-
Early Miocene Exhumation of High-Pressure Rocks in the Himalaya: A Response to Reduced India-Asia Convergence Velocity Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-25 Giridas Maiti; Nibir Mandal
Low-viscosity channel flow, originating from a melt-weakened mid-crustal layer, is one of the most popular tectonic models to explain the exhumation of deep-seated rocks in the Greater Himalayan Sequence (GHS). The driving mechanism of such channel flow, generally attributed to focused erosion in the mountain front, is still debated, and yet to be resolved. Moreover, the channel flow model cannot explain
-
Controls on the Precipitation of Carbonate Minerals Within Marine Sediments Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-21 Alexandra V. Turchyn; Harold J. Bradbury; Kathryn Walker; Xiaole Sun
The vast majority of carbonate minerals in modern marine sediments are biogenic, derived from the skeletal remains of organisms living in the ocean. However, carbonate minerals can also precipitate abiotically within marine sediments, and this carbonate mineral precipitation within sediments has been suggested as a third major, and isotopically distinct, sink in the global carbon cycle, particularly
-
The Early Upper Paleolithic Site Crvenka-At, Serbia–The First Aurignacian Lowland Occupation Site in the Southern Carpathian Basin Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-21 Janina J. Nett; Wei Chu; Peter Fischer; Ulrich Hambach; Nicole Klasen; Christian Zeeden; Igor Obreht; Lea Obrocki; Stephan Pötter; Milivoj B. Gavrilov; Andreas Vött; Dušan Mihailović; Slobodan B. Marković; Frank Lehmkuhl
The Carpathian Basin is a key region for understanding modern human expansion into western Eurasia during the Late Pleistocene because of numerous early hominid fossil find spots. However, the corresponding archeological record remains less understood due to a paucity of well dated, contextualized sites. To help rectify this, we excavated and sampled Crvenka-At (Serbia), one of the largest Upper Paleolithic
-
Sensitivity of ENSO Simulation to the Convection Schemes in the NESM3 Climate System Model: Atmospheric Processes Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-08 Libin Ma; Zijun Jiang
The El Niño-Southern Oscillation (ENSO) is the most prominent climate system in the tropical Pacific. However, its simulation, including the amplitude, phase locking, and asymmetry of its two phases, is not well reproduced by the current climate system models. In this study, the sensitivity of the ENSO simulation to the convection schemes is discussed using the Nanjing University of Information Science
-
QQuake, a QGIS Plugin for Loading Seismological Data From Web Services Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-07 Mario Locati; Roberto Vallone; Matteo Ghetta; Nyall Dawson
An increasing number of web services providing convenient access to seismological data have become available in recent years. A huge effort at multiple levels was required to achieve this goal and the seismological community was engaged in the standardization of both data formats and web services. Although access to seismological data is much easier than in the past, users encounter problems because
-
Stable Strontium Isotopic Compositions of River Water, Groundwater and Sediments From the Ganges–Brahmaputra–Meghna River System in Bangladesh Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-04 Toshihiro Yoshimura; Shigeyuki Wakaki; Hodaka Kawahata; H. M. Zakir Hossain; Takuya Manaka; Atsushi Suzuki; Tsuyoshi Ishikawa; Naohiko Ohkouchi
The Sr isotopic composition of rivers and groundwaters in the Bengal Plain is a major contributor to the global oceanic Sr inventory. The stable strontium isotope ratios (δ88Sr) provide a new tool to identify chemical weathering reactions in terrestrial water. In this study, we investigated the spatiotemporal variations of δ88Sr in samples of river water, bedload sediment, and groundwater collected
-
Ultrafine Magnetic Particles: A DIET-Proxy in Organic Rich Sediments? Front. Earth Sci. (IF 2.689) Pub Date : 2020-12-30 Andrea Teixeira Ustra; Carlos Mendonça; Aruã da Silva Leite; Melina Macouin; Rory Doherty; Marc Respaud; Giovana Tocuti
In this work we present results of the magnetic properties characterization of sediment samples from a brownfield site that is generating methane biogas in São Paulo–Brazil. We applied interpretation procedures (frequency dependent susceptibility and time-dependent Isothermal Remanent Magnetization) appropriate to study the ultrafine magnetic fraction response of the samples. The higher content of
-
The Role of Crystal Accumulation and Cumulate Remobilization in the Formation of Large Zoned Ignimbrites: Insights From the Aso-4 Caldera-forming Eruption, Kyushu, Japan Front. Earth Sci. (IF 2.689) Pub Date : 2020-12-24 Franziska Keller; Olivier Bachmann; Nobuo Geshi; Ayumu Miyakawa
