bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessing the Risk of Potential Tsunamigenic Earthquakes in the Mentawai Region by Seismic Imaging, Central Sumatra
Authors: Qin Yanfang , Chen Jian , Singh Satish C. , Hananto Nugroho , Carton Helene , Tapponnier Paul 
Published: May 2024

AbstractIn the marginal regions along subduction zones, oceanic plates subducting beneath continental plates produce the largest number of earthquakes on Earth and sometimes devastating tsunamis. The lateral segmentation of earthquakes along the Sumatra subduction zone is well documented. However, the entirely different seismic behaviors among the segments indicate that local structures are key elements controlling coseismic slip propagation; in particular, frontal accretionary prism structures are closely associated with tsunami generation. Offshore of Central Sumatra, in the Mentawai segment, large earthquakes nucleated in 2007 and 2010 caused many human casualties and a great deal of property loss. Using seismic reflection data, we show the subsurface structure of accretionary over a significant portion of the frontal wedge that did not rupture during the 2007 earthquake, and this area remains locked. The subsurface deformation structure at the wedge front, which is similar to that in the 2010 Mw7.8 tsunami earthquake rupture zone, suggests the potential for a large tsunami earthquake in the near future. On the other hand, the along‐strike variations of the effective basal friction at shallow depth may indicate that different coseismic behaviors are caused by a sudden failure of the deeper seismogenic zone.
Local Magnetic Anomalies Explain Bias in Paleomagnetic Data: Consequences for Sampling
Authors: Meyer Romy , de Groot Lennart V. 
Published: May 2024

AbstractVolcanic rocks are considered reliable recorders of past changes in the Earth's magnetic field. Recent flows, however, sometimes fail to produce the known magnetic field at the time of cooling. Previous research on Mt. Etna suggests paleomagnetic data might not be accurately recorded. Here we test the accuracy of paleomagnetic data obtained from Mt. Etna lavas by comparing paleomagnetic data from historical flows to direct measurements of the magnetic field above the current topography. The inclinations and intensities in both data sets are biased toward lower values, while there is no such trend for the declination. Inclinations are on average 2.9° lower than expected; intensities are on average 8.8 µT lower. The deviations from the expected values depend on the height above the flow. Moreover, the inclinations and intensities vary as a function of topography. Both are higher above ridges and lower in gullies; the variations within a site are up to 14.1° in inclination and 12.9 µT for intensity. To suppress this paleomagnetic data bias it is important to take samples several meters apart and from different parts of the flow whenever possible. While this leads to a higher degree of scatter in paleodirections, the results better represent the Earth's magnetic field at the time of cooling. This emphasizes the importance of reporting paleomagnetic sampling strategies in detail.
Increasing Fire Activity in African Tropical Forests Is Associated With Deforestation and Climate Change
Authors: Wimberly M. C. , Wanyama D. , Doughty R. , Peiro H. , Crowell S. 
Published: May 2024

AbstractFires were historically rare in tropical forests of West and Central Africa, where dense vegetation, rapid decomposition, and high moisture limit available fuels. However, increasing heat and drought combined with forest degradation and fragmentation are making these areas more susceptible to wildfires. We evaluated historical patterns of Moderate Resolution Imaging Spectroradiometer active fires in African tropical forests from 2003 to 2021. Trends were mostly positive, particularly in the northeastern and southern Congo Basin, and were concentrated in areas with high deforestation. Year‐to‐year variation of fires was synchronized with increasing temperature and vapor pressure deficit. There was anomalously high fire activity across the region during the 2015–2016 El Niño. These results contrast with the drier African woodlands and savannas, where fire has been decreasing. Further attention to fires in African tropical forests is needed to understand their global impacts on carbon dynamics and their local implications for biodiversity and human livelihoods.
Relativistic Electron Precipitation Events Driven by Solar Wind Impact on the Earth's Magnetosphere
Authors: Roosnovo Alexandra , Artemyev Anton V. , Zhang Xiao‐Jia , Angelopoulos Vassilis , Ma Qianli , Grimmich Niklas , Plaschke Ferdinand , Fischer David , Werner Magnes 
Published: May 2024

