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The 2021 Mw7.0 and Mw6.7 Miyagi-Oki earthquakes nucleated in a deep seismic/aseismic transition zone Possible effects of transient instability due to the 2011 Tohoku earthquake J. Geophys. Res. Solid Earth (IF 4.39) Pub Date : 2022-08-13 Keisuke Yoshida, Toru Matsuzawa, Naoki Uchida
In March and May 2021, Mw7.0 and Mw6.7, respectively, deep interplate earthquakes occurred off Miyagi, Japan, near the downdip edge of the rupture area of the 2011 M9 Tohoku earthquake. We study the two Mw∼7 earthquakes to investigate how a great (Mw∼9) earthquake cycle impacts the generation of smaller (Mw7-8) earthquakes in the deep seismic/aseismic transition zone. Our hypocenter relocation results
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Magnetic properties of ferrofluid change over time: Implications for magnetic pore fabric studies J. Geophys. Res. Solid Earth (IF 4.39) Pub Date : 2022-08-13 A.R. Biedermann, J.M. Parés
The anisotropy of magnetic susceptibility of ferrofluid-impregnated samples is an efficient and powerful proxy for pore space anisotropy and preferred flow directions. One of the main assumptions in pore fabric studies is that all pores > 10-20 nm are homogeneously filled with ferrofluid, and that the ferrofluid has constant properties throughout the pore space and over time. If only part of the pore
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Brittle faulting at elevated temperature and vanishing effective stress J. Geophys. Res. Solid Earth (IF 4.39) Pub Date : 2022-08-13 N. M. Beeler
If brittle fault strength depends only on friction, slip instability is discouraged at low effective normal stress, σ. Stress drop and the critical stiffness necessary for unstable sliding both vanish with σ; small earthquakes cannot occur. Very low σ is inferred in the source region of low frequency earthquakes (LFEs) on the San Andreas fault (SAF). Moreover, if pore pressure, p, is undrained at low
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Geoid Reveals the Density Structure of Cratonic Lithosphere J. Geophys. Res. Solid Earth (IF 4.39) Pub Date : 2022-08-13 Yaoyi Wang, Lijun Liu, Quan Zhou
Geoid is a key observable for understanding the dynamics of the deep Earth, but has been considered largely transparent to long-wavelength shallow density structures, especially those of the cratonic lithosphere. Here, we demonstrate that the observed flat craton-ocean geoid pattern, traditionally interpreted as reflecting neutrally buoyant cratonic keels, provides critical constraints on both the
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A Rotation Procedure to Improve Seasonally Varying Empirical Orthogonal Function Bases for MJO Indices Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-09 Sarah Weidman, Ned Kleiner, Zhiming Kuang
Various indices have been defined to characterize the phase and amplitude of the Madden-Julian oscillation (MJO). One widely used index is the outgoing longwave radiation (OLR) based MJO index (OMI), which is calculated using the spatial pattern of 30–96-day eastward-filtered OLR. The empirical orthogonal functions (EOFs) used to calculate the OMI in observations are prone to degeneracy and exhibit
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Formation of Continental Crust by Diapiric Melting of Recycled Crustal Materials in the Mantle Wedge Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-09 Shi-Min Li, Qing Wang, Di-Cheng Zhu, Peter A. Cawood, Robert J. Stern, Zhidan Zhao
The compositional similarity between high-Mg andesite-dacite from accretionary orogens and bulk continental crust (CC) provides an opportunity to unravel the CC formation paradox. Compositional data from a global compilation of Quaternary magmatic arcs indicate the presence of low-Mg series (LMS) and high-Mg series (HMS). The LMS show trends of crystal fractionation and can be subdivided into high
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Sign of Observed California Temperature Trends Depends on Data Set Homogenization: Implications for Weighting and Downscaling Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-09 Alexander B. Charn, Travis A. O’Brien, Mark D. Risser, Julia M. Longmate, Daniel R. Feldman
Because downscaling methods can yield substantially different projections of future climate, it is imperative to constrain these projections with information from existing observations, while also recognizing observational uncertainty. California is a natural test case to develop observational constraints on future projections given prior studies that have purportedly found contrasting spatial patterns
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Dissimilar Sensitivities of Ocean Acidification Metrics to Anthropogenic Carbon Accumulation in the Central North Pacific Ocean and California Current Large Marine Ecosystem Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-09 Mar C. Arroyo, Andrea J. Fassbender, Brendan R. Carter, Christopher A. Edwards, Jerome Fiechter, Addie Norgaard, Richard A. Feely
