地球科学最新文献

{"title":"The Shock-Substorm of 24 September 1998: A Different Type of Substorm Trigger Onset","authors":"Bruce T. Tsurutani,&nbsp;Rajkumar Hajra,&nbsp;Yusuke Ebihara,&nbsp;Gurbax S. Lakhina,&nbsp;Yasuhito Narita,&nbsp;Karl-Heinz Glassmeier","doi":"10.1029/2025GL115509","DOIUrl":"https://doi.org/10.1029/2025GL115509","url":null,"abstract":"<p>An interplanetary shock triggered a substorm with a peak intensity SML = −1,781 nT on 24 September 1998. This is called a shock-substorm here to differentiate it from generic substorms. The shock, with a speed of ∼790 km s⁻¹, caused the release of prestored magnetosphere/magnetotail energy plus additional solar wind input energy, the latter unusual for a shock-nonsupersubstorm event. The internal magnetospheric shock/wave had a speed of ∼630 km s⁻¹, consistent with arriving at <i>x</i> = −6 <i>R</i>_<i>E</i> at the time of substorm onset. The internal shock arrival to <i>x</i> = −10 <i>R</i>_<i>E</i> would have been after the substorm onset time, so magnetic reconnection for the substorm triggering can be ruled out. Akasofu (2023, https://doi.org/10.1093/mnras/stac3187) has stated that there are many different types of substorm onsets. We believe that this shock-substorm is different than generic substorms.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 16","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025GL115509","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144853839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Provenance, diagenesis, and paleoclimate of Albian-Lower Turonian deposits in the Douala sub-basin, Cameroon: Sedimentological, mineralogical, and petrographical approaches","authors":"Christel Sobdjou-Kemteu ,&nbsp;Milan Stafford Tchouatcha ,&nbsp;Wael Fathi Galal ,&nbsp;Soureiyatou Fadil-Djenabou ,&nbsp;Usman Abubakar ,&nbsp;Francis Thierry Togozo ,&nbsp;Emmanuel Ndjeng","doi":"10.1016/j.sesci.2025.100259","DOIUrl":"10.1016/j.sesci.2025.100259","url":null,"abstract":"<div><div>The sedimentological, mineralogical, and petrographic compositions of the Albian - Lower Turonian deposits at four sites in the northern part of the Douala sub-basin located in the heart of the Guinea Gulf were investigated to determine their provenance, paleoclimate, and diagenetic effects from thirty-eight (38) samples. Several lithologies are identified, ranging from clays/shales to silty clays, poor consolidated fine-to coarse-grained sandstones, and conglomerates to conglomeratic sandstones. The deposits are made up of successive positive sequences in the eastern part of the Mungo River and cyclic deposits in the western part. The sandstones are primarily arkose wacke, secondarily arkose, subarkose, sublith-arenite, and rare lithic arenite and wacke derived from the Neoproterozoic basement formed during the Pan-African orogenesis. The presence of heavy minerals such as tourmaline, kyanite and sillimanite indicates that the deposits originate from plutonic and metamorphic sources. The rarity of these latest in the sediments suggest the intense chemical weathering that has affected the source rocks. These deposits are mainly proximal. Additionally, the association of polycrystalline quartz with undulatory extinction and monocrystalline quartz with non-undulatory extinction suggests a mixed source. The various microstructures and morphologies of zircon grains including prismatic, sub-angular and sub-prismatic shapes further support a mixed provenance. The dominance of prismatic shape and non-undulatory monocrystalline quartz grains indicates a predominance of plutonic sources. X-ray diffraction analysis revealed that kaolinite is the dominant clay mineral found in clayey facies, though its moderate to low quantity indicates a more humid climate during the Albian-Cenomanian and a less humid climate during the Cenomanian. Physical alteration processes have mainly affected the studied deposits.</div></div>","PeriodicalId":54172,"journal":{"name":"Solid Earth Sciences","volume":"10 3","pages":"Article 100259"},"PeriodicalIF":2.0,"publicationDate":"2025-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144852843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Automatic Classification of Primary and Secondary Craters Near Copernicus Crater With Updated Insights on Its Impact Trajectory and Age","authors":"Yiran Wang,&nbsp;Miao Zhuo,&nbsp;Bo Wu,&nbsp;Shuo Liu,&nbsp;Dijun Guo","doi":"10.1029/2024JE008516","DOIUrl":"https://doi.org/10.1029/2024JE008516","url":null,"abstract":"<p>Impact cratering is the dominant geological process shaping the Moon's surface. Primary craters form from direct asteroid or comet impacts, while secondary craters are created by debris ejected from these primary impacts. Accurately identifying secondary craters within the primary crater population is essential for understanding planetary processes and surface