Geophysical Research Letters最新文献_第6页

Abundant Quasi-Repeating Earthquakes Occurring Within Repeater Sequences on the Erkenek-Pütürge Fault (SE Turkey)

IF 4.6 1区地球科学

Geophysical Research Letters Pub Date : 2025-03-26 DOI: 10.1029/2024GL114367

Yijian Zhou, Abhijit Ghosh

{"title":"Abundant Quasi-Repeating Earthquakes Occurring Within Repeater Sequences on the Erkenek-Pütürge Fault (SE Turkey)","authors":"Yijian Zhou, Abhijit Ghosh","doi":"10.1029/2024GL114367","DOIUrl":"https://doi.org/10.1029/2024GL114367","url":null,"abstract":"Repeaters are known as earthquakes that rupture the same asperity in similar manners. However, the complexity of repeater asperities is poorly investigated. In this study, we developed a new strategy to systematically detect quasi-repeaters that rupture the same asperities in different ways. It begins by identifying repeaters using waveform cross-correlation (CC) ≥0.9 and CC-measured Δ(S-P) times ≤0.01 s. We then adopt a much lower CC threshold to detect quasi-repeaters, classifying repeater sequences as simple (lacking quasi-repeaters) or complex (including quasi-repeaters). Applying this workflow to the Erkenek-Pütürge fault in Turkey, we detected 43 repeater sequences during 2020–2023/04. Notably, 30 sequences (∼70%) are complex. The repeater magnitudes show weak correlation with their recurrence interval, with only complex sequences following the 2023 Mw 7.8 mainshock an exception. Moreover, ∼74% sequences have the first two events following the mainshocks exhibiting decreasing magnitude. These results suggest that slip rate and asperity complexity may be key factors in such modulation.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 6","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL114367","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143699020","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}

引用次数: 0

AMOC Modulates Ocean Heat Content During Deglaciations

IF 4.6 1区地球科学

Geophysical Research Letters Pub Date : 2025-03-26 DOI: 10.1029/2024GL114415

Markus Grimmer, Daniel Baggenstos, Jochen Schmitt, Florian Krauss, Sarah Shackleton, Jeffrey P. Severinghaus, Hubertus Fischer

{"title":"AMOC Modulates Ocean Heat Content During Deglaciations","authors":"Markus Grimmer, Daniel Baggenstos, Jochen Schmitt, Florian Krauss, Sarah Shackleton, Jeffrey P. Severinghaus, Hubertus Fischer","doi":"10.1029/2024GL114415","DOIUrl":"https://doi.org/10.1029/2024GL114415","url":null,"abstract":"During deglaciations, Earth takes up vast amounts of energy, about half of which heats the global ocean. Thus, ocean heat content (OHC) is a key metric to assess Earth's energy budget. Recent modeling studies suggest that OHC changes not only in response to orbitally driven climate change but is also modulated on millennial timescales by the Atlantic Meridional Overturning Circulation (AMOC). Here, we present the first OHC record for the last four deglaciations using noble-gas ratios in the EPICA Dome C ice core. The record reveals millennial-scale OHC variability in all studied deglaciations, most prominently as OHC maxima at the end of Terminations II, III, and IV. These millennial-scale OHC changes are anti-correlated with AMOC strength, suggesting that the AMOC modulates OHC across different climate states. Furthermore, given the magnitude of the end-of-termination OHC maxima, AMOC-induced OHC changes may be an important control of early interglacial atmospheric CO2, sea level, and climate.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 6","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL114415","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143707402","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}

引用次数: 0

Effect of Satellite Spatial Resolution on Submesoscale Variance in Ocean Color and Temperature

IF 4.6 1区地球科学

Geophysical Research Letters Pub Date : 2025-03-26 DOI: 10.1029/2024GL114266

Luke Carberry, David A. Siegel, Nicholas J. Nidzieko

引用次数: 0

Meltwater-Induced Lake Freshening and Muted Warming in Northern China Under Contemporary Global Warming

