To understand where Earth might be headed, it's important to know where it has been. Throughout its existence, especially over the past couple of million years, Earth has experienced periodic cold and warm intervals, known as glacial and interglacial periods.
New research led by Curtin University and QUT (Queensland University of Technology) has revealed that repeated asteroid impacts may have been the dominant force shaping early Earth, delivering vast amounts of heat into the planet's interior and delaying the formation of stable continents. The study suggests that during the Hadean—more than four billion years ago—Earth was struck far more frequently than today, with each impact injecting energy deep into the planet.
On Wednesday evening just after 6 p.m. local time, two earthquakes violently shook northern Venezuela.
Last fall, the 12 students in the Jackson School of Geosciences' GEO 347G "Climate System Modeling" class set out to understand something that hit close to home: What were the climatological factors that made the July 4, 2025, rainstorm in Central Texas so severe? What they discovered was that the storm—which caused catastrophic flooding that killed at least 139 people—very well could have been worse.
A study led by geoscientists at the University of Sydney has revealed why some ancient continental edges became fertile sites for major mineral deposits, while others with apparently similar geology did not.
Place-specific strategies for adapting to increasing temperatures are crucial to keeping remote towns and communities across northern Australia habitable, according to a recent study on the future impacts of climate change–intensified heat on people on the geographic edges of Australia.
Gold has long held a special place in Australia's history, shaping the nation's economic fortunes and driving waves of migration since the 1850s gold rushes. Today, Australia stands as one of the world's largest gold producers, with the precious metal a key driver of both regional development and national prosperity.
A new international study has found that Indigenous oral traditions, some thousands of years old, hold valuable and often overlooked insights into volcanic eruptions—offering important lessons for modern disaster preparedness. The research, published in the journal Volcanica, was led by Museums Victoria Research Institute volcanologist Dr. Heather Handley and draws on case studies from Australia, Fiji, Hawai'i, Papua New Guinea, the Solomon Islands and Vanuatu to demonstrate how Traditional Knowledge and scientific data can be integrated to better understand volcanic history and hazards.
SummaryWe present a new, regionally adjusted local magnitude (ML) model for Switzerland and surrounding regions. The model is derived based on Wood-Anderson displacement amplitudes (AWA) calculated from 150,000 high-quality waveforms from 15,000 earthquakes between 2000 and 2025, recorded by more than 700 seismic instruments. This dataset is substantially richer than those used in previous ML studies in Switzerland, with a large number of near-source recordings and data from low-magnitude events, which were notably sparse in earlier works. AWA attenuation over hypocentral distance is parametrised through linear and logarithmic distance terms along with hinge distance points, which allow proper modelling of the attenuation characteristics at long distances and changes in attenuation associated with post-critical reflected phases. Regional differences in attenuation between the Alpine region in southern Switzerland and the northern Foreland are smoothly modelled through a ray-path-specific regional adjustment parameter, allowing the model coefficients and the hinge distances to vary spatially. The coefficients of the parametric attenuation curves are estimated using mixed-effects regressions, and the model is anchored to yield a magnitude 3 for an AWA of 10 mm measured at a hypocentral distance of 17 km. The station terms are calculated with respect to Swiss reference rock conditions. The new ML model reduces uncertainty by 33 per cent compared to the current ML scale used by the Swiss Seismological Service and does not exhibit any residual trends with respect to hypocentral distance, earthquake depth, local site conditions, or event magnitude. Empirical radiation pattern corrections are derived, further reducing the uncertainty by 8 per cent for strike-slip events. Alternative models, based on non-parametric and cell-based 2D approaches, are derived independently to validate the parametrisation of the parametric model. The new model – MLS26 – yields lower magnitudes for smaller events (with catalogue magnitudes lower than about 2.5) and for events located in the northern Foreland, whereas the magnitudes of the larger Alpine events remain similar. The reduced magnitudes of smaller events decrease the b-value of the input earthquake catalogue from 1.00 to 0.93, corresponding to a reduction of about 7 per cent. MLS26 scales one-to-one with moment magnitude (MW) for MLS26 > 4, while for smaller events, it scales with the logarithm of the seismic moment.
