Journal of Geophysical Research: Solid Earth最新文献

{"title":"Legacy Seismic and Gravity Data in the Vicinity of Great Meteor Seamount and Its Tectonic Implications","authors":"A. B. Watts,&nbsp;I. Grevemeyer","doi":"10.1029/2024JB030016","DOIUrl":"https://doi.org/10.1029/2024JB030016","url":null,"abstract":"<p>The Great Meteor seamounts are located in the eastern Atlantic Ocean, about 750 km south of the Azores. Conjugate to the Corner seamounts in the western Atlantic Ocean, it has been suggested they formed at the same hotspot that generated the New England Seamount chain. However, isotopic data suggest the Great Meteor seamounts are genetically linked to the Azores rather than to the New England hotspot. To test this, we have used seismic, gravity and bathymetry data acquired onboard M/V <i>Meteor</i> in 1990 to reassess the crustal structure, elastic thickness, <i>T</i>_<i>e</i>, and tectonic setting of the seamounts. The most prominent is Great Meteor, the largest seamount in the Atlantic Ocean. We show that the guyot comprises a pelagic, limestone (2.0–4.5 km s⁻¹) and extrusive basaltic lava (5.0–6.0 km s⁻¹) drape that overlies a relatively high <i>P</i>-wave velocity (6.0–6.5 km s⁻¹) intrusive “core” of mafic and possibly ultramafic rocks. The seismic structure has been verified by gravity modeling assuming a Gardner and Nafe-Drake relationship between <i>P</i>-wave velocity and density. The best fit between the observed and calculated gravity anomaly based on a plate flexure model is for an elastic thickness, <i>T</i>_<i>e</i>, of ∼20 km which implies an edifice age of ∼43 Ma, assuming a 450°C controlling oceanic isotherm. While the edifice age is greater than the sample age (∼17 Ma), it explains the subsidence history of Great Meteor and is compatible with dynamic models of plume-ridge interactions that predict the Azores hotspot has migrated north during the Cenozoic.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 5","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JB030016","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143889066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unraveling Processes and Rheology of the Tohoku Earthquake Cycle Using Bayesian Inference","authors":"C. P. Marsman,&nbsp;F. C. Vossepoel,&nbsp;M. D’Acquisto,&nbsp;Y. van Dinther,&nbsp;L. van de Wiel,&nbsp;R. Govers","doi":"10.1029/2024JB029665","DOIUrl":"https://doi.org/10.1029/2024JB029665","url":null,"abstract":"<p>Geodetic data spanning different phases of the earthquake cycle offer insights into the spatiotemporal interplay between processes driving surface deformation, such as viscoelastic relaxation, afterslip, and (re)locking. However, quantifying their contributions and explaining pre- and post-earthquake displacements with a single set of rheological parameters is challenging. We set up a 2-D earthquake cycle finite element model that simulates the mantle and a thin low-viscosity shear zone with a temperature-dependent linear Maxwell or nonlinear power-law rheology. We use the ensemble smoother with multiple data assimilation to estimate ensembles of parameters describing the rheological makeup of the subduction zone. We assimilate onshore and offshore displacement time series acquired before and after the 2011 Tohoku-Oki earthquake. Our models provide a unique, robust solution using a temperature-dependent power-law rheology. The estimated creep parameters for the mantle wedge deeper than ∼50 km and sub-slab mantle align with laboratory experiments. However, different creep parameters are required for the shallow part of the mantle wedge than the deeper part to explain the observed postseismic response—highlighting the need for shallow viscoelastic relaxation. The trade-off between water fugacity and activation energy hinders their individual estimation but yields a well-constrained viscosity structure. The spatial distribution of vertical displacements as well as the temporal signature of early postseismic horizontal displacements are required to estimate individual parameters for afterslip and viscoelastic relaxation. Afterslip occurs downdip of the coseismic rupture. Near-trench landward motion during the early postseismic period is driven by elastic stress release beneath the oceanic plate and sub-slab asthenospheric flow.