IF 4.6 1区地球科学

Geophysical Research Letters Pub Date : 2025-03-25 DOI: 10.1029/2024GL112819

Jiawei Jiang, Bowen Meng, Aifeng Zhou, Rong Chen, Cheng Zhao, Zhouqing Xie, Huanye Wang, Weiguo Liu, Zhonghui Liu, Peng Gong

引用次数: 0

A New Approach to Constrain Crustal Vp/Vs From Rayleigh Wave Phase Velocity and Local Amplification: Application to the Western US 从瑞利波相位速度和局部放大率推测地壳 Vp/Vs 的新方法：在美国西部的应用

IF 4.6 1区地球科学

Geophysical Research Letters Pub Date : 2025-03-24 DOI: 10.1029/2024GL111980

Yiran Huang, Colleen A. Dalton, Anant Hariharan

引用次数: 0

Projected Antarctic Land Warming and Uncertainty Driven by Atmospheric Heat Transport

IF 4.6 1区地球科学

Geophysical Research Letters Pub Date : 2025-03-24 DOI: 10.1029/2025GL114630

Yihan Zhang, Xiaoming Hu, Peixi Wang, Song Yang

{"title":"Projected Antarctic Land Warming and Uncertainty Driven by Atmospheric Heat Transport","authors":"Yihan Zhang, Xiaoming Hu, Peixi Wang, Song Yang","doi":"10.1029/2025GL114630","DOIUrl":"10.1029/2025GL114630","url":null,"abstract":"A significant warming is projected in Antarctic climate change under high CO2 forcing, involving complex interactions between ocean and land surfaces. While previous studies have emphasized the seasonal mechanism driving Antarctic ocean surface warming, the processes governing land surface warming remain less explored. Here we show that, under abrupt quadrupled CO2 forcing, Antarctic land surface experiences uniform warming throughout the year, primarily driven by poleward atmospheric heat transport, with latent energy transport playing a dominant role. This moisture-related transport not only delivers energy but also amplifies the water vapor feedback, significantly contributing to the warming. Our findings suggest that the discrepancies in representing these atmospheric processes across models, contribute substantially to the uncertainties in Antarctic land surface warming projections. The result emphasizes the need for improved understanding of the atmospheric dynamics in polar regions to reduce model uncertainties under future climate scenarios.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 6","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025GL114630","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143678248","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}

引用次数: 0

Energetic Compact Strokes as the Major Source of Downward Terrestrial Gamma-Ray Flashes in Winter Thunderstorms

IF 4.6 1区地球科学

Geophysical Research Letters Pub Date : 2025-03-24 DOI: 10.1029/2024GL113194

Ting Wu, David M. Smith, Yuuki Wada, Kazuhiro Nakazawa, Manari Oguchi, Masashi Kamogawa, Tomoyuki Suzuki, Qingliu Yang, Daohong Wang

{"title":"Energetic Compact Strokes as the Major Source of Downward Terrestrial Gamma-Ray Flashes in Winter Thunderstorms","authors":"Ting Wu, David M. Smith, Yuuki Wada, Kazuhiro Nakazawa, Manari Oguchi, Masashi Kamogawa, Tomoyuki Suzuki, Qingliu Yang, Daohong Wang","doi":"10.1029/2024GL113194","DOIUrl":"10.1029/2024GL113194","url":null,"abstract":"Terrestrial gamma-ray flashes (TGFs) are short bursts of intense gamma radiation associated with lightning discharges. Although thousands of TGFs have been observed from space, TGFs detected at ground level, known as downward TGFs, are still very limited, and their relationship with lightning discharge processes remains elusive. Here we report a special type of strong negative lightning stroke, termed energetic compact stroke (ECS), in winter thunderstorms in Japan, and provide strong evidence that ECSs are consistently associated with downward TGFs. Based on this relationship, we successfully identified three new downward TGFs by the observations of ECSs. Further, 12 out of 19 (63%) of downward TGFs analyzed in this paper were associated with ECSs, indicating that ECSs are the major source of downward TGFs in winter thunderstorms in Japan. These findings open up the possibility of remotely monitoring a large fraction of downward TGFs with simple lightning observations.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 6","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL113194","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143678245","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}

