Source study of the 28 January 2020 (MW 7.7) and 8 February 2025 (MW 7.6) North
Caribbean margin earthquakes
Estudio de los terremotos ocurridos del 28 de enero de 2020 (MW 7.7) y 8 de febrero de 2025
(MW 7.6) en el margen norte del Caribe
Quetzalcoatl Rodríguez-Pérez1,2,*
, F. Ramón Zúñiga2
1 Secretaría de Ciencias, Humanidades, Tecnología e Innovación (SECIHTI). Avenida Insurgentes Sur 1582, Crédito Constructor, Benito Juárez, 03940, CDMX, México.
2 Instituto de Geociencias, Universidad Nacional Autónoma de México. Blv. Juriquilla 3001, Juriquilla, 76230, Querétaro, México.
*Corresponding author: (Q. Rodríguez‑Pérez) This email address is being protected from spambots. You need JavaScript enabled to view it.
How to cite this article:
Rodríguez‑Pérez, Q., & Zúñiga, F. R. (2026). Source study of the 28 January 2020 (MW 7.7) and 8 February 2025 (MW 7.6) North Caribbean margin earthquakes: Boletín de la Sociedad Geológica Mexicana, 78(2), A160126. https://doi.org/10.18268/BSGM2026v78n2A160126
Manuscript received: June 29, 2025. Corrected manuscript received: October 22, 2025. Manuscript accepted: October 24, 2025
ABSTRACT
We studied the source characteristics of the 28 January 2020 (MW = 7.7) and 8 February 2025 (MW = 7.6) North Caribbean margin earthquakes. We employed two distinct methodologies to characterize the seismic source: spectral analysis and finite‑fault slip inversion. Our results suggest that the analyzed events have a regular nature in terms of apparent stress, stress drop, and radiated seismic energy. The obtained apparent stresses combined with the reported centroid time shift observations indicate that the studied earthquakes can be classified as regular events compared to other oceanic transform fault earthquakes that have been identified as slow earthquakes. Finite‑fault slip distributions exhibit complex slip patterns with very large rupture lengths, resulting in maximum displacements of 18.49 and 14.80 m for the 2020 and 2025 events, respectively. The 2020 event shows an almost unilateral rupture propagation with a rupture velocity of 2.9 km/s, while the 2025 event describes a bilateral rupture propagation with a rupture velocity of 2.5 km/s.
Keywords: finite-fault mod- els, seismic source parame- ters, Caribbean, strike-slip earthquakes.
RESUMEN
Estudiamos las características de la fuente sísmica de los terremotos del margen norte de la placa del Caribe del 28 de enero de 2020 (MW = 7.7) y del 8 de febrero de 2025 (MW = 7.6). Empleamos dos metodologías distintas para caracterizar la fuente sísmica: análisis espectral e inversión de deslizamiento de falla finita. Nuestros resultados sugieren que los eventos analizados tienen una naturaleza regular en términos de esfuerzo aparente, caída de esfuerzo y energía sísmica radiada. Los esfuerzos aparentes obtenidos, combinados con las observaciones de desfase temporal del centroide, indican que los terremotos estudiados pueden clasificarse como eventos regulares en comparación con otros terremotos de falla transformante oceánica que han sido identificados como sismos lentos. Las distribuciones de deslizamiento de falla finita exhiben patrones de deslizamiento complejos con longitudes de ruptura muy grandes, lo que resulta en desplazamientos máximos de 18.49 y 14.80 m para los eventos de 2020 y 2025, respectivamente. El evento de 2020 muestra una propagación de ruptura casi unilateral con una velocidad de ruptura de 2.9 km/s, mientras que el evento de 2025 describe una propagación de ruptura bilateral con una velocidad de ruptura de 2.5 km/s.
Palabras clave: modelos de falla finita, parámetros de la fuente sísmica, Caribe, sismos laterales.