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 5","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JB029665","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143884026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Influence of Variable Host Rock Cohesion and Magma Viscosity on Intrusion-Fault Interaction: Insights From Laboratory Models","authors":"Sonja H. M. Greiner,&nbsp;Olivier Galland,&nbsp;Freysteinn Sigmundsson,&nbsp;Steffi Burchardt,&nbsp;Halldór Geirsson,&nbsp;Rikke Pedersen,&nbsp;Xia Wen","doi":"10.1029/2024JB029870","DOIUrl":"https://doi.org/10.1029/2024JB029870","url":null,"abstract":"<p>Magma transport through the Earth's shallow crust can be affected by pre-existing weaknesses like faults. Consequently, fault-channeled magma may reach the surface in unexpected locations. Hence, better understanding of magma-fault interaction is needed to improve hazard assesment. We investigate the effect of host rock cohesion and magma viscosity on intrusion-fault interaction using laboratory experiments. Vegetable oil and glucose syrup, serving as low- and high-viscosity analogue magmas, were injected into intact and faulted granular materials with variable cohesion (mixtures of silica flour and micro-glass beads), serving as a brittle plastic model crust. High-cohesion models produced sheet intrusions, that propagated along fault segments upon intersection. Low-cohesion models produced low-aspect ratio intrusions low width/thickness ratio. Without tectonic stresses, the cohesion strongly controls intrusion-fault interaction, while tested model magma viscosities exerted a weaker control. Our findings show that intrusion-fault interaction is a highly complex process and important to consider at active volcanoes.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 4","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JB029870","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143871792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sound Velocities of Zoisite at High Pressures and Temperatures and Implications for the Water Content in Subducting Oceanic Crust","authors":"Rui Zhang,&nbsp;Duojun Wang,&nbsp;Nao Cai","doi":"10.1029/2024JB030238","DOIUrl":"https://doi.org/10.1029/2024JB030238","url":null,"abstract":"&lt;p&gt;The &lt;i&gt;P&lt;/i&gt;- and &lt;i&gt;S&lt;/i&gt;-wave velocities of zoisite were measured simultaneously using ultrasonic techniques under pressure and temperature of up to 11 GPa and 773 K, respectively. The results indicate that the velocity of zoisite increases with increasing pressure and decreases with increasing temperature. Using finite strain fitting, values of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;K&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;S&lt;/mi&gt;\u0000 &lt;mn&gt;0&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msub&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mn&gt;129&lt;/mn&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mn&gt;3&lt;/mn&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mspace&gt;&lt;/mspace&gt;\u0000 &lt;mtext&gt;GPa&lt;/mtext&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${K}_{S0}=129(3)hspace*{.5em}text{GPa}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msubsup&gt;\u0000 &lt;mi&gt;K&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;S&lt;/mi&gt;\u0000 &lt;mn&gt;0&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;′&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msubsup&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mn&gt;4.9&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${K}_{S0}^{mathit{prime }}=4.9$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;(3), &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;G&lt;/mi&gt;\u0000 &lt;mn&gt;0&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mn&gt;73&lt;/mn&gt;\u0000 &lt;mspace&gt;&lt;/mspace&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mspace&gt;&lt;/mspace&gt;\u0000 &lt;mtext&gt;GPa&lt;/mtext&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${G}_{0}=73hspace*{.5em}(2)hspace*{.5em}text{GPa}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msubsup&gt;\u0000 &lt;mi&gt;G&lt;/mi&gt;\u0000 &lt;mn&gt;0&lt;/mn&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;′&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msubsup&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mn&gt;2.0&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${G}_{0}^{mathit{prime }}=2.0$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;(2), &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msubsup&gt;\u0000 &lt;mi&gt;G&lt;/mi&gt;\u0000 &lt;mn&gt;0&lt;/mn&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;″&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msub","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 4","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143871795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating the Mechanisms of Earthquake-Induced Groundwater Radon Changes in a Hot Spring-Insight From Coupled Flow Rates, Water Temperature, and Radon Observation","authors":"Wei