Feed aggregator

Author(s): Ash Pascale, Cormac Corr, Landry Riou, and Trevor Lafleur

Instabilities are a common occurrence in plasma discharges where they play an important role in system behavior and performance. While such instabilities are typically in the kHz and MHz range, this work reports a low frequency (∼100Hz) instability observed in supersonic inductively coupled plasmas.…

[Phys. Rev. E 114, 025203] Published Tue Aug 11, 2026

On 4 July 2026, 19 people were killed in a massive landslide in Zamora Chinchipe province, Ecuador. Planet Labs imagery shows that this was caused by a c.1 km long landslide that occurred 13 km upstream of Cantzama. This transitioned into a channelised debris flow that destroyed the community.

On 4 July 2026, a massive landslide swept through Cantzama in Zamora Chinchipe province, Ecuador. News reports indicate that 19 people were killed and around 50 houses were destroyed or damaged. As is often the case with disasters of this type in places like Ecuador, this event garnered little press coverage in the west, but it is quite significant event.

There is some Youtube drone footage of the aftermath of the disaster:-

Fundacion Pachamama has quite a detailed analysis of the event, compile using radar imagery, which describes a large, long run out debris flow / mudflow event. They were unable to pinpoint a cause of the flow, but I think Planet Labs optical imagery allows us to diagnose what happened.

The location of the most seriously damaged parts of Cantzama is 3.85480° S, 78.89506° W [-3.85480, -78.89506]. This is a Google Earth view of that site, with the village in the foreground and the tributary valley down which the landslide flowed in the background:-

Google Earth image of Cantzama in Ecuador.

This is a Planet Labs image, dated 5 July 2026, showing the aftermath of the landslide. The path of the flow is very clear, as is the damage to a range of buildings around the channel:-

Planet Labs image of Cantzama in Ecuador, overlain into Google Earth, showing the aftermath of the landslide. Image copyright Planet Labs, used with permission, collected on 5 July 2026.

If we go upstream from Cantzama we reach this point:-

Planet Labs image of the area upstream of Cantzama in Ecuador, overlain into Google Earth, showing the landslide that triggered the catastrophic debris flow. Image copyright Planet Labs, used with permission, collected on 5 July 2026.

The location of the crown of this major landslide is 3.88474° S, 79.00312° W [-3.88474, -79.00312]. The initial failure of the landslide is about 1 km long and 300 m wide. This major failure has transitioned into a channelised debris flow – the linear distance to the Cantzama is about 13.5 km – this is an extremely long runout event. It appears that the landslide has entrained a significant amount of sediment from the channel, leading to an extremely damaging flow.

As such this is an unusual landslide. There is another interesting and intriguing aspect. The image below, collected on 04 December 2025, shows the area around the main failure of the landslide. The marker shows the location of the crown of the 4 July 2026 landslide:-

Planet Labs image of the site of the Cantzama landslide in Ecuador, overlain into Google Earth, showing the multiple shallow failurses at the site of the landslide that triggered the catastrophic debris flow. Image copyright Planet Labs, used with permission, collected on 5 July 2026.

There is a host of shallow failures across the hillslopes, which appear to have been triggered between 22 June 2025 and 08 August 2025. Presumably this was a response to a heavy rainfall event. Note that the site of the 4 July 2026 landslide had suffered a substantial failure in this earlier rainfall event.

Is it possible that this 2025 rainfall event destabilised the slope, creating a situation in which it then destabilised in the next major rainstorm? It would be interesting to look at the InSAR data for this slope.

As for Cantzama, there is a proposal to relocate the population located close to the channels, redesignating the site for tourism. That is probably wise.

Acknowledgement

Many thanks to Planet Labs for making the imagery available to me.

Return to The Landslide Blog homepage Text © 2026. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Prediction is the goal and test of all science, one might argue. Meteorologists have been curious about the inherent limits of weather forecasting ever since the dawn of numerical weather prediction in the late 1950s.

