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USGS streamgages show flood conditions are now underway, with live cameras providing real-time views on the USGS HIVIS website. Glacier-caused flooding has become an annual threat since 2011, with record-breaking floods over the past two years that impacted more than 300 homes and threatened public safety.

Since the mid-1990s, the Greenland ice sheet has been losing mass, leaving only three floating tongues remaining. One of these, Nioghalvfjerdsbræ or the 79°N Glacier, is already showing the first signs of instability.

Using geochemical analyses of marine sediments, researchers have been able to quantitatively reconstruct the Atlantic Meridional Overturning Circulation over the past 12,000 years. The international research team, led by scientists from Heidelberg University and the University of Bern (Switzerland), is the first to calculate the large-scale circulation patterns of the Holocene. Their reconstruction shows that, while the AMOC experienced natural fluctuations over millennia, it remained stable for long periods of time.

Parts of Greater New Orleans are sinking by millimeters per year, increasing their vulnerability to floods and storm surges.

Flood protection infrastructure put in place in the months and years following Hurricane Katrina in 2005 could lose effectiveness more quickly than expected.

Though most of the city is stable, areas near the Louis Armstrong New Orleans International Airport, sections of flood protection walls, and certain industrial sites and wetlands are losing elevation, researchers reported in Science Advances earlier this summer. The rate and scale of these losses vary because rates of subsidence are affected by multiple factors, including groundwater pumping, wetland drainage, construction and urban development, and natural soil compaction.

Coupled with rising sea levels, the rapid subsidence could mean that without regular upgrades, flood protection infrastructure put in place in the months and years following Hurricane Katrina in 2005 could lose effectiveness more quickly than expected.

Spotting Subsidence from Above

As part of the new research, remote sensing expert Simone Fiaschi and his colleagues used interferometric synthetic aperture radar, or InSAR, to map subsidence across the city in 2002–2007 and 2016–2020. InSAR measures the distance between a satellite orbiting Earth and the planet’s surface. When averaged over measurements taken at different times, the satellite data can be used to detect millimeter-scale changes in elevation.

Knowing where and how quickly subsidence is occurring can clue scientists in to potential causes, said Fiaschi, who now works at the InSAR company TRE ALTAMIRA. “And that’s, of course, necessary if you want to intervene or…make adjustments to protect the city.”

During both periods, research showed that much of Greater New Orleans was stable, sinking or rising by less than 2 millimeters per year.

But a few hot spots revealed larger changes. For example, the area in and around the Louis Armstrong International Airport sank by up to 27 millimeters per year between 2016 and 2020, likely because of construction of a new terminal during that time.

Areas of concrete floodwall near the airport and along sections of the Mississippi River, built as part of the city’s $15 billion Hurricane and Storm Damage Risk Reduction System, also sank by more than 10 millimeters per year as the floodwalls settled.

Identifying Problem Areas

About half of New Orleans is already below sea level; even a small change in elevation raises the risk of flooding.

The city’s infrastructure may already be showing the effects of subsidence, said Krista Jankowski, a geoscientist at the consulting firm Arcadis who lives in New Orleans but did not participate in the new research. Filled potholes become artificial high spots as the land around them continues to sink, and fire hydrant collars that used to be level with surrounding lawns now sit several inches higher.

Wetlands within and beyond the floodwalls are sinking, too. Both natural erosion and human-driven water removal could be contributing to this subsidence.

“It’s an existential consideration for people who live in New Orleans.”

Other areas are even gaining elevation in response to human activity—or lack thereof. The Michoud neighborhood, in the city’s Ninth Ward, rose by up to 6 millimeters per year between 2016 and 2020. Until 2016, groundwater extraction by a local power plant caused Michoud to sink. But when the plant was decommissioned and pumping stopped in 2016, the water table started to recover and the land began to rebound. That finding showed that at least some of the subsidence can be fixed.