AbstractCertain forms of solar wind transients contain significant enhancements of dynamic pressure and may effectively drive magnetosphere dynamics, including substorms and storms. An integral element of such driving is the generation of a wide range of electromagnetic waves within the inner magnetosphere, either by compressionally heated plasma or by substorm plasma sheet injections. Consequently, solar wind transient impacts are traditionally associated with energetic electron scattering and losses into the atmosphere by electromagnetic waves. In this study, we show the first direct measurements of two such transient‐driven precipitation events as measured by the low‐altitude Electron Losses and Fields Investigation CubeSats. The first event demonstrates storm‐time generated electromagnetic ion cyclotron waves efficiently precipitating sub‐relativistic and relativistic electrons from >300 keV to 2 MeV at the duskside. The second event demonstrates whistler‐mode waves leading to scattering of electrons from 50 to 700 keV on the dawnside. These observations confirm the importance of solar wind transients in driving energetic electron losses and subsequent dynamics in the ionosphere.
Effects of an Intrinsic Magnetic Field on Ion Escape From Ancient Mars Based on MAESTRO Multifluid MHD Simulations
Authors: Sakata R. , Seki K. , Terada N. , Sakai S. , Shinagawa H. 
Published: May 2024

AbstractIon escape has played a key role in atmospheric loss on ancient Mars due to intense solar activity. Under the existence of a strong global intrinsic magnetic field, as expected on ancient Mars, differential flows between different ion species can be important for ion escape. To assess effects of differential flows, we here developed a new global multifluid magnetohydrodynamics model with a cubed sphere grid named Multifluid Atmospheric Escape Simulations Toward Real elucidatiOn (MAESTRO). A test simulation under present‐day Mars conditions showed solar wind‐Mars interactions, for example, plasma boundaries, ionospheric profiles, and tailward outflows, consistent with observations and simulation studies. We then conducted multifluid and multispecies simulations with six different dipole field strengths under ancient Mars conditions. The multifluid cases show asymmetric outflow distributions with respect to the solar wind convection electric field, as pointed out by previous studies on present‐day Mars. Compared with multispecies cases, the multifluid representation increases the escape rates of O2+ and CO2+ by more than two orders of magnitude in the strong dipole field cases where the cusp outflow is dominant. The O+ escape rate is slightly lower in the multifluid cases with no or weak dipole field due to suppression of ion pickup in the −E hemisphere, while it is reduced by one order of magnitude in the strongest dipole field case. The existence of a dipole field can reduce the total escape rate by a factor of six. The impact on atmospheric evolution is diminished but still significant.
Reassessment of Birch's Law on hcp‐Fe From Ultrasonic Sound Velocity Measurement and Implications on the Velocity Profiles of Earth's Inner Core
Authors: Wang Siheng , Chen Sibo , Qi Xintong , Xu Man , Yu Tony , Wang Yanbin , Li Baosheng 
Published: May 2024

AbstractWe performed in situ X‐ray diffraction and ultrasonic sound velocity measurements on hcp‐Fe up to 15 GPa, 873 K in a multi‐anvil apparatus. The elastic moduli and their pressure and temperature derivatives were determined by fitting the velocity and density data to the third‐order finite strain equations, yielding KS0 = 169.0(57) GPa, KS0′ = 5.4(6), (∂KS/∂T)P = −0.031(3) GPa/K, G0 = 104.5(27) GPa, G0′ = 1.7(2), (∂G/∂T)P = −0.060(2) GPa/K. Within the experimental P‐T range, we find significant temperature effect on the density‐velocity (ρ − VP or S) relations and caution the use of the temperature‐independent Birch's law for extrapolation to core conditions. Furthermore, temperature‐induced velocity decrease is more significant in VS than in VP, offering a possible explanation for the high Poisson's ratio in the core. Extrapolations based on our results together with previous experimental data suggest that VP of hcp‐Fe aligns with PREM at Earth's core conditions, while Vs and density are approximately 10% and 2.7% higher than PREM, respectively.
Viscosity Measurements at High Pressures: A Critical Appraisal of Corrections to Stokes' Law
Authors: Ashley Aaron Wolfgang , Mookherjee Mainak , Xu Man , Yu Tony , Manthilake Geeth , Wang Yanbin 
Published: May 2024