Liu,&nbsp;Zheming Shi,&nbsp;Yunfei Bai,&nbsp;Rui Yan,&nbsp;Yuchuan Ma","doi":"10.1029/2024JB030878","DOIUrl":"https://doi.org/10.1029/2024JB030878","url":null,"abstract":"<p>Radon (²²²Rn), a radioactive inert gas commonly found in the earth's crust, is sensitive to crustal strain. Radon monitoring is widely recognized as an effective method for earthquake precursor detection. However, the underlying physical mechanisms responsible for these anomalies have not been investigated quantitatively. Thus, in this study, changes in radon concentration were systematically analyzed by integrating flow rates and water temperature data from the Banglazhang #1 hot spring in Yunnan, China, following the 1996 Lijiang Mw 7.0 earthquake and the 2004 Sumatra Mw 9.1 earthquake, both of which induced significant hydrological responses. Our analysis demonstrated that meteorological factors were not the primary drivers of radon concentration changes. The change in the mixing ratio from different depths of water was identified as the primary mechanism driving radon concentration changes following the Lijiang earthquake. Furthermore, the release of radon from particle movement, along with the change in the mixing ratio after the earthquake, might explain the co-seismic response following the Sumatra earthquake. The water–rock interaction surface area increased from about 7 × 10⁴ m² to 1.85 × 10⁵ m² following the Sumatra earthquake. Our study showed that coupling of flow rates, water temperature, and radon could provide a robust explanation of the earthquake-induced hydrological response. Thus, monitoring multiple parameters is essential for accurately and promptly detecting earthquake-related signals.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 4","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143871796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Extent and Mechanisms of the North China Craton Lithospheric Destruction Revealed by Multi-Geophysical Inversions","authors":"Anqi Zhang,&nbsp;Risheng Chu,&nbsp;Pengxiang Zhou,&nbsp;Chunquan Yu,&nbsp;Yingjie Yang","doi":"10.1029/2025JB031104","DOIUrl":"https://doi.org/10.1029/2025JB031104","url":null,"abstract":"<p>The North China Craton (NCC) has undergone significant destruction, yet the spatial extent and underlying mechanisms of the destruction remain subjects of debate. In this study, we conduct a joint inversion by integrating multiple geophysical data sets to establish an unprecedented large-scale compositional structure of the NCC lithospheric mantle. By incorporating lithospheric thickness constrained by thermal state, we provide a comprehensive assessment of the spatial extent and intensity of NCC destruction. Our results reveal significant variations in lithospheric thickness and mantle composition across the NCC and delineate a boundary marking the extent of its destruction. West of this boundary, including the core of the Ordos block, the lithosphere exhibits refractory characteristics and a thick lithospheric root, maintaining craton stability. In contrast, east of the boundary, including the Eastern NCC (ENCC), most of the Trans-North China Orogen (TNCO), and the northeastern part of the Western NCC (WNCC), the lithosphere shows signs of extensive modification. The ENCC features a refertilized lithospheric mantle and thin lithosphere, reflecting extensive reworking likely driven by large-scale lithospheric delamination during the Mesozoic. The TNCO and northeastern WNCC display localized mantle refertilization and high-degree partial melting in the asthenosphere, suggesting ongoing thermal erosions, likely driven by the influence of the Pacific slab's leading edge or its rollback. We propose that Cenozoic thermal erosion has extended the destruction of the NCC farther west than previously anticipated. This study identifies regions of significant lithospheric thinning and mantle compositional modification, improving our understanding of the NCC destruction and its evolving mechanisms.