Physics of the Earth and Planetary Interiors最新文献

{"title":"Modelling array beams for the 1979, 1984 and 2021 Granada earthquakes (southern Spain)","authors":"Daniel Stich ,&nbsp;Pınar Büyükakpınar ,&nbsp;Simone Cesca","doi":"10.1016/j.pepi.2025.107379","DOIUrl":"10.1016/j.pepi.2025.107379","url":null,"abstract":"<div><div>Despite the occurrence of large, past earthquakes in the Central Betic Range (Southern Spain), seismicity recorded with digital seismographs is limited to small magnitude events. Here we are interested in the three strongest events (M_W 4.5 to 5.0), of which source models are unclear for different reasons: The June 20th 1979 and June 24th 1984 earthquakes are still characterized by a lack of regional recordings, while the August 12th 2021 earthquake occurred during a teleseismic M8 event. We use beamforming at distant seismic arrays and waveform modelling of depth phases to estimate source parameters for seven earthquakes altogether. The technique is successful at reproducing P-waveforms and at estimating the depth of four recent (1997–2021) earthquakes with M_W &gt; 4. In addition, it is also used along with an inverse scheme that yields source mechanisms similar to regional moment tensor solutions. Inversion suggests normal faulting at depths of 7 km and 9 km for the 1984 and 2021 events, which is consistent with our understanding of regional seismotectonics. Beamforming has been able to extract the 2021 waveforms from the M8 coda wavefield, and could be a suitable approach also for other cases of earthquake coincidence. The most noteworthy result is a strike-slip mechanism at 60 km depth for the 1979 earthquake, which is a singular subcrustal event in this area and might be related to tearing at the edge of the Gibraltar slab.</div></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"365 ","pages":"Article 107379"},"PeriodicalIF":2.4,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144083714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Attenuation and scattering in the innermost inner core","authors":"Vernon F. Cormier,&nbsp;Ravi Wickramathilake","doi":"10.1016/j.pepi.2025.107368","DOIUrl":"10.1016/j.pepi.2025.107368","url":null,"abstract":"<div><div>Attenuation of PKIKP waves transmitted through the inner core of Earth is modeled to constrain the depth of a transition between an outer and inner inner core having a change in elastic anisotropy. Using reference waveforms inverted from earthquake source-time functions and an average mantle attenuation operator, fits to observed PKIKP waveforms are determined for a two layered model of P wave attenuation in the inner core in which 1/Q_P at 1 Hz has a sharp decrease in a 100 km thick transition zone centered at 650 km radius from Earth's center, coincident with the radius estimated for a change in elastic anisotropy. The attenuation of broadband PKIKP waveforms is found to be dominated by viscoelastic rather than by scattering attenuation. Bounds for parameters describing the spatial spectrum of heterogeneity of the inner inner core, consistent with the scattered coda of both forward scattered PKIKP and back-scattered PKiKP, are estimated to between 4 and 6 km at 2 % and 1 to 2 km at 1 %, for the corner scale length and P velocity fluctuation assuming an exponential autocorrelation. Strong antipodal focusing of scattered waves is observed and predicted from this heterogeneity, particularly within 0.5 great circle degrees of the antipode. Hypotheses for the transition in anelasticity and anisotropy of the - inner inner core include changes in the inner core's composition, superionic state, and/or a change in its heterogeneity texture or crystalline lattice structure.</div></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"364 ","pages":"Article 107368"},"PeriodicalIF":2.4,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143937350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The impact of LLVPs on regional secular variation of the magnetic field","authors":"Hannah F. Rogers ,&nbsp;Ciarán D. Beggan ,&nbsp;Kathryn A. Whaler","doi":"10.1016/j.pepi.2025.107367","DOIUrl":"10.1016/j.pepi.2025.107367","url":null,"abstract":"<div><div>The Large Low Velocity Provinces (LLVPs) are two poorly understood features at the base of the mantle that are typically studied with seismology and explained using geodynamical models of Earth evolution. However, there are few insights from the geomagnetic perspective about how these mantle features affect main field generation, or if they perturb the motion of the Earth's outer core, without assuming their physical properties. In this study, we test three regional methodologies, namely pointwise estimate on a spatial grid, spherical harmonic analysis, and spherical Slepian functions, to separate secular variation (SV, the first time derivative of the magnetic field) in the areas beneath the LLVPs and their complement.