ages. However, manually distinguishing these secondary craters can be time-consuming and challenging. In this work, a statistical analysis of 5,460 primary and secondary craters reveals significant differences in their spectral characteristics. These differences are postulated to originate from distinct degrees of modification to the target materials and weathering processes. Employing a deep learning model, the research specifically targets the Copernicus crater region to automate the identification of secondary craters. The model classified ∼285,000 secondary and ∼39,000 primary craters with diameters from 200 m to 5 km. Secondary craters make up 89% of the total at 200–280 m, decreasing to around 65% at 4,520–5,000 m. The azimuthal distribution of identified secondary craters suggests an oblique impact from southeast to northwest that formed the Copernicus crater. The model age, based on craters superposed on the ejecta, estimates the Copernicus crater to be ∼755 Ma, overlaying a 3.69 Ga surface. The estimated ages align with previous research. The method is best suited for geologically homogeneous, airless surfaces, and is limited when older primary craters are buried by later ejecta or when ancient craters exhibit similar spectral features due to degradation.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"130 8","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144853654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 Efficiency of Water Vapor on Top-of-Atmosphere Radiation","authors":"Jing Feng,&nbsp;David Paynter,&nbsp;Nicole Feldl,&nbsp;Zhihong Tan,&nbsp;Pu Lin","doi":"10.1029/2025GL115210","DOIUrl":"https://doi.org/10.1029/2025GL115210","url":null,"abstract":"<p>Earth's climate sensitivity is greatly affected by the compensation between temperature feedback and water vapor (WV) feedback. Using abrupt 4xCO₂ experiments, we show that the global-mean WV feedback is nearly a linear function of the temperature feedback, the slope of which is explained by the longwave radiative efficiency of WV <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>(</mo>\u0000 <mi>ϵ</mi>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation> $({epsilon})$</annotation>\u0000 </semantics></math>. Although <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>ϵ</mi>\u0000 </mrow>\u0000 <annotation> ${epsilon}$</annotation>\u0000 </semantics></math> remains constant across models in the global mean, it exhibits substantial spatial variations and is particularly weak in Antarctica, where near-surface inversions decouple the surface from the free troposphere. We introduce a surface–free troposphere temperature difference (SFTD) metric, showing that positive SFTD (e.g., high lifting condensation level) amplifies <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>ϵ</mi>\u0000 </mrow>\u0000 <annotation> ${epsilon}$</annotation>\u0000 </semantics></math>, while negative SFTD (e.g., strong surface inversion) suppresses it. These findings provide a clear explanation of how local climate conditions modulate the radiative compensation between temperature and WV feedbacks.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 16","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025GL115210","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144853835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Interpreting Energy-Latitude Dispersions in Mercury's Northern Magnetospheric Cusp With MESSENGER","authors":"Ryan M. Dewey,&nbsp;Jim M. Raines,&nbsp;Jamie M. Jasinski,&nbsp;James A. Slavin","doi":"10.1029/2025JA034278","DOIUrl":"https://doi.org/10.1029/2025JA034278","url":null,"abstract":"<p>We examined energy-latitude dispersions in Mercury's northern magnetospheric cusp. These systematic trends in plasma energy originate from differences in particle travel time from the dayside magnetopause reconnection site to the low altitude, high latitude cusp. Compared to other planetary magnetospheres, the small size of Mercury's magnetosphere, large relative size of the cusps, and MESSENGER's orbital geometry require careful tracking of spacecraft motion with respect to the planetary field. We incorporate this relative motion into a physical model for these dispersions and apply it to a set of MESSENGER cusp crossings with coherent dispersions. Fitting these dispersions returns the distance of the open-closed field line boundary from the cusp and the length of the field line to the reconnection site. We demonstrate that these physical parameters can be used to probe both Mercury's solar wind coupling as well as the structure of the dayside magnetosphere. From the set of crossings, we find that dispersions are common to Mercury's cusp, that they indicate that the cusp is typically located poleward of the open-closed boundary by ∼6 <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>±</mo>\u0000 </mrow>\u0000 <annotation> $mathit{pm }$</annotation>\u0000 </semantics></math> 3° invariant latitude, and that Mercury's magnetosphere often exhibits steady conditions for multiple Dungey cycle durations at a time. Individual case studies further demonstrate that the structure of Mercury's dayside magnetosphere can be decoupled from magnetopause reconnection and that MESSENGER can cross the dayside magnetopause into open northward planetary field lines. As part of this work, we advance uncertainty quantification and fitting techniques that can be applied to other features in Mercury's magnetosphere and other planetary systems.