SummaryGeodetic observations, such as GNSS and InSAR, are increasingly used to investigate co-seismic surface deformation. Efficiently and simultaneously resolving fault geometry and slip distribution from surface displacements is essential for understanding earthquake processes, accurately estimating seismic magnitude and comprehensively assessing seismic hazard. Current mainstream approaches typically rely on Bayesian inference, such as Monte Carlo sampling. However, these methods typically suffer from long burn-in periods, low computational efficiency, strong sensitivity to initial parameter values and step sizes. Given these limitations, conventional approaches may yield suboptimal fits for the observations. To overcome these limitations, we propose and develop a novel Tree-structured Bayesian Optimization method (TBO), integrated with Helmert Variance Component Estimation (HVCE), to jointly determine fault geometry and slip distribution. To rigorously assess the feasibility and reliability of the proposed approach, we test it using both synthetic and real earthquake data. In the synthetic tests, we evaluate its robustness under a variety of conditions, including different fault types, varying types and densities of geodetic observations, diverse sub-fault sizes and asperities, and complex multi-fault scenarios. Four sets of synthetic experiments are designed, and the results conclusively demonstrate that the proposed method achieves stable and reliable performance in inverting fault geometry and slip distribution. Furthermore, comparative analysis with existing methodologies shows that our approach yields substantially improved computational efficiency, significantly reduced sensitivity to initial conditions, and smaller misfits to observations. Finally, we apply the method to the 2021 Mw 6.4 Yangbi earthquake in Yunnan, China. The retrieved fault geometry and slip distribution successfully explain the fault kinematics and the observed surface deformation field, thereby confirming the applicability and robustness of the method for real earthquake event analysis.
East Antarctica hosts the largest ice sheet on Earth, containing enough water to raise global sea levels by 52 meters (171 feet) were it to fully melt. Yet scientists have been puzzled for decades about how and why this ice sheet formed.
In May 2018, the island of Mayotte, between Madagascar and Mozambique, began to experience a series of earthquakes that led to the discovery of an underwater volcano, now called Fani Maoré. Multiple scientific expeditions followed, taking samples of the recently erupted lava. When a team of researchers analyzed 13 samples from Fani Maoré and eight additional samples from eastern Mayotte, they discovered remnants of a mineral called bridgmanite that they believe came from Earth's earliest geologic time period, the Hadean eon. Their findings were recently published in Nature.
Author(s): Chiharu Nakatsuji, Yuji Takagi, Gabriele Cristoforetti, Sota Matsuura, Takuya Honda, Daisuke Tanaka, Dimitri Batani, Takumi Sato, Shun Horimoto, Hideo Nagatomo, Yasuhiko Sentoku, Philippe D. Nicolaï, Kai Taketoshi, Naoki Yamagata, Norimasa Ozaki, Yasunobu Arikawa, Akifumi Yogo, Shinsuke Fujioka, and Keisuke Shigemori
We present an experimental investigation demonstrating that the suppression of parametric instabilities in laser-plasma interactions under conditions relevant to direct-drive inertial confinement fusion, specifically backward stimulated Raman scattering (SRS) and two-plasmon decay (TPD), shows the e…
[Phys. Rev. E 114, 015202] Published Mon Jul 06, 2026
Author(s): Ao Xu and Yan Feng
Equilibrium molecular dynamical simulations of three-dimensional (3D) Yukawa fluids are performed to investigate thermodynamics and supercritical transition of 3D dusty plasma fluids. The normalized reduced excess entropy sex/sexm of 3D Yukawa fluids (where sexm is the excess entropy at the melting …
[Phys. Rev. E 114, 015203] Published Mon Jul 06, 2026
Author(s): Djamel Benredjem and Jean-Christophe Pain
The aim of this work is to predict the opacity of plasmas under stellar conditions. We focus on iron and nickel, as these elements have been extensively investigated both theoretically and experimentally. In certain regimes, notably under nonlocal thermodynamic equilibrium, calculating the spectral …
[Phys. Rev. E 114, 015204] Published Mon Jul 06, 2026
The state of the Atlantic Meridional Overturning Circulation (AMOC) has been a hot topic among climate scientists in recent years. The AMOC is crucial for climate regulation because it pulls warm surface water from the tropics north and sends colder, deeper water south, redistributing large amounts of heat, helping to sustain marine ecosystems and keeping global weather patterns steady. However, most standard AMOC-focused climate models may be missing an important piece of the puzzle—they don't include the growing pulse of freshwater from Greenland ice melt, which could further disrupt the AMOC.