AbstractFluids and melts in planetary interiors significantly influence geodynamic processes from volcanism to global‐scale differentiation. The roles of these geofluids depend on their viscosities (η). Constraining geofluid η at relevant pressures and temperatures relies on laboratory‐based measurements and is most widely done using Stokes' Law viscometry with falling spheres. Yet small sample chambers required by high‐pressure experiments introduce significant drag on the spheres. Several correction schemes are available for Stokes' Law but there is no consensus on the best scheme(s) for high‐pressure experiments. We completed high‐pressure experiments to test the effects of (a) the relative size of the sphere diameter to the chamber diameter and (b) the top and bottom of the chamber, that is, the ends, on the sphere velocities. We examined the influence of current correction schemes on the estimated viscosity using Monte Carlo simulations. We also compared previous viscometry work on various geofluids in different experimental setups/geometries. We find the common schemes for Stokes' Law produce statistically distinct values of η. When inertia of the sphere is negligible, the most appropriate scheme may be the Faxén correction for the chamber walls. Correction for drag due to the chamber ends depends on the precision in the sinking distance and may be ineffective with decreasing sphere size. Combining the wall and end corrections may overcorrect η. We also suggest the uncertainty in η is best captured by the correction rather than propagated errors from experimental parameters. We develop an overlying view of Stokes' Law viscometry at high pressures.
Parameterization of Shear‐To‐Strain Ratio Used in Finescale Parameterization
Authors: Sun H. , Yang Q. , Li J. , Zhao W. , Tian J. 
Published: May 2024

AbstractThe Gregg‐Henyey‐Polzin (GHP) finescale parameterization is widely employed to infer turbulent mixing when microstructure measurements are unavailable. However, the strain‐only GHP scaling is the only option when shear information is lacking, in which case the shear‐to‐strain ratio (Rω) is commonly treated as a constant. Since Rω has been reported to vary spatiotemporally, using a fixed value of Rω might result in a significant bias in inferring turbulent mixing. In this study, we present a global map of Rω, based on the microstructure database contributed by the Climate Process Team on internal wave‐driven ocean mixing, which covers the Indian, Pacific, and Atlantic oceans across both high and low latitudes. Then, we propose a parameterization of Rω by considering buoyancy frequency, Coriolis frequency, and topographic features. Compared to the GHP scaling with constant Rω, the turbulent dissipation rate values inferred from the GHP scaling with parameterized Rω are more accurate. In this manner, this study provides a reference for choosing optimal Rω when using the strain‐only GHP scaling to explore turbulent mixing in the open ocean.
On the Mechanisms Driving Latent Heat Flux Variations in the Northwest Tropical Atlantic
Authors: Fernández Pablo , Speich Sabrina , Bellenger Hugo , Lange Vega Diego , Karstensen Johannes , Zhang Dongxiao , Rocha Cesar Barbedo 
Published: May 2024

AbstractThe Northwest Tropical Atlantic (NWTA) is a region of complex surface ocean circulation. The most prominent feature is the North Brazil Current (NBC) and its retroflection at 8°N, which leads to the formation of numerous mesoscale eddies known as NBC rings. The NWTA also receives the outflow of the Amazon River, generating freshwater plumes that can extend up to 100,000 km2. We show that these two processes influence the spatial variability of the region's surface latent heat flux (LHF). On the one hand, the presence of surface freshwater modifies the vertical stratification of the ocean, the mixed layer heat budget, and thus the air‐sea heat exchanges. On the other hand, NBC rings create a highly heterogeneous mesoscale sea surface temperature (SST) field that directly influences the near‐surface atmospheric circulation. These effects are illustrated by observations from the ElUcidating the RolE of Cloud‐Circulation Coupling in ClimAte ‐ Ocean Atmosphere (EUREC4A‐OA) and Atlantic Tradewind Ocean‐Atmosphere Interaction Campaign (ATOMIC) experiments, satellite and reanalysis data. We decompose the LHF budget into several terms controlled by different atmospheric and oceanic processes to identify the mechanisms leading to LHF changes. We find LHF variations of up to 160 W m2, of which 100 W m2 are associated with wind speed changes and 40 W m2 with SST variations. Surface currents or heat release associated with stratification changes remain as second‐order contributions with LHF variations of less than 10 W m2 each. This study highlights the importance of considering these three components to properly characterize LHF variability at different spatial scales, although it is limited by the scarcity of collocated observations.
Possible Maximum Earthquake Tsunami Along the South Coast of China Inferred From GPS‐Derived Surface Velocities
Authors: Zhao G. , Niu X. 
Published: May 2024