“I think that’s a nice aspect of the study, that it updates earlier studies and documents what parts have been fixed and what parts are still a problem,” said Tim Dixon, a geologist at the University of South Florida who was not involved in the new research.

Monitoring and managing subsidence is “an existential consideration for people who live in New Orleans,” Jankowski said. Having a better understanding of where subsidence is concentrated and how quickly those areas are sinking, she explained, will help “make sure we’re paying attention to places where there may be issues.”

—Skyler Ware (@skylerdware.bsky.social), Science Writer

Citation: Ware, S. (2025), Parts of New Orleans are sinking, Eos, 106, https://doi.org/10.1029/2025EO250300. Published on 14 August 2025. Text © 2025. 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.

Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: Earth and Space Science

Measurements of bathymetry, the underwater depth of the ocean floor, are typically done for shallow coastal waters from boats with echosounders or from aircraft using green-wavelength lidar. However, these methods can be expensive to field, hard to update, and cannot access all locations.

NASA’s Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) mission has introduced a new satellite-derived shallow water bathymetry product that will provide free, easy-to-access, and ready-to-use measurements for the world’s shallow coastal waters. This information is of value for navigational safety, in particular for measurements in very shallow water or close to shore where boats cannot safely operate. Scientists can also use the data to study coral reefs and near-shore aquatic habitats.

The shallow water bathymetry product is derived using data from the ICESat-2 green-wavelength Advanced Topographic Laser Altimeter System (ATLAS) lidar, which operates from an orbit about 500 kilometers above the Earth’s surface.

Parrish et al. [2025] present their results of the first processing of the ICESat-2 archive, providing bathymetric measurements from approximately 0.5 to 21.5 meters depth for 13.7 million kilometers of coastal waters. This initial data set has been validated against high accuracy airborne bathymetry data acquired over eight locations in the eastern United States and the Caribbean islands. The products will be regularly updated as ICESat-2 acquires new data, filling in areas not initially measured because of rough seas or cloud cover and updating earlier measurements over time.

 ​Citation: Parrish, C. E., Magruder, L. A., Perry, J., Holwill, M., Swinski, J. P., & Kief, K. (2025). Analysis and accuracy assessment of a new global nearshore ICESat-2 bathymetric data product. Earth and Space Science, 12, e2025EA004391. https://doi.org/10.1029/2025EA004391

—Cathleen Jones, Editor, Earth and Space Science

Text © 2025. 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.

Author(s): A. V. Bernatskiy, I. I. Draganov, N. A. Dyatko, I. V. Kochetov, V. V. Lagunov, and V. N. Ochkin

Experimental and numerical studies of the features of the spatial distribution of plasma parameters in a discharge not limited by walls were performed. A discharge supported by a hollow cathode in helium at low pressure was ignited in a chamber with dimensions much larger than the dimensions of the …

[Phys. Rev. E 112, 025204] Published Thu Aug 14, 2025

Author(s): Michael F. Zhang, Seth Davidovits, and Nathaniel J. Fisch

We study the amplification of isotropic, incompressible turbulence through multiple planar, collisional shocks, using analytical linear theory. There are two limiting cases we explore. The first assumes shocks occur rapidly in time such that the turbulence does not evolve between shocks. Whereas the…

[Phys. Rev. E 112, 025205] Published Thu Aug 14, 2025

Author(s): Feiyu Li, Seth Dorfman, and Xiangrong Fu

The parametric decay instability (PDI) of Alfvén waves—where a pump Alfvén wave decays into a backward-propagating child Alfvén wave and a forward ion acoustic wave—is a fundamental nonlinear wave-wave interaction and holds significant implications for space and laboratory plasmas. However, to date …

[Phys. Rev. E 112, 025206] Published Thu Aug 14, 2025

The Mediterranean Sea is particularly susceptible to marine heat waves—such as the record-breaking 2022 heat wave, which was characterized by anomalously high sea surface temperatures—due to the interplay of air-sea heat fluxes and local oceanographic processes, leading to significant impacts on marine ecosystems and coastal communities.