The Aso-4 caldera-forming event (86.4 ± 1.1 ka, VEI-8) is the second largest volcanic eruption Earth experienced in the past 100 ka. The ignimbrite sheets produced during this event are some of the first ever described compositionally zoned pyroclastic flow deposits exhibiting clear compositional, mineralogical and thermal gradients with stratigraphic position. Large quantities of the deposits are
-
Source Mechanism of Seismic Explosion Signals at Santiaguito Volcano, Guatemala: New Insights From Seismic Analysis and Numerical Modeling Front. Earth Sci. (IF 2.689) Pub Date : 2020-12-24 Alicia Rohnacher; Andreas Rietbrock; Ellen Gottschämmer; William Carter; Yan Lavallée; Silvio De Angelis; Jackie E. Kendrick; Gustavo Chigna
Volcanic activity at the Santiaguito dome complex (Guatemala) is characterized by lava extrusion interspersed with small, regular, gas-and-ash explosions that are believed to result from shallow magma fragmentation; yet, their triggering mechanisms remain debated. Given that the understanding of source processes at volcanoes is essential to risk assessments of future eruptions, this study seeks to
-
The Succession of Upper Eocene- Upper Miocene Limestone Growth and Corresponding Tectonic Events in Luconia Shelf, Sarawak, Malaysia Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-27 Siti Nur Fathiyah Jamaludin; Benjamin Sautter; Manuel Pubellier; Mirza Arshad Beg
Using high quality regional seismic lines, we evidence major structures resulting from successive phases of tectonic events that affected the Luconia shelf from the Upper Cretaceous to Pliocene. Each tectonic event (Classified as Event 1–Event 3) is associated with different episodes of limestone growth in Luconia Province. The successive limestone growths are used as markers in constraining the timing
-
Exposure Elements in Disaster Databases and Availability for Local Scale Application: Case Study of Kuala Lumpur, Malaysia Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-26 Nurfashareena Muhamad; Siti Hasniza M. Arshad; Joy Jacqueline Pereira
Exposure elements in open-access disaster databases that are relevant to critical infrastructure and basic services in the Sendai Framework on Disaster Risk Reduction (SFDRR) were transformed into spatial data, to investigate the impact of flash flood hazards in Kuala Lumpur, Malaysia. In this era of big data and hyper-connectivity, the availability of open-access data on exposure elements across scales
-
Earthquake Shocks Around Delhi-NCR and the Adjoining Himalayan Front: A Seismotectonic Perspective Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-25 Prosanta Kumar Khan; Sarada P. Mohanty; Partha P. Chakraborty; Rashmi Singh
An increase in the number of earthquakes and subsequent clustering in northwest India, particularly around the Delhi-National Capital Region (NCR) and adjacent NW Himalayan front, provides a good opportunity to understand the underpinning tectonic controls and the likelihood of any large earthquake in the future. The 2001 Mw 7.7 Bhuj, 2011 Mw 6.9 Sikkim and 2015 Mw 7.8 and 7.3 Nepal earthquakes (and
-
Tephrostratigraphy and Magma Evolution Based on Combined Zircon Trace Element and U-Pb Age Data: Fingerprinting Miocene Silicic Pyroclastic Rocks in the Pannonian Basin Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-25 Réka Lukács; Marcel Guillong; Olivier Bachmann; László Fodor; Szabolcs Harangi
We present a novel approach to use zircon as a correlation tool as well as a monitor for magma reservoir processes in silicic volcanic systems. Fingerprinting eruption products based on trace element content and U-Pb dates of zircon offers a promising, previously underestimated tephra correlation perspective, particularly in cases where the main minerals and glass are altered. Using LA-ICP-MS analyses
-
An Automatic System for Continuous Monitoring and Sampling of Groundwater Geochemistry in Earthquake-Prone Regions of SW Taiwan Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-25 Ching-Chou Fu; Chun-Wei Lai; Tsanyao Frank Yang; David R. Hilton; Cheng-Hong Chen; Vivek Walia; Arvind Kumar; Lou-Chuang Lee
Previous studies have revealed that gas compositions of fluid samples collected from southwestern Taiwan, where many hot springs and mud volcanoes are distributed along with tectonic structures, show significant variation before and after some disaster seismic events. Such variations, including radon activity, CH4/CO2, and 3He/4He ratios of gas compositions, are considered precursors of earthquakes
-
The North American Spring Coldness Response to the Persistent Weak Stratospheric Vortex Induced by Extreme El Niño Events Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-15 Xin Zhou; Quanliang Chen; Yang Li; Yawei Yang; Shaobo Zhang; Yong Zhao; Yulei Qi; Jingtao Zhou