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 4","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143871794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Remagnetization of Serpentinite During Deformation: Evidence From a Fossil Oceanic Transform Fault Zone of the Troodos Ophiolite","authors":"Liang Qi,&nbsp;Simon Allerton,&nbsp;Adrian R. Muxworthy,&nbsp;Yong Zhang,&nbsp;Hristo Gergov","doi":"10.1029/2024JB030790","DOIUrl":"https://doi.org/10.1029/2024JB030790","url":null,"abstract":"<p>Serpentinization and associated chemical remagnetization of ultramafic rocks are common in tectonically active oceanic zones such as transform zones; however, it remains unclear how chemical remagnetization occurs during the deformation of serpentinite. This study aims to discuss this magnetization process with evidence from a serpentinite shear zone within the fossil transform fault of the Troodos ophiolite. We examine how serpentinite microstructures, serpentine polytypes, iron behaviors, rock magnetic properties and paleomagnetic directions evolve with increasing shearing deformation—a process that provides pathways for serpentinization fluid circulation. As serpentinite deformation increases from massive-fractured serpentinite adjacent to the shear zone to scaly and phyllonitic serpentinites within the shear zone, rock microstructure changes from unoriented mesh textures to oriented ribbon and fibrous structures. Meanwhile, the dominant serpentine mineral shifts from lizardite to chrysotile, indicating dynamic recrystallization during increasing deformation, likely resulting from elevated water/rock ratios driven by hydrothermal circulation. Rock magnetic results suggest that highly deformed scaly and phyllonitic serpentinites contain coarser magnetite grains and higher magnetite concentration compared to the less deformed massive-fractured serpentinites. These coarser magnetite grains are also attributed to higher water/rock ratios within the shear zone. More magnetite forms due to the iron released from the replacement of iron-rich lizardite by iron-poor chrysotile. The formation of magnetite records remagnetization, which helps reconstruct the deformation history of tectonically active zones. For example, paleomagnetic directions of the differentially deformed serpentinites in Troodos ophiolite indicate clockwise block rotations of up to 90°, providing evidence for dextral slip along a fossil transform fault.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 4","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JB030790","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143865796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Laboratory Measurement of Sonic (1–20 kHz) P-Wave Velocity and Attenuation During Melting of Ice-Bearing Sand","authors":"Hanif S. Sutiyoso,&nbsp;Sourav K. Sahoo,&nbsp;Laurence J. North,&nbsp;Ismael Himar Falcon-Suarez,&nbsp;Timothy A. Minshull,&nbsp;Angus I. Best","doi":"10.1029/2024JB030465","DOIUrl":"https://doi.org/10.1029/2024JB030465","url":null,"abstract":"<p>We measured the acoustic properties of ice-bearing sand packs in the laboratory using an acoustic pulse tube within the frequency range of 1–20 kHz, similar to sonic well-logs. We analyzed how wave velocity and attenuation (the inverse of quality factor) change with ice saturation and measurement frequency during melting. We found strong frequency-dependent correlations for both acoustic parameters with ice saturation. For any frequency within the studied range, velocity decreases and attenuation increases as the ice melts. For lower ice saturations (<i>S</i>_<i>i</i> &lt; ∼0.5), attenuation was particularly sensitive to frequency linked to acoustic wave scattering from patchy ice saturation. We used rock physics models with three-phase approaches to assess our experimental results. The comparison highlights the influence of ice formation distribution (i.e., uniform vs. patchy), permeability, and gas content on both velocity and attenuation. Our results pave the way for monitoring ice saturation from sonic measurements, as ice saturation has contrasting effects on velocity and attenuation, and the effects vary with frequency. Overall, this research contributes to a better understanding of the acoustic response of ice-bearing sediments and provides valuable insights for various applications, including permafrost monitoring and natural gas hydrate dissociation studies.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 4","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JB030465","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143865936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Shallow Lingering and Deep Transient Seismicity Related to Hydraulic Fracturing in the Changning Shale Gas Field, Sichuan Basin, China","authors":"Jian Xu,&nbsp;Junlun Li,&nbsp;Wen Yang,&nbsp;Guoyi Chen,&nbsp;Yajing Liu,&nbsp;Alessandro Verdecchia,&nbsp;Rebecca M. Harrington,&nbsp;Renqi Lu,&nbsp;Yuyang Tan,&nbsp;Yapei Ye,&nbsp;Jizhou Tang","doi":"10.1029/2024JB030279","DOIUrl":"https://doi.org/10.1029/2024JB030279","url":null,"abstract":"<p>Characterizing seismic responses to hydraulic fracturing (HF) in shale-gas development is crucial for seismic-hazard assessment and mitigation-strategy design. Although intensive HF operations have led to severe induced seismic hazards in the Changning shale gas field (CSF) in China for over