</div><div>While all three methodologies have drawbacks and differences, our findings of the proportion of SV energy inside and outside LLVPs are robust. When inverting data from geomagnetic virtual observatories over the satellite era, the proportion of SV energy under the LLVPs is found to be between 12 % and 18 % of the total SV energy at the Earth's surface which is less than the percentage surface area of the LLVPs. However, the percentage of SV energy is larger than the corresponding surface area when separating the COV-OBS.x2 SV model, between 29 % and 37 % inside LLVPs at the Earth's surface and 33 % and 49 % at the core-mantle boundary (CMB). For both datasets the African LLVP contributes approximately 2.5 times the amount of SV energy as the Pacific LLVP at the Earth's surface but only around 1.3 times more energy at the CMB.</div><div>LLVPs show time-varying SV under their footprint on decadal timescales which, therefore, indicates that core flow varies significantly underneath them rather than being regions of stilted flow. As well as presenting a novel inversion methodology that inverts for a spherical Slepian model, rather than using spherical Slepian functions to separate an existing spherical harmonic model, we also show for the first time that the timings of geomagnetic jerks correspond with inflection points in the magnitude of spectral or spatial energy in regional SV models. We conclude that there is no evidence that SV is systematically suppressed beneath LLVPs.</div></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"364 ","pages":"Article 107367"},"PeriodicalIF":2.4,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144067991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Core-climate coupling: Changes in the Earth’s core dynamics driven by climatic processes","authors":"Mostafa Kiani Shahvandi","doi":"10.1016/j.pepi.2025.107366","DOIUrl":"10.1016/j.pepi.2025.107366","url":null,"abstract":"<div><div>Changes in the Earth's global parameters—particularly variations in the length of day, <span><math><mi>Δ</mi></math></span>LOD—are caused by a multitude of geophysical processes, including that of core dynamics. New signals have emerged in the recent space-geodetic record of <span><math><mi>Δ</mi></math></span>LOD that are not explained solely based upon dynamics of the Earth's core. On the other hand, recent studies emphasize the increasing impact of climatic processes on <span><math><mi>Δ</mi></math></span>LOD, yet even these fail to account for the mentioned emerging signals. Here we propose that these signals are explained once we account for ‘core-climate coupling’ (3C). For this purpose, we develop a new deep learning-based algorithm termed interpretable Bayesian physics-informed quantum deep learning (PIQDLIB) that takes into account all the possible connections between core and climate dynamics. Employing PIQDLIB and using the observations of <span><math><mi>Δ</mi></math></span>LOD, global climate change, and core flow models, we unravel a 3C with a coupling strength of 4<span><math><mo>±</mo></math></span>2 %. This dynamic link elucidates nonlinear interactions between the climate and core processes. To explain the origin of this coupling, we propose a mechanism that accounts for 79<span><math><mo>±</mo></math></span>18 % of the coupling strength and is based upon the pole tide caused by the deviations of the Earth's rotational pole induced by climatic processes, namely, barystatic processes that result in continental-ocean mass redistribution as a result of polar ice sheet and global glaciers melting and shifts in terrestrial water storage. This newly discovered 3C phenomenon is manifested in <span><math><mi>Δ</mi></math></span>LOD as a quasi-decadal oscillation with a main period of 12<span><math><mo>±</mo></math></span>1 year and amplitude of 0.1<span><math><mo>±</mo></math></span>0.02 milliseconds, though it also encompasses small-amplitude interannual and intradecadal periods in the range of <span><math><mo>∼</mo></math></span>6–9 years. These results demonstrate the interplay between internal and external geodynamics, which is fundamental for a better understanding of global geophysics.