1. Introducción
The plate boundaries that comprise transform faults exhibit particular slip characteristics (Abercrombie and Ekström, 2001; Pérez‑Campos et al., 2003a). Previous studies suggested that oceanic earthquakes present slow rupture due to weak seismic radiation at high frequencies. On the contrary, others suggested that transform fault earthquakes show high apparent stress, indicating intense high‑frequency radiation (Choy and Boatwright, 1995; Choy and McGarr, 2002). Pérez‑Campos et al. (2003a) reported the existence of both ordinary and slow earthquakes on adjacent sections of the same transform. Abercrombie and Ekström (2003) concluded that anomalous (or slow) earthquakes are not so common in oceanic transform environments. According to De Melo et al. (2025), most oceanic strike‐slip events show unilateral rupture behavior, while a few larger earthquakes exhibit a complex rupture. Additionally, earthquakes in oceanic transforms exhibit longer rupture lengths than those of events with equal magnitudes in continental environments (Rodríguez‑Pérez and Ottemöller, 2014; De Melo et al., 2025). The northern margin of the Caribbean plate is a tectonically complex region where large strike‑slip events (MW > 7.0) occur regularly. In this region, the North American (NA) and the Caribbean (CA) plates interact, ranging from transcurrent to subduction margins. Several geological structures are present in the zone. Among them, we have 1) the Oriente Fault (OF), 2) the Swan Fault (SF), 3) the Cayman spreading center (CSC), and 4) the Yucatan Basin (YB) (Figure 1). The YB is located on the North American Plate and covers 110,000 km2 (Rosencrantz, 1990; Ramos and Mann, 2023). The OF defines a segment of the NA and the CA plate boundary along which strike‑ slip deformation dominates (Moreno et al., 2002). The SF is a sinistral transform fault extending from the CSC to the Motagua‑Polochic fault zone in Central America. Here, the relative motion is about 18‑20 mm/yr (DeMets et al., 2010) (Figure 1). The Swan Islands experienced a series of three events: the 28 May 2009 (MW 7.3), the 10 January 2018 (MW 7.5), and the 2 February 2025 (MW 7.6). The 2009 earthquake occurred along a 250 km rupture segment that generated a coseismic slip of 1 m (Graham et al., 2012). For its part, Cheng and Wang (2020) studied the rupture process of the 2018 event, reporting three subevents, the fastest with a rupture velocity of 5 km/s, indicating supershear rupture. On the other hand, in the OF, the recent event was in 2020 (MW 7.7) (Table 1). The 2020 event was studied by Tadapansawut et al. (2021) and Calais et al. (2025); they found that the earthquake has a complex source, suggesting a supershear rupture. In this article, we studied the source characteristics of the latest large oceanic transform fault earthquakes (MW > 7.6) at the North Caribbean margin. For this purpose, we determined slip distributions based on teleseismic data and seismic source parameters based on finite-fault and spectral estimations. Our results will be useful in understanding the rupture process of large transform earthquakes in the Caribbean region.
2. Data
For calculating spectral source parameters, we used seismograms recorded at regional distances (223 < R < 1022 km) compiled by the IRIS DMC (2013) (Natural Resources Canada, 1975; Cayman Islands; GEOFON Data Centre, 1993; Haitian; Instituto Nicaraguense de Estudios Territoriales (INETER), 1975; Pulliam, J., 2013; Servicio Nacional de Estudios Territoriales de El Salvador; National Centre for Seismological Research (Cuba), 1998). Additionally, we used three‑component broadband teleseismic records to determine slip distributions. In this case, the selected seismograms were from stations ranging from 30° to 90° to minimize complications due to upper mantle structure and core effects (Northern California Earthquake Data Center, 2014; Natural Resources Canada, 1975; GEOFON Data Centre, 1993; Institut de Physique du Globe de Paris (IPGP) and École et Observatoire des Sciences de la Terre de Strasbourg (EOST), 1982; Albuquerque Seismological Laboratory USGS, 1988; EarthScope Consortium, 1986; Albuquerque Seismological Laboratory USGS, 1993; International Miscellaneous Stations, 1965; California Institute of Technology and United States Geological Survey Pasadena,1926). We also used teleseismic radiated seismic energy estimations derived in the frequency band of 0.5‑70 s from vertical‑component seismograms recorded in the distance (Δ) interval of 25º-80º reported by the Earthscope consortium (IRIS DMC, 2013; Hutko et al., 2017) to quantify the energy‑to‑moment ratio and the apparent stress.
3. Methods
In our analysis, we characterize seismic sources using two distinct methodologies: 1) spectral analysis and 2) finite-fault slip inversion. Spectral analysis was conducted at regional distances, while finite-fault slip inversion was conducted at teleseismic distances. The former methodology provides the following source parameters: moment magnitude (MW), seismic moment (M0), corner frequency (fC), fault radius (r), stress drop (Δσ), apparent stress (τa), energy‑to‑moment ratio(ER/M0), and radiated seismic energy (ER). By using the latter methodology, we obtained the following information: rupture velocity (Vr), fault dimensions (length, L; width, W; and area, A), MW, M0, average and maximum displacements from slip distributions (Dmean and Dmax, respectively). The teleseismic estimate of τa, ER/M0, and Δσ can be calculated indirectly with the finite-fault slip inversion output parameters in combination with teleseismic seismic energy estimates reported by Earthscope. Based on finite-fault results, we also determined effective fault parameters following Mai and Beroza (2000). A brief explanation of the methodologies used is provided in the following sections.