a decade, the typical spatiotemporal characteristics of induced seismicity during and after HF in this region remain unclear, due to a lack of detailed fluid-injection data. Using a 70-day-long dense deployment of 336 nodal-sensors in 2019, we develop an enhanced seismicity catalog and combine it with focal mechanism solutions, fluid-injection time series, seismic-reflection profiles, and geomechanical models to identify the distinct shallow and deep seismicity responses to HF. The first pattern consists of deep earthquake clusters that migrate along strike-slip faults in the limestone formation ∼1 km below the treatment depth. These clusters contain frequent <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>M</mi>\u0000 <mi>L</mi>\u0000 </msub>\u0000 <mo>&gt;</mo>\u0000 <mn>2</mn>\u0000 </mrow>\u0000 <annotation> ${M}_{mathrm{L}} &gt; 2$</annotation>\u0000 </semantics></math> earthquakes, including the largest <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>M</mi>\u0000 <mi>L</mi>\u0000 </msub>\u0000 <mn>3.3</mn>\u0000 </mrow>\u0000 <annotation> ${M}_{mathrm{L}}3.3$</annotation>\u0000 </semantics></math> event, and exhibit transient seismicity-rate changes in rapid response to HF. In contrast, the second pattern consists of shallow clusters in the target shale formation that persist for over a year following HF. The shallow clusters include smaller earthquakes and exhibit thrust-style faulting with no discernible spatial migration. Our geomechanical simulations suggest the deep fault reactivation is best explained by the combined effects of poroelastic-stress loading and pore-pressure increases. Stable seismicity rate and frequent casing deformation indicate post-HF, long-term aseismic deformation may drive the shallow seismicity. These distinct seismic responses during and after HF operations underscore the need for a spatiotemporally adaptive hazard mitigation strategy for the CSF.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 4","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143865939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 Effect of Hydrothermal Alteration and Microcracks on Hydraulic Properties and Poroelastic Deformation: A Case Study of the Blue Mountain Geothermal Field","authors":"Valerian Schuster,&nbsp;Erik Rybacki,&nbsp;Anja M. Schleicher,&nbsp;Roshan Koirala,&nbsp;Thomas H. W. Göbel","doi":"10.1029/2024JB030541","DOIUrl":"https://doi.org/10.1029/2024JB030541","url":null,"abstract":"<p>Geothermal energy plays a vital role in decarbonizing electricity and heat supply. Effective utilization of geothermal resources hinges on identifying or generating permeable reservoir zones and understanding how effective pressure variations affect fluid circulation and reservoir properties by poroelastic deformation. Hydrothermal alteration can modify the petrophysical properties of geothermal reservoir rocks, which may increase or decrease its productivity. Understanding these alteration effects is essential to predict and optimize long-term sustainable geothermal operations. Here, we investigate the impact of hydrothermal alteration on poroelastic and hydraulic properties of diverse lithologies in a series of deformation tests performed at several confining (0–80 MPa) and pore pressure (10–30 MPa) levels. Experimental results of hydrothermally altered dikes and phyllites obtained from the Blue Mountain geothermal field (Nevada, USA) are compared to thermally cracked La Peyratte granite (France) and correlated with petrophysical properties, mineral composition, and microstructures. Argillic alteration of dikes increases porosity and storage capacity but lowers thermal conductivity and increases pore compressibility. Conversely, silicate precipitation in phyllites increases stiffness and thermal conductivity but also reduces porosity and permeability. Experimentally determined effective pressure coefficients range from 0.1 to 0.9, differ for permeability and volumetric strain and decrease with increasing effective pressure. The presence of compliant microcracks and crack-like pores significantly increases the stress sensitivity of La Peyratte granite and silicified phyllites. This study demonstrates how thermal and chemical alteration impacts poromechanical and petrophysical characteristics of geothermal targets, which ultimately govern reservoir stability and subsidence, induced seismicity as well as fluid and heat extraction efficiency during geothermal operations.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 4","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JB030541","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143865938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}