SummaryThe North Maladeta fault system, reactivated after the Alpine orogeny as a normal fault (Ortuño et al., 2008; Ortuño and Viaplana-Muzas, 2018) extends for almost 75 km across the border between Spain and France. This system is considered the most probable source of the historical M6.3 Ribagorça earthquake (1373). Within the system, the Coronas Fault is a secondary fault subparallel to the North Maladeta Fault and located in the southern slope of the Maladeta massif. Recent seismic activity in the massif has markedly increased since 2020, with previously unknown clusters of shallow earthquakes detected. Using a Template Matching approach, we verified that this apparent increase is not an artifact of network evolution, identifying additional clusters during 2014–2016, with far fewer events however. Relocation and focal mechanism analysis suggest that most of the seismicity is associated with the Coronas Fault, which appears to be less vertical and flatter than previously assumed. The seismicity is distributed on both sides of the fault, surrounding a 5–6 km wide aseismic segment. Another cluster, active since 2022 (Gerbosa cluster), likely corresponds to a previously unknown parallel fault.Temporal correlations indicate that cluster activation coincides with periods of low surface water levels. In particular, one cluster at the Western part of the Coronas fault, beneath the most rapidly shrinking part of the Aneto glacier, reactivated in late June 2020 and 2024, suggesting a possible influence of glacier melting. In the eastern Coronas fault, the two largest clusters were triggered within days of major rainfall events recorded in the past five years, consistent with a combination of short-term infiltration processes, and longer-term surface unloading from reduced snow and water storage since 2019. These observations raise the possibility of a climate–seismicity link in the Maladeta Massif, whereby rainfall and snowmelt infiltrations, and/or surface unloading may contribute to triggering shallow seismicity. Longer-term monitoring and detailed studies are required to confirm these processes and assess their potential implications for seismic hazard in the Pyrenees.

body {background-color: #D2D1D5;} Research & Developments is a blog for brief updates that provide context for the flurry of news regarding law and policy changes that impact science and scientists today.

11 August: This article was updated to include comments from Kim Doster, Rick Thoman, and Melody Brown Burkins.

The Trump administration is pulling funding from NOAA’s Arctic Report Card, an annual, peer-reviewed report about the state of the region, which is warming more quickly than anywhere else on Earth.

Three non-NOAA editors of the Arctic Report Card learned of the news in a regular biweekly meeting with staff from the Arctic Research Program, part of the Global Ocean Monitoring and Observing Arctic Research Program, which coordinates and financially supports the report, according to Rick Thoman, an Arctic scientist at the University of Alaska Fairbanks and one of the editors of the 2026 report. Afterward, Thoman informed the lead chapter authors for the 2026 report of the news.

Politico was first to report the news. The absence of federal support means that NOAA will no longer provide the report with coordinating editors nor will the agency fund the report’s web presence, summary video, external peer review, graphics, or publicity, Thoman said.

“Coordination of the 2026 Arctic Report Card will not be facilitated through NOAA,” Kim Doster, director of NOAA Communications, wrote in an email statement. “All data historically contributed by NOAA to the product will continue to be collected and will remain publicly available.”

 Related

•  NOAA to end support for Arctic climate change report
•  2025 Arctic Report Card
•  Amid the Arctic’s Hottest Year, Arctic Science Faces a Data Deficiency
 

“The loss of the Arctic Report Card would be significant not only for the scientific community, but also for decision-makers and the public,” Zack Labe, a climate scientist who has been an author of the report since 2020, told Eos via email. “Written for a broad audience and developed by more than 100 scientists from around the world, the report is an important resource for consistently documenting changes in one of the fastest warming regions on our planet. Discontinuing it would create a significant gap in our ability to track and connect these changes from year to year, with implications for people and communities around the world.”

Last year marked the 20th year of the Arctic Report Card, which is typically announced at AGU’s annual meeting in December. The report often highlights harsh realities about how climate change is affecting the Arctic.

In 2025, for example, the region’s maximum sea ice extent was the lowest observed in the 47-year satellite record. In 2024, the report’s authors described a “new regime” in which the climate is changing much more drastically and quickly than it was in the 20th century. And in 2023, summer temperatures were the warmest ever and snow cover for the North American Arctic hit an all-time low.

Scientists and members of the public decried the news on social media.

If you had detectable cancer but decided not to let the oncologist scan you — indeed if you decided not to ever mention the word "cancer" again — you would die quickly and in a lot of pain, in contrast to someone who treated the same cancer early, before it metastasized out of control.

— Dr. Genevieve Guenther (she/they) (@doctorvive.bsky.social) 2026-08-10T22:17:16.602Z

Just to add–while the global climate and local cultural importance for polar peoples are the top of the fold issues here, keep an eye on another ball as well. NOAA's report would have been public. The military's report on the arctic's climate, and you bet they are researching it, will not be public

— Kathleen E. Kennedy (@themedievaldrk.bsky.social) 2026-08-10T22:34:11.720Z

This is terrible news, the Arctic Report Card is an invaluable resource.