Tropical moist forests account for 70% of global living biomass. Deforestation and degradation—that is, the partial damage to tree stands—as well as the subsequent regeneration of forests therefore play a pivotal role in the global carbon cycle. While the effects of large-scale tropical deforestation are well understood, the impacts of forest degradation have remained highly uncertain until now.
The Southern Ocean has long stood out as an oddity in the global climate system. While most of the planet's surface oceans have warmed in response to rising greenhouse gases, waters circling Antarctica showed an unexpected tendency to cool during the late 20th and early 21st centuries. This cooling coincided with a period when Antarctic sea ice briefly expanded before its more recent decline, adding to the mystery.
Every summer, communities across northern Australia brace for the tropical cyclone season. Tropical cyclones draw their power from the warm seas, extracting heat and moisture from ocean water.
Europe's summer heat wave has exposed tens of millions of people to temperatures above 35°C, broken records and claimed hundreds of lives. Early climate attribution studies suggest Europe's event would have been "virtually impossible" just 50 years ago without human-caused climate change.
The Congo River is the second-largest river in the world, releasing an average of 40,000 cubic meters of water per second into the Atlantic Ocean. This huge discharge rate creates a large plume of fresh water that fans out 800 kilometers (500 miles) offshore.
SummaryGravity inversion is an essential technique for recovering subsurface density variations. Constructing stratigraphic models from gravitational observations, however, remains challenging because gravity data provide limited vertical resolution and the inverse problem is strongly non-unique. To address these limitations, we develop a Bayesian geometry-based gravity inversion framework aimed specifically for stratigraphic reconstruction. Stratigraphic interfaces are parameterized using a Fourier series, which provides a compact set of variables, enables a controllable representation of layer geometry, and improves the vertical resolution of the recovered density model. Uncertainty in the inferred stratigraphy is quantified with Stein variational inference, yielding an ensemble approximation to the posterior distribution. The resulting posterior models reveal the confidence level and spatial variability of stratigraphic layers. The proposed method has been validated using two toy examples to illustrate the main concepts. Two synthetic lunar basin models, representing alternative interpretive hypotheses for upper-crustal layering, are further designed to evaluate algorithm performance. Finally, application to satellite gravity observations from the Orientale Basin demonstrates that the proposed framework can recover the basin’s large-scale tectonic structure.
When NASA's Cyclone Global Navigation Satellite System, or CYGNSS, launched into orbit in 2016, none of the University of Michigan Engineering researchers who developed the system expected it to transform earth science. They certainly had high hopes for the system's original mission to improve hurricane forecasting, but its ability to pick up reflected GPS signals also proved useful for much more.
Many of the boulders scattered across the Swiss landscape did not originate where they now stand. Instead, they were carried by ice nearly 24,000 years ago. For the first time, researchers at the University of Lausanne (UNIL) have reconstructed the journeys of these giant rocks across the entire Alpine region using a simulation. The model makes it possible to visualize the paths taken by millions of rocks that helped shape today's landscapes.
Prescribed fires are vital for reducing wildfire risk and sustaining forest biodiversity. But they also contribute significantly to air pollution and smoke exposure, according to new research from the University of Georgia. The issue is especially pertinent to the southeastern United States, where 60% of all prescribed fires in the country occur. More than 20% of the fine-particle pollution in the southeastern U.S. can be attributed to prescribed burns, the study found.
One seismometer is often not enough to reliably detect earthquakes or human activity such as underground nuclear tests. Rather, researchers combine readings from seismometers distributed across a small geographic area to gain confidence in their analysis. Artificial intelligence (AI) can combine readings from multiple sensors more effectively than classic technology, enabling more reliable detection of weak seismic signals, a new study by A. Köhler and colleagues shows.
Scientists have uncovered why Antarctica became engulfed by ice millions of years before the Arctic. The international research, published in Science, helps solve one of climate science's longest-standing puzzles: how a vast ice sheet could form when Earth was around 5°C warmer than today.
Nearly 660 kilometers (410 miles) beneath Earth's surface lies one of the planet's most important internal boundaries. Known as the 660-km seismic discontinuity, it separates the mantle transition zone from the lower mantle and plays a central role in controlling how heat and materials circulate through Earth's interior. This circulation helps drive mantle convection, plate tectonics, volcanic activity and the long-term evolution of the planet. Although scientists have generally attributed this boundary to the breakdown of the mineral ringwoodite into bridgmanite and ferropericlase, that explanation has struggled to account for the complex structures detected by seismic observations beneath subduction zones and mantle plumes.
If you have ever hiked in the high peaks of Colorado, the Wasatch Range in Utah or the Tetons in Wyoming, you've almost certainly seen a rock glacier, perhaps without even knowing it.