We analyze and compare changes in ocean acidification metrics caused by anthropogenic carbon (Canth) accumulation in the North Pacific Ocean and California Current Large Marine Ecosystem (CCLME). The greatest declines in pH and carbonate mineral saturation state occur near the surface, coincident with the highest Canth concentrations. However, maximal increases in the partial pressure of carbon dioxide
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Formation of an Al-Rich Niccolite-Type Silica in Subducted Oceanic Crust: Implications for Water Transport to the Deep Lower Mantle Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-09 Lu Liu, Hongsheng Yuan, Yao Yao, Ziqiang Yang, Federico Aiace Gorelli, Nico Giordano, Lixin He, Eiji Ohtani, Li Zhang
Subducted oceanic crust is enriched in free silica. Although being one of the silica polymorphs at lower-mantle pressures, niccolite-type phase (Nt-phase) has not been documented in multicomponent metabasaltic or metasediment compositions relevant to subducting oceanic crust. Here, we report the formation of an Al-rich Nt-phase (∼24.4 to 32.4 wt% Al2O3), coexisting with Al-depleted bridgmanite (∼6
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Kinetic Generation of Whistler Waves in the Turbulent Magnetosheath Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-09 I. Svenningsson, E. Yordanova, G. Cozzani, Yu. V. Khotyaintsev, M. André
The Earth's magnetosheath (MSH) is governed by numerous physical processes which shape the particle velocity distributions and contribute to the heating of the plasma. Among them are whistler waves which can interact with electrons. We investigate whistler waves detected in the quasi-parallel MSH by NASA's Magnetospheric Multiscale mission. We find that the whistler waves occur even in regions that
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A Stimulated Emission Diagnostic Technique for Electron Temperature of the High Power Radio Wave Modified Ionosphere Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-09 H. Y. Fu, M. L. Jiang, J. Vierinen, I. Häggström, M. T. Rietveld, E. Varberg, H. Sato, J. Wu, W. A. Scales, Y. Q. Jin
We report observations of stimulated electromagnetic emission (SEE) induced by high power high frequency (HF) radio waves near the third electron gyroharmonic (3) at European Incoherent Scatter Radar (EISCAT). It is discovered that stimulated Brillouin scattering (SBS) spectrum behaves similarly as spectral ion lines of the incoherent scatter radar (ISR) for HF pumping frequency above 3. The SBS spectral
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A Minimally Cemented Shallow Crust Beneath InSight Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-09 Vashan Wright, Jhardel Dasent, Richard Kilburn, Michael Manga
Ice and other mineral cements in Mars' shallow subsurface affect the mechanical properties of the shallow crust, the geologic processes that shape the planet's surface, and the search for past or extant Martian life. Cements increase seismic velocities. We use rock physics models to infer cement properties from seismic velocities. Model results confirm that the upper 300 m of Mars beneath InSight is
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A Review on Applications of Time-Lapse Electrical Resistivity Tomography Over the Last 30 Years : Perspectives for Mining Waste Monitoring Surv. Geophys. (IF 7.965) Pub Date : 2022-08-12 Adrien Dimech, LiZhen Cheng, Michel Chouteau, Jonathan Chambers, Sebastian Uhlemann, Paul Wilkinson, Philip Meldrum, Benjamin Mary, Gabriel Fabien-Ouellet, Anne Isabelle
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Acoustic and Electrical Properties of Tight Rocks: A Comparative Study Between Experiment and Theory Surv. Geophys. (IF 7.965) Pub Date : 2022-08-12 Mengqiang Pang, Jing Ba, José M. Carcione, Martin Balcewicz, Wenzheng Yue, Erik H. Saenger
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Heterogeneous subgreenschist deformation in an exhumed sediment-poor mélange J. Geophys. Res. Solid Earth (IF 4.39) Pub Date : 2022-08-12 H. Leah, Å. Fagereng, N. Groome, D. Buchs, A. Eijsink, A. Niemeijer
Many described subduction complexes (or mélanges) exhumed from seismogenic depths comprise thick, turbidite-dominated sequences with deformed zones containing clasts or boudins of more competent sandstone and/or basalt. In contrast, many active subduction zones have a relatively small thickness of sedimentary inputs ( < 2 km), turbidite sequences are commonly accreted rather than subducted, and the
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Quantifying large-scale surface change using SAR amplitude images: Crater morphology changes during the 2019-2020 Shishaldin Volcano eruption. J. Geophys. Res. Solid Earth (IF 4.39) Pub Date : 2022-08-12 M. Angarita, R. Grapenthin, S. Plank, F. J. Meyer, H. Dietterich
Morphological processes often induce meter-scale elevation changes. When a volcano erupts, tracking such processes provides insights into the style and evolution of eruptive activity and related hazards. Compared to optical remote-sensing products, Synthetic Aperture Radar (SAR) observes surface change during inclement weather and at night. Differential SAR interferometry estimates phase change between
