Feed aggregator

Publication date: 1 January 2025

Source: Advances in Space Research, Volume 75, Issue 1

Author(s): Uzair Majeed, B. Ramzan

Publication date: 1 January 2025

Source: Advances in Space Research, Volume 75, Issue 1

Author(s): Kalpesh Ghag, Anil Raghav, Zubair Shaikh, Georgios Nicolaou, Omkar Dhamane, Mohit Shah, Utsav Panchal, Prathmesh Tari, Kishor Kumbhar

Publication date: 1 January 2025

Source: Advances in Space Research, Volume 75, Issue 1

Author(s): Xumin Sun, Rui Zhang, Hua Zhang, Zhenyu Hu, Weijun Wang, Meng Zou

Publication date: 1 January 2025

Source: Advances in Space Research, Volume 75, Issue 1

Author(s): Axel Bouquety, Lucile Fayon, Detlef Koschny, Robin Narbey, Tomaso R.R. Bontognali, Laurent Jorda, Marie Josset, Gabriela Ligeza, Nikolaus Kuhn, Jean-Luc Josset

Publication date: 1 January 2025

Source: Advances in Space Research, Volume 75, Issue 1

Author(s): Chukwuebuka J. Ugwu, Jibrin A. Alhassan, Ogbonnaya Okike, Firew M. Menteso, Ngozi M. Ugwu, Augustine E. Chukwude, Evaristus U. Iyida, Innocent O. Eya, Romanus E. Ugwoke, Dominic C. Obiegbuna, Finbar C. Odo, Orji P. Orji

Publication date: 1 January 2025

Source: Advances in Space Research, Volume 75, Issue 1

Author(s): Hongyang Zhao, Jing Jin, Xingdong Li, Yi Liu, Yanan Guo

Publication date: 1 January 2025

Source: Advances in Space Research, Volume 75, Issue 1

Author(s): Vinay Kumar Gundeboina, Shanti Priya Devarapalli, Rukmini Jagirdar

Publication date: 1 January 2025

Source: Advances in Space Research, Volume 75, Issue 1

Author(s): V.G. Lozitsky, I.I. Yakovkin, N.I. Lozitska

Publication date: 1 January 2025

Source: Advances in Space Research, Volume 75, Issue 1

Author(s): Predrag Jovanović, Saša Simić, Vesna Borka Jovanović, Duško Borka, Luka Č. Popović

Iron is one of the main elements found in the Earth's inner core, which is characterized by extremely high temperatures and pressures. Determining how iron behaves in these extreme conditions could thus help to advance the current understanding of our home planet's structure and geodynamics.

Land clearing for nickel mines is causing a more severe threat to the climate than initially thought, a study led by a University of Queensland researcher has found.

A study provides compelling new evidence that a colossal "megaflood" refilled the Mediterranean Sea, ending a period during which the Mediterranean was a vast expanse of salt flats. The research suggests the Zanclean Megaflood ended the Messinian Salinity Crisis, which lasted between 5.97 and 5.33 million years ago.

A study led by researchers at The University of Manchester has exposed significant gaps in global research on transboundary rivers, revealing that the water needs of people in the Global South are being disproportionately overlooked.

After millennia as a carbon deep-freezer for the planet, regional hotspots and increasingly frequent wildfires in the northern latitudes have nearly canceled out that critical storage capacity in the permafrost region, according to a study published in Nature Climate Change.

Author(s): Shipra Verma and Kannabiran Seshasayanan

We study the effects of conductivity variation on the Ponomarenko dynamo. Taking monotonically increasing, decreasing and sinusoidally varying radial profiles, we study the kinematic dynamo problem. The threshold of the dynamo, given by the critical magnetic Reynolds number Rmc, is found to strongly…

[Phys. Rev. E 111, 015207] Published Tue Jan 21, 2025

The Dutch TROPOMI space instrument creates daily global maps of carbon monoxide (CO) in the atmosphere. Researchers from SRON and TNO have now measured CO emissions over a full year from the 21 largest European steel plants. The preprint is available on EGUsphere.

SummaryMonitoring volcanic deformation is crucial for understanding volcanic behavior, but challenges like limited GNSS coverage, infrequent SAR data acquisitions, and coherence loss during eruptions complicate this task. Our study on the 2018 eruption of Sierra Negra utilizes Sentinel-1A/B images to track surface deformation patterns that revert to their initial state across three phases: before, during, and after the eruption. We implemented an adaptive workflow using the shortest temporal baseline of consecutive SAR image pairs, including InSAR, optical flow, and pixel offset tracking methods, to accurately capture surface displacement linked to the dynamics of the magma reservoir in the caldera and a nearby (sub-) horizontal dike. Results show that while the caldera subsided gradually over two months during lava flow (initially at a rate of several meters) until it began to uplift again, the northern region alternated between uplift and subsidence twice in the line-of-sight (LOS) direction. This pattern suggests repeated magma injections into the sub-horizontal dike sustained the lava flows from the northeastern fissure. The one-day difference between SAR images from ascending and descending tracks enabled us to estimate the underground magma transfer rate at approximately 60 m/h, which aligns with the magma migration trajectory indicated by seismic data. By integrating InSAR and offset tracking methods, we provide a comprehensive view of surface displacement throughout the volcanic eruption cycle.

AbstractCrystallographic preferred orientation (CPO) of peridotite minerals is frequently invoked to explain the widespread dependence of seismic wave speed on propagation direction in Earth’s mantle — a property known as seismic anisotropy. As established by rock mechanics experiments, CPO constitutes a direct signature of past and ongoing strain regimes experienced by rocks during mantle flow. Therefore, an improved understanding of CPO generation promises to yield valuable information on the rheology and corresponding deformation mechanisms activated through mantle dynamics. Simulating CPO in geodynamical models is computationally challenging and has often been restricted to steady-state mantle flows. However, within Earth’s vigorously convecting mantle the steady-state assumption is questionable, thus motivating the need to couple CPO simulations with time-evolving mantle flow models. Here, we present a new Python implementation of the D-Rex CPO model, called PyDRex, which predicts salient features of mineral grain size and orientation evolution whilst providing a well-documented, user-friendly interface that supports flexible coupling to geodynamical modelling frameworks. PyDRex also packages numerous post-processing routines for strain analysis and visualisation of grain orientation distributions. We provide a set of benchmark simulations based on previous D-Rex implementations that validate PyDRex and demonstrate sensitivities to model parameters for both steady-state and time-dependent flows. Analysis of benchmark results highlights the role of dynamic recrystallisation in controlling competing grain growth in both the softest and hardest crystallographic orientations. When employing a commonly used value for the grain boundary mobility parameter (M* = 125), we also find that transient CPO textures are generally not well resolved if crystals are represented by fewer than 5000 ‘grains’ (weighted orientation samples) — a configuration rarely employed in most previously published studies. Furthermore, kinematic corner-flow models suggest that CPO produced at mid-ocean ridges has a non-linear dependence on depth, which implies that even ostensibly simple mantle flows can result in complex distributions of seismic anisotropy. Our analyses motivate further experimental calibration of parameters controlling dynamic recrystallisation and potential improvements to the numerical treatment of subgrain nucleation.

The Vrancea Seismic Zone (VSZ) is an atypical intermediate-depth earthquake nest located in the South-East Carpathians in Romania, often regarded as a relic slab sinking into the mantle. The origin of the slab...