region and 24 km at the coast and southern ends of them. The continental Moho was not fully characterized because of the geometry of the seismic transects, but a low-velocity layer associated with Rivera Plate subduction was observed beneath the Jalisco Block. Our results constrain the complexity of the area and reveal new structural features from the oceanic to continental crust and will be pivotal to assess geohazards in this area.

The geodynamic complexity in the western Mexican margin is controlled by the multiple interactions between the Rivera, Pacific, Cocos, and North American plates, as evidenced by a high seismicity rate, most of whose hypocenters are poorly located. To mitigate this uncertainty with the aim of improving these hypocentral locations, we undertook the TsuJal Project, a passive seafloor seismic project conducted from April to November 2016. In addition to the Jalisco Seismic Network, 10 LCHEAPO 2000 Ocean Bottom Seismometers (OBSs) were deployed by the BO El Puma in a seafloor array from the Islas Marías Archipelago (Nayarit) to the offshore contact between the states of Colima and Michoacan. We located 445 earthquakes in four or more OBSs within the deployed array. Most of these earthquakes occurred in the contact region of the Rivera, Pacific, and Cocos plates, and a first analysis suggests the existence of three seismogenic zones (West, Center, and East) along the Rivera Transform fault that can be correlated with its morphological expression throughout the three seismogenic zones. The seismicity estimates that the Moho discontinuity is located at 10 km depth and supports earlier works regarding the West zone earthquake distribution. Subcrustal seismicity in the Central zone suggests that the Intra-Transform Spreading Basin domain is an ultra-low spreading ridge. A seismic swarm occurred during May and June 2016 between the eastern tip of the Paleo-Rivera Transform fault and the northern tip of the East Pacific Rise-Pacific Cocos Segment, illuminating some unidentified tectonic feature.

The geodynamic complexity in the interaction between Rivera, Cocos and NOAM plates is mainly reflected in the high and not well located seismicity of the region. In the framework of TsuJal Project, a study of the passive seismic activity was carried out. A temporal seismic network with 25 Obsidian stations with sensor Le-3D MkIII were deploying from the northern part of Nayarit state to the south of Colima state, including the Marias Islands, in addition to the Jalisco telemetric Seismic Network, being a total of 50 seismic stations on land. Offshore, ten Ocean Bottom Seismographs type LCHEAPO 2000 with 4 channels (3 seismic short period and 1 pressure sensors) were deployed and recover by the BO El Puma from UNAM in an array from the Marias Islands to off coast of the border of Colima and Michoacan state, in the period from 19th April to 7th November 2016. A seismic sequence started on May 7, 2016 with an earthquake Mw = 5.6 reported by CMT-Harvard, USGS and SSN at the area north of Paleo Rivera Transform fault and west of the Middle America Trench, an area with a very complex tectonics due to the interaction of Rivera, Cocos and NOAM plates. An analysis of this earthquake sequence from May 7 to May 11 using data from OBS and adequate P-Wave velocity model for Rivera plate is presented, 87 earthquakes were located. Data from onland stations were integrated after a travel-time residual analysis. We observed that the new location is about 50 km southwest direction, from previous one, between the Paleo Rivera Transform fault and the northern tip of the East Pacific Rise – Pacific Cocos Segment. This area has a different tectonic stress regime.

Mexico es una Region Sismotectonica activa, mayoritariamente en la placa continental de Norteamerica y tiene los 2 tipos de sismicidad (entreplacas y de interior de placa). La estructura jerarquica contiene 3 Provincias Sismotectonicas (Norte-Occidental, Occidental y Centro-Oriental), en ellas hay 11 Unidades Sismotectonicas y en estas se localizan las zonas sismogeneticas. Estas ultimas estan segmentadas. La Provincia Occidental es la de mas nivel y donde se encuentra el contacto de las placas convergentes.

Structural and tectonic features in the Pacific Coast of Mexico generate a high level of seismic activity in the Jalisco block (JB) region, making it one of the most attractive areas of the world for geophysical investigations. The Rivera-North America contact zone has been the object of different tectonic studies in recent years framed within the TsuJal project. To this day, this project is generating numerous crucial geophysical results, which significantly improve our understanding of the region. Our study is focused on the interaction between the south of the JB and Rivera plate (RP), which crosses the Middle America trench. We also cover an offshore-onshore transect of 130 km length between the eastern Rivera fracture zone and La Huerta region, in the Jalisco state. To characterize this region, we interpreted wide-angle seismic, multichannel seismic, and multibeam bathymetry data. The integration of these results, with the local and regional seismicity recorded by the Jalisco Seismic Accelerometric Telemetric Network and by the Mapping the Rivera Subduction Zone experiment, provides new insights into the geometry of the southern RP, which is dipping 12 degrees-14 degrees under the JB in the northeast-southwest direction. Moreover, our results provide new seismic images of the accretionary wedge, the shallow crust, the deep crust, and the upper-mantle structure along this profile.