— Jonathan Mingle (@jmingle.bsky.social) 2026-08-10T21:24:52.345Z

The move is the latest in a series of funding cuts and layoffs faced by the scientific community under the Trump administration. In recent months, the federal government has also attempted to dismantle the National Center for Atmospheric Research, terminated the entire National Science Board, and proposed sweeping changes to the federal grantmaking process.

Thoman said non-NOAA editors and authors are currently scrambling to figure out two open questions. First, they’re working to determine what will happen to the 2026 Arctic Report Card, which had been planned to be finalized in about two months. Next, he said, the team wants to figure out a “sustainable way to continue [to publish the report without NOAA support] in the future.” A meeting to discuss future directions, which will include the report’s lead authors and editors, is planned for next week, he said. “We’re getting strong support within the author team of the Arctic Report Card to do what we can to find a way to make this happen.”

According to Doster, the Global Ocean Monitoring and Observing Arctic Research Program, which coordinated and financially supported the Arctic Report Card in the past, “will continue to support observations, models and products that contribute to national security, weather prediction, safety of navigation, and the economic vitality of coastal communities.”

Melody Brown Burkins, a polar scientist and director of the Institute of Arctic Studies at Dartmouth, said that the report has served as a consistent and internationally coordinated resource that plays a major role in the United States’ reputation as a credible leader in Arctic science.

“The people are still doing the science, but we’ve lost the backbone of the coordination and the dissemination. I’m actually already talking to folks about how we can recreate it, because it’s so important for how we work in the Arctic and in partnership with Arctic peoples who are experiencing these rapid changes firsthand,” said Brown Burkins, who was also the American author of this year’s Group of 7 report on critical issues facing the global Arctic. “This was just a foundational piece of knowledge that was shared widely and trusted. And to dismantle that is sad and confusing.”

—Emily Gardner (@emfurd.bsky.social), Deputy Editor, and Grace van Deelen (@gvd.bsky.social), Staff Writer

These updates are made possible through information from the scientific community. Do you have a story about how changes in law or policy are affecting scientists or research? Send us a tip at eos@agu.org. Text © 2026. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Every monsoon, India's rivers turn brown. To most of us, that color simply means muddy water. But hidden within it is the material that builds fertile floodplains, creates river islands, nourishes deltas and even shapes coastlines: sediment.

A study led by Professor Jimmy Jiujiu Jiao from the Department of Earth and Planetary Sciences at The University of Hong Kong (HKU) and Professor Meng Li from Shenzhen University has identified microbial fermentation as the likely main pathway for ammonium production in sediments beneath the Pearl River Delta, helping to explain the region's exceptionally high natural groundwater ammonium levels.

El Niños and La Niñas are the third-most dominant influences on Earth's climate, after the sun and the greenhouse effect. But they haven't been easy to decipher or to predict in terms of when they will happen and what exact effects they will have on the global climate.

Roughly 2.5–2 billion years ago, Earth's surface experienced the biggest chemical change in its history when oxygen became abundant in the atmosphere, eventually leading to the evolution of complex life forms such as plants and animals that emerged half a billion years ago.

body {background-color: #D2D1D5;} Research & Developments is a blog for brief updates that provide context for the flurry of news that impacts science and scientists today.

Western Colombia was struck by a magnitude 7.4 earthquake this morning at 7:34 a.m. local time. The epicenter was near San Jose Del Palmar in the region of Chocó, about 280 kilometers (173 miles) west of the capital of Bogota. It was followed by a magnitude 4.8 aftershock at 8:18 a.m. local time and a magnitude 3.8 aftershock at 10:01 a.m. local time.

The earthquake was the result of a strike-slip faulting of the Nazca plate beneath the South American plate, at the intermediate depth of about 110 kilometers (68 miles), the U.S. Geological Survey reported.

 Related

•  USGS Event Page
•  Updates from the Colombian Geological Survey
•  At least 47 dead and buildings collapsed after 7.4-magnitude earthquake shakes western Colombia
 

Julio Fierro Morales, general director of the Colombian Geological Survey, said in a statement that shaking was also felt in Venezuela, Ecuador, and Panama, and that this was the strongest earthquake recorded in Colombia in the last decade. The Colombian Maritime Authority reported that there is no associated threat of a tsunami.

As of 12:24 p.m. ET, the death toll was at least 47, with 18 deaths in the town of Pereira, three in Manizales, and one in Buenaventura, according to The Guardian. The USGS issued an orange alert, indicating that “significant casualties and damage are likely and the disaster is potentially widespread. Past orange alerts have required a regional or national level response.”

