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New index reveals global water resources' growing dependence on extreme rainfall

Phys.org: Earth science - Tue, 03/31/2026 - 13:40
As global temperatures climb, rainfall patterns are shifting in ways that could put water resources and agriculture under increasing strain, a new study published in Water Resources Research suggests.

How scientists prepare expeditions in remote environments

Phys.org: Earth science - Tue, 03/31/2026 - 01:10
Scientific expeditions require months of planning before scientists can acquire the first data. A bark cuts through the Arctic silence, waking Anna up. She slept only three hours after collecting the last sample. Anna reaches for her rifle, exits the tent, and steps onto the midnight ice. She pets the guard dog she rented a few days earlier. It might be a false alarm, but she scans the darkness for polar bears, hoping her training pays off. She cannot afford to lose the samples. Nor her life.

Shallow Slip Pattern of the Laohushan-Haiyuan Fault Zone Characterized by Geodetic and Seismicity Observations

Geophysical Journal International - Tue, 03/31/2026 - 00:00
SummaryKinematic characteristics (creeping or locked) and high-precision seismic catalogs can constrain the shallow (<20 km) slip pattern of active fault zone. We collect Sentinel-1 Synthetic Aperture Radar (SAR) images and extract a high-resolution deformation velocity field along the active Laohushan-Haiyuan (LHS-HY) fault zone in the northeastern margin of the Qinghai-Tibet Plateau. We invert the shallow fault coupling and slip distribution using two-dimensional (2D) and three-dimensional (3D) models, indicating that the fault zone exhibits an alternating pattern of large strong coupling asperities and creeping zones, and the deep slip rate decreases from 5.2 mm/yr in the west to 3.4 mm/yr in the east, accompanied by a transition from strike-slip to dip-slip components. Then we calculate cumulative seismic energy release, seismic slip rate, and statistical parameters including $b - \textit{value}$, coefficient of variation of seismicity interevent times, and Nearest-Neighbor Distance (NND) with regional seismic catalog. The geodetic and seismic results demonstrate a complex shallow slip pattern in the fault zone. The following characteristics are highlighted. A significant throughgoing locked-creeping transition zone with variable depth range extends from the eastern part of the Laohushan segment (LHS) to the eastern segment of Haiyuan Fault (HYE). A shallow (<6 km) creeping zone with weak coupling and seismicity in the western HYE segment differs from the shallow part of the locked-creeping transition zone between the eastern LHS segment and the western part of the western segment of Haiyuan Fault (HYW). A transition zone with strong coupling and active seismicity in the eastern HYE segment ranges from 4 km to 12 km in depth. The results provide new insights into the shallow slip behavior of the LHS-HY fault zone, and offer valuable references for seismic hazard assessment in the region.

Estimating Sensor Orientation Deviations of ChinArray-Ⅱ Stations by P- and Rayleigh-Wave Polarizations

Geophysical Journal International - Tue, 03/31/2026 - 00:00
SummaryAccurate sensor orientation estimation is critical for reliable seismological processing, especially when rotating three-component seismograms is required. In this study, we determine the sensor orientation angles of 676 broadband stations of ChinArray-II deployed in northeastern Tibet between August 2013 and June 2016. The polarizations of both Rayleigh waves and teleseismic P-waves are used to estimate the azimuthal deviation. The results demonstrate that both approaches are consistent and approximately 600 stations are well-aligned, with mis-orientation angles less than 10°. The remaining stations exhibit various orientation problems, such as vertical component reversal and temporal variations in sensor alignments. Moreover, detailed multi-event analysis reveals that three-component sensor gain discrepancies may lead to failures of both P- and Rayleigh-wave approaches, while post-validation of multi-event estimation can identify such issues. Compared with previous studies, our results provide comprehensive sensor orientation information and indicate that combining noise level and wave polarization yields robust estimations.

From flat to steep subduction: the South Peru margin imaged by a new high-density seismic catalog

Geophysical Journal International - Tue, 03/31/2026 - 00:00
SummaryThe South Peru subduction zone is a complex, highly active region, which has hosted four Mw 8 + earthquakes over the last 100 years. It marks the transition between the flat slab associated with the Nazca Ridge subduction in the North and more steeply dipping subduction in the South, causing the slab to contort and affecting seismicity patterns in the region. In this study, we present the first high-density, high-quality seismic catalog of the region between the arc and the trench, totaling 166 825 events between January 1st 2022 and December 31st 2024, including 125 467 well-located ones. We first picked and associated phases using PhaseNet and PyOcto, then located the resulting events with NonLinLoc-SSST and GrowClust3D. Finally, we derived a new slab model from the seismicity, allowing us to classify the earthquakes as upper plate (16 per cent), interface (12 per cent), lower plate (68 per cent), outer rise (0.20 per cent) and human-related (3.1 per cent).The region is broadly divided into four subregions with different seismicity patterns and slab geometries: the flat slab, with intense interface and intraslab activity, the slab transition zone, where the plate contorts to accommodate its change in geometry, the Arequipa region, with intense upper plate seismicity but very low intraslab and interface seismicity, and the North Chile region, with a large band of dense intraslab seismicity.We find that in the flat slab region, the Nazca Ridge is linked to the presence of dense seismicity close to the trench, and seismic swarms hinting at the presence of slow slip. Meanwhile, the intraslab seismicity in that region is organized in trench-parallel bands which are likely related to slab bending. In the slab transition region, we image multiple orthogonal faults just south of the slab contortion, suggesting a damaged slab. Further south, in the Arequipa region, upper plate seismicity forms a large, trenchward-dipping structure seemingly connected to the Incapuquio fault at the surface. Finally, in North Chile, the deep band of intraslab seismicity appears to locate further downdip as we move to the north, perhaps reflecting changes in slab properties.