The TsuJal geophysical survey was conducted during the spring of 2014 with the aim to characterize the crustal structure of western Mexico. This geophysical experiment focused on active geological formations such as subduction, faults, and accretionary prisms, which are related to the seismic and tsunamigenic activity. In this work, we used seismic and bathymetric data to characterize the interaction between the Rivera plate (RP) and the North America plate south of Maria Cleofas Island. By defining the structural trends and subsurface geology, we sought to understand the complexity of the tectonic framework of western Mexico. A migrated seismic section and bathymetric maps were generated via the acquisition and processing of TsuJal geophysical data. Bathymetric data show major seafloor structures related to two basins (Tres Marias and TsuJal), one canyon (Cocodrilo Canyon), and an uplift structure with a north-south trend (Sierra de Cleofas [SC]). Seismic data reveal a compressional regime related to the movement of the RP at the westernmost end of the seismic section and lack of deformation in sediments within the two basins found adjacent to SC. From the results of our data analysis as well as corroborating literature, we interpret an underthrusting of RP beneath the North America plate, causing a compressional tectonic regime with the formation of palm-tree structures. The lack of deformation may be associated with a heated oceanic plate that facilitates the relative motion of the basement below the sediments.

México es una Región Sismotectónica activa, mayoritariamente en la placa continental de Norteamérica y tiene los 2 tipos de sismicidad (entreplacas y de interior de placa). La estructura jerárquica contiene 3 Provincias Sismotectónicas (Norte-Occidental, Occidental y Centro-Oriental), en ellas hay 11 Unidades Sismotectónicas y en éstas se localizan las zonas sismogenéticas. Estas últimas están segmentadas. La Provincia Occidental es la de más nivel y donde se encuentra el contacto de las placas convergentes.

Mexico is an active seismotectonic region mainly sitting on the continental plate of North America and has two types of seismicity: interplate and interior plate. The hierarchical structure embraces 3 seismotectonic provinces (north-western, western and central-eastern), comprised of 11 seismotectonic units wherein seismogenetic zones are located. The latter are segmented. The western province shows the highest level of seismicity and is the area where convergent plates make contact.

The contact between the Caribbean and North American plates is a tectonically complicated boundary where the deformation is accommodated in north and south of Hispaniola by the Enriquillo Plantain Garden and Septentrional Oriente Fault Zones. We present a crustal and tectonic study of the Northeastern Caribbean Plate Boundary from wide-angle seismic data acquired during the GEOPRICO-DO and CARIBE NORTE surveys, showing two transects crossing, from north to south, North American Plate, Bahamas Platform, central Hispaniola and Caribbean Plate. The results presented include two 2D P wave velocity models of 425 km and 200 km long oriented NNE SSW and ENE SSW, respectively, obtained by the travel time forward and inverse modeling of the WAS data. Our study defines that the contact between Bahamas Platform, North American Plate and Hispaniola corresponds to oblique subduction with the Moho dipping 11 in the NNE SSW direction. Furthermore, in the south, our results reveal the existence of an anomalous deep-reaching zone of lateral velocity variation in the mantle that could be associated with EPGFZ and a possible detached oceanic slab from NOAM that could explain the deep seismicity in the region.

La aplicación del método morfotectónico de Rantsman al territorio de Cantabria muestra su estructura contemporánea como parte de un macrobloque emergido y activo en la Península Ibérica. En este macrobloque Septentrional se delimitaron 2 mesobloques (Este y Oeste), con un total de 13 bloques, 10 morfoalineamientos de 2º- 4º órdenes y 10 intersecciones principales (orden / cantidad= 2º / 1, 3º / 4, y 4º / 5). El territorio tiene una manifiesta diferencia neotectónica con las regiones vecinas de Asturias y País Vasco, con independencia de su localización. Sus características indican una menor actividad, ante la influencia de los esfuerzos desde los Pirineos, el Cantábrico y el Atlántico. Existe una correspondencia directa entre el relieve y la estructura profunda, y con la sismicidad.

The occurrence of 130 earthquakes (2007-2017) in the intraplate zone of the Iberian Peninsula validates the morphotectonic regionalization of the province of Guadalajara in 2004. These earthquakes were located in three blocks (BG6, BG7, and BG8) of the eastern-most mesoblock (6.3) included in the intermediate macroblock.

Stress transfer from the subduction zone in the Pacific towards the continental interior has determined the current configuration of the morphotectonic rim for the Mexican environment. This process produced two transverse deformed zones, Puerto Vallarta and Tehuantepec. By using the Rantsman methodology, we found the same morphostructural and morphotectonic pattern with certain changes in Puerto Vallarta. We determined 6 blocks, 29 micro blocks, 6 main lineaments and 4 main intersections of lineaments. These elements are in correspondence with the zones with most significant activity and neotectonic deformation (similar to 38000 km(2)), with a NW-SE main axis. We used the same technique for the Oaxaca region - adjacent to Tehuantepec, where 8 blocks, 25 micro blocks, 8 main lineaments and 14 major intersections of lineaments were identified. This set delimits a deformation zone (similar to 40000 km(2)) with an E-W main axis. The analysis of seismicity, focal mechanisms, main active faults, fractures, lineaments, volcanic bodies and speed of plates convergence with the obtained models allows considering a rotation movement linked to Rivera microplate in Puerto Vallarta, while in Oaxaca there is a direct convergence of Cocos Plate - where there is no rotation.