SummaryThe Semail Ophiolite in Oman represents one of the well-preserved ophiolite complexes globally and provides a unique window into the processes of obduction. The emplacement of Semail ophiolite onto the Arabian lithosphere is a result of intra-oceanic subduction, was strongly influenced by inheritance features preserved from pre-obduction tectonic processes. Therefore, a detailed characterization of the crustal architecture and rheological properties of the lithosphere are essential for improving our understanding of obduction processes. In this study, we investigated the crustal structure and Moho depth beneath the central Oman Mountains through analysis of P-wave receiver functions (PRFs) and Bouguer gravity anomalies. We utilize broadband seismic data recorded at 12 seismic stations spanning the ophiolite belt and surrounding regions (Ghaba basin and Saih Hatat Dome). PRFs analysis reveals noticeable lateral variations in Moho depths ranging from ∼39 km beneath the sedimentary basin to ∼46 km beneath the ophiolite belt, and decreasing to ∼30 km underneath Saih Hatat Dome (SHD). 2D forward modeling of Bouguer gravity anomalies (−36 to 91 mGal) constraints with seismological results shows flexural bending of the Moho topography and thin crust (∼ 30 km) beneath the SHD. The 2D forward flexural modelling analysis suggests that lithospheric flexure is due to the emplacement of the ∼5 km thick Semail Ophiolite. The presence of a thin crust beneath the SHD is caused by Permian rifting and thinning of the continental lithosphere. The observed high value of Vp/Vs (1.75 – 1.87) also provides support for Permian mafic intrusions to the lower crust. The Arabian lithosphere exhibits lower mechanical strength in the southern region (Te = 25 km) relative to the northern area, a characteristic likely inherited from pre-obduction magmatic processes. These results provide new geophysical constraints on the crustal architecture of the southern Oman Mountains and emphasize the role of surface loading in shaping lithospheric structure during ophiolite emplacement.
SummaryThis study aims to evaluate the effectiveness of the remove-restore method applied to GRACE (Gravity Recovery and Climate Experiment) gravity solutions, in which climate-related signals are first removed to allow a more meaningful interpretation of residual gravity signals associated with dynamic processes in Earth’s deep interior. By removing seasonal cycles and long-term trends, the analysis focuses on non-seasonal variations where causal attribution is clearer. Results indicate that climate correction reduces GRACE signal variability by approximately 30% over both oceanic and continental regions, with the strongest impact observed in major river basins. The correction is most effective for temporal scales below 10 years and spatial scales up to spherical harmonic degree 25. While overall variability decreases, certain frequency bands exhibit increased variability, suggesting a potential degradation of the signal due to model or data limitations. Globally, correlations between corrected GRACE signals and key climate indices largely diminish, confirming substantial removal of climate-related variability. However, the climate contribution to time-variable gravity beyond seasonal scales likely exceeds 30%, indicating incomplete correction and occasional alteration of residual signals that complicate the interpretation of deeper Earth processes. Despite these challenges, climate model-based correction shows promise for advancing source separation and deepening understanding of Earth’s interior dynamics via time-variable gravity data, contingent on future improvements in climate modelling.
SummaryFull-waveform inversion has been broadly adopted for acoustic and elastic media, but it lacks widely accepted methods for robust uncertainty quantification. This lack is in part due to an absence of assessment of proposed uncertainty quantification strategies. Here, we investigate four relatively inexpensive uncertainty estimation approaches based on truncated singular value decomposition of the inverse problem Hessian and its inverse. We numerically test these approaches across a range of parameter scales and application problems. We find that uncertainty estimates based on truncated singular value decomposition of the Hessian outperform those based on singular values of the inverse Hessian, due to both favorable singular value spectra of the former, and the greater ease of sampling the Hessian.
SummaryPalaeomagnetic studies of impact glasses offer valuable insights into their magnetization processes and thermal histories associated with impact cratering events. Australasian tektites are broadly distributed in the largest and youngest strewn field of the Cenozoic, and they provide a unique opportunity to investigate the intensity of Earth’s magnetic field around 788 ka and potential impact-induced magnetic fields. The northern part of the Australasian strewn field covers South China, and it corresponds to the uprange zone of the impactor’s trajectory. Magnetic properties of Australasian tektites in South China may contain unique information about this impact event, but their palaeomagnetic characteristics remain poorly constrained. Here, we report the first palaeointensity data of Australasian tektites sampled from the Early-Middle Pleistocene strata in South China. The results show that Muong Nong-type tektites recorded palaeointensities of 30 ± 8 μT, consistent with the geomagnetic field intensity around 780–790 ka. These findings suggest that around 788 ka, Earth’s magnetic field had partially recovered from the earlier intensity decline associated with the precursor event of the Matuyama–Brunhes reversal. By contrast, the splash-form tektites in South China are characterized by extremely weak natural remanent magnetization and unstable magnetization components, posing challenges for deriving reliable palaeointensity data. Although strong impact-induced remanent magnetization was not detected in the samples, this study demonstrates that Australasian tektites, particularly Muong Nong-type, are well suited for palaeomagnetic studies that may reveal potential impact-induced magnetization.