3.1. SPECTRAL SOURCE PARAMETER ESTIMATION
We used the amplitude spectrum of S-wave displacement to determine seismic source parameters recorded at regional distances. In this method, the observed spectrum at a receiver can be expressed as (Brune, 1970)
where G(r) is the geometrical spreading coefficient; r is the hypocentral distance; R_ΘΦ is the radiation pattern coefficient; ρh and ρr are the rock densities at the hypocenter and at the receiver (2700 kg/m3), respectively; ch and cr are the seismic velocities at the hypocenter and the receiver, respectively (3.5 km/s) (Moreno et al., 2002); M0 is the seismic moment; fc is the corner frequency; and t* is a parameter that includes anelastic path attenuation (quality factor) and station-specific effects. Following Boatwright et al. (2002), G(r) is defined as
with
where r0 = 100 km. After correcting the spectra for the geometrical spreading effect, an inversion procedure is applied to determine M0 (MW), fC, and t*. Following the equations by Madariaga (2011), stress drop (Δσ) and quality factor Q0 are computed for each station. Energy estimates are based on the integration of the energy flux, as described by Lancieri et al. (2012). The method is implemented in the software SourceSpec (Satriano, 2022), which was used for this purpose. Results of spectral fitting for the studied events are shown in Figures 2 and 3. Table 2 summarizes the calculated source parameters.
3.2. TELESEISMIC FINITE-FAULT SLIP INVERSION
We used the iterative deconvolution method (Kikuchi and Kanamori, 1982, 1986, 1991) to determine finite-fault slip distributions of the studied earthquakes. This method has been used to study earthquakes in a wide range of magnitudes (MW > 5.5), particularly for large earthquakes (MW > 7.0). Estimates of finite-fault models involve many assumptions and constraints, making it difficult to evaluate the confidence in the models. The input parameters that are well‑constrained are the rupture dimensions, focal mechanisms, and hypocentral locations based on teleseismic data. On the other hand, the poorly constrained parameters include the rupture velocity, duration, and number of subevents. In a trial‑and‑error procedure, we tested rupture velocities in the 2.0‑4.5 km/s range and chose the one resulting in the smallest waveform misfit. The seismic rupture is represented by a sequence of subevents, each specified by a moment tensor, its onset time, and location (Kikuchi and Kanamori, 1991). The number of subevents was also estimated using a trial‑and‑error procedure to minimize waveform misfit. In the inversion scheme, symmetric triangular source time functions are assigned to each subevent with specific durations (Kikuchi and Kanamori, 1991). The number of triangles defined the slip or dislocation duration. We explored many fault models with different subfault durations and triangle combinations. The simulations revealed that the 2020 earthquake comprised eight subevents, while the 2025 earthquake consisted of 4 subevents, exhibiting complex slip distributions in both cases (Figures 4 and 6). We subsequently carried out the inversion of the studied events with a series of subevents with individual time functions and window time lengths from 0.5 to 4 seconds. The best results were obtained with 8 and 4 subevents, each of 4s duration, for the 2020 and 2025 events, respectively. Adding more subevents did not show any improvement in the overall fit of the signals. The selected slip models were obtained after simulating several scenarios with different parameters (fault geometry, rupture velocity, rise time, hypocenter depth, and focal mechanisms) after choosing the ones with low residual between the synthetics and the observations and geologically meaningful. The Green’s functions were computed using a crustal velocity layered model for the southern Cuban margin based on the seismic study of Moreno et al. (2002) and the AK135‑F velocity model as the receiver structure (Kennett et al., 1995; Montagner and Kennett, 1995). We used P and SH waves recorded within a distance range of 30° to 90° with good azimuthal coverage (Figures 5 and 7). The inversions were performed in the frequency range of 0.001 to 1 Hz. We considered attenuation constants for P and SH waves as t*P = 1 s and t*sh= 4 s, respectively.