</div></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"364 ","pages":"Article 107366"},"PeriodicalIF":2.4,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143917988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The structural, electronic, and elastic properties of Fe-P binary compounds under extreme pressures: First-principles calculations","authors":"Xiaoxia Wang,&nbsp;Ziying Liang,&nbsp;Chongyang Fu,&nbsp;Weiqi Li,&nbsp;Xiaojuan Ma","doi":"10.1016/j.pepi.2025.107369","DOIUrl":"10.1016/j.pepi.2025.107369","url":null,"abstract":"<div><div>The structural, electronic and elastic properties of Fe-P binary compounds under the pressure range of 60–360 GPa are investigated using first-principles calculations. Firstly, based on the calculations of formation enthalpy (<span><math><mo>∆</mo><mi>H</mi></math></span>) and mechanical stability criteria, it is proved that FeP and Fe₁₅P do not undergo phase transition, and they are stable within the pressure range of 60–360 GPa. It is noteworthy that Fe₂P and Fe₃P suffer phase transition, and they remain stable within each phase. Secondly, the formation of chemical bonds between P and Fe atoms in Fe₁₅P is demonstrated through Bader charge and Electron Localization Function (ELF). The electronic properties of Fe-P binary compounds are examined using Partial Density of States (PDOS) and band structures. Additionally, the presence of P elements is found to reduce the density (<span><math><mi>ρ</mi></math></span>) of these compounds, bringing Fe₁₅P and Fe₃P closer to the Preliminary Reference Earth Model (PREM) data. On the one hand, bulk modulus (<span><math><msub><mi>B</mi><mi>H</mi></msub></math></span>) and shear modulus (<span><math><msub><mi>G</mi><mi>H</mi></msub></math></span>) of Fe-P compounds increase with increasing pressure, but remain lower than those of pure iron. On the other hand, the compressional sound velocity (<span><math><msub><mi>V</mi><mi>P</mi></msub></math></span>) of the Fe₃P and Fe₁₅P in the pressure range of 135–360 GPa, which is lower than that of pure iron and closer to the PREM data. Moreover, the shear sound velocity (<span><math><msub><mi>V</mi><mi>S</mi></msub></math></span>) of the Fe-P binary compounds at 330–360 GPa, which is also lower than that of pure iron and closer to the PREM data. The Poisson's ratio (<span><math><mi>σ</mi></math></span>) of FeP, Fe₂P and Fe₃P is consistently higher than that of pure iron, but aligns more closely with PREM data under pressure of the Earth's inner core. Lastly, the <span><math><mi>ρ</mi></math></span>, <span><math><mi>σ</mi></math></span>, <span><math><msub><mi>V</mi><mi>S</mi></msub></math></span> and <span><math><msub><mi>V</mi><mi>P</mi></msub></math></span> of Fe₃P can all match PREM data. Therefore, Fe-P binary compounds may serve as a suitable model for the Earth's core, suggesting that the light elements P could potentially exist within the Earth's core.</div></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"364 ","pages":"Article 107369"},"PeriodicalIF":2.4,"publicationDate":"2025-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143946615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Core-surface kinematic control of polarity reversals in advanced geodynamo simulations","authors":"Julien Aubert,&nbsp;Maylis Landeau,&nbsp;Alexandre Fournier,&nbsp;Thomas Gastine","doi":"10.1016/j.pepi.2025.107365","DOIUrl":"10.1016/j.pepi.2025.107365","url":null,"abstract":"<div><div>The geomagnetic field has undergone hundreds of polarity reversals over Earth's history, at a variable pace. In numerical models of Earth's core dynamics, reversals occur with increasing frequency when the convective forcing is increased past a critical level. This transition has previously been related to the influence of inertia in the force balance. Because this force is subdominant in Earth's core, concerns have been raised regarding the geophysical applicability of this paradigm. Reproducing the reversal rate of the past million years also requires forcing conditions that do not guarantee that the rest of the geomagnetic variation spectrum is reproduced. These issues motivate the search for alternative reversal mechanisms. Using a suite of numerical models where buoyancy is provided at the bottom of the core by inner-core freezing, we show that the magnetic dipole amplitude is controlled by the relative strength of subsurface upwellings and horizontal circulation at the core surface. A relative weakening of upwellings brings the system from a stable to a reversing dipole state. This mechanism is purely kinematic because it operates irrespectively of the interior force balance. It is therefore expected to apply at the physical conditions of Earth's core. Subsurface upwellings may be impeded by stable stratification in the outermost core. We show that with weak stratification levels corresponding to a nearly adiabatic core surface heat flow, a single model reproduces the observed geomagnetic variations ranging from decades to millions of years. In contrast with the existing paradigm, reversals caused by this stable top core mechanism become more frequent when the level of stratification increases i.e. when the core heat flow decreases. This suggests that the link between mantle dynamics and magnetic reversal frequency needs to be reexamined.