The stratospheric pathway is a major driver of El Niño–Southern Oscillation (ENSO) impacts on mid-latitude tropospheric circulation and winter weather. The weak vortex induced by El Niño conditions has been shown to increase the risk of cold spells, especially over Eurasia, but its role for North American winters is less clear. This study involved idealized experiments with the Whole Atmosphere Community
-
Investigation of the Effect of the Dataset Size and Type in the Earthquake-Triggered Landslides Mapping: A Case Study for the 2018 Hokkaido Iburu Landslides Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-11 Resul Comert
Rapid mapping of landslides that occur after an earthquake is important for rapid crisis management. In this study, experimental research was conducted on the size of the model area and the data types used in developing classifiers for the supervised classification approaches used in rapid landslide mapping. The Hokkaido Iburu earthquake zone that occurred on September 6, 2018, was selected as the
-
Tools for Comprehensive Assessment of Fluid-Mediated and Solid-State Alteration of Carbonates Used to Reconstruct Ancient Elevation and Environments Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-07 Miquela Ingalls; Kathryn E. Snell
Carbonates are ubiquitous in the rock record and provide a broad array of stable isotope-based paleoclimatic proxies (i.e., δ18O, δ13C, ∆17O, ∆47, ∆48) that provide information on stratigraphy, carbon cycling, temperature, hydrology, and the altitude of ancient land surfaces. Thus, carbonates are an essential archive of environmental and topographic histories of continental terranes. However, carbonate
-
Strong Earthquakes Recurrence Times of the Southern Thessaly, Greece, Fault System: Insights from a Physics-Based Simulator Application Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-07 Christos Kourouklas; Rodolfo Console; Eleftheria Papadimitriou; Maura Murru; Vassilios Karakostas
The recurrence time, Tr, of strong earthquakes above a predefined magnitude threshold on specific faults or fault segments is an important parameter, that could be used as an input in the development of long-term fault-based Earthquake Rupture Forecasts (ERF). The amount of observational recurrence time data per segment is often limited, due to the long duration of the stress rebuilt and the shortage
-
Atmospheric and Oceanographic Forcing Impact Particle Flux Composition and Carbon Sequestration in the Eastern Mediterranean Sea: A Three-Year Time-Series Study in the Deep Ierapetra Basin Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-06 Rut Pedrosa-Pamies; Constantine Parinos; Anna Sanchez-Vidal; Antoni Calafat; Miquel Canals; Dimitris Velaoras; Nikolaos Mihalopoulos; Maria Kanakidou; Nikolaos Lampadariou; Alexandra Gogou
Sinking particles are a critical conduit for the export of organic material from surface waters to the deep ocean. Despite their importance in oceanic carbon cycling, little is known about the biotic composition and seasonal variability of sinking particles reaching abyssal depths. Herein, sinking particle flux data, collected in the deep Ierapetra Basin for a three-year period (June 2010 to June 2013)
-
Paroxysms at Stromboli Volcano (Italy): Source, Genesis and Dynamics Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-18 Nicole Métrich; Antonella Bertagnini; Marco Pistolesi
Deciphering the triggering mechanisms of violent explosive activity is of broad interest for understanding the dynamics of basaltic open-vent volcanic systems. For nearly 1300 years Stromboli has been renowned not only for its continuous degassing activity and mild explosions at the summit craters, but also for short-lived, violent explosive events of variable scale, known as major explosions and paroxysms
-
Local Explosion Detection and Infrasound Localization by Reverse Time Migration Using 3-D Finite-Difference Wave Propagation Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-18 David Fee; Liam Toney; Keehoon Kim; Richard W. Sanderson; Alexandra M. Iezzi; Robin S. Matoza; Silvio De Angelis; Arthur D. Jolly; John J. Lyons; Matthew M. Haney
Infrasound data are routinely used to detect and locate volcanic and other explosions, using both arrays and single sensor networks. However, at local distances (<15 km) topography often complicates acoustic propagation, resulting in inaccurate acoustic travel times leading to biased source locations when assuming straight-line propagation. Here we present a new method, termed Reverse Time Migrati
-
Monitoring and Assessment for the Susceptibility of Landslide Changes After the 2017 Ms 7.0 Jiuzhaigou Earthquake Using the Remote Sensing Technology Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-18 Xinyi Guo; Bihong Fu; Jie Du; Pilong Shi; Jingxia Li; Zhao Li; Jiaxin Du; Qingyu Chen; Han Fu