Water flow in prairie watersheds is increasingly unpredictable—but AI could help

Phys.org: Earth science - Mon, 03/30/2026 - 23:50
In recent years, the Prairies have seen bigger swings in climate conditions—very wet years followed by very dry ones. That makes an already unpredictable landscape even harder to forecast, with real consequences for flood preparedness and water quality.

Animals are powerful landscape engineers shaping the Earth's surface, global study finds

Phys.org: Earth science - Mon, 03/30/2026 - 23:20
Wild animals are not just inhabitants of the natural world. Many also act as natural landscape engineers, reshaping Earth's surface as they burrow, feed, and build shelters that move soil and sediment across ecosystems. From animals disturbing riverbeds to burrowing species redistributing soil, wildlife constantly modifies the physical structure of landscapes through everyday activities.

Global human population is pushing Earth past its breaking point

Phys.org: Earth science - Mon, 03/30/2026 - 16:40
Earth has already exceeded its ability to support the global population sustainably, with new research warning of increasing pressure on food security, climate stability, and human well-being. However, slowing population growth and raising global awareness could still offer humanity some hope.

Tropical volcanic eruptions trigger atmospheric changes that drive droughts in Asia

Phys.org: Earth science - Mon, 03/30/2026 - 14:00
Volcanoes are both captivating and disastrous. Most are likely familiar with the common short-term dangers associated with them: explosive forces, lava, and even atmospheric particles disrupting air traffic. But researchers also explore longer-term impacts of eruptions, as their contributions to broader climate patterns are important, but not well understood. For example, it's known that ejected material can reach high into the atmosphere and cause local or even global cooling to some degree.

Thawing permafrost becomes 25 to 100 times more permeable, experiments find

Phys.org: Earth science - Mon, 03/30/2026 - 10:44
Experiments by University of Leeds researchers, published in Earth's Future, have shown that thawing of permafrost makes it between 25 and 100 times more permeable, allowing more climate change forcing gases to escape.

Recovery from sudden permafrost collapse ranges from 10 years to a century, study suggests

Phys.org: Earth science - Mon, 03/30/2026 - 09:00
Some Arctic regions regain their "greenness" within a decade of a sudden permafrost collapse, while others can take a century or more to recover, researchers report in a new study. The difference is directly related to each site's gross primary productivity, a measure of its photosynthetic capacity, the researchers discovered. This finding will allow scientists to accurately predict how long it will take a specific site to recover after a permafrost collapse.

Subsurface Density Structure of the Orientale Basin Revealed by 3D Gravity Inversion of GRAIL Data

Geophysical Journal International - Mon, 03/30/2026 - 00:00
SummaryThe Orientale Basin is the youngest and best-preserved multi-ring impact basin on the Moon. It is approximately 930 km in diameter and comprises three concentric rings—the Cordillera, Inner Rook, and Outer Rook rings. We used Gravity Recovery and Interior Laboratory (GRAIL) mission gravity data (GRGM1200B, truncated to degree 660) to invert the three-dimensional (3D) density structure associated with the basin’s mascon and ring-related crustal anomalies. To separate longer and shorter-wavelength signals, we performed inversions using (1) spherical harmonic degrees 2–660 to characterise the basin’s deep structure and (2) degrees 60–660 to highlight crustal-scale heterogeneity. The inversion with degree and order of 2–660 resolves a basin-wide central positive density anomaly beneath the inner depression, extending from a depth of ∼16–80 km, corresponding to uplifted mantle. This anomaly persists below the crust–mantle boundary; however, its deep continuation should be interpreted cautiously because it may partially reflect vertical smearing in the gravity inversion. Nonetheless, the spatial association of this anomaly with a mascon rooted in the upper mantle is compatible with impact-driven uplift of dense material from depth, followed by post-impact thermal evolution and relaxation processes. The inversion with degree and order of 60–660 indicates alternating positive and negative density anomalies associated with the ring system. Prominent ring-parallel positive anomalies occur along the Outer Rook Ring and Cordillera Ring, extending to ∼30–35 km depth and exhibiting a density contrast of ∼60–200 kg/m3. The geometry and lateral continuity of these anomalies across multiple rings support an interpretation of ring-controlled crustal heterogeneity, consistent with either intrusion and structurally focused modification along ring-related discontinuities or impact-generated fracturing that provided pathways for magma ascent. The results of this study provide quantitative constraints on the depth, magnitude, and spatial distribution of density anomalies associated with the Orientale mascon and ring system, thereby improving the subsurface framework for regional geological interpretation and supporting future lunar landing-site geophysical investigations and in situ sampling. Based on the inferred crustal density architecture, we propose that future geophysical sampling efforts should prioritise the Outer Rook Ring and Cordillera Ring, where the observed ring-parallel anomalies may provide insights into crustal modification processes and the composition of the lunar interior.