SummaryFluid-rock interactions in geological reservoirs can influence pore pressure and induce ground deformation at rates from millimeters to centimeters per year. Elastic deformation models often simplify structural heterogeneity that controls pore pressure and strain distributions, leading to inaccurate interpretations of reservoir properties from geodetic data. Here we investigate how depth-varying rock hydromechanical properties affect the magnitude, rate, and spatiotemporal characteristics of poroelastic deformation and pore pressure. Motivated by the Salton Sea geothermal field, we develop finite-element models of multilayered reservoirs to assess their transient and steady-state behavior in single-well fluid-extraction scenarios. These cases include (1) caprock-reservoir systems with varying permeability and caprock thickness, (2) compaction-induced porosity variations following Athy’s law, and (3) depth-dependent Young’s modulus. While uniformly lower porosity or permeability produces higher rates and earlier onset of deformation and pore-pressure changes, a less permeable or thicker caprock reduces vertical surface displacements, with pressure change reversals near the surface. Young’s modulus varying in alternating or linear profiles generally produces larger vertical displacements and non-monotonic displacement rate histories due to cross-layer fluid migration. Regarding spatiotemporal patterns, porosity or permeability decreasing with depth, or a thicker caprock, accelerates radial expansion of the deformation signal. In contrast, only layered mechanical properties can substantially alter the initial crossover distance and peak-value ratio between the vertical and radial surface displacements, indicating distinct impacts on deformation signatures. Our findings highlight the importance of accounting for structural heterogeneity in predicting and inferring the evolution of poroelastic processes in reservoir systems.
New UBC Okanagan research shows that wildfire can change how much water remains in streams during the driest months of the year.
In early January, a giant sinkhole formed at an intersection in the West Oak Lane neighborhood of North Philadelphia after a water main break. Just two weeks earlier, the city reopened a section of the Schuylkill River Trail in Center City that had been shut down for two months due to a sinkhole. Last summer, some residents of Point Breeze in South Philly also waited two months for a sinkhole on their block to be repaired.
The ocean is continuously ventilated when surface waters sink and transport, for example, oxygen and carbon to greater depths. The efficiency of this process can be estimated using the so-called water age, which describes the time elapsed since a water mass last was in contact with the atmosphere.
A new analysis of air quality data from the past 70 years shows that Canada's record wildfire smoke in 2023 is part of a broader, continent-wide trend toward smokier skies across North America.
A team of scientists announced Tuesday they have developed new deep-sea landers specifically to test their contentious discovery that metallic rocks at the bottom of the ocean are producing "dark oxygen".
Cuts in sulfur emissions from oceangoing vessels have been tied to a reduction in lightning stroke density along heavily trafficked shipping routes in the Bay of Bengal and the South China Sea, according to new research from the University of Kansas.
An atmospheric scientist at The University of Alabama in Huntsville (UAH), a part of The University of Alabama System, has helped uncover a previously unknown chemical pathway that plays a major role in the formation of air pollution particles in environments influenced by both natural and human-made emissions—an advance that could reshape how scientists understand air quality and climate impacts.
Publication date: 1 March 2026
Source: Earth and Planetary Science Letters, Volume 677
Author(s):
Publication date: 1 March 2026
Source: Earth and Planetary Science Letters, Volume 677
Author(s): Tuo Zhang, Christoph Sens-Schönfelder, Ye Yuan
Publication date: 1 March 2026
Source: Earth and Planetary Science Letters, Volume 677
Author(s): Jon M. Husson, Shanan E. Peters
Publication date: 1 March 2026
Source: Earth and Planetary Science Letters, Volume 677
Author(s): Laurence A. Coogan, Stan E. Dosso
Publication date: 1 March 2026
Source: Earth and Planetary Science Letters, Volume 677
Author(s): Heather Kirkpatrick, Emily Stoll, Nadja Drabon
Publication date: 1 March 2026
Source: Earth and Planetary Science Letters, Volume 677
Author(s): Qiuling Wang, Huilin Wang, Zhuang Li
Publication date: 1 March 2026
Source: Earth and Planetary Science Letters, Volume 677
Author(s): Camilla Sani, Alessio Sanfilippo, Felix Genske, Carlotta Ferrando, Daniele Brunelli, Anna Cipriani, Alexander Peyve, Sergey Skolotnev, Marco Ligi, Andreas Stracke
Publication date: 1 March 2026
Source: Earth and Planetary Science Letters, Volume 677
Author(s): Erina Prastyani, Benoît Cordonnier, François Renard