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Spatio-temporal Structure of Far Ultraviolet Martian Dayglow Observed by EMM-EMUS Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 S. L. England, S. Jain, J. Deighan, M. Chaffin, G. Holsclaw, J. S. Evans, J. Correira, M. O. Fillingim, R. L. Lillis, H. Al Matroushi, F. Lootah, H. Al Mazmi
Mars’ ultraviolet dayglow has been used to study its upper atmosphere for over four decades. Identifying variations in emission features has provided information on composition, density and temperature. The Emirates Mars Ultraviolet Spectrometer onboard the Emirates Mars Mission observes Mars’ dayglow at Far and Extreme UV wavelengths. Variations in disk emission features are studied, with a focus
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The role of mid-latitude westerly jet in the impacts of November Ural blocking on early-winter warmer Arctic-colder Eurasia pattern Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 Xinping Xu, Shengping He, Botao Zhou, Huijun Wang, Stephen Outten
Based on statistical analysis using observations and idealized model simulations, previous studies have revealed the potential response of early-winter atmospheric circulation and temperature anomalies to November Ural blocking (UB) anomalies. Using a large number of coupled simulations, this study found that the response is sensitive to the intensity of November mid-latitude westerly jet over Eurasia
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Impact of vertical mixing parameterizations on internal gravity wave spectra in regional ocean models Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 Ritabrata Thakur, Brian K. Arbic, Dimitris Menemenlis, Kayhan Momeni, Yulin Pan, W. R. Peltier, Joseph Skitka, Matthew H. Alford, Yuchen Ma
We present improvements in the modeling of the vertical wavenumber spectrum of the internal gravity wave continuum in high-resolution regional ocean simulations. We focus on model sensitivities to mixing parameters and comparisons to McLane moored profiler observations in a Pacific region near the Hawaiian Ridge, which features strong semidiurnal tidal beams. In these simulations, the modeled continuum
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Neglected spatiotemporal variations of model biases in ensemble-based climate projections Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 Tangnyu Song, Guohe Huang, Xiuquan Wang
The Bayesian Model Averaging (BMA) method has been widely used for generating probabilistic climate projections. However, the averaging weights used in BMA can only reflect the spatially- and temporally-averaged performance of each ensemble member, without the ability to address the spatiotemporal variations of model biases. This can lead to inevitable exaggeration or understatement of the contributions
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Synoptic Impacts on the Occurrence of Mesoscale Boundaries and Their Associated Convection over an Area of Sharp Vegetation Contrast Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 Yipeng Huang, Zhiyong Meng, Murong Zhang
This study examined synoptic impacts on the occurrence of boundaries and their associated convection during summers from 2012–2016 over Hetao Irrigation District in North China, where there is a sharp vegetation contrast. Objective classification showed that boundary days, especially convective boundary days, were more frequent under a mid-troposphere, high-pressure ridge or pre-trough pattern. Such
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Intensified Northern Hemisphere glaciation facilitates continuous accumulation of late Pliocene loess on the western margin of the Pamir Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 Jinbo Zan, Wenxiao Ning, Friedrich Heller, Xiaomin Fang, Weilin Zhang, Jian Kang
Thick eolian loess sequences in arid Central Asia (CA) contain a wealth of information on the intensity variations of mid-latitude westerlies and the aridification history of the nearby deserts. In this study, detailed lithologic and magnetostratigraphic investigations suggest that loess deposits on the western margin of the Pamir Plateau began to accumulate at around 2.7 Ma, representing the most
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Monitoring in-situ microbial growth and decay in soil column experiments by induced polarization Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 Yalin Song, Xiaoqing Shi, André Revil, Xueyuan Kang
Real-time monitoring of the microbial activity in porous media faces considerable challenges because conventional analytical procedures are intrusive. Induced polarization (IP) has shown promises as a non-intrusive monitoring approach for such processes. However, quantitative analysis of soil column experiments to show how IP-based parameters can be related to the density of bacteria is still lacking
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"Double door" opening of the Japan Sea inferred by Pn attenuation tomography Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 Geng Yang, Lian-Feng Zhao, Xiao-Bi Xie, Xi He, Yan Lü, Zhen-Xing Yao