</div></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"364 ","pages":"Article 107365"},"PeriodicalIF":2.4,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143942898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Crustal shear-wave velocity structure of the Namche Barwa massif, eastern Himalayan Syntaxis, Tibet from ambient noise tomography","authors":"Jiawei Tan ,&nbsp;Xuzhang Shen ,&nbsp;Siyuan Cheng ,&nbsp;Rui Gao ,&nbsp;Wentian Wang","doi":"10.1016/j.pepi.2025.107363","DOIUrl":"10.1016/j.pepi.2025.107363","url":null,"abstract":"<div><div>The eastern termination of the Himalayan orogeny, known as Namche Barwa, serves as a crucial natural laboratory for geodynamic studies of the Tibetan Plateau due to its distinctive geological and geomorphological characteristics. To enhance the understanding of regional tectonics, we deployed a dense array of 374 short-period geophones from June to July 2020 to record continuous waveforms. Using vertical-component data, we computed cross-correlation functions and extracted 13,466 Rayleigh wave phase-velocity dispersion curves for periods ranging from 0.8 to 8 s. We applied the direct surface wave tomography method to invert the three-dimensional shear-wave velocity structure at depths of 0–6 km in the region. Our results reveal that the shallow crustal velocity structure in this region exhibits significant lateral heterogeneity, reflecting the complexity of the geological units. Low-velocity anomalies are primarily observed near faults, including the Indus-Yarlung Suture Zone and the Jiali Fault, while a high-velocity anomaly is detected beneath the Namche Barwa massif. In combination with previous geophysical studies, including magnetotelluric (MT) and seismic imaging results, this high-velocity anomaly is speculated to reflect the intrusion of deep crustal material into the shallow crust. The spatial correlation between the velocity model and seismicity distribution suggests that earthquakes are closely associated with local stress conditions, velocity structure, and the presence of aqueous fluids and geothermal anomalies.</div></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"363 ","pages":"Article 107363"},"PeriodicalIF":2.4,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143858721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variations in mantle flow beneath the Eastern Himalaya inferred from shear wave splitting","authors":"Arti Devi ,&nbsp;Sunil K. Roy ,&nbsp;Jyotima Kanaujia ,&nbsp;Venkatesh Vempati ,&nbsp;M. Ravi Kumar","doi":"10.1016/j.pepi.2025.107364","DOIUrl":"10.1016/j.pepi.2025.107364","url":null,"abstract":"<div><div>This study attempts to understand the upper mantle deformation patterns beneath the Eastern Himalaya by performing shear wave splitting analysis of core-refracted phases. Out of the 83 broadband seismic stations used, data from 70 stations are analysed for the first time. This includes 21 stations which were newly deployed along two profiles in Arunachal Himalaya, to fill the gaps in the stations used for previous studies. In total, 172 well constrained new splitting and 215 null measurements are obtained in this study. Average delay time values of 0.64 and 0.76 s in the Bhutan and Arunachal Himalaya respectively, suggest weak anisotropy, probably due to a steep subduction of the Indian mantle lithosphere. There is a systematic variation in the orientation of fast polarization azimuths in the western (Bhutan Himalaya and western part of Arunachal Himalaya) and eastern segments (central to the eastern part of Arunachal Himalaya). In both these segments, the orientation of fast polarization azimuths varies dominantly from N<em>E</em>-SW or/and ENE-WSW, to E-W, from west to east. In the western and central parts of Bhutan Himalaya, the influence of absolute plate motion related strain in the asthenospheric mantle cannot be ruled out, while in its eastern part and Arunachal Himalaya, the azimuthal anisotropy can be explained by arc parallel mantle flow due to slab rollback. In addition, a few observations in the central part of Arunachal Himalaya indicate a slightly larger delay time, along NNE-SSW, which could be associated with mantle wedge flow. The eastern part of Arunachal Himalaya might be associated with a repulsive arc parallel flow from the Arunachal and Burmese arcs, resulting in null measurements. The optimal depth of anisotropy in Bhutan and Arunachal Himalaya is around <span><math><mn>220</mn><mo>−</mo><mn>270</mn></math></span> and <span><math><mn>200</mn><mo>−</mo><mn>240</mn></math></span> km respectively, suggesting that the source of anisotropy lies in the upper part of the asthenosphere.