The 200,000 cubic metre collapse of a rock pillar has destroyed two extremely challenging climbing routes.

At a time when there is a great deal going on in the landslide world, another really interesting event has almost passed me by. Thanks to loyal reader Scott for highlighting another remarkable event.

Overnight on 1 – 2 August 2025, a large rock pillar collapsed at Carne Wall in the Blue Mountains of New South Wales in Australia. This has destroyed a series of famously challenging climbing routes. ABC News has a really good article about the landslide – they estimate that the volume was about 200,000 m3.

This collapse at Carne Wall is located at [-33.65233, 150.33885].

On Facebook, Monty Curtis has posted a nice before and after image pair:-

Before and after images of the 1-2 August 2025 rockfall at Carne wall in the Blue Mountains of Australia. Images by Monty Curtis.

And there is a really fantastic before and after drone video posted to Youtube by Simmo:-

Failures of this type would normally be via a topple, but I wonder if the debris field supports that interpretation? An alternative might be that the toe of the pillar failed and collapsed, with the subsequent pillar failure involving more vertical movement. This still from Simmo’s video shows that the pillar had a remarkably narrow base, which would have been under a high compressive load.

A still from a drone video collected a week before the 1-2 August 2025 rockfall at Carne wall in the Blue Mountains of Australia. Video posted to Youtube by Simmo.

Perhaps the base of the pillar underwent progressive failure, leading to the collapse of the mass?

Either way, it was fortunate that there were no climbers on the pillar when it failed.

Return to The Landslide Blog homepage Text © 2023. 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.

SummaryDetecting marsquakes is crucial for understanding the interior structure of Mars. However, the detection and analysis of such seismic events is challenging due to the strong background noise and low signal-to-noise ratios (SNR) of marsquake seismograms. Moreover, the volume of the seismic data needed to create an efficient method to detect marsquakes, and the required amplitudes of such events is limited by the low energy of the seismic. Here, we develop a new deep learning-based detection algorithm, MarsConvNet (MANet), which can fully exploit the latent information of seismic sequences by upsampling and downsampling for detecting marsquakes in the continuous seismic records. Our approach is to construct a deep encoder structure and nonlinear mapping relationship between seismic signals and arrival times of P and S waves by training on the STanford EArthquake Dataset (STEAD) from Earth. Application to the continuous waveform data from the InSight seismic data from 2019 to 2022 shows that the algorithm can detect marsquakes with weak amplitude in addition to reproducing all events detected manually by the Marsquake Service (MQS). Using our method, we detected 67 previously undetected marsquakes.

SummaryA new approach for the parallel forward modelling of transient electromagnetic (TEM) fields is presented. It is based on a family of uniform-in-time rational approximants to the matrix exponential that share a common denominator independent of the evaluation time points. The partial fraction decomposition of this family is exploited to devise a fast solver with high parallel efficiency. The number of shifted linear systems that need to be solved in parallel does not depend on the number of required time channels nor the spatial discretization. We also argue that similar parallel efficiency gains can be expected when solving the inverse TEM problem.

As human activity across the world's oceans expands, scientists are zeroing in on shifts in atmospheric composition—particularly ozone, a key player in marine atmospheric chemistry. In a new study, researchers have completed China's first shipborne ozone-sounding campaign in the South China Sea, yielding high-resolution data that addresses a gap in understanding oceanic ozone dynamics.

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.

The Mendenhall River in Juneau, Alaska, reached a record-breaking crest Wednesday morning thanks to a glacial outburst flood (GLOF) from Suicide Basin. At 16.65 feet, the crest exceeded the previous record flood stage of 15.99 feet in 2024.

