SummaryOn 22 January 2024, a MW 7.0 earthquake struck the southern sector of the Tian Shan Mountains in Wushi County, northwestern China, causing damage and casualties. In this study, using Interferometric Synthetic Aperture Radar (InSAR) measurements (Sentinel-1 satellites), we constrained the geometry of the fault segment responsible for the seismic event, the coseismic slip distribution, and the source of the subsequent MW 5.7 aftershock deformation. Finally, we evaluated the potential state of stress of the unruptured portions of the causative fault as well as of adjacent fault segments, using the Coulomb stress failure function variations. Our findings indicate rupture along a transpressive left-lateral NNW dipping high-angle fault, associated with the Southern Tian Shan Fault (STF) alignment, likely the Maidan fault, with slip up to 3.5 m only occurring between 10 and 20 km depth. The position of the hypocenter with respect to our estimated slip distribution supports the evidence of a marked bilateral ENE-WSW rupture directivity during the mainshock. The modeling of the postseismic deformation that includes the MW 5.7 aftershock occurred on 29 January 2024, and that is located about 15 km to the south of the mainshock, indicates a main patch with up to 90 cm of slip that may have occurred on a shallow back-thrust segment, in agreement with the observed surface breaks. We propose a potential structural and/or lithological influence on the coseismic rupture extent, consistent with observations from other intracontinental earthquakes. Finally, based on the Coulomb stress distribution computation, we find that the MW 5.7 aftershock was likely triggered by the preceding mainshock and that the Wushi earthquake also increased the stress level at both terminations of the modeled fault plane, particularly along the southwestward continuation of the Maidan fault. In addition, we also find that a wide up-dip fault patch remained unruptured, and considering that these areas have been dynamically loaded it could represent potential further aseismic deformation and/or future significant ruptures, posing a continuing seismic hazard to Wushi County and surroundings areas.
Northwestern University researchers are actively overturning the conventional view of iron oxides as mere phosphorus "sinks." A critical nutrient for life, most phosphorus in the soil is organic—from remains of plants, microbes or animals. But plants need inorganic phosphorus—the type found in fertilizers—for food.
The overall amount of carbon dioxide in the atmosphere has been steadily increasing, a clear trend linked to human activities and climate change. Less concerning but more mysterious, the difference between the highest and lowest amounts of carbon dioxide in the atmosphere each year has also been increasing.
Publication date: Available online 21 February 2025
Source: Advances in Space Research
Author(s): Qijia Yao, Qing Li, Shumin Xie, Hadi Jahanshahi
Publication date: Available online 21 February 2025
Source: Advances in Space Research
Author(s): Haochen Ma, He Zheng, Tiance Liang, Jiapeng Li, Liqiu Wei, Liang Han, Hong Li, Yongjie Ding
Publication date: Available online 20 February 2025
Source: Advances in Space Research
Author(s): Naveen Kumar, Sudheer Siddapureddy
Publication date: Available online 20 February 2025
Source: Advances in Space Research
Author(s): Soumaya Azzi, Xanthi Oikonomidou, Stijn Lemmens
Publication date: Available online 20 February 2025
Source: Advances in Space Research
Author(s): Peiyuan Wang, Rui Tu, Xiaolei Wang, Junqiang Han, Junjian Zhang, Fang Cheng, Xiaochun Lu
Publication date: Available online 20 February 2025
Source: Advances in Space Research
Author(s): Qiang Guo, Bo Na, Stepan Douplii
Publication date: Available online 20 February 2025
Source: Advances in Space Research
Author(s): Varsha Parthasarathy, Sajad Saraygord Afshari, Philip Ferguson
Publication date: Available online 20 February 2025
Source: Advances in Space Research
Author(s): Peter J. Schubert
Publication date: Available online 20 February 2025
Source: Advances in Space Research
Author(s): Chao Liu, Runfa Tong, Yuan Tao, Jian Chen, Jian Wang
Publication date: Available online 19 February 2025
Source: Advances in Space Research
Author(s): Bin Liu, Bing Li, Shuofeng Li
University of Idaho researchers have developed a mathematical model that simplifies the way scientists understand changes in glacier movement. This new approach demonstrates that diverse patterns of ice flow—ranging from short-term fluctuations to multi-year trends—can be explained using a single set of fundamental equations.
Seismology has revealed much of the basics about earthquakes: Tectonic plates move, causing strain energy to build up, and that energy eventually releases in the form of an earthquake. As for forecasting them, however, there's still much to learn in order to evacuate cities before catastrophes like the 2011 magnitude 9.0 Tōhoku earthquake that, in addition to causing the tsunami that led to the Fukushima nuclear disaster, resulted in more than 18,000 deaths.
In the last few years, Antarctic sea ice has been behaving erratically. Sea ice cover has been much more variable than it used to be, with anomalies lasting much longer than previously documented. Most concerning for scientists is that sea ice cover has been remarkably low in recent years. A new study shows that the extreme lows are highly unlikely to have happened in the last century.
The Greenland Ice Sheet is the largest ice mass in the Northern Hemisphere, and it's melting rapidly. Climate change is causing more intense atmospheric rivers, which can deliver intense snowfall—enough to slow Greenland's ice mass loss, a new study finds.
SummaryWe introduce MTUQ, an open-source Python package for seismic source estimation and uncertainty quantification, emphasizing flexibility and operational scalability. MTUQ provides MPI-parallelized grid search and global optimization capabilities, compatibility with 1D and 3D Green’s function database formats, customizable data processing, C-accelerated waveform and first-motion polarity misfit functions, and utilities for plotting seismic waveforms and visualizing misfit and likelihood surfaces. Applicability to a range of full- and constrained-moment tensor, point force, and centroid inversion problems is possible via a documented application programming interface (API), accompanied by example scripts and integration tests. We demonstrate the software using three different types of seismic events: 1) a 2009 intra-slab earthquake near Anchorage, Alaska; 2) an episode of the 2021 Barry Arm landslide in Alaska; and 3) the 2017 Democratic People’s Republic of Korea (DPRK) underground nuclear test. With these events, we illustrate the well-known complementary character of body waves, surface waves, and polarities for constraining source parameters. We also convey the distinct misfit patterns that arise from each individual data type, the importance of uncertainty quantification for detecting multi-modal or otherwise poorly constrained solutions, and the software’s flexible, modular design.
SummaryThis short paper presents a new equation of state for condensed phases. The equation of state is built on the premise that K′, the first derivative of the bulk modulus, monotonically increases with volume according to a power law. The input parameters are the zero-pressure volume V0, bulk modulus K0, and first and second derivatives of the bulk modulus, $K^{\prime }_0$ and $K^{\prime \prime }_0$, and also $K^{\prime }_{\infty }$, the value of K′ at infinite compression. Expressions are provided for the internal energy, pressure, and bulk modulus. The equation of state is robust for all compressions as long as $K^{\prime \prime }_0 < 0$ and $K^{\prime }_{\infty } < K^{\prime }_0$. Heuristic values are suggested for situations in which available data is not sufficient to independently constrain $K^{\prime \prime }_0$ and $K^{\prime }_{\infty }$. The equation of state compares favourably with other equations of state using recently published experimental data on Au and Pt.
To reduce the loss of human lives and damage to property caused by typhoon disasters, it is crucial to continuously improve numerical models and enhance their capacity to forecast typhoon tracks and intensities. Numerical models serve as important tools in typhoon numerical simulations and operational forecasts. Since 1990, the accuracy of typhoon track forecasts using numerical models has gradually improved. However, improvement in intensity forecasts has been slow.