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":"130 8","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JA034278","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144858588","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":"Stress Heterogeneities Governed by Fault Structure and Stress Transfer: The 2016–2017 Central Italy Seismic Sequence","authors":"Patricia Martínez-Garzón,&nbsp;Men-Andrin Meier,&nbsp;Cristiano Collettini,&nbsp;Federica Lanza,&nbsp;Georg Dresen","doi":"10.1029/2024JB029763","DOIUrl":"https://doi.org/10.1029/2024JB029763","url":null,"abstract":"<p>We analyze the evolution of stress parameters from the 2016–2017 central Italy seismic sequence taking advantage of ∼13,747 robust focal mechanisms from a deep learning catalog. The density of the catalog allows us to invert focal mechanisms over distances of a few km and different time periods. We inferred a number of stress-related parameters, including the fault plane variability, the orientation of principal stress axes and maximum horizontal stress, the relative magnitudes of principal stresses and the variability of the principal stress orientations with respect to the median. From the uniform regional stress field consistent with the extension of the Apennine Belt, we observe local stress heterogeneities that are driven by the structural features and the coseismic stress history. A variation of the principal stress magnitudes and regimes from pure normal faulting toward transtension with depth is observed. Stress differences at the 1–10 km wavelength are observed between each side of two of the main regional fault structures. The reported stress results suggest a partial mechanical coupling and a strong interaction between the shallow normal faults and the detachment horizon at depth. Furthermore, distinct trends are observed in the stress parameters after the largest mainshocks, and before the <i>M</i>_W 6.5 Norcia mainshock, potentially indicating the high shear stress still available in well oriented faults after the <i>M</i>_W 6.0 Amatrice earthquake. Our analysis holds implications toward (a) constraining stress magnitudes, (b) illuminating the interaction between the shallow normal faults and detachment horizons, and (c) tracking stress evolution during seismic sequence.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 8","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2024JB029763","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144858589","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":"Time and Length Scales of the Martian Atmospheric Turbulence as Observed by the InSight Lander","authors":"Orkun Temel,&nbsp;Ozgur Karatekin","doi":"10.1029/2025GL115539","DOIUrl":"https://doi.org/10.1029/2025GL115539","url":null,"abstract":"<p>We provide a statistical analysis of the Martian near-surface atmospheric turbulence based on in situ wind observations from NASA's InSight lander. We focus on the variations in length and time scales of the Martian atmospheric turbulence caused by the diurnal cycle and changes in atmospheric dust loading. We observe that the length and time scales of the turbulence have distinct behaviors before and after the dust storms. Moreover, we report an asymmetric trend in the diurnal evolution of the Martian near-surface meteorological conditions, with stronger turbulence observed in the planetary boundary layer during late afternoon-early evening compared to sunrise. We also find that strong nocturnal turbulence can occur following the collapse of the daytime boundary layer under a certain range of dust opacity.