IF 5.2 1区地球科学

Geophysical Research Letters Pub Date : 2025-10-16 DOI: 10.1029/2025gl118949

Haoyu Wang, Jing Wang, Xiaofeng Li

引用次数: 0

Seesaw Shift in Sea Surface Height Drives Spring Decline of the Antarctic Slope Current in the Cosmonaut Sea, East Antarctica 海面高度的跷跷板变化驱动东南极洲Cosmonaut海的南极斜坡流春季下降

IF 5.2 1区地球科学

Geophysical Research Letters Pub Date : 2025-10-16 DOI: 10.1029/2025gl116792

Guijun Guo, Libao Gao, Haihua Xu, Jiuxin Shi, Bin Kong, Yongming Sun

引用次数: 0

RETRACTION: A Physics-Aware Machine Learning-Based Framework for Minimizing Prediction Uncertainty of Hydrological Models 一个基于物理感知的机器学习框架，用于最小化水文模型的预测不确定性

IF 5.4 1区地球科学

Water Resources Research Pub Date : 2025-10-16 DOI: 10.1029/wrcr.70439

引用次数: 0

Magnetofossil Gigantism in Modern Andaman Sea Sediments 安达曼海现代沉积物中的磁化石巨人论

IF 3.9 2区地球科学

Journal of Geophysical Research: Solid Earth Pub Date : 2025-10-16 DOI: 10.1029/2025jb031437

Shiva Kumar Kamasani, Firoz Badesab, Nitin Kadam, Dominic D'souza, Tim Grieb, Thomas Frederichs, Tilo von Dobeneck, Andreas Rosenauer, Omkar Sagavekar, Satish Sangode

{"title":"Magnetofossil Gigantism in Modern Andaman Sea Sediments","authors":"Shiva Kumar Kamasani, Firoz Badesab, Nitin Kadam, Dominic D'souza, Tim Grieb, Thomas Frederichs, Tilo von Dobeneck, Andreas Rosenauer, Omkar Sagavekar, Satish Sangode","doi":"10.1029/2025jb031437","DOIUrl":"https://doi.org/10.1029/2025jb031437","url":null,"abstract":"“Giant” magnetofossils were first discovered in pelagic Paleogene-Eocene Thermal Maximum event sections, but have also been recently identified in Late Pleistocene hemipelagic sediments such as the Bay of Bengal (BoB). Their obvious time-transgressive existence raises questions on the modern niches and habitat conditions of their still unknown producers. Here we report the occurrence of giant magnetofossils in Holocene surface sediments of the Andaman Sea (AS). Rock magnetic analyses indicate mixed (single, vortex, and multidomain state) magnetic mineral assemblages, where a prominent central ridge in first-order reversal curve diagrams signalizes a dominant biogenic magnetite component. Transmission electron microscopy reveal coexistence of conventional (prismatic, cuboctahedral, bullet) and giant (needle, bullet) magnetofossil morphologies, composed of stoichiometric, non-oxidized magnetite as confirmed by low-temperature magnetometry, energy dispersive spectrometry and crystallography. Based on the water column conditions, magnetofossil abundance and morphologies, we make inferences on habitat and environmental factors favored by the respective iron-biomineralizing organisms. Comparative analyses of water column profiles from AS and BoB revealed that relatively low, but uniform bottom water oxygenation and persistent suboxic conditions maintained by rapid renewal of deep water through circulation accompany the biomineralization of giant magnetic particles in the AS. Our investigations of two deep sediment core sites suggest that the modern AS is an ecological niche and promising investigation area for the yet-to-be-discovered, putative eukaryotic organisms, that biomineralize and release giant needle- and bullet-shaped magnetosomes to the sediment.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"10 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145296182","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}

引用次数: 0

Seismic Evidence for Cocos Slab Tearing and Nazca Slab Emplacement in the Southern Costa Rican Subduction Zone 哥斯达黎加南部俯冲带Cocos板块撕裂和Nazca板块侵位的地震证据

IF 5.2 1区地球科学

Geophysical Research Letters Pub Date : 2025-10-16 DOI: 10.1029/2025gl116194

Mingye Feng, Shengji Wei, Ling Chen, Xu Wang, Marino Protti, Lujia Feng

引用次数: 0

Atmospheric Nonlinearity Controls ENSO Asymmetry in a Hybrid Statistical‐Dynamical Climate Model 统计-动力混合气候模式中大气非线性控制ENSO不对称性

IF 5.2 1区地球科学

Geophysical Research Letters Pub Date : 2025-10-16 DOI: 10.1029/2025gl117456

Jacob Stuivenvolt‐Allen, Alexey V. Fedorov

引用次数: 0

Apparent Changes in Pacific Decadal Variability Caused by Anthropogenically Induced Mean State Modulations 人为平均状态调制引起的太平洋年代际变率的明显变化