3.3 FINITE-FAULT SOURCE PARAMETERS
We characterized the obtained slip distributions. Slip models commonly contain parts of the fault plane with near‑zero slip; consequently, the fault size is often overestimated. To overcome this pitfall, Mai and Beroza (2000) introduced the concept of effective fault dimensions based on the definition of autocorrelation width. WACF is the area under the autocorrelation function defined as f*f=f(u)f(u-x)dx, normalized by the zero lag value (x = 0) of the autocorrelation function:
The effective fault length and width (Leff and Weff, respectively) are calculated with Equation 4, where f is the slip distribution. Leff is defined along the strike direction, while Weff is defined as a function alongside the dip direction. The effective rupture area (Aeff) is represented by a rectangular fault plane. After determining fault dimensions, we used them to quantify the static stress drop, considering both finite-fault and effective fault dimensions (Δσ and Δσeff) separately (Table 3). Static stress drop is defined as the variation in the average state of stress on a fault before and after an earthquake. The mean stress-drop is defined as (Eshelby, 1957; Knopoff, 1958; Borok, 1959)
where C is a constant that depends on the fault geometry, D is the average slip on the fault, Lc is a characteristic rupture dimension, and μ is the rigidity of the rocks. Considering a strike‑slip fault geometry, Δσ can be expressed as Δσ = (2/)(M0/W2L) where M0 is the seismic moment, W is the fault width, and L is the fault length. Calculated stress drops are shown in Table 3.
4. Results
From spectral analysis of regional data, we determined that stress drops for both events are 63 and 54 MPa. MW are 7.65 and 7.62; ER are 1.40 × 1016 and 4.67 × 1017 J; ER/M0 are 2.92 × 10-5 and 1.43 × 10-3, and τa are 1.11 and 43 MPa for the 2020 and 2025 earthquakes, respectively (Table 2). On the other hand, from the slip inversion, we obtained that both events exhibit complex slip patterns with large rupture dimensions (Figures 4 and 6). The 2020 earthquake had the largest rupture length (L = 250 km). By implementing effective fault dimensions, we observed a considerable reduction in the rupture length, resulting in 134.23 and 79.68 km for the 2020 and 2025 events, respectively. The calculated magnitudes for these events are 7.79 and 7.67 (similar to those reported by the global CMT catalog). Our results indicated that the maximum displacements (Dmax) are 18.49 and 14.80 m, while the average displacement (Dm) exhibits similar values of 2.61 and 2.46 m. We modeled the 2020 and 2025 earthquakes with a rupture velocity of 2.9 and 2.5 km/s, respectively. Using finite-fault dimensions led to stress drops of 1.62 and 1.84 MPa for the 2020 and 2025 events, respectively. On the contrary, effective stress drops are 2.05 and 2.33 MPa. Our seismic moment estimations, derived from the slip inversion in conjunction with the reported radiated seismic energies, yield the following ER/M0 and τa values: 1.57 × 10-5 and 1.78 × 10-5, 0.47 and 0.53 MPa (Table 3).
5. Discussion
Seismic energy is a fundamental parameter for understanding earthquake rupture dynamics and is a direct indicator of earthquake size. Significant discrepancies in energy measurements for the same event have been reported using different datasets (Pérez‑Campos et al., 2003b). On the other hand, other authors noted that regional seismic energy estimations are larger than the teleseismic estimates for the same event (Singh and Ordaz, 1994). The differences between regional and teleseismic energy estimates may be explained by the type of wave used, attenuation operator, and site amplification (Pérez‑Campos et al., 2003b). In this sense, our calculations of ER are consistent with these observations (Tables 2 and 3). Regarding the behavior of the ER/M0 ratio, it has been reported that the ratio is different for distinct types of earthquakes (Venkataraman and Kanamori, 2004a). Crustal earthquakes have ratios in the interval from 2 × 10-5 to 3 × 10-4, but commonly ER/M0 data exhibit significant scatter. Our teleseismic estimations of ER/M0 are close to the lower bound (Table 3). On the other hand, in the case of regional data, only the 2020 event is within the proposed interval. The ER/M0 ratio for the 2025 earthquake has the largest value (Table 2). The ER/M0 interval for crustal earthquakes, proposed by Venkataraman and Kanamori (2004a), encompasses events of various types, including continental and oceanic earthquakes with distinct focal mechanisms. On the contrary, Convers and Newman (2011) and Rodríguez‑Pérez and Zúñiga (2024) determined a mean ER/M0 ratio of 3.63 × 10-5 and 3.06 ×10-5—3.75 x10-5 for strike‑slip earthquakes. Our ER/M0 estimates are within the confidence limits present in these global source studies. Due to the disparities in regional and teleseismic seismic energy data, we consider that teleseismic ER/M0 estimations of the studied events are more reliable and agree with previous studies. Also, following the formulation of Zúñiga and Rodríguez‑Pérez (2025) in terms of the stress difference, both events analyzed displayed an overshoot type of stress mechanism, a condition that was observed for approximately 30% of strike‑slip events globally. Another important factor to consider in the regional spectral results is that the distribution of stations was not the most appropriate since there was no complete azimuthal coverage (Figure 1, lower left panel) due to different factors such as the availability and quality of the records. This can bias our results because of the non‑bilateral nature of the rupture. A good azimuthal coverage of stations is essential to have accurate energy estimates (Venkataraman and Kanamori, 2004b). Despite these difficulties, our regional estimates of source parameters, such as the size of events, agree with seismic reports.