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 16","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025GL115539","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144843451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Genetic diversity must be explicitly recognized in ecological restoration","authors":"Magdalene N. Ngeve","doi":"10.1038/s41558-025-02405-y","DOIUrl":"https://doi.org/10.1038/s41558-025-02405-y","url":null,"abstract":"<p>The Global Forest Watch estimated a net change of −101 Mha in tree cover between 2000 and 2020, and a net carbon sink of −5.59 GtCO₂e yr⁻¹ (ref. ²). Global degradation of seagrass could emit, on average, 1.15 GtCO₂ if no conservation measures are put in place³. Rising carbon emissions and associated climate change are happening alongside other types of anthropogenic disturbance, including land-use change, habitat loss and pollution, collectively disrupting biodiversity across diverse global ecosystems. Such magnitude of loss is linked to erosion of the genetic integrity in ecosystems: adaptive gene variants can be lost, gene flow networks altered⁴ and degraded sites are further prone to reduced effective population sizes due to increased genetic drift. Genetic diversity is crucial for disease resistance, fitness and the long-term survival of species, and is particularly important in the context of ongoing rapid multi-factor global change. For climate change in particular, as species’ habitats and ranges shrink in response, genetic homogenizations and loss of variation and adaptability potential have been observed⁵. Despite this, genetic diversity is often neglected in restoration planning and management, and seldom included in monitoring assessments of restoration outcomes.</p><p>The absence of clear language defining biodiversity in the UN and other restoration documents forces stakeholders to have to define it for themselves. Within a broader biodiversity context that includes species, functional and ecosystem diversity, genetic diversity may be less likely to be prioritized for a variety of reasons. In many regions and for most species (and populations), there remains a lack of an established baseline of genetic data, with costs and expertise required to obtain such baselines and conduct ongoing monitoring. Decisions on the sources of germplasm used in restoration typically prioritize short-term cost savings over long-term benefits⁶, despite the demonstrated potential for decreased long-term costs because there would be less need to replace planted trees in forest restoration⁶. In other contexts, for example community-led restoration projects, the concept of within-species (genetic) diversity may remain relatively obscure.</p>","PeriodicalId":18974,"journal":{"name":"Nature Climate Change","volume":"42 1","pages":""},"PeriodicalIF":30.7,"publicationDate":"2025-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144851332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Increasing physical work capacity losses due to heat stress increase.","authors":"Seok-Geun Oh, Seok-Woo Son, Dong-Chan Hong","doi":"10.1007/s00484-025-03008-0","DOIUrl":"https://doi.org/10.1007/s00484-025-03008-0","url":null,"abstract":"<p><p>As global warming continues, hotter and more humid weather conditions become increasingly frequent, heightening population exposure to heat-stress environments. This could lead to a loss of physical work capacity (PWC loss) and result in significant economic risks. Here, we investigate the PWC loss risks and their recent changes under different heat stress environments for the period of 1985-2023. Changes in PWC loss risks on comfort days, defined by heat stress values of 20-29 °C, show a latitudinal contrast, with an overall decrease in low latitudes and an increase in high latitudes. However, they have increased everywhere on both discomfort days (30-45 °C) and dangerous days (above 45 °C), with a greater increase in the latter condition. This suggests that global warming is exacerbating the risks of PWC loss in more intense heat stress environments. Geographically, Western Europe, the Mediterranean, Siberia, the Caribbean, and northeastern South America have experienced more significant increases in PWC loss risks, exceeding 1.5 times relative to the climatological mean over the past four decades. Such changes are due more to changes in the frequency of heat stress days than to changes in the severity of PWC loss. This finding suggests that the spatio-temporal variations in meteorological aspects should be taken into account when designing policies to address PWC loss risks due to heat stress.</p>","PeriodicalId":588,"journal":{"name":"International Journal of Biometeorology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144854157","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":"Closing the flood insurance protection gap","authors":"June Choi","doi":"10.1038/s41558-025-02385-z","DOIUrl":"https://doi.org/10.1038/s41558-025-02385-z","url":null,"abstract":"Climate change is increasing financial impacts for households, yet flood insurance coverage remains insufficient. Now research affirms that there are still opportunities to substantially close the protection gap, in particular for disadvantaged groups.","PeriodicalId":18974,"journal":{"name":"Nature Climate Change","volume":"23 1","pages":""},"PeriodicalIF":30.7,"publicationDate":"2025-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144851333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}