Monitoring the change of post-seismic landslides could provide valuable information for geological disaster treatment. The 2017 Jiuzhaigou Ms 7.0 earthquake has triggered a large number of landslides in the Jiuzhaigou United Nations Educational, Scientific and Cultural Organization (UNESCO) Natural Heritage site, which provides a unique opportunity for monitoring the spatio-temporal characteristics
-
Sedimentological Influence on Physical Properties of a Tight Sandstone Reservoir: The Cretaceous Nenjiang Formation, Southern Songliao Basin, Northeast China Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-06 Jinkai Wang; Jialin Fu; Jieming Wang; Kai Zhao; Jinliang Zhang; Jifu Liu
Abstract: The Nenjiang Formation, south of Songliao Basin, has many hydrocarbon bearing units, but currently the understanding of the distribution of viable reservoir sandstones is too limited to support a development strategy. Therefore, a detailed study on the sedimentary microfacies and reservoir properties has been completed in order to reduce uncertainty and improve subsurface predictions. Nine
-
Observational Evidence of Distinguishable Weather Patterns for Three Types of Sudden Stratospheric Warming During Northern Winter Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-19 Hyesun Choi; Joo-Hong Kim; Baek-Min Kim; Seong-Joong Kim
Sudden stratospheric warming (SSW) events often lead to a cold surface air temperature anomaly over the extratropical regions. In this study, we propose, through observational evidence, that the types of SSW determine the severity of the cold anomaly. Based on the three-type classification of SSW, it is found that the surface air temperature drops notably over central to eastern North America following
-
The Seismotectonic Significance of Geofluids in Italy Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-11 Paola Vannoli; Giovanni Martinelli; Gianluca Valensise
There is growing interest in how geofluid emissions are released in the atmosphere by the planet’s geodynamic activity, and how much they contribute to the global budget of greenhouse gases. Many workers are addressing this issue with studies conducted at global scale, so as to get the required global-scale answers. The data available at the global scale on geofluids, faults, earthquakes and volcanoes
-
A New Automatic Statistical Microcharcoal Analysis Method Based on Image Processing, Demonstrated in the Weiyuan Section, Northwest China Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-08 Yaguo Zou; Yunfa Miao; Shiling Yang; Yongtao Zhao; Zisha Wang; Guoqian Tang; Shengli Yang
Microcharcoal is a proxy of biomass burning and widely used in paleoenvironment research to reconstruct the fire history, which is influenced by the climate and land cover changes of the past. At present, microcharcoal characteristics (amount, size, shape) are commonly quantified by visual inspection, which is a precise but time-consuming approach. A few computer-assisted methods have been developed
-
Controls on Gas Emission Distribution on the Continental Slope of the Western Black Sea Front. Earth Sci. (IF 2.689) Pub Date : 2020-12-15 Michael Riedel; Line Hähnel; Jörg Bialas; Anna Katharina Bachmann; Stefanie Gaide; Paul Wintersteller; Ingo Klaucke; Gerhard Bohrmann
The continental slopes of the Black Sea show abundant manifestations of gas seepage in water depth of <720 m, but underlying controls are still not fully understood. Here, we investigate gas seepage along the Bulgarian and Romanian Black Sea margin using acoustic multibeam water column, bathymetry, backscatter, and sub-bottom profiler data to determine linkages between sub-seafloor structures, seafloor
-
Fluid Inclusions and H–O–C–S–Pb Isotopic Systematics of the Jinba Gold Deposit, NW China: Implications for Ore Genesis Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-18 Shun-Da Li; Chuan Chen; Ling-Ling Gao; Fang Xia; Xue-Bing Zhang; Ke-Yong Wang
The Jinba gold deposit is located in the Maerkakuli Shear Zone of the south Altay Orogenic Belt, NW China. Mineralization types are classified as altered rock–and quartz vein–type. Orebodies occur as veins or lenses controlled by NW–trending faults, and are hosted in phyllite (Early–Middle Devonian Ashele Formation) and plagiogranite (Early Devonian Habahe Pluton). Three paragenetic stages were identified:
-
Optimal Transponder Array and Survey Line Configurations for GNSS-A Observation Evaluated by Numerical Simulation Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-14 Yuto Nakamura; Yusuke Yokota; Tadashi Ishikawa; Shun-ichi Watanabe
The Global Navigation Satellite System-Acoustic ranging combination technique (GNSS-A) has enabled us to measure seafloor crustal deformation in the precision of centimeters, leading to numerous discoveries of subseafloor tectonic phenomena. The moving observation conducted by our research group allows us to measure both the horizontal and vertical absolute positions of a reference point on the seafloor
-
Distinguishing Late Holocene Storm Deposit From Shore-normal Beach Sediments From the Gulf of Thailand Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-11 Stapana Kongsen; Sumet Phantuwongraj; Montri Choowong