Nubia Carolina Córdoba-Curi, governor of the department of Chocó, reported that the department’s capital city of Quibdó has experienced injuries and severe damage to buildings. Buildings have collapsed in the cities of Cali, Manizales, and Pereira—including Pereira’s passenger airport terminal.

Un terremoto de magnitud 6.6 – 7.4 sacudió a Colombia a las 7:34 a.m. de este 10 de agosto. El epicentro fue en San José del Palmar (Chocó), a 96 km de profundidad.

El temblor se sintió con fuerza en Bogotá, Medellín, Cali y Bucaramanga, generando evacuaciones preventivas. Las… pic.twitter.com/Ra8k6jKzsF

— Jhannely González | Periodista (@gazareportes_ve) August 10, 2026

According to the USGS, the region does not typically experience earthquakes exceeding magnitude 7; only two earthquakes of magnitude 7 or larger have occurred within 250 kilometers of this earthquake since 1950.

The quake is the latest along the Pacific Ring of Fire, a tectonic belt surrounding most of the Pacific Ocean where the vast majority of the world’s earthquakes occur. Two days earlier, Alaska, also along the Ring of Fire, experienced a 5.6 magnitude earthquake. In June, thousands died when Venezuela was hit by a magnitude 7.2 foreshock, followed almost immediately by a magnitude 7.5 mainshock.

—Emily Gardner (@emfurd.bsky.social), Deputy Editor

These updates are made possible through information from the scientific community. Do you have a story about science or scientists? Send us a tip at eos@agu.org. Text © 2026. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Source: GeoHealth

A changing climate increases the health risks posed by extreme weather. However, according to the 2024 Yale Climate Opinion Maps, only 47% of U.S. survey participants believed that global warming would harm them personally.

Poor risk communication can leave affected populations underprepared to face the health dangers that can accompany extreme heat and cold, flooding, wildfire smoke, and severe drought. Manware et al. compared mortality risk estimates with public perception of climate risk to establish “risk perception gaps.” They found that a belief in anthropogenic climate change was associated with smaller gaps between perceived and actual risk, suggesting that a greater public understanding of climate change could help communities better prepare for the health effects that come alongside extreme weather.

Researchers used climate risk perception data from the 2024 Yale Climate Opinion Maps, which are derived from 31 nationally representative surveys of nearly 35,000 participants, with demographic and political information estimated to predict county-level opinions. The study defined climate risk perception as the percentage of adults in each county who believe that global warming will directly harm them.

Then, by comparing climate risk perception with estimates of mortality caused by wildfire smoke, flooding, drought, and extreme temperatures, the researchers identified where the greatest risk perception gaps exist. Accounting for differences in age, income, education, racial demographics, and location, researchers then built a statistical model to examine the relationship between this perception gap and awareness of climate change. The results can be viewed in a publicly available dashboard.

The percentage of adults who believed that climate change would personally harm them ranged by county from 28.5% to 60.5%, with an average of 37.7%. The gap between perceived and actual risk varied across the country and by hazard, but it was generally smaller in counties where more residents agreed that “global warming is happening.”

Residents in the midwestern and northern United States showed an underawareness of the health risks of wildfire smoke and flooding, and residents in the western and southern United States showed an underawareness of drought. The study suggested that the same regions with higher risk perception gaps show higher climate-related mortality rates. Improving public awareness and understanding of climate change may help communities better prepare for the health risks associated with extreme weather, the researchers suggest. (GeoHealth, https://doi.org/10.1029/2025GH001782, 2026)

—Rebecca Owen (@beccapox.bsky.social), Science Writer

Citation: Owen, R. (2026), Many Americans underestimate health risks of extreme weather, new study finds, Eos, 107, https://doi.org/10.1029/2026EO260259. Published on 10 August 2026. Text © 2026. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Extreme rainfall in July 2025 triggered numerous landslides and debris flows that killed over 60 people.

Between 23 and 29 July 2025, the Yanshan (Yan Mountain) [41.0, 120.0] area of Hebei Province in China suffered extreme rainfall that triggered extensive flooding and landslides. As is so often the case in China, I found it difficult to get good information about this event at the time, but a good new paper (Xie et al. 2026) in the journal Landslides has provided a detailed review of this event. The paper is behind a paywall, but at the time of writing this link should give readers access.