AbstractThis study aims to assess the tsunami hazard of the maximum possible earthquake along the south coast of China. GPS‐derived surface velocities around the Manila Trench have been used to clarify the active tectonics and estimate the seismic potential of Manila subduction, where catastrophic tsunamis may originate and cause devastating damage to the surrounding area of the South China Sea. Based on the maximum potential earthquake magnitude estimated from the accumulated seismic moment, more than 100,000 possible tsunami scenarios with varying epicenters have been simulated considering the slip heterogeneity. The impact of several uncertain parameters including the release period and release ratio of accumulated seismic moment are investigated, as well as some assumptions in the model of tsunami generation. Although different release conditions for accumulated seismic moment result in a significant impact on the value of tsunami height, similar trend in spatial distribution has been shown. The results show that the tsunami wave height along the south coast of China has an increasing trend from west to east, with the maximum tsunami wave height exceeding 10 m corresponding to the potential earthquake Mw = 9.1 with a 1,000‐year release period. The impact of fault slip heterogeneity on tsunami wave height is significant. Compared to uniform slip, considering stochastic slip will increase the average tsunami wave height by about 15%. Considering locking distribution will increase the average tsunami wave height by about 20%–30% and also increase the maximum tsunami wave height by about 60%–70%.
Spatial and Temporal Patterns in Observed Extreme Precipitation Change Over Northern Part of the Korean Peninsula
Authors: Om Kum‐Chol , Ren Guoyu , Jong Sang‐Il , Ham Yong‐Sik , Hong Chang‐Won , Kang‐Chol O. , Tysa Suonam Kealdrup 
Published: May 2024

AbstractThe present study aims to detect the variation of precipitation extreme events in the northern part of the Korean Peninsula during 1961–2020, as well as to investigate its possible causes, based on daily precipitation data from 37 representative stations. Nonparametric tests such as Mann‐Kendall and Kendall‐tau were used to detect statistical characteristics of changes in precipitation indices and climate variables. Findings are as follows: (a) the annual total precipitation manifested a clear shifting point in 1968, with a decreasing rate of about −37.7 mm/decade, conversely, daily precipitation intensity had a clear upward trend, and extreme precipitation events above 100 mm/day became more frequent. (b) There occurred significant upward trends of 8.9 mm/decade for intense rainfall (>95th percentile) and 6.3 mm/decade for extreme intense rainfall (>99th percentile). (c) The continuous wet (dry) days showed a decreasing (increasing) trend of about −0.2 days/decade (1.0 days/decade). The decrease rate of 5‐day max precipitation is five times as large as 1‐day max precipitation. (d) For June‐September, the strengthened West Pacific Subtropical High intensity and the variation of its ridge‐axis position, the southerly shift of the upper subtropical Jetstream and the weakening of lower moisture supplement may have suppressed the northerly move of the summer rain band and delayed the development of rainy season over the study area. (e) In view of the urbanization effect, the possible causes of the precipitation externalization were investigated, and it was found that the upward trends in daily precipitation intensity and 95th percentile intense precipitation in big cities are generally higher than rural regions.
Reconciling Mars InSight Results, Geoid, and Melt Evolution With 3D Spherical Models of Convection
Authors: Murphy J. P. , King S. D. 
Published: May 2024