The extension of back-arc basins and formation of marginal seas following the subduction of oceanic lithosphere are usually attributed to the rollback of subducting slabs and distorted mantle convection. However, for the Japan Sea, the largest marginal sea in the northwestern Pacific, its opening is unlikely only resulted from the subduction of the Pacific plate because of the coeval Philippine plate
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Significantly increased lightning activity over the Tibetan Plateau and its relation to thunderstorm genesis Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 Xiushu Qie, Kai Qie, Lei Wei, Kexin Zhu, Zhuling Sun, Shanfeng Yuan, Rubin Jiang, Hongbo Zhang, Chen Xu
Under the context of global warming, we identified a significant increase in lightning activity in the last two decades over the Tibetan Plateau (TP), the highest and largest plateau on earth, based on two datasets. The largest rise of lightning activity was found over the region with high lightning density represented by the eastern TP at a rate of 0.072±0.069 fl km-2 yr-1 during 1996-2013 from OTD/LIS
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Linking distributed and integrated fiber-optic sensing Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 Daniel C. Bowden, Andreas Fichtner, Thomas Nikas, Adonis Bogris, Christos Simos, Krystyna Smolinski, Maria Koroni, Konstantinos Lentas, Iraklis Simos, Nikolaos S. Melis
Distributed Acoustic Sensing (DAS) has become a popular method of observing seismic wavefields: backscattered pulses of light reveal strains or strain-rates at any location along a fiber-optic cable. In contrast, a few newer systems transmit light through a cable and collect integrated phase delays over the entire cable, such as the Microwave Frequency Fiber Interferometer (MFFI). These integrated
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Electron-scale reconnection in three-dimensional shock turbulence Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 J. Ng, L.-J. Chen, N. Bessho, J. Shuster, B. Burkholder, J. Yoo
Magnetic reconnection has been observed in the transition region of quasi-parallel shocks. In this work, the particle-in-cell method is used to simulate three-dimensional reconnection in a quasi-parallel shock. The shock transition region is turbulent, leading to the formation of reconnecting current sheets with various orientations. Two reconnection sites with weak and strong guide fields are studied
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Robust Subsurface Biological Response during the Decaying Stage of an Extreme Indian Ocean Dipole in 2019 Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 Hongliang Li, Jingjing Zhang, Xinyang Wang, Yuanli Zhu, Lin Liu, Baodong Wang, Xuelei Zhang, Qinsheng Wei, Ruibin Ding, Jiliang Xuan, Lu Shou, Feng Zhou, Jianfang Chen
The Indian Ocean Dipole (IOD) is the predominant interannual climate mode and is critical in regulating the biogeochemical cycles of the equatorial Indian Ocean (EIO). However, the dynamics of nutrient supply and the magnitude of biological responses are less understood. Here, by comparing the biophysical in situ observations across the eastern EIO during the decaying period of an positive IOD in 2019
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Water-induced Diamond Formation at Earth’s Core-Mantle Boundary Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 Byeongkwan Ko, Stella Chariton, Vitali Prakapenka, Bin Chen, Edward J. Garnero, Mingming Li, Sang-Heon Shim
The carbon and water cycles in the Earth’s interior are linked to key planetary processes, such as mantle melting, degassing, chemical differentiation, and advection. However, the role of water in the carbon exchange between the mantle and core is not well known. Here, we show experimental results of a reaction between Fe3C and H2O at pressures and temperatures of the deep mantle and core-mantle boundary
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Quasi-universal length scale of river anabranches Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 Niccolò Ragno, Marco Redolfi, Marco Tubino
Looping patterns, where channels divide and reconnect further downstream, are widespread in natural rivers. Here, we build an extensive dataset of different gravel-bed and sand-bed rivers around the world encompassing a wide range of physiographic and sedimentological conditions. Field data show the existence of quasi-universal relations for the anabranches length when scaled with bankfull hydraulic
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A novel approach for reconstructing slip histories for bedrock fault scarps using rock surface luminescence dating Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 Ming Luo, Jie Chen, Lewis A. Owen, Jintang Qin, Jinhui Yin, Huili Yang, Jinfeng Liu, Zhijun Gong, Jiahong Luo
A newly developing method, optically stimulated luminescence (OSL)-depth profiles (DPs), provides a novel means of reconstructing and quantifying fault slip on timescales of 101–4 years. A targeted bedrock fault scarp along Langshan in north China, used as proof of concept, is divided into four sections based on four groups of OSL-DPs at different heights up the bedrock fault scarp. These have seismic