SummaryThis study aims to understand the recurrent seismicity that occurs in a limited volume along a major fault in the French western Alps, the Vuache Fault, which crosses the geological Jura in a flat-and-ramp zone. In 1996, an M5.3 earthquake occurred near Annecy (France), located at a depth of approximately 2 km. In this article, we analyze the seismicity that has occurred since then and calculate the seismic velocity variations at local permanent seismic stations. The magnitude and focal mechanism of the 1996 M5.3 earthquake indicate that the process was tectonic in origin. However, the duration of the Omori decay of its aftershocks, their migration, the variations in spring flow, the existence of repeated swarms, the seasonal variations in seismic velocity and their relationship to rainfall and seismicity show that the continuation of this seismicity is linked to the pressurization of fluids in a deep, fractured aquifer connected to the surface. This aquifer appears to be limited to the sedimentary formations. Earthquakes, especially during the M5.3 aftershock migration, reach the depth of the Triassic gypsum. The aftershock sequence occurred in two different phases: an initial phase lasting around ten days, during which the earthquakes did not show any migration but rather a random spatial distribution, and a second phase showing a clear migration, suggesting a fluid diffusion process. During this last phase, the hydraulic diffusivity of the aquifer was calculated and estimated at around 2 m²/s. The same order of magnitude was obtained by using the correlation between seismic velocity variations and rainfall. This is a high value, close to those found during man-made fluid injections. This aquifer forms a confined, pressurized reservoir between two thrusts in the regional flat-and-ramp structure. The scenario described in this article could be found, at various scales, in flat-and-ramp regions where tectonic stresses are sufficient to generate seismicity.
SummaryModeling seismic wave attenuation and dispersion in fluid-saturated porous media is essential for reservoir characterization; however, significant challenges remain in accurately capturing the effects of anisotropy. Unified theoretical frameworks that combine Biot and squirt flow mechanisms have often been limited by two key factors: they are typically based on the isotropic assumptions and rely on oversimplified physical models for squirt flow. Consequently, a time-domain numerical implementation for advanced, physically-based anisotropic squirt models has been lacking. This study presents a unified theoretical and numerical framework that, for the first time, integrates Biot’s theory of anisotropic poroelasticity with a state-of-the-art model for anisotropic squirt flow based on one-dimensional fluid pressure diffusion in cracks partially connected to spherical pores. The core innovation is a time-domain implementation achieved through a semi-analytical conversion of the complex, frequency-dependent frame moduli into a Generalized Zener Model representation. With parameters optimized via a genetic algorithm, the system is expressed as a set of differential equations with memory variables, enabling efficient finite-difference time-domain (FDTD) simulations in complex heterogeneous media. Our numerical results demonstrate that the model accurately captures frequency- and angle-dependent velocity dispersion and attenuation in VTI media due to squirt flow in the seismic-to-sonic frequency band. The FDTD algorithm is rigorously validated against analytical solutions, and simulations in heterogeneous media highlight its capability to capture spatially-varying anisotropic attenuation effects. This framework bridges a critical gap between advanced rock physics theory and practical wavefield simulation, providing an accurate forward modeling tool for interpreting seismic data to characterize complex reservoir rocks.
Publication date: 1 September 2026
Source: Earth and Planetary Science Letters, Volume 689
Author(s):
Publication date: 1 September 2026
Source: Earth and Planetary Science Letters, Volume 689
Author(s): Chenguang Sun, Lijing Yao
Publication date: 1 September 2026
Source: Earth and Planetary Science Letters, Volume 689
Author(s): Germain Bayon, Jung-Hyun Kim, Charlotte Skonieczny, Guillaume Soulet, Sujin Kang, Mathilde Levacher, Barnabé Djatibeye, Jean-François Ghienne, Bernard Dennielou, Eduardo Garzanti
Publication date: 1 September 2026
Source: Earth and Planetary Science Letters, Volume 689
Author(s): Pinku Saha, Motohiko Murakami, Paolo A. Sossi, Shinji Kitao, Makoto Seto, Takaya Mitsui, Pierre Lefebvre, Julien Allaz
Publication date: 1 September 2026
Source: Earth and Planetary Science Letters, Volume 689
Author(s): Tyson M. Smith, Sean P. Gaynor, Brenhin C. Keller, Magdalena E. Curry, Blair Schoene, Tom J. Lapen
Publication date: 1 September 2026
Source: Earth and Planetary Science Letters, Volume 689
Author(s): Y. Yuan, J.K. Magali, X. Deng, F. Rochira, X. Jiang, C. Thomas
Publication date: 1 September 2026
Source: Earth and Planetary Science Letters, Volume 689
Author(s): Fubing He, Yubin Cui, Ruijie Li, Kai Wang, Wenzhi Niu, Xiaoyong Liu, Mengmeng Cao, Xinhe Lv, Yueze Zhang, Lingyan Bai, Jing Liu, Xiwei Xu
Publication date: 15 July 2026
Source: Advances in Space Research, Volume 78, Issue 2
Author(s): Mei Liu, Huaqiang Ge, Lishan Ma, De Li, Zunbing Sheng
Publication date: 15 July 2026
Source: Advances in Space Research, Volume 78, Issue 2
Author(s): Hao Li, Xing Wang, Yue Zhang