Xie et al. (2026) have analysed the rinfall that triggered these landsldies, conckuding that it was in the order of 549.6 mm – a very substantial total. Daily rainfall totals were as high as 285.1 mm.

This rainfall triggered multiple shallow landslides and debris flows, causing over 60 fatalities. Xie et al. (2026) provide some detailed examples, one of which is at the Xiaomiaohougou catchment in Yangjiatai Village, Xinglong County. This is located at [40.37591, 117.24141]. The Planet Labs image below, collected on 22 June 2025, shows the site:-

Satellite image image of part of the area in Yanghshan, Hebei, China affected by the July 2026 landslides. Image copyright Planet Labs, used with permission, collected on 22 June 2025.

This is the same area of Yangshan after the rainfall and landslides:-

Satellite image of the aftermath in part of the area in Yanghshan, Hebei, China affected by the July 2026 landslides. Image copyright Planet Labs, used with permission, collected on 30 July 2025.

And here is an image compare:-

Image copyright Planet Labs

Xie et al. (2026) describe this site as follows:-

“The catchment exhibits steep hillslopes, high local relief, and well-developed gully systems, which promote efficient runoff concentration and rapid sediment transport during the extreme rainfall event. Field investigations indicated that sediment was primarily supplied by channel-bank failures and shallow hillslope failures, with sediment-source areas widely distributed throughout the catchment. Despite the relatively high vegetation coverage, prolonged extreme rainfall triggered rapid sediment mobilization and severe channel erosion. The resulting debris flow caused numerous fatalities and widespread damage to infrastructure.”

The multiple channelised debris flows are clear in the satellite images, as is the severe damage to the communities in the valley. This was replicated across a wide area.

Interestingly, the analyses by Xie et al. (2026) highlight the availability of large amounts of loose sediment in the Yangshan, and that “anthropogenic slope modification substantially altered sediment availability and intensified debris-flow activity under extreme rainfall conditions.” They particularly highlight the role of terracing of slopes in inducing an increase in landslide susceptibility.

Thus, they highlight the need for an increased focus on terrace modification, roadcuts and and village construction on landslide susceptibility. This is good advice application more widely, in mountain areas as we continue to see an increase in rainfall intensity associated with climate change.

Reference and acknowledgement

Xie, C., Xu, C., Yang, Z. et al. 2026. Characteristics and formation mechanisms of catastrophic geological hazards triggered by extreme rainfall in the Yanshan Mountains, China, in July 2025. Landslides. https://doi.org/10.1007/s10346-026-02829-3.

Thanks as always to the kind people at Planet Labs for making the satellite imagery available.

Return to The Landslide Blog homepage Text © 2026. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

This summer, millions of people across the country have been digging out sunscreen to protect themselves from a record-breaking series of heat waves.

SummarySeismic stratigraphic interpretation of shelf-edge clinothems is essential for revealing tectonic evolution, paleoclimate change, depositional dynamic conditions, and hydrocarbon generation and accumulation during basin filling. However, traditional interpretation methods remain labor-intensive, time-consuming, and highly subjective. Although AI-based method offer a potential solution for automated this task, its development has been limited by the scarcity of comprehensive and representative benchmark datasets for shelf-edge clinothems. This limitation primarily arises from limited field data availability, the scarcity of reliable geological labels, and the structural complexity and strong variability of clinothem-dominated systems. To address this gap, we develop a hybrid benchmark dataset through two complementary strategies of field data curation and geological and geophysical forward modeling, ultimately generating 3,000 unlabeled field and 4,000 labeled synthetic seismic data, respectively. We further evaluate several representative baseline deep learning models on these datasets, and the accurate results demonstrate that the curated dataset provides an effective and representative basis for model training, quantitative assessment, and practical application. Finally, we have publicly released this hybrid benchmark dataset (https://doi.org/10.5281/zenodo.20769762) to facilitate the development, validation, and assessment of deep learning methods for automated seismic stratigraphic interpretation.

SummaryAdvances in high-precision gravimetric instrumentation have significantly improved the quality of gravity data and increased the need for refined theoretical modeling of local gravitational fields. Although analytical expressions for vertical gravitation (VG) of variable density two-dimensional (2-D) frustums has been studied earlier, these formulas are relatively complex, and much less attention has been paid to three-dimensional (3-D) frustums. This study derives analytical solutions for VG and vertical gradient of the vertical component of gravitation (VGG) of 2-D and 3-D frustums with a quadratic density function in the z-direction. Validation through comparison with numerical methods and previous computational results confirms the correctness and effectiveness of the proposed algorithm. Analysis of the derived formulas enables the quantitative determination of the relationship between the number of VGG extreme points (possibly three or five), the frustum size, and the observation points location. Based on the multibeam data and gravity model, the RMS misfits are 4.1, 3.5, and 3.1 mGal for the three Necker Ridge profiles, and approximately 10.5 Eötvös for the Horizon Tablemount VGG profile. Additionally, we apply this formula to calculate VGG of Horizon Tablemount, and successfully verify the existence of five extreme points. This characteristic demonstrates that the occurrence of significantly smaller local VGG is an inherent property of the VGG itself, independent of terrain undulation and specific density distribution patterns. This study provides effective computational tools and a theoretical framework for high-precision gravitation modeling.

SummaryThermal conductivity anisotropy influences heat flow in the crust, yet predicting it from rock fabric remains difficult because the effective conductivity of a polycrystalline rock depends not only on mineral thermal properties and crystallographic preferred orientation, but also on grain shape, phase distribution and grain-scale interactions. Here we extend an asymptotic expansion homogenization–finite element (AEH–FE) framework for polycrystals to anisotropic heat conduction in rocks. Single-crystal conductivity tensors are rotated according to measured crystallographic orientations and assigned throughout the microstructure, and 2-D electron backscatter diffraction (EBSD) maps are analysed as representative sections extruded normal to the section. The method yields both the homogenized conductivity tensor and microscale heat-flux fields for prescribed macroscopic temperature gradients. To characterize section-based anisotropy, we define a coordinate-independent in-plane measure from the extrema of directional conductivity. We apply the method to a simple natural microstructure comprising a single mica grain in a quartz matrix and to three natural phyllosilicate-rich rocks representing planar foliation, transitional crenulation cleavage, and fully developed crenulation cleavage. Progressive fabric reorganization reduces in-plane anisotropy (max/min thermal conductivity) from A2D = 2.77 for planar foliation to A2D = 1.22 for fully developed crenulation cleavage. The transitional fabric remains substantially anisotropic (A2D = 2.26) despite similar diagonal tensor components because a large off-diagonal term rotates the principal conductivity directions. Comparisons with Voigt, Reuss, Voigt–Reuss–Hill and geometric-mean estimates show that classical averages capture broad trends but can misrepresent both anisotropy magnitude and principal directions when microstructures are strongly textured or spatially organized. These results demonstrate that EBSD-resolved multiscale homogenization provides a physically grounded route from rock fabric to effective thermal conductivity tensors and microscale heat-flow patterns relevant to geophysical models of anisotropic crustal heat transport.

SummaryReflectivity estimation aims to enhance the resolution of seismic data, providing crucial support for the detailed inversion of reservoir parameters. We propose a method that combines supervised pre-training with synthetic data and physics-guided fine-tuning in field data to estimate reasonable reflectivity from seismic data. Initially, a U-shaped network is pre-trained by supervised learning on a large amount of synthetic seismic data. Subsequently, multiple geophysically meaningful constraints including structure-oriented smoothness, reflectivity sparsity, and data reconstruction, are introduced to formulate a self-supervised or unsupervised learning mechanism to fine-tune the pre-trained model so that it is better adapted to field data for obtaining more reasonable reflectivity. The pre-trained model provides an initial reflectivity that aligns with fundamental structural features. Based on the initial estimate, the model is further optimized through physics-guided fine-tuning to obtain a more reasonable reflectivity estimation that better reflects the characteristics of the field data and geophysical priors. Furthermore, the well-log-based correlation evaluation metric is applied to automatically and adaptively determine the early-stopping point of the fine-tuning process where favorable results are achieved. Experiments on synthetic and field seismic data confirm that the proposed method yields reasonable and high-resolution reflectivity estimation.

How much ice is stored in the world's glaciers? And where exactly is it located? A new study led by Ca' Foscari University of Venice, in collaboration with the Institute of Polar Sciences of the National Research Council of Italy (CNR-ISP), provides an updated global map of glacier ice volume.

The initiation of rain in clouds without ice remains one of the largest unsolved mysteries in atmospheric science.

Zooming from her office, Michigan State University researcher Kelly Kapsar showed satellite images from across the United States. In some, different colors revealed the precise heights of the forested ridges in the Sierra Nevada or the craggy peaks of the Rockies and the valleys between them. Others showed the pine flatwoods of southern Florida or the smooth, rolling grasslands of the Kansas prairie.