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Transcrustal compressible fluid flow explains the Altiplano-Puna gravity and deformation anomalies Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 J. Gottsmann, E. Eiden, M. E. Pritchard
Enigmatic large-scale ( > 150 km wide) ground deformation in southern Bolivia has been ongoing for more than 50 years. Concurrent changes in gravity recorded between 2010 and 2018 imply minor changes in subsurface density in the absence of significant mass changes. Numerical modelling of the gravity changes and concurrent InSAR LOS displacements gives annual bulk density changes of 0.002 kg m−3 in
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Increasing trends in oceanic surface poleward eddy heat flux observed over the past three decades Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 Yiming Guo, Scott Bachman, Frank Bryan, Stuart Bishop
Mesoscale processes make the largest contribution to ocean variability and are significant agents in ocean heat transport. In this investigation, we provide evidence based on satellite observations for an increasing trend in surface transient eddy heat flux (EHF) over the period 1993–2020. The enhanced EHF is particularly prominent in western boundary currents and their extensions at mid-latitudes
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Atmospheric radiative and oceanic biological productivity responses to increasing anthropogenic-combustion iron emission in the 1850-2010 period Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 S. D. Rathod, D. S. Hamilton, L. Li, N. M. Mahowald, H. Matsui, J. R. Pierce, T. C. Bond
Anthropogenic emission is an important component of the present-day iron cycle yet its long-term impacts on climate are poorly understood. Iron mineralogy strongly affects its radiative and oceanic interactions and was unrepresented in previous studies. We perform simulations using a mineralogy-based inventory and an atmospheric transport model and estimate the 1850-to-2010 global mean direct radiative
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Projected changes of surface winds over the Antarctic continental margin Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 Julia Neme, Matthew H. England, Andrew McC. Hogg
Surface winds around the Antarctic continent control coupled ocean-ice processes that influence the climate system, including bottom water production, heat transport onto the continental shelf and sea ice coverage. However, few studies have examined projected changes in these winds, even though it would aid in the interpretation and understanding of the ocean’s response to climate change. Using Coupled
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Abundances of uranium and thorium elements in Earth estimated by geoneutrino spectroscopy Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 S. Abe, S. Asami, M. Eizuka, S. Futagi, A. Gando, Y. Gando, T. Gima, A. Goto, T. Hachiya, K. Hata, K. Hosokawa, K. Ichimura, S. Ieki, H. Ikeda, K. Inoue, K. Ishidoshiro, Y. Kamei, N. Kawada, Y. Kishimoto, M. Koga, M. Kurasawa, N. Maemura, T. Mitsui, H. Miyake, T. Nakahata, K. Nakamura, K. Nakamura, R. Nakamura, H. Ozaki, T. Sakai, H. Sambonsugi, I. Shimizu, Y. Shirahata, J. Shirai, K. Shiraishi, A
The decay of the primordial isotopes 238U, 235U, 232Th, and 40K have contributed to the terrestrial heat budget throughout the Earth’s history. Hence the individual abundance of those isotopes are key parameters in reconstructing contemporary Earth models. The geoneutrinos produced by the radioactive decays of uranium and thorium have been observed with the Kamioka Liquid-Scintillator Antineutrino
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Elastic Anomalies across the α-β Phase Transition in Orthopyroxene: Implication for the Metastable Wedge in the Cold Subduction Slab Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 Luo Li, Ningyu Sun, Weigang Shi, Zhu Mao, Yingxin Yu, Yanyao Zhang, Jung-Fu Lin
Single-crystal elasticity of both α- and β-orthopyroxene was determined up to 20 GPa and 300 K by Brillouin scattering. Using the derived full elastic moduli (Cij), we investigated the contribution of the metastable pyroxene to the seismically-observed 3-5% low-velocity anomalies along the subducting slab in the top transition zone. Our modelled results show that a harzburgite wedge with a 1000-K colder
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The Role of Extratropical Pacific in crossing ENSO Spring Predictability Barrier Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 Yingying Zhao, Yishuai Jin, Jianping Li, Antonietta Capotondi
This paper investigates the impacts of extratropical Pacific on El Niño-Southern Oscillation (ENSO) spring predictability barrier (SPB). Using an empirical dynamical model - Linear Inverse Model (LIM), we find that the dynamics of the northern and southern extratropical Pacific can significantly and equally weaken the Eastern Pacific (EP)-ENSO SPB, while the North Pacific is more important for weakening