Climate change is altering Saharan dust—and Europe is downwind

Phys.org: Earth science - Sun, 03/29/2026 - 13:00
In recent years, residents of Spain, France and the UK have looked up to see an eerie sight: deep orange sunrises and skies thick with a yellowish haze. These hazy skies often deposit "blood rain," rust-colored precipitation that leaves a fine grit on cars and windows.

How internal waves transport energy thousands of miles across the ocean

Phys.org: Earth science - Sun, 03/29/2026 - 12:00
Both winds and tides inject energy into the ocean. Much of that energy is then transported up to thousands of miles by internal waves: large-scale underwater waves that can travel between ocean basins. Quantifying the amount of energy transported by internal waves and assessing their dynamics are difficult given their location and scale. Still, the question is important because internal wave dynamics interact with the global climate and underwater ecosystems by influencing currents, ocean mixing, and more.

North Sea wind farms may be reshaping sediment flows by 1.5 million tons a year

Phys.org: Earth science - Sat, 03/28/2026 - 16:20
Offshore wind farms are an important pillar of the European Union's strategy for renewable energy—by 2050, the EU aims to increase capacity in the North Sea more than tenfold. A new study by the Helmholtz-Zentrum Hereon shows that the expansion of wind farms can alter the natural transport and deposition of sediments on a large scale and over the long term. The German Bight is particularly affected. The researchers have published their findings in the journal Nature Communications Earth & Environment.

Alaska analysis shows continued loss of Arctic landfast sea ice

Phys.org: Earth science - Sat, 03/28/2026 - 13:00
Sea ice is sticking to Alaska's northern coast for less time each year, according to 27 years of data analyzed by University of Alaska Fairbanks scientists. Such landfast ice, which stays attached to the shoreline instead of drifting with winds and currents, also has covered less total area in recent winters.

Study explains Antarctic sea ice growth and sudden decline

Phys.org: Earth science - Sat, 03/28/2026 - 11:00
A new Stanford University study has helped solve a mystery about dramatic swings in sea ice extent around Antarctica.

Ionospheric changes immediately before the 2025 March 28 Mw7.7 Myanmar earthquake

Geophysical Journal International - Sat, 03/28/2026 - 00:00
SummaryWe studied ionospheric changes associated with the 2025 March 28 Myanmar earthquake (Mw7.7) using global navigation satellite system receivers to measure ionospheric electrons, as a part of the project to predict earthquake precursors. The total electron contents above the fault changed their trends ~36 minutes before the earthquake, with the positive anomaly reaching ~1 per cent of the background. These quantities fit well with the past ~20 cases despite relatively large day-to-day variability due to high geomagnetic activities. The positive anomaly was sandwiched by two negative anomalies to the north and the south, suggesting within-ionosphere electron transportation along geomagnetic fields possibly driven by surface positive electric charges released from the fault.

Uncertainty Estimation for Multi-Phenomenology Explosion Monitoring

Geophysical Journal International - Sat, 03/28/2026 - 00:00
SummaryWe develop and demonstrate a new paradigm for modeling prompt forensics data from potential nuclear explosions of concern. Related scenarios include nuclear terrorism, which may involve low-yield detonations. Traditional modeling appropriate for higher-yield historical nuclear testing is generalized to capture uncertainties in yields (such as when using conversion to obtain “equivalent” nuclear yields for conventional explosives in low-yield experiments) and to capture variation among source-to-sensor path effects for which no calibration data are available. Special attention is paid to quantifying these sources of uncertainty and to their formal inclusion in comprehensive yield uncertainty — uncertainty that would otherwise be underestimated and potentially lead to mistaken conclusions. For the example scenario considered, two useful stand-alone monitoring phenomenologies are based on geophysical data (from surface effects characteristics and local seismic metrics). By fusing signatures from multiple phenomenologies, the Multi-Phenomenology Explosion Monitoring (MultiPEM) framework provides improved yield characterization relative to reliance on single-phenomenology analysis alone, especially when individual sensors have complementary sensitivities to emplacement/environmental conditions.

Editorial Board

Earth and Planetary Science Letters - Fri, 03/27/2026 - 19:11

Publication date: 15 May 2026

Source: Earth and Planetary Science Letters, Volume 682

Author(s):

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