In a global study, Allmann and Shearer (2009) employed spectral analysis to determine stress drops. They reported stress drop values in the range of 0.4–100 MPa for strike‑slip events. Notably, they also reported a median stress drop of 6.03 MPa for oceanic transform. Our estimates of stress drop derived from a Brune‑ type source model are within the range reported for strike‑slip earthquakes. The disparities between our results and those reported by Allmann and Shearer (2009) may be due to the use of different datasets (regional S-wave and teleseismic P-wave data). Our results for stress drop derived from fault dimensions (or static stress drop) are consistent with reported values for crustal events (1 < Δσ < 100 MPa) (Venkataraman and Kanamori, 2004a; Zúñiga and Rodríguez‑Pérez, 2025), but we have to keep in mind that for most earthquakes, we could obtain more than one estimate of the static stress drop. In some cases, we used subjective judgment to determine the representative rupture area. We reduced uncertainty by delineating fault dimensions based on aftershock distributions. The obtained slip distributions revealed complexity in rupture dynamics despite the apparent linearity of the oceanic‑transform‑ fault geometry, particularly for the 2020 event. We have similarities and differences with the results of Tadapansawut et al. (2021) for the 2020 earthquake. The similarities include the complex geometry and rupture process, while the difference mainly lies in the rupture velocity: in our case, 2.9 km/s, compared to their reported velocity of 6 km/s. On the other hand, Bao et al. (2022) analyzed the rupture velocity of the subevents of the 2020 earthquake. They found that regarding the rupture velocity, some subevents exhibit both subshear and supershear velocities. The subshear velocity is in the range of 2.2–2.6 km/s, while supershear velocity varies from 4.6–5.6 km/s, resulting in an average rupture velocity of 2.9–3.3 km/s. We interpreted that our estimated rupture velocity is representative of the average velocity. Our results also differ from previous finite-fault studies for the 2020 event (Tadapansawut et al., 2021; Calais et al., 2025) in the obtained maximum displacement. We reported a maximum slip of 18.49 m, a value higher than some reports (4 < Dmax < 7 m), but agree with others (Dmax = 24 m, USGS). This can be explained by the non‑uniqueness nature of the slip inversion, which means that different rupture models can explain the observed data. Other examples of earthquakes with complex rupture, as expressed by their slip patterns, include the 2016 Romanche (MW = 7.1) (Hicks et al., 2020) and the 2017 Komandorsky Islands (MW = 7.7) (Kehoe and Kiser, 2020) earthquakes. The slip inversion results also confirm that earthquakes in oceanic transforms have longer ruptures than events of the same magnitude in continental faults. According to De Melo et al. (2025), disparities in the scaling relation between oceanic and continental strike‑ slip events may be explained by the lower rigidity of the oceanic lithosphere, which is caused by hydration. There are reports of both low and high apparent stresses for oceanic earthquakes in transform zones (Choy and McGarr, 2002; Pérez‑ Campos et al., 2003a). According to Choy and McGarr (2002), high apparent stress is defined as values greater than 5.0 MPa. They also found that many of these high τa events are located near plate‑boundary triple junctions, where there appear to be high rates of intraplate deformation. On the other hand, Pérez‑Campos et al. (2003a) reported low apparent stresses as values lower than 0.2 MPa. Apparent stresses of strike‑slip events tend to increase with depth (Choy and McGarr, 2002; Rodríguez‑Pérez and Zúñiga, 2024). Our τa estimates are consistent with most reported apparent stress values (0.47 and 0.53 MPa), which can be explained by the fact that the 2020 and 2025 events occurred on linear oceanic transform faults at shallow depths. Regarding the nature of the earthquakes studied, slow earthquakes can be identified using a combination of a large centroid time shift and low apparent stress (Pérez‑ Campos et al., 2003a). In that sense, the reported centroid time shift (Δt) (centroid time minus the origin time) from the global CMT catalog (Dziewonski et al., 1981; Ekström et al., 2012) is 27.5 and 14.4 s for the 2020 