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Three-dimensional measurements of air entrainment and enhanced bubble transport during wave breaking Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 Daniel J. Ruth, Baptiste Néel, Martin A. Erinin, Megan Mazzatenta, Robert Jaquette, Fabrice Veron, Luc Deike
We experimentally investigate the depth distributions and dynamics of air bubbles entrained by breaking waves in a wind-wave channel over a range of breaking wave conditions using high-resolution imaging and three-dimensional bubble tracking. Below the wave troughs, the bubble concentration decays exponentially with depth. Patches of entrained bubbles are identified for each breaking wave, and statistics
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Seismic evidence for crustal modification across the Tanlu fault zone in eastern China Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 Ziqiang Lü, Jianshe Lei
The continental collision and subduction between the North China Craton and Yangtze Plate resulted in complex multistage tectonic episodes of the Tanlu fault zone. To adequately understand the geodynamic processes of the continental collision, we construct a high-resolution shear-wave velocity model of the crust and uppermost mantle using full-wave ambient noise tomographic method based on a new broadband
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Contrasting circulation patterns of dry and humid heatwaves over southern China Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 Ming Luo, Sijia Wu, Zhen Liu, Ngar-Cheung Lau
Heatwaves pose severe threats to human health, especially those combining heat and humidity. Here, we use dry- and wet-bulb temperatures as indicators to classify dry and humid heatwaves in southern China and distinguish their different mechanisms. We find that both dry and humid heatwaves are accompanied by an eastward extension of the South Asian high, a westward extension of the western North Pacific
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Carbonation of Serpentinite in Creeping Faults of California Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 Frieder Klein, David L. Goldsby, Jian Lin, Muriel Andreani
Several large strike slip faults in central and northern California accommodate plate motions through aseismic creep. Although there is no consensus regarding the underlying cause of aseismic creep, aqueous fluids and mechanically weak, velocity-strengthening minerals appear to play a central role. This study integrates field observations and thermodynamic modeling to examine possible relationships
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Explosive Eruption of the Tonga Underwater Volcano Modulates the Ionospheric E-Region Current on 15 January 2022 Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-09 Yang-Yi Sun, Chieh-Hung Chen, Pengyu Zhang, Sheng Li, Hui-Ru Xu, Tao Yu, Kai Lin, Zhiqiang Mao, Dixin Zhang, Chi-Yen Lin, Jann-Yenq Liu
The sudden eruption of the Tonga underwater volcano (20.53°S, 175.38°W) on 15 January 2022 generated explosions that triggered blast waves traveling away from the eruption. In this study, the analysis of the geomagnetic field observations on the ground shows that the eruption perturbed the E-region current density by 22–55 mA/m within a radius of 8,000 km away from the eruption. The perturbation evolved
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The 1820s Marks a Shift to Hotter-Drier Summers in Western Europe Since 1360 Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-09 Lu Wang, Hongyan Liu, Deliang Chen, Peng Zhang, Steven Leavitt, Yu Liu, Congxi Fang, Changfeng Sun, Qiufang Cai, Zhengyang Gui, Boyi Liang, Liang Shi, Feng Liu, Yukun Zheng, Jussi Grießinger
Recent soil moisture (SM) reconstructions revealed plunging trends and enhanced SM-temperature couplings over the last two decades in dry regions. However, how SM changed and whether the land-atmosphere interaction was intensified over time in humid regions remained unknown. Here we reported the first six-century-long regional summer SM reconstruction (1360–2000 CE) in western Europe (WE) using three
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Extreme Poleward Expanding Super Plasma Bubbles Over Asia-Pacific Region Triggered by Tonga Volcano Eruption During the Recovery-Phase of Geomagnetic Storm Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-09 P. K. Rajesh, C. C. H. Lin, J. T. Lin, C. Y. Lin, J. Y. Liu, T. Matsuo, C. Y. Huang, M. Y. Chou, J. Yue, M. Nishioka, H. Jin, J. M. Choi, S. P. Chen, Marty Chou, H. F. Tsai
The Tonga volcano eruption of 15 January 2022 unleashed a variety of atmospheric perturbations, coinciding with the recovery-phase of a geomagnetic storm. The ensuing thermospheric variations created rare display of extreme poleward-expanding conjugate plasma bubbles seen in the rate of total electron content index over 100–150°E, reaching ∼40°N geographic latitude. This is associated with fluctuations
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Subduction Zone Interface Structure Within the Southern MW9.2 1964 Great Alaska Earthquake Asperity: Constraints From Receiver Functions Across a Spatially Dense Node Array Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-09 Evans A. Onyango, Lindsay L. Worthington, Brandon Schmandt, Geoffrey A. Abers