IF 5.2 1区地球科学

Geophysical Research Letters Pub Date : 2025-10-16 DOI: 10.1029/2025gl116499

C. Xing, S. Stevenson, E. Di Lorenzo, M. Newman, A. Capotondi, J. Fasullo, N. Maher

{"title":"Apparent Changes in Pacific Decadal Variability Caused by Anthropogenically Induced Mean State Modulations","authors":"C. Xing, S. Stevenson, E. Di Lorenzo, M. Newman, A. Capotondi, J. Fasullo, N. Maher","doi":"10.1029/2025gl116499","DOIUrl":"https://doi.org/10.1029/2025gl116499","url":null,"abstract":"Pacific decadal variability (PDV), reflected in low‐frequency Pacific sea surface temperature (SST) changes, impacts global climate. Disentangling anthropogenic effects upon PDV is challenging because PDV and anthropogenic forcing vary on similar time scales. Using single‐forcing climate model large ensembles, we find that anthropogenic forcing drives a spatially varying pattern of mean‐state change in Pacific SST that projects onto PDV patterns, principally the Pacific Decadal Oscillation (PDO) and the North Pacific Gyre Oscillation (NPGO). When the trend is removed by subtracting the ensemble mean, there is no forced change of either PDV mode. However, analysis of individual ensemble members, where the mean‐state trend cannot be cleanly removed, yields apparent anthropogenic changes in PDO and NPGO decadal variability. This suggests that observed PDV responses to anthropogenic forcing may be erroneously convolved with the background trend pattern. Therefore, correctly determining the mean‐state trend is a necessary precursor for identifying possible forced changes to PDV.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"9 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145295225","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}

引用次数: 0

Continental‐Scale Lightning Observations at High Frequency 大陆尺度高频闪电观测

IF 5.2 1区地球科学

Geophysical Research Letters Pub Date : 2025-10-16 DOI: 10.1029/2025gl116075

Yunjiao Pu, Steven A. Cummer, Yongze Jia

引用次数: 0

A Drone-Borne GPR System for Lake and River Ice Thickness Monitoring 用于湖、河冰厚度监测的无人机探地雷达系统

IF 5.4 1区地球科学

Water Resources Research Pub Date : 2025-10-16 DOI: 10.1029/2025wr040290

Xu Meng, Zhenjun Zhu, Hai Liu, Yunlong Lian, Haijing Lu, Yikang Wang, Ruige Shi, Billie F. Spencer

{"title":"A Drone-Borne GPR System for Lake and River Ice Thickness Monitoring","authors":"Xu Meng, Zhenjun Zhu, Hai Liu, Yunlong Lian, Haijing Lu, Yikang Wang, Ruige Shi, Billie F. Spencer","doi":"10.1029/2025wr040290","DOIUrl":"https://doi.org/10.1029/2025wr040290","url":null,"abstract":"Monitoring ice on water is critical to study global and regional environmental change. However, accurate ice thickness mapping over a water body like a lake is still challenging. In this study, we first develop a drone-borne ground penetrating radar (GPR) system for ice thickness monitoring. This GPR system comprises a micro vector network analyzer, a Vivaldi antenna, a GNSS module, a microcomputer, and an independent power supply. The whole system weighs 1.6 kg, making it easy to mount on a drone. Then, a combined algorithm based on energy ratio and cross-correlation analysis is proposed to automatically extract the time delays between the ice surface and bottom reflections, from which the ice thickness is calculated. Finally, laboratory and field tests were conducted in our laboratory and at three reservoirs in China. Results verified that the GPR system could accurately produce high-resolution ice maps with thicknesses from a few centimeters to ∼one meter. Drilling validated that the relative error of ice thickness estimation is less than 2%. Our findings demonstrate that the developed drone-borne GPR system provides an efficient and accurate method for monitoring ice thickness over lakes, rivers, and reservoirs.","PeriodicalId":23799,"journal":{"name":"Water Resources Research","volume":"1 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145296178","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}

引用次数: 0

Electromagnetic Fields Generated by an Earthquake Due to the Piezomagnetic Effect 由压磁效应引起的地震产生的电磁场

IF 3.9 2区地球科学

Journal of Geophysical Research: Solid Earth Pub Date : 2025-10-16 DOI: 10.1029/2025jb031181

Yongxin Gao, Jie Zhao, Guanqun Zhou, Chieh-Hung Chen, Yang-yi Sun, Xuemin Zhang, Yuanyuan Li, Cheng Yao, Zeng Meng, Xiaodong Bai

{"title":"Electromagnetic Fields Generated by an Earthquake Due to the Piezomagnetic Effect","authors":"Yongxin Gao, Jie Zhao, Guanqun Zhou, Chieh-Hung Chen, Yang-yi Sun, Xuemin Zhang, Yuanyuan Li, Cheng Yao, Zeng Meng, Xiaodong Bai","doi":"10.1029/2025jb031181","DOIUrl":"https://doi.org/10.1029/2025jb031181","url":null,"abstract":"Stress change in ferromagnetic-minerals-bearing rocks can change the rock magnetization and lead to the variation in magnetic field, known as the piezomagnetic effect, which is a possible mechanism for the earthquake-associated electromagnetic (EM) signals. Previous studies are mostly based on elastostatics to obtain a static piezomagnetic field generated by a dislocation or pressure source, which is not sufficient to explain the observed time-varying EM signals during an earthquake. In this study, we investigate the time-varying EM response generated by an earthquake due to the piezomagnetic effect. We propose an analytically-based method to simulate the seismic and EM fields in a horizontally layered model, in which the coupled elastodynamic and Maxwell's equations are solved in the frequency-wavenumber domain. The time-space-domain seismic and EM responses are obtained through the Hankel transform and inverse Fourier transform. We conduct numerical simulations to investigate the properties of the EM responses to earthquakes. The results show that variations in not only magnetic fields but also electric fields can be generated due to the piezomagnetic effect. For an <i>M</i><sub>w</sub> 6.0 earthquake, a receiver with an epicentral distance of 85 km can receive coseismic electric and magnetic fields of ∼0.1 μV/m and ∼0.1 nT, which are detectable by current EM equipment, demonstrating that the piezomagnetic field is an effective mechanism for the generation of earthquake-associated EM disturbances. We apply the method to simulating the coseismic EM signals observed in an actual earthquake and find that the piezomagnetic effect possibly contribute to the observed data.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"159 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145296181","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}

引用次数: 0

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