Grain size, as one of sedimentological proxies, coupled with a detailed description of the sedimentary structures and luminescence dating were used to unveil the sediment sources and transport process of the Holocene ancient coastal storm events recorded in the beach ridge plain, wet swale and muddy environments at Prachuap Khiri Khan, in the Southern Peninsula of Thailand. In this study, a total of
-
Which Fault Threatens Me Most? Bridging the Gap Between Geologic Data-Providers and Seismic Risk Practitioners Front. Earth Sci. (IF 2.689) Pub Date : 2020-12-28 Oona Scotti; Francesco Visini; Joanna Faure Walker; Laura Peruzza; Bruno Pace; Lucilla Benedetti; Paolo Boncio; Gerald Roberts
The aim of the Fault2SHA European Seismological Commission Working Group Central Apennines laboratory is to enhance the use of geological data in fault-based seismic hazard and risk assessment and to promote synergies between data providers (earthquake geologists), end-users and decision-makers. Here we use the Fault2SHA Central Apennines Database where geologic data are provided in the form of characterized
-
Investigating Possible Gastroliths in a Referred Specimen of Bohaiornis guoi (Aves: Enantiornithes) Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-25 Shumin Liu; Zhiheng Li; Alida M. Bailleul; Min Wang; Jingmai O’Connor
Gastroliths, where preserved, can provide indirect evidence regarding diet in extinct avian and non-avian dinosaurs. Masses of gastroliths consistent with the presence of a gastric mill are preserved in many Early Cretaceous Jehol birds mostly belonging to the Ornithuromorpha. Gastroliths are also present in basal birds Sapeornis and Jeholornis in which herbivory is supported by direct evidence these
-
Asymmetric Relationship Between Mid-latitude Eurasian Circulation and Summer Rainfall in Hong Kong in Different Phases of ENSO Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-18 Yana Li; Ho-Nam Cheung; Wen Zhou
During the period 1979–2019, the interannual variation of summer rainfall in Hong Kong (HK), located on the South China coast, is weakly correlated with tropical forcing, including the El Niño/Southern Oscillation (ENSO). Instead, HK summer rainfall is strongly correlated with the mid-latitude circulation over the Urals and the preceding spring sea surface temperature (SST) over the North Atlantic
-
On the Differences in Precipitation Type Between the Arctic, Antarctica and Tibetan Plateau Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-11 Diyi Yang; Minghu Ding; Tingfeng Dou; Wei Han; Weigang Liu; Jianyong Zhang; Zhiheng Du; Cunde Xiao
Under the effect of global warming, more precipitation will shift to rainfall in cryospheric regions. Considering the influence of the precipitation type on surface energy and mass cycles, it is important to determine the specific precipitation features and to classify the precipitation type in key areas correctly. We analyzed the monthly distribution, variations in each precipitation type’s annual
-
Enhancing Engagement of Citizen Scientists to Monitor Precipitation Phase Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-25 Monica M. Arienzo; Meghan Collins; Keith S. Jennings
Recent literature has highlighted how citizen science approaches can engage volunteers, expand scientific literacy, and accomplish targeted research objectives. However, there is limited information on how specific recruitment, retention, and engagement strategies enhance scientific outcomes. To help fill this important information gap, we detail the use of various approaches to engage citizen scientists
-
Low-Frequency Elastic Properties of a Polymineralic Carbonate: Laboratory Measurement and Digital Rock Physics Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-18 Ken Ikeda; Shankar Subramaniyan; Beatriz Quintal; Eric James Goldfarb; Erik H. Saenger; Nicola Tisato
We demonstrate that the static elastic properties of a carbonate sample, comprised of dolomite and calcite, could be accurately predicted by Digital Rock Physics (DRP), a non-invasive testing method for simulating laboratory measurements. We present a state-of-the-art algorithm that uses X-ray Computed Tomography (CT) imagery to compute the elastic properties of a lacustrine rudstone sample. The high-resolution
-
How Can Climate Models Be Used in Paleoelevation Reconstructions? Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-13 Svetlana Botsyun; Todd A. Ehlers
Paleoelevation reconstructions derived from proxy data such as stable oxygen isotope records in terrestrial archives have been determined for Cenozoic mountain ranges around the world. Recent studies have highlighted that a variety of paleoclimate processes can contribute to the isotopic composition of a measured precipitation (δ18Op) signal used in elevation reconstructions. These processes can include:
-
Historical Landslide Fatalities in British Columbia, Canada: Trends and Implications for Risk Management Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-11 Alex Strouth; Scott McDougall
According to a Canadian government database, landslides are the most common type of disaster that occurs in the province of British Columbia. Recently there has been a trend in British Columbia toward using quantitative risk assessments to estimate life-loss risk at landslide hazard sites, and to compare these estimates with risk tolerance thresholds to determine the necessity for, and extent of, risk
-
The Late Capitanian Mass Extinction of Terrestrial Vertebrates in the Karoo Basin of South Africa Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-07 Michael O. Day; Bruce S. Rubidge
The Beaufort Group of the main Karoo Basin of South Africa records two major extinction events of terrestrial vertebrates in the late Palaeozoic. The oldest of these has been dated to the late Capitanian and is characterized by the extinction of dinocephalian therapsids and bradysaurian pareiasaurs near the top of Tapinocephalus Assemblage Zone. Faunal turnover associated with the extinction of dinocephalians
-
A Monte Carlo Model of Gas-Liquid-Hydrate Three-phase Coexistence Constrained by Pore Geometry in Marine Sediments Front. Earth Sci. (IF 2.689) Pub Date : 2020-12-18 Jiangzhi Chen; Alan W. Rempel; Shenghua Mei
Gas hydrates form at relatively high pressures in near-surface, organic-rich marine sediments, with the base of the hydrate stability field and the onset of partial gas saturation determined by temperature increases with depth. Because of pore-scale curvature and wetting effects, the transition between gas hydrate and free gas occurrence need not take place at a distinct depth or temperature boundary
-
Impacts of Amazon Fire Aerosols on the Subseasonal Circulations of the Mid-High Latitudes Front. Earth Sci. (IF 2.689) Pub Date : 2020-12-14 Yu Zhou; Huiping Yan; Jing-Jia Luo
The strong radiative effects of fire aerosols have been well accepted in the climate community. However, there have been few studies on the aerosol effects at a monthly to subseasonal range. We used the National Centers for Environmental Prediction (NCEP) reanalysis datasets and Community Atmosphere Model Version 5 (CAM5) to explore the impacts of Amazon fire aerosols on the subseasonal climate. With
-
Deriving Centimeter-Level Coseismic Deformation and Fault Geometries of Small-To-Moderate Earthquakes From Time-Series Sentinel-1 SAR Images Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-14 Heng Luo; Teng Wang; Shengji Wei; Mingsheng Liao; Jianya Gong
Small-to-moderate earthquakes (e.g. ≤Mw5.5) occur much more frequently than large ones (e.g. >Mw6.0), yet are difficult to study with InSAR due to their weak surface deformation that are severely contaminated by atmospheric delays. Here we propose a stacking method using time-series SAR images that can effectively suppress atmospheric phase screens and extract weak coseismic deformation in centimeter
-
Thickness Characteristics of Pāhoehoe Lavas in the Deccan Province, Western Ghats, India, and in Continental Flood Basalt Provinces Elsewhere Front. Earth Sci. (IF 2.689) Pub Date : 2020-12-18 Stephen Self; Tushar Mittal; Anne Elizabeth Jay
Constraining the eruption rates of flood basalt lava flows remains a significant challenge despite decades of work. One potential observable proxy for eruption rates is flood basalt lava-flow lobe thicknesses, a topic that we tackle here quantitatively. In this study, we provide the first global compilation of pāhoehoe lava-lobe thicknesses from various continental flood basalt provinces (∼ 3,800 measurements)
-
Variation of Open-Pit Waste Dump Specimens Under Effective Pressure Influence Front. Earth Sci. (IF 2.689) Pub Date : 2020-12-16 Gerson. S. V. Tovele; Liu Han; Ji Sen Shu
The waste dump is a giant artificial loose pile body composed of fine, medium, and coarse particle sizes. Rising incidents of landslides caused by overburden pressure and effective pressure are of increasing concern in the open-pit waste dump and, if not well-controlled, are a dangerous threat to the workers, the environment, and the equipment. The purpose of this research is to investigate the connection
-
Glacier-Related Hazards Along the International Karakoram Highway: Status and Future Perspectives Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-19 Yongpeng Gao; Shiyin Liu; Miaomiao Qi; Fuming Xie; Kunpeng Wu; Yu Zhu
The China–Pakistan international Karakoram Highway passes through the core area of the “Karakoram Anomaly,” whose glaciers have maintained or increased their mass during a period when most glaciers worldwide have receded. We synthesized the literature and used remote-sensing techniques to review the types, distribution, characteristics, causes and frequency of major glacial hazards along the Karakoram