</div></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"363 ","pages":"Article 107364"},"PeriodicalIF":2.4,"publicationDate":"2025-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143858749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial variation of crustal anisotropy in Simeulue Island, Indonesia, from shear wave splitting analysis","authors":"Syuhada Syuhada ,&nbsp;Faiz Muttaqy ,&nbsp;Titi Anggono ,&nbsp;Bayu Pranata ,&nbsp;Nanang T. Puspito ,&nbsp;Mohamad Ramdhan ,&nbsp;Febty Febriani ,&nbsp;Muhammad Ma'ruf Mukti ,&nbsp;Cinantya Nirmala Dewi ,&nbsp;Mohammad Hasib ,&nbsp;Aditya Dwi Prasetio ,&nbsp;Atin Nur Aulia ,&nbsp;Ade Surya Putra","doi":"10.1016/j.pepi.2025.107362","DOIUrl":"10.1016/j.pepi.2025.107362","url":null,"abstract":"<div><div>Simeulue Island sits near the northern subduction margin of the Sumatran Megathrust, which is characterized by high tectonic activities and earthquakes. The oblique subduction along this margin has developed a complicated crustal deformation on the island, including faulting, uplifting and crustal segmentation. In the subduction zone, crustal anisotropy is often caused by stress-induced anisotropy in which the anisotropy direction is parallel to the stress direction. However, the complex crustal structure around the study area may produce a complicated anisotropy pattern. Here, we measure crustal seismic anisotropy from shear wave splitting analysis using the seismic data recorded at eight temporary stations spread across Simeulue Island. We apply the 2-D tomographic inversion and spatial averaging technique to map the splitting anisotropy patterns around the region. This research allows us to gain new insight into the crustal deformation pattern and its relationship with the complicated crustal structure beneath the island. The splitting result shows variations of anisotropy pattern around the study area. The spatially averaged fast directions at the northern region are trench-parallel, consistent with the strike of the geological features resulting from the strain partitioning deformation of the oblique convergence. Higher strength anisotropy is also observed in this area, indicating that the local fault system may strongly contribute to the crustal anisotropy. In the southern part of the island, the spatial averaging of fast direction gives a consistent pattern with the maximum regional stress direction, suggesting that anisotropy is mainly associated with stress-aligned microcracks. The central part of the island exhibits different splitting directions, marking the boundary of the geological structures between the areas in the north and south of the island. This pattern is also accompanied by high-strength anisotropy, suggesting that the source may be associated with the subducting geological structures beneath the area playing a significant role in the rupture barrier of the great events, as suggested by several previous studies.</div></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"363 ","pages":"Article 107362"},"PeriodicalIF":2.4,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seismotectonics of the Gulf of Gökova, Southwest Anatolia, using double-difference seismic tomography, earthquake relocation, and moment tensor solutions: The 20 July 2017 Mw6.5 Bodrum-Kos earthquake","authors":"Tuğba Özdemirli-Esat ,&nbsp;Melike Doğanay-Özkan ,&nbsp;Korhan Esat","doi":"10.1016/j.pepi.2025.107361","DOIUrl":"10.1016/j.pepi.2025.107361","url":null,"abstract":"<div><div>The 20 July 2017 Mw6.5 Bodrum-Kos main shock that occurred in the Gulf of Gökova is one of the largest earthquakes in the north-south extensional Aegean region. In this study, we generated the first three-dimensional local earthquake tomography model for the Gökova region using the double-difference tomography algorithm to provide a contribution to discussions on the source fault of the main shock. The 2500 earthquake records of magnitude ≥2.3 between 01 January 2017 and 31 December 2017 were chosen from the 19 strong-motion accelerometer and 11 weak-motion seismometer stations. The P- and S-wave velocity models and Vp/Vs ratio model of the study area were created, and 1488 earthquakes were relocated. With the help of seismic tomographic imaging, we concluded that the main shock occurred on the south-dipping Gökova Fault Zone, not on the north-dipping fault plane suggested in some studies. We also determined that some earthquakes that occurred in 2017 were associated with a north-dipping normal fault observed down to 10 km depth immediately north of the Gökova Fault Zone. Additionally, the Datça-Kale Main Breakaway Fault, which separates the sedimentary cover and the basement rocks, was also determined in the tomographic profiles. The kinematic analysis of moment tensor solutions of 64 earthquakes, mostly with magnitudes greater than 4, is consistent with the north-south extensional tectonic regime in the Aegean region.</div></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"364 ","pages":"Article 107361"},"PeriodicalIF":2.4,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143907705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}