AbstractWe investigate the geodynamic and melting history of Mars using 3D spherical shell models of mantle convection, constrained by the recent InSight mission results. The Martian mantle must have produced sufficient melt to emplace the Tharsis rise by the end of the Noachian–requiring on the order of 1–3 × 109 km3 of melt after accounting for limited (∼10%) melt extraction. Thereafter, melting declined; however, abundant evidence for limited geologically recent volcanism necessitates some present‐day melt even in the cool mantle inferred from InSight data. We test models with two mantle activation energies and a range of crustal Heat Producing Element (HPE) enrichment factors and initial core‐mantle boundary temperatures. We also test the effect of including a hemispheric (spherical harmonic degree‐1) step in lithospheric thickness to model the Martian dichotomy. We find that a higher activation energy (350 kJ mol−1) rheology produces present‐day geotherms consistent with InSight results, and crustal HPE enrichment factors of 5–10‐times produce localized melting near or up to present‐day. The 10‐times crustal HPE enrichment is consistent with both InSight and geochemical results and also produces present‐day geoid power spectra consistent with Mars. However, calculations that match the present‐day geoid power spectra require more than 60% melt extraction to produce the Tharsis swell. The addition of a degree‐1 hemispheric dichotomy, as an equatorial step in lithospheric thickness, does not significantly improve upon melt production or the geoid.
Treatment of newly diagnosed moderate or severe chronic graft-versus-host disease with prednisone and everolimus (PredEver first): a prospective multicenter phase IIA study
Authors: Ayuk Francis , Wagner-Drouet Eva-Maria , Wolff Daniel , von Huenerbein Natascha , von Pein Ute-Marie , Klyuchnikov Evgeny , von Harsdorf Stephanie , Koenecke Christian , Sayer Herbert , Kröger Nicolaus 
Published: May 2024

AbstractAlthough most patients with chronic graft-versus-host disease (cGVHD) show initial response to first-line therapy, long-term clinically meaningful success of first-line treatment remains rare. In a prospective multicentre phase II trial in 6 German centers, patients with newly diagnosed moderate or severe cGVHD received prednisone and everolimus for 12 months followed by a 1-year follow-up period. Primary endpoint was treatment success (TS) at 6 months defined as patient being alive, achieving PR or CR of cGVHD, having no relapse of underlying disease and requiring no secondary treatment for cGVHD. Of the 34 patients evaluable for efficacy, 19 (56%) had TS at 6 months with 22 and 52% of the patients in a CR and PR respectively. Overall 30 patients (88%) had a CR or PR as best response, nearly all responses (29/30) occurring within the first 6 weeks of treatment. The cumulative incidence of treatment failure at 1 year was 63%, corresponding to 37% TS. Predefined safety endpoint (thrombotic microangiopathy, pneumonitis, and avascular necrosis) were not observed in any patient. Addition of everolimus to prednisolone is well tolerated and may improve long-term treatment success. Larger studies are necessary to ascertain the possible role of everolimus in first-line treatment of cGVHD.
Differential contribution for ERK1 and ERK2 kinases in BRAFV600E-triggered phenotypes in adult mouse models
Authors: Bosso Giuseppe , Cintra Herpst Ana Carolina , Laguía Oscar , Adetchessi Sarah , Serrano Rosa , Blasco Maria A. 
Published: May 2024

AbstractThe BRAF gene is mutated in a plethora of human cancers. The majority of such molecular lesions result in the expression of a constitutively active BRAF variant (BRAFV600E) which continuously bolsters cell proliferation. Although we recently addressed the early effects triggered by BRAFV600E-activation, the specific contribution of ERK1 and ERK2 in BRAFV600E-driven responses in vivo has never been explored. Here we describe the first murine model suitable for genetically dissecting the ERK1/ERK2 impact in multiple phenotypes induced by ubiquitous BRAFV600E-expression. We unveil that ERK1 is dispensable for BRAFV600E-dependent lifespan shortening and for BRAFV600E-driven tumor growth. We show that BRAFV600E-expression provokes an ERK1-independent lymphocyte depletion which does not rely on p21CIP1-induced cell cycle arrest and is unresponsive to ERK-chemical inhibition. Moreover, we also reveal that ERK1 is dispensable for BRAFV600E-triggered cytotoxicity in lungs and that ERK-chemical inhibition abrogates some of these detrimental effects, such as DNA damage, in Club cells but not in pulmonary lymphocytes. Our data suggest that ERK1/ERK2 contribution to BRAFV600E-driven phenotypes is dynamic and varies dependently on cell type, the biological function, and the level of ERK-pathway activation. Our findings also provide useful insights into the comprehension of BRAFV600E-driven malignancies pathophysiology as well as the consequences in vivo of novel ERK pathway-targeted anti-cancer therapies.