引用次数: 0

An Empirical Parameterization to Separate Coarse and Fine Mode Aerosol Optical Depth Over Land

IF 4.6 1区地球科学

Geophysical Research Letters Pub Date : 2025-03-24 DOI: 10.1029/2024GL114397

Xiaohan Li, Paul Ginoux

引用次数: 0

Shear-Layer Thickness and Structure Evolves With Effective Stress in Subglacial Environments

IF 4.6 1区地球科学

Geophysical Research Letters Pub Date : 2025-03-24 DOI: 10.1029/2024GL114109

Ian Madden, Dougal D. Hansen, Lucas K. Zoet, Jenny Suckale

{"title":"Shear-Layer Thickness and Structure Evolves With Effective Stress in Subglacial Environments","authors":"Ian Madden, Dougal D. Hansen, Lucas K. Zoet, Jenny Suckale","doi":"10.1029/2024GL114109","DOIUrl":"10.1029/2024GL114109","url":null,"abstract":"Moving glaciers shear and deform the subglacial till beneath them, with deformation concentrated in a thin shear-layer. This shear-layer's properties are partially controlled by effective stress, which depends on ice thicknesses and subglacial hydrological networks. Understanding the relationship between effective stress and shear-layer thickness helps characterize basal resistance to ice motion and inform subglacial landform formation. While experiments agree increasing effective stresses beget decreasing shear-layer thicknesses at high effective stresses, a trend is unclear at low effective stresses. Continuum models predict that increased effective stresses yield increasing shear-layer thicknesses, inconsistent with experiments. Here, we identify how properties of a medium's persistent contact network lead to non-monotonic shear-layer thicknesses in effective stress through Discrete Element Method simulations. We find effective stress can alter both shear-layer thickness and structure, and thereby depth-averaged friction. We integrate these insights into an existing continuum model by modifying its yield parameters, resolving inconsistency between model and experiment.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 6","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL114109","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143678254","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}

引用次数: 0

Collapse of the Atlantic Meridional Overturning Circulation in a Strongly Eddying Ocean-Only Model

IF 4.6 1区地球科学

Geophysical Research Letters Pub Date : 2025-03-24 DOI: 10.1029/2024GL114532

René M. van Westen, Michael Kliphuis, Henk A. Dijkstra

{"title":"Collapse of the Atlantic Meridional Overturning Circulation in a Strongly Eddying Ocean-Only Model","authors":"René M. van Westen, Michael Kliphuis, Henk A. Dijkstra","doi":"10.1029/2024GL114532","DOIUrl":"10.1029/2024GL114532","url":null,"abstract":"A collapse of the Atlantic Meridional Overturning Circulation (AMOC) under a quasi-equilibrium freshwater forcing has now been found in a hierarchy of ocean-climate models and up to a fully-coupled climate model, the Community Earth System Model (CESM). However, the effects of eddies on the ocean flows are represented in a highly idealized way in the CESM and it is unknown how these affect AMOC stability. Here, we show results of the first quasi-equilibrium hosing simulation with a strongly eddying ocean-only model in which the AMOC collapses. By comparing these results to those of a companion non-eddying simulation with the same model, it is found that eddies are able to maintain a weak (<math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>∼</mo>\u0000 </mrow>\u0000 <annotation> ${sim} $</annotation>\u0000 </semantics></math>5 Sv) AMOC flow in the collapsed state. In addition, we find that the AMOC induced freshwater transport at 34<math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>°</mo>\u0000 </mrow>\u0000 <annotation> ${}^{circ}$</annotation>\u0000 </semantics></math>S is a reliable physics-based early warning indicator for the onset of the AMOC collapse.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 6","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL114532","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143678253","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}

引用次数: 0