We conduct a high-resolution teleseismic receiver function investigation of the subducting plate interface within the Alaskan forearc beneath Kodiak Island using data collected as part of the Alaska Amphibious Community Seismic Experiment in 2019. The Kodiak node array consisted of 398 nodal geophones deployed at ∼200–300 m spacing on northeastern Kodiak Island within the southern asperity of the 1964
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Complex Patterns of Past and Ongoing Crustal Deformations in Southern California Revealed by Seismic Azimuthal Anisotropy Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-09 Shucheng Wu, Chengxin Jiang, Vera Schulte-Pelkum, Ping Tong
We present a high-resolution P-wave azimuthally anisotropic velocity model for the upper and middle crust beneath southern California by a novel adjoint-state traveltime tomography technique. Our model reveals significant anisotropy variations between tectonic blocks that clearly reflect both past and current plate boundary deformation. In the shallow crust, seismic anisotropy is mostly controlled
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Sulfur Isotopic Fractionation of the Youngest Chang'e-5 Basalts: Constraints on the Magma Degassing and Geochemical Features of the Mantle Source Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-09 Xiaoying Liu, Jialong Hao, Rui-Ying Li, Yuyang He, Heng-Ci Tian, Sen Hu, Jing Li, Lixin Gu, Wei Yang, Yangting Lin
The unusually prolonged volcanism at the Chang'e-5 (CE-5) landing site remains a mystery. To constrain the geochemical features of the CE-5 mantle source, we performed in situ sulfur isotope analysis on sulfides of the CE-5 basalts. The modal abundance of sulfides is ∼0.1 wt%, dominated by troilite with trace cubanite, chalcopyrite and pentlandite, yielding a S-abundance of ∼360 ± 180 ppm for the bulk
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NASA Satellite Measurements Show Global-Scale Reductions in Free Tropospheric Ozone in 2020 and Again in 2021 During COVID-19 Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-12 Jerry R. Ziemke, Natalya A. Kramarova, Stacey M. Frith, Liang-Kang Huang, David P. Haffner, Krzysztof Wargan, Lok N. Lamsal, Gordon J. Labow, Richard D. McPeters, Pawan K. Bhartia
NASA satellite measurements show that ozone reductions throughout the Northern Hemisphere (NH) free troposphere reported for spring-summer 2020 during the COronaVIrus Disease 2019 pandemic have occurred again in spring-summer 2021. The satellite measurements show that tropospheric column ozone (TCO) (mostly representative of the free troposphere) for 20°N–60°N during spring-summer for both 2020 and
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A song of volumes, surfaces and fluxes – The case study of the Central Mallorca Depression (Balearic Promontory) during the Messinian Salinity Crisis Basin Res. (IF 4.1) Pub Date : 2022-08-11 Fadl Raad, Ronja Ebner, Hanneke Heida, Paul Meijer, Johanna Lofi, Agnès Maillard, Daniel Garcia-Castellanos
The Central Mallorca Depression (CMD) located in the Balearic Promontory (Western Mediterranean), contains a well-preserved evaporitic sequence belonging to the Messinian Salinity Crisis (MSC) salt giant, densely covered by high- and low-resolution seismic reflection data. It has been proposed recently that the MSC evaporitic sequence in the CMD could be a non-deformed analogue of the key MSC area
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Seismic Response of Rectangular Liquid Container with Dual Horizontal Baffles on Deformable Soil Foundation J. Earthq. Eng. (IF 2.997) Pub Date : 2022-08-11 Xun Meng, Ding Zhou, Yun Mook Lim, Jiadong Wang, Ruili Huo
ABSTRACT Seismic response of liquid sloshing in horizontally baffled rectangular container on deformable ground is evaluated. An equivalent mechanical model of baffled sloshing is developed. The strip partition method is presented to analytically derive the foundation impedances reproduced by nested lumped-parameter model. The system equations of motion are constructed via applying Hamilton’s principle
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Velocity and azimuthal anisotropy structures beneath the Dianzhong Block and its vicinity, SE Tibetan Plateau, revealed by eikonal equation-based traveltime tomography Tectonophysics (IF 3.66) Pub Date : 2022-08-08 Shaolin Liu, Kai Chang, Dinghui Yang, Xiwei Xu, Wenshuai Wang, Shuxin Yang, Mengyang Li
The Dianzhong Block (DZB) located on the southeastern margin of the Tibetan Plateau is an important tectonic zone characterized by the intense flow of crustal material. Although it is widely accepted that materials originating from the Tibetan Plateau migrate southeastward in the DZB and its vicinity, the flow mechanism and subsurface structures remain controversial. Here, we image the subsurface velocity
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Extension in the West Kunlun Mountains, NW Tibet: Insights from seismicity and analytical modeling Tectonophysics (IF 3.66) Pub Date : 2022-08-08 Yingfeng Zhang, Wenyu Gong, Xinjian Shan, Chisheng Wang