and 2025 earthquakes, respectively. The studied earthquakes can be classified as regular events despite having large values of centroid time shifts because they do not exhibit low values of apparent stress (Figure 8). These large Δt could be explained as a result of multiple subevents (Berberian et al., 1999). This is also consistent with slip inversion results. The event with the largest centroid time shift was modeled using eight subevents. The occurrence of large earthquakes (MW ≥ 6) along the transform faults of the Cayman Trough underscores their tectonic significance, highlighting the left-lateral motion between the North American and Caribbean plates. In particular, the Oriente transform fault, with its anomalously flat and deep bathymetric expression and high mantle Bouguer anomaly (Hayman et al., 2011; Peirce et al., 2019), exemplifies how lithological heterogeneity and crustal structure may influence rupture nucleation and propagation. These earthquakes not only accommodate a substantial portion of the relative plate motion but also provide proxies for understanding similar strike‑slip systems in the region. To the east, the shear zone extends into the Enriquillo‑Plantain‑Garden fault in Hispaniola, where comparable large, destructive earthquakes have occurred, including the devastating Haiti earthquake of 2010 (e.g., Douilly et al., 2013). While both systems host moderate to large strike‑ slip ruptures, the Oriente fault appears to favor relatively continuous long segments, whereas the Enriquillo‑Plantain‑Garden fault is characterized by segmentation and partial rupture arrest, leading to more variable patterns of strain release. This contrast highlights how variations in fault geometry, bathymetry, and lithospheric properties across the boundary modulate rupture dynamics and contribute to the seismic hazard of this trans‑Caribbean transform system.
6. Conclusions
We studied the source characteristics of the latest earthquakes on the North Caribbean margin, specifically the 28 January 2020 (MW 7.7) and 8 February 2025 (MW 7.6) events. Stress drop estimates derived from spectral analysis (63 and 54 MPa) are consistent with global studies of strike‑slip events with MW > 7.5, although an order of magnitude larger than the static stress drop from finite and effective fault dimensions. Our teleseismic ER/M0 estimations are close to the lower bound of the interval proposed by Venkataraman and Kanamori (2004a) for crustal earthquakes (2 × 10-5–3 × 10-4) and agree with global reports of the ER/M0 ratio for strike‑slip events. Similarly, apparent stress stimates from regional and teleseismic energy data agree with previous reports. Calculations of apparent stress exhibit common behavior and cannot be considered as events with low or high apparent stress (τa < 0.2 MPa and 5.0 MPa > τa, respectively). The results of τa, in combination with the centroid time shift, indicate that the analyzed earthquakes do not exhibit a slow rupture. Slip distributions depict complex slip patterns with very large rupture lengths, resulting in maximum displacements of 18.49 and 14.80 m for the 2020 and 2025 earthquakes, respectively. The 2020 event exhibits an almost unilateral rupture propagation with a rupture velocity of 2.9 km/s, while the 2025 event describes a bilateral rupture propagation with a rupture speed of 2.5 km/s.
Contributions of authors
(1) Conceptualization: QRP, FRZ; (2) Analysis and data acquisition: QRP; (3) Writing of the original manuscript: QRP, FRZ.
Acknowledgments
We thank guest editor Dr. Raul Castro and Dr. Xyoli Pérez‑Campos and two anonymous reviewers for comments on the manuscript. QRP was supported by the Secretaría de Ciencia, Humanidades, Tecnología e Innovación (SECIHTI) (project 7197). We used regional and teleseismic data from the Berkeley Digital, the Canadian National, the Cayman Islands, GEOFON, GEOSCOPE, the Haitian, the Nicaraguan and the Southern California seismic networks, as well as the Greater Antilles Seismic Program; Servicio Nacional de Estudios Territoriales de El Salvador; Servicio Sismológico Nacional de Cuba; the Global Seismograph Network; the French Global Network; and the Global Telemetered Seismograph Network.
Conflicts of interest
There are no conflicts of interest.
Handling editor
Raúl Castro Escamilla.
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