-
A Database of Laboratory Analogue Models of Caldera Collapse Testing the Role of Inherited Structures Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-12 Daniele Maestrelli; Marco Bonini; Giacomo Corti; Chiara Del Ventisette; Giovanna Moratti; Domenico Montanari
Since caldera collapse deformation is extremely difficult to study in real time - due to the high deformation rates that characterize this process and the difficult access to the caldera structures-analogue modeling has been widely used during past decades to integrate field data and, more recently, remote-sensing data (e.g., InSAR). However, the relationships between caldera collapse and inherited
-
Different Human–Dog Interactions in Early Agricultural Societies of China, Revealed by Coprolite Front. Earth Sci. (IF 2.689) Pub Date : 2020-12-30 Yunan Zhang; Guoping Sun; Dong Zhang; Xiaoyan Yang; Xiaohong Wu
Dogs served in a variety of capacities in prehistory. After their domestication in Paleolithic hunter-gatherer societies, the emergence of agriculture shifted their partnerships with people. However, the associations between dogs and early farmers are not readily visible in the archaeological record. In the present study, dog coprolites, uncovered from two groups of early agricultural societies in
-
Estimating the Relative Concentration of Superparamagnetic and Stable Single Domain Particles in Geological, Biological, and Synthetic Materials Front. Earth Sci. (IF 2.689) Pub Date : 2020-12-24 Ann M. Hirt; Pengfei Liu
Obtaining an estimate of the relative proportion of superparamagnetic (SP) to stable single-domain (SSD) particle sizes in a material can be useful in evaluating environmental conditions in natural materials, or in understanding the homogeneity of particle size and the degree of agglomeration in synthesized particles. Frequency dependent magnetic susceptibility is one of the most common methods used
-
Dike Inflation Process Beneath Sakurajima Volcano, Japan, During the Earthquake Swarm of August 15, 2015 Front. Earth Sci. (IF 2.689) Pub Date : 2020-12-24 Midori Koike; Haruhisa Nakamichi
Magma intrusion usually causes seismicity and deformation in the surrounding rock and often leads to eruptions. A swarm of volcano-tectonic (VT) earthquakes associated with rapid dike intrusion in hours occurred beneath Sakurajima volcano on August 15, 2015. We determined the hypocenters and focal mechanisms of the VT earthquake swarm. The distributions of pressure (P)- and tension (T)-axes of the
-
Megathrust Slip Behavior for Great Earthquakes Along the Sumatra-Andaman Subduction Zone Mapped From Satellite GOCE Gravity Field Derivatives Front. Earth Sci. (IF 2.689) Pub Date : 2020-12-10 Orlando Álvarez; Stefanie Pechuan Canet; Mario Gimenez; Andrés Folguera
During the last two decades, space geodesy allowed mapping accurately rupture areas, slip distribution, and seismic coupling by obtaining refined inversion models and greatly improving the study of great megathrust earthquakes. A better understanding of these phenomena involving large areas of hundreds of square kilometers came from the last gravity satellite mission that allowed detecting mass transfer
-
High-Resolution Stable Isotope Paleotopography of the John Day Region, Oregon, United States Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-14 Tyler Kukla; Daniel Enrique Ibarra; Jeremy K. Caves Rugenstein; Jared T. Gooley; Casey E. Mullins; Samuel Kramer; Danielle Y. Moragne; C. Page Chamberlain
The John Day region of central Oregon, United States contains ∼50 million years of near-continuous, fossiliferous sedimentation, representing one of the world’s richest archives of Cenozoic terrestrial ecosystems and climate. Stable isotope proxy data from this region are commonly used to infer the elevation history of the Cascades, which intercept westerly moisture in transit to the John Day region
-
Strong-Motions From Damaging Moderate Magnitude (5.9 ≥ Mw) Earthquakes in Japan Recorded by K-NET and KiK-net Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-11 Yadab P. Dhakal
Strong-motions from 79 moderate magnitude (5.9 ≥ Mw) earthquakes that caused various degrees of impact on humans and built-environment in Japan between 1996 and 2019, after the start of K-NET and KiK-net, are presented. As such, most of the earthquakes occurred beneath the land, and agencies had reported damages from events as small as Mw 4.1. Together, large peak ground accelerations exceeding 500 cm/s2
-
Biomarker and Isotopic Composition of Seep Carbonates Record Environmental Conditions in Two Arctic Methane Seeps Front. Earth Sci. (IF 2.689) Pub Date : 2020-12-30 Haoyi Yao; Giuliana Panieri; Moritz F. Lehmann; Tobias Himmler; Helge Niemann