Normal faulting in orogens is usually associated with gravitational potential energy (GPE) due to elevation differences and contrasting material rheology between mountains and foreland areas. The 2008–2020 Yutian normal earthquake sequence in the West Kunlun Mountains has been closely studied over the last decade, but the mechanisms of normal faulting in the region are still an open question as both
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Formation of clast-cortex aggregates in experimental fault gouges Tectonophysics (IF 3.66) Pub Date : 2022-08-08 Jae Hoon Kim, Jin-Han Ree, Takehiro Hirose, Kiyokazu Oohashi
Clast–cortex aggregates (CCAs) have been commonly reported in experimental and natural fault gouges. Here we discuss the formation process of CCAs and its mechanical implications, based on experimentally simulated fault gouges. We conducted low- to high-velocity rotary shear experiments on Ca-bentonite gouges at a normal stress of 1 MPa, slip rates of 0.01–1.31 m s−1, and ambient temperature and humidity
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Competing Controls of Effective Stress Variation and Chloritization on Friction and Stability of Faults in Granite: Implications for Seismicity Triggered by Fluid-Injection J. Geophys. Res. Solid Earth (IF 4.39) Pub Date : 2022-08-10 Fengshou Zhang, Rui Huang, Mengke An, Ki-Bok Min, Derek Elsworth, Hannes Hofmann, Xiaoguang Wang
Fluids injection for hydraulic stimulation and fracturing, typical in the development of enhanced geothermal systems (EGS) in granites, can reactivate deep faults and induce seismicity. Such faults typically contain chlorite coatings as an alteration product that may impact styles of deformation – aseismic through seismic. We performed low velocity shear experiments on simulated granite fault gouges
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Spatiotemporal variations in earthquake triggering mechanisms during multistage hydraulic fracturing in Western Canada J. Geophys. Res. Solid Earth (IF 4.39) Pub Date : 2022-08-10 Fangxue Zhang, Ruijia Wang, Yunfeng Chen, Yangkang Chen
Dense arrays deployed near the hydraulic-fracturing (HF) wells greatly enhance the understanding of injection-induced seismicity. In this study, we revisit the continuous recordings that are acquired by 69 three-component nodes at a HF site in Alberta, Canada, taking advantage of a machine learning-based seismic detection and location workflow (LOC-FLOW). The obtained new earthquake catalog contains
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Investigating the Physical Drivers for the Increasing Tropical Cyclone Rainfall Hazard in the United States Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 Dazhi Xi, Ning Lin
In this study, we investigate both the changes of tropical cyclone (TC) rainfall hazard in the United States under climate change and the relative importance of the factors that cause the changes. We find that under the SSP5 8.5 scenario, the 100-year TC rainfall level can increase by up to 320% along the U.S. coastline by the end of this century. The influence of TC rainfall-producing ability increase
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Diurnal Variability in EMIRS Daytime Observations of Water Ice Clouds During Mars Aphelion-Season Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 Samuel A. Atwood, Michael D. Smith, Khalid Badri, Christopher S. Edwards, Philip R. Christensen, Michael J. Wolff, François Forget, Saadat Anwar, Nathan Smith, M. R. El-Maarry
Diurnal analyses of water ice cloud optical depths retrieved from thermal infrared spectra by the Emirates Mars Infrared Spectrometer showed changing cloud abundance throughout the Martian day. Observations began with the start of the Emirates Mars Mission science phase near the beginning of aphelion-season in Mars Year 36 and included the prominent aphelion cloud belt (ACB) and orographic clouds in
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Extended Rift-Associated Volcanism in Ganis Chasma, Venus Detected From Magellan Radar Emissivity Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-11 J. Brossier, M. S. Gilmore, J. W. Head
Exploration of Venus in the 1970–1990s revealed that the geology of Venus, the most Earth-like of the terrestrial planets, was decidedly un-Earth-like, with no plate tectonics, and no record of the first 80% of its history. A major outstanding question is whether Venus is still volcanically active today. We find that regions of Ganis Chasma have low radar emissivity values, due to low volumes of high
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Incorporating Uncertainty Into a Regression Neural Network Enables Identification of Decadal State-Dependent Predictability in CESM2 Geophys. Res. Lett. (IF 5.576) Pub Date : 2022-08-09 Emily M. Gordon, Elizabeth A. Barnes
Predictable internal climate variability on decadal timescales (2–10 years) is associated with large-scale oceanic processes, however these predictable signals may be masked by the noisy climate system. One approach to overcoming this problem is investigating state-dependent predictability—how differences in prediction skill depend on the initial state of the system. We present a machine learning approach