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Publication date: Available online 6 May 2026

Source: Advances in Space Research

Author(s): Jumah Ain

Combined extreme climate events are likely to become more common in the future if carbon emissions continue to rise, a paper in Nature suggests. The study finds that the frequency of compound events—such as concurrent hot–wet and drought–heat extremes—is linked to cumulative carbon dioxide (CO2) emissions. In particular, the frequency of more severe events is predicted to escalate rapidly.

The retreat of glaciers and ice sheets is expected to have widespread impacts on communities around the world because of its effect on sea levels. Already, the global average sea level is more than 10 centimeters higher than it was just 3 decades ago; and the rate of rise is increasing, contributing to increased storm surges and flooding, lost infrastructure and community lands, and more.

Recent reports on the instability of Antarctica’s Thwaites Glacier, for example, have focused attention on how accelerating ice flow can lead to ice sheet collapse and rising sea levels.

Recent reports on the instability of Antarctica’s Thwaites Glacier, for example, have focused attention on how accelerating ice flow can lead to ice sheet collapse and rising sea levels. Yet there is still substantial uncertainty about how quickly Thwaites and other glaciers will lose ice, in part because we don’t fully understand the myriad processes that contribute to their mass balance.

Earth’s ice sheets accumulate ice through snowfall and lose mass through a mix of surface ablation, iceberg calving, and melting at their interface with the ocean. Glacial ice flows under its own weight, and the rate at which it flows to coastal areas is a primary control on ice sheet mass loss.

Flow rates depend on how much resistance an ice sheet encounters at its interface with the ground (e.g., whether it is frozen to its substrate) and on its effective viscosity, a measure of how strongly it resists deformation. The viscosity of ice, in turn, varies based on properties including temperature, crystal size and orientation, and impurity content.

Some properties within and beneath ice sheets that affect how they flow are anisotropic, meaning they vary by direction. For example, roughness in some directions at the ice bed can facilitate ice sliding more effectively than roughness in other directions, similar to the way a properly oriented corrugated metal roof allows snow to slide off. Several forms of anisotropy within ice also affect how ice flows from land to ocean (Figure 1).

Fig. 1. Anisotropy in glaciers and ice sheets has various sources, including from ice fabric and other properties within the ice (englacial) or at the ice-bed interface. Many forms of anisotropy in glacial ice can be measured with radar. Credit: Adapted from Hills et al., 2025, https://doi.org/10.1029/2024RG000842, CC BY 4.0

Measuring anisotropic properties is key to better understanding how quickly changes at the edges of the Greenland and Antarctic ice sheets will lead to sea level rise. Recent advances in ice-penetrating radar technology and in processing radar data are revolutionizing how we observe directionally varying ice sheet properties, paving the way for projections of mass changes that account for previously neglected processes.

Crystal Fabric: Memory and Modulator of Ice Flow

Fabric, the orientation of crystals composing ice, is the best studied and arguably most important of anisotropic ice sheet properties. As ice deforms, for example, by stretching horizontally as it flows toward the coast, its millimeter-scale crystals are reoriented (Figure 1).

Fabric thus contains a memory of past flow. Simultaneously, fabric influences flow because ice crystals are about 3 orders of magnitude easier to shear in some directions than others—similar to how stacked playing cards slide easily against each other when held along their edges but resist motion when pinched top to bottom.

Over the past 20 years, radar polarimetry has matured into a quicker and easier alternative means for inferring fabric.

The potential importance of fabric on large-scale ice flow has long been recognized, but a shortage of observations has made it difficult to quantify and validate its effect in ice sheet models. Until recently, fabric could be measured only directly in ice cores or inferred through seismic soundings. These methods provide highly detailed information about how fabric develops but are expensive, logistically taxing, and provide information only about sparse point locations.

Over the past 20 years, though, radar polarimetry has matured into a quicker and easier alternative means for inferring fabric, enabling observations at the scale of entire glaciers and providing new constraints on how fabric influences ice sheet flow.

How Radar Reveals Fabric

Ice-penetrating radar instruments emit electromagnetic energy as radio frequency waves. These waves reflect off interfaces within and beneath glacial ice, including transitions in ice chemistry and the contact surface between the ice sheet and the ground or water below. The properties of the reflected waves are then measured when they return to the radar. Just as fabric leads to anisotropic ice deformation, it also introduces directional dependence in the measured electrical properties.

The speed of a radar wave through an ice crystal is approximately 1% faster if the wave is polarized across the crystal’s principal (c) axis rather than aligned with it. Though small, this difference can compound enough that it causes measurable changes in returned radar signals.

In a typical radar survey over anisotropic ice, waves with different polarizations travel at slightly different speeds (Figure 2). The times that return signals arrive back at the receiver thus vary directionally, a difference that can be identified using polarimetric radars that transmit and receive radio waves at multiple orientations.

Fig. 2. Propagation of polarized radio waves through anisotropic ice reveals structural variations with depth because waves aligned across the prevailing ice fabric (represented by the ball, in which darker shading indicates a greater concentration of c axes) travel faster than waves aligned with the fabric. The phase delay increases as the effect of the anisotropy accumulates with depth. Credit: Adapted from Hills et al., 2025, https://doi.org/10.1029/2024RG000842, CC BY 4.0

Fabric’s effect on radar signal travel times accumulates through an ice column, so it is more prominent in thicker ice with stronger horizontal fabric (i.e., the ice crystals are more consistently aligned). In such cases, differences in travel times between polarizations can be measured even by standard radars.

When fabric is weaker or ice is thinner, the offset is smaller and detectable only by systems that can identify the phases of radar returns—that is, the exact positions of the returned waves in their oscillation cycle. Even small wave speed differences from weak fabrics accumulate into measurable phase shifts between polarizations, which can be used to determine the consistency of crystal alignment and the predominant crystal orientation.

Small differences in fabric through an ice column can also change the strength, or amplitude, of returned signals. This amplitude difference offers an independent way to identify fabric orientation and its depth variation.

Polarimetric radar has been widely applied in cryospheric science in recent years largely due to the advent of low-cost systems that can measure signal phases. For example, the popular Autonomous phase-sensitive Radio Echo Sounder (ApRES) is a lightweight, ground-based system that can be used to infer ice fabric at single points down to 2 kilometers deep. In the past decade, polarimetric ApRES systems have revealed ice flow histories, including changes in flow directions, of key glaciers over the past few millennia. These measurements offer windows into how ice sheets responded to previous climate variations.

A mobile, quad-polarimetric radar is dragged by snowmobile over the surface of Müller Ice Cap on Axel Heiberg Island in Nunavut, Canada, in May 2023. Credit: David Lilien

The next generation of polarimetric radars go beyond one-point-at-a-time stationary soundings, offering full polarimetry capabilities on moving platforms. These systems may soon allow scientists to map directional ice properties at the scale of entire ice sheets.

Insights into Fast-Flowing Ice Fabric

The growing number of radar studies conducted near sites where ice cores have been collected, which allow fabric to be investigated up close, has provided validation and bolstered confidence that fabric can be inferred accurately from its effects on radar. Researchers now infer fabric from radar in more dynamic areas, such as Thwaites Glacier, Whillans Ice Stream, and the Northeast Greenland Ice Stream (NEGIS), where ice fabrics change over short spatial scales and where drilling ice cores is logistically difficult. Airborne radar surveys are particularly effective in these settings because they can efficiently map fabric variations across large, fast-moving areas.

Observations of strong fabrics in fast-flowing regions suggest that fabric is an important control on ice viscosity, although its implications for ice flow are just beginning to be explored. For example, at Rutford Ice Stream in Antarctica, ApRES data indicate that fabric causes sharp changes in viscosity in different directions with depth, a complexity not captured by current ice flow models.

A combination of airborne and ground-based radar shows that the fabric of the NEGIS varies substantially across the ice stream, which facilitates horizontal shear that allows faster and more cohesive flow in the middle of the ice stream while simultaneously stiffening this ice against along-flow stretching. These viscosity variations may alter how quickly coastal changes, such as increased melt due to climate warming, influence inland ice flow.

Scientists have studied ice sheet mass balance at glacier-mounted stations along the renowned “K-transect” near Kangerlussuaq in southwestern Greenland since the early 1990s. This image shows a view up the transect in April 2025. Polarimetric radar offers another tool with which to study ice flow here and at other locations on the ice sheets. Credit: Tamara Gerber

The emerging consensus from radar observations and recent progress in fabric modeling is that ice fabric can soften ice stream shear margins by a factor of 10. In other words, the fabric tends to develop in a way that greatly reduces the ice’s effective viscosity at lateral boundaries between fast-flowing and slower-flowing ice, which enables the ice to deform more easily at the margins. The agreement between observations and process-scale modeling highlights fabric as a major, but largely ignored, control on ice flow that may affect estimates of how ice dynamics will contribute to future sea level rise.

Beyond Fabric

Most polarimetric radar studies so far have focused on fabric, but other ice characteristics can cause directional effects too. For instance, bubbles trapped in ice have dramatically different properties than ice itself. Ice deformation can bring bubbles into alignment, such that they affect radar waves differently in different directions.

Likewise, ice at its melting point can contain liquid water along boundaries between crystals, and if those pockets of water are aligned in one direction, they can also affect radar returns. Each of these properties has important influences on ice flow, but their implications are yet to be explored.

Another source of anisotropy is the bottom boundary of the ice sheet. This interface can be rougher in some directions than others, though the roughness is typically aligned with the prevailing ice flow direction or the direction of meltwater trapped within the ice.

Polarimetric radar can measure directionally dependent properties of ice sheet bases at a finer scale than radar profiling can. Such work is leading to new insights into glacier geomorphology, interactions of ice shelf bottoms with the underlying ocean, and how ice slides over substrate surfaces. Rates and extents of sub-ice-shelf melt and basal sliding are widely recognized as key controls on the future of the ice sheets.

Expanding Horizons: Large-Scale and Planetary Applications

Radar polarimetry has already transformed our understanding of ice fabric, revealing much about how crystal alignment modulates the flow of Earth’s ice sheets and filling critical gaps between the handful of direct measurements from ice cores. As polarimetric techniques mature, their applications are expanding.

Researchers are moving from studying isolated profiles of ice fabric to mapping it across whole basins, a key shift for validating bespoke models of fabric and its effects on flow. These models are also rapidly developing to include additional physical processes (e.g., migration recrystallization) and key simplifications (e.g., reducing directionally varying viscosity to a single number) that allow them to interface more easily with—and be incorporated into—large-scale models used for projecting sea level rise.

Techniques pioneered for measuring ice on Earth may also prove useful elsewhere in the solar system.

Techniques pioneered for measuring ice on Earth may also prove useful elsewhere in the solar system. Orbital radar sounders have already probed Mars’s ice masses, and the icy shell of Jupiter’s moon Europa will soon be surveyed by single-polarization radars aboard NASA’s Europa Clipper and the European Space Agency’s Jupiter Icy Moons Explorer (JUICE). These radars might be useful for polarimetry at some locations on Europa, which could reveal past and present motion of ice features and answer fundamental questions about the moon. Whether Europa’s shell flows, for example, may be key to whether its subsurface ocean can harbor life.

As polarimetric radar systems become routine tools for glaciologists and as similar instruments begin operating on spacecraft exploring icy worlds, a technique once limited to a few isolated core sites on Earth could be poised to transform our understanding of ice across the solar system.

Author Information

David Lilien (dlilien@iu.edu), Indiana University Bloomington; T. J. Young, University of St Andrews, Fife, Scotland; Benjamin Hills, Colorado School of Mines, Golden; Tamara Gerber, Université de Lausanne, Lausanne, Switzerland; and Matthew Siegfried, Colorado School of Mines, Golden

Citation: Lilien, D., T. J. Young, B. Hills, T. Gerber, and M. Siegfried (2026), New directions in mapping ice sheet fabrics and flow, Eos, 107, https://doi.org/10.1029/2026EO260154. Published on 14 May 2026. 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.

When it comes to thriving at high elevation, diminutive plants are always a safe bet. And low-lying vegetation is in fact colonizing higher and higher reaches as the climate changes, new results reveal. Researchers analyzed more than 2 decades’ worth of satellite data and showed that the vegetation line in the Himalayas is moving upward, in some cases by up to several meters per year. These changes have implications for the hydrology of the region and therefore for water resources for the population centers located downstream, the team reported last month in Ecography.

Mountains and People

“If you’re going to understand climate change across the Himalayas, you can’t just look at one location.”

The Himalayas, with their massive stores of frozen water, are part of a region known as the planet’s “Third Pole.” Nearly a billion people rely on water sourced from this area, but the Himalayas aren’t immune to climate change—shifts in temperature and precipitation patterns are causing glaciers to melt and permafrost to thaw, among other effects. “The Himalayan mountains are experiencing a lot of ecosystem changes,” said Ruolin Leng, an Earth scientist who led this new research while at the University of Exeter in the United Kingdom. She currently works at H2Tab, a wellness company.

And while the macroscopic effects of climate change in mountainous regions—the melting of the aforementioned glaciers, for example—have been readily studied, shifts in vegetation are often overlooked, said Leng. That’s a problem because plant cover affects everything from soil moisture levels to water runoff to the albedo of the planet’s surface, all of which have consequences for how water moves through the larger system, she said. “It’s a very important factor in the hydrological system.”

Leng and her colleagues focused on six sites, each roughly 40,000 square kilometers in size, in Bhutan, Nepal, and politically disputed areas farther west. Altogether the locales spanned roughly 15° in longitude (about the width of a U.S. time zone). The choice to analyze several locations along an east-west gradient was deliberate, said Stephan Harrison, a climate scientist also at the University of Exeter and a member of the research team. “The western Himalayas are very different from the eastern Himalayas in terms of climate. If you’re going to understand climate change across the Himalayas, you can’t just look at one location.”

Spotting Vegetation from Space

For each of those sites, the researchers mined satellite observations collected from 1999 to 2022 by the NASA/U.S. Geological Survey Landsat program. The researchers focused on visible and near-infrared observations to calculate a metric known as the normalized difference vegetation index (NDVI). Vegetation tends to reflect relatively little visible light while reflecting much more near-infrared light, and that fact can be exploited to infer the presence of vegetation in remote sensing data, said Karen Anderson, a remote sensing scientist at the Environment and Sustainability Institute at the University of Exeter and a member of the research team.

After masking out pixels too obscured by clouds or snow to correctly analyze, Leng and her colleagues calculated the NDVI for each 30- × 30-meter Landsat pixel within their study regions. The team retained pixels with NDVI levels above a minimum threshold and used those data, combined with topography information, to estimate the maximum elevation that was reliably vegetated each year. All six sites exhibited upward trends in the elevations of their vegetation lines over time, the researchers found. A site in central Nepal straddling the country’s northern border recorded the largest changes: From 1999 to 2022, the elevation of its vegetation line rose from roughly 5,520 meters to 5,670 meters, an increase of just under 7 meters per year on average. The five remaining sites all recorded annual upward shifts ranging from about 1 to 