Present-day activity of cold seeps in the ocean is evident from direct observations of methane emanating from the seafloor, the presence of chemosynthetic organisms, or the quantification of high gas concentrations in sediment pore waters and the water column. Verifying past cold seep activity and biogeochemical characteristics is more challenging but may be reconstructed from proxy records of authigenic
-
Tectonic Fabric, Geochemistry, and Zircon-Monazite Geochronology as Proxies to Date an Orogeny: Example of South Delhi Orogeny, NW India, and Implications for East Gondwana Tectonics Front. Earth Sci. (IF 2.689) Pub Date : 2020-12-17 Subhash Singh; Bert De Waele; Anjali Shukla; B. H. Umasankar; Tapas Kumar Biswal
We have dated the South Delhi orogeny, Aravalli-Delhi Mobile Belt (ADMB), NW India, using the tectonic fabric, geochemistry, and zircon-monazite geochronology as the proxies. The South Delhi Terrane (SDT), a passive margin domain in the ADMB, consists of multiply deformed (D1–D4) greenschist facies rocks and several granite plutons. The D1 deformation is characterized by pervasive isoclinal recumbent
-
Magnetic Susceptibility Properties of Loess From the Willendorf Archaeological Site: Implications for the Syn/Post-Depositional Interpretation of Magnetic Fabric Front. Earth Sci. (IF 2.689) Pub Date : 2020-12-16 Christian Zeeden; Ulrich Hambach
At the Willendorf site Upper Paleolithic archeological layers associated to early Aurignacian cultures were found. The environmental conditions of the associated society, potentially co-existing with Neanderthal groups, is still not fully understood. Here, we report on environmental magnetic analyses including anisotropy of the magnetic susceptibility (AMS) carried out on loessic aeolian sediments
-
Stratigraphic Architecture of the Karoo River Channels at the End-Capitanian Front. Earth Sci. (IF 2.689) Pub Date : 2020-12-15 Emese M. Bordy; Francisco Paiva
The main Karoo Basin of southern Africa contains the continental record of the end-Triassic, end-Permian, and end-Capitanian mass extinction events. Of these, the environmental drivers of the end-Capitanian are least known. Integrating quantitative stratigraphic architecture analysis from abundant outcrop profiles, paleocurrent measurements, and petrography, this study investigates the stratigraphic
-
Modelling the Effect of Electrification on Volcanic Ash Aggregation Front. Earth Sci. (IF 2.689) Pub Date : 2020-12-07 Stefano Pollastri; Eduardo Rossi; Costanza Bonadonna; Jonathan P. Merrison
The fine ash released into the atmosphere (particles <63 μm) during explosive volcanic eruptions represents a significant threat for both the ecosystem and many sectors of society. In order to mitigate the associated impact, ash dispersal models need to accurately estimate ash concentration through time and space. Since most fine ash sediments in the form of aggregates, ash dispersal models require
-
Quantifying Downstream, Vertical and Lateral Variation in Fluvial Deposits: Implications From the Huesca Distributive Fluvial System Front. Earth Sci. (IF 2.689) Pub Date : 2020-12-22 Ben Martin; Amanda Owen; Gary J. Nichols; Adrian J. Hartley; Richard D. Williams
Quantifying sedimentary deposits is crucial to fully test generic trends cited within facies models. To date, few studies have quantified downstream trends alongside vertical and lateral variations within distributive fluvial systems (DFS), with most studies reporting qualitative trends. This study reports on the generation of a quantitative dataset on the Huesca DFS, Ebro Basin, Spain, in which downstream
-
A Decade of Global Navigation Satellite System/Acoustic Measurements of Back-Arc Spreading in the Southwestern Okinawa Trough Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-07 Horng-Yue Chen; Ryoya Ikuta; Ya-Ju Hsu; Toshiaki Tsujii; Masataka Ando; Yoko Tu; Takeru Kohmi; Kiyomichi Takemoto; Koto Mizuno; Hsin Tung; Chin-Shang Ku; Cheng-Horng Lin
Long-term seafloor geodetic measurements are important for constraining submarine crustal deformation near plate boundaries. Here we present an integrated analysis of a decade of GNSS/acoustic data collected at a site 60 km to the east of northeast Taiwan near the axis of the Okinawa Trough back-arc basin. We obtained a time-series of horizontal and vertical positions based on 18 measurements from
-
Application of Phase-Only Correlation to Travel-Time Determination in GNSS-Acoustic Positioning Front. Earth Sci. (IF 2.689) Pub Date : 2021-01-06 Chie Honsho; Motoyuki Kido; Toshihito Ichikawa; Toru Ohashi; Taichi Kawakami; Hiromi Fujimoto
The GNSS-acoustic technique is a geodetic method for oceanic areas that combines GNSS positioning of a sea-surface platform and acoustic ranging of seafloor stations. Its positioning accuracy is typically a few and several centimeters for the horizontal and vertical positions, respectively. For further accuracy enhancement, we examined the errors in travel time, the most fundamental data in acoustic
Contents have been reproduced by permission of the publishers.