Image created for the National Weather Service webpage monitoring Suicide Basin, www.weather.gov/ajk/suicidebasin

As glaciers melt, they leave behind lakes that rest in valleys. The melting of the Suicide Glacier has created a glacial lake in Suicide Basin, which lies above the Mendenhall Glacier. The Mendenhall Glacier, about 12 miles (19 kilometers) north of Juneau, acts as an ice dam for the lake. But, when enough snowmelt and precipitation occur, the lake drains through and over the glacier into Mendenhall Lake and the Mendenhall River.

The basin has filled and drained at least 39 times since July 2011, according to the National Weather Service.

During the crest on Wednesday morning, a gauge at Mendenhall Lake recorded a peak streamflow of 47,700 cubic feet per second (1,350 cubic meters per second), according to USGS data. In August 2023, the same gauge recorded a streamflow of 25,200 cubic feet per second (714 cubic meters per second), which Andrew Park, a meteorologist at NWS Juneau, called “historic”  at the time. The highest recorded streamflow before that was 16,300 cubic feet per second (462 cubic meters per second), in 2016. During the 2023 event, Rick Thoman, Alaska Climate Specialist at the Alaska Center for Climate Assessment and Policy, also told Climate.gov that “Decades worth of erosion happened in one weekend.”

The City and Borough of Juneau installed barriers provided by the United States Army Corps of Engineers earlier in 2025. According to the city and borough’s website, the barriers are intended to be an “interim solution,” but are designed to protect against GLOFs up to 18 feet high (5.4 meters). According to USA Today, the barriers seem to have successfully held back most of the water.

 
Related

•  Suicide Basin Monitoring and Current Conditions
•  Juneau Glacial Flood Dashboard
•  National Weather Service Flood Statement
•  Update: Mendenhall River crests, levels now falling
 

A flood statement issued by the National Weather Service in Juneau urged residents to heed road closures and local emergency management team guidance.

Water levels above 15 feet are considered the “major flood stage.” Zoe Kaplan, a meteorologist at the National Weather Service in Juneau, said the office predicts levels will drop to moderate flood stage (below 12 feet) by early afternoon, and to minor flood stage (below 10 feet) by late afternoon.

GLOFs could grow more common as rising temperatures increase glacier melt around the world. A 2020 study found that the number, total volume, and total area of glacial lakes have each increased by about 50% between 1990 and 2018. And, according to the Environmental Protection Agency, Alaska has warmed faster than any other U.S. state, and faster than the global average, over the past 100 years.

—Emily Dieckman, Associate Editor (@emfurd.bsky.social)

These updates are made possible through information from the scientific community. Do you have a story idea about science or scientists? We’re listening! Send us a tip at eos@agu.org. Text © 2025. 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.

A new wave of climate research is sounding a stark warning: Human activity may be driving drought more intensely—and more directly—than previously understood.

An international team of researchers led by the University of Massachusetts Amherst has tracked changes in more than 114,000 rivers in High Mountain Asia over a 15-year period. The paper, published in AGU Advances, reported that nearly 10% of these rivers saw an increase in flow, with an increasing proportion of that water coming from glacial ice melt compared to precipitation.

Extreme rainfall in New Zealand from future cyclones could rise by up to 35%. New high-resolution modeling predicts that rainfall from tropical cyclones will significantly increase under global warming.

Researchers at The University of Alabama in Huntsville (UAH) have published a paper in Communications Earth & Environment that demonstrates for the first time that using data gathered on atmospheric particles from Chinese megacities to characterize air quality for U.S. urban centers leads to significant inaccuracies.

An international study led by Prof. Tamar Guy-Haim and Dr. Ximena Velasquez from the Israel Oceanographic and Limnological Research (IOLR) has revealed that tiny planktonic crustaceans carry a unique microbial signature that better reflects ocean currents and environmental gradients than microbes found freely in seawater.

As glaciers melt, huge chunks of ice break free and splash into the sea, generating tsunami-sized waves and leaving behind a powerful wake as they drift away. This process, called calving, is important for researchers to understand. But the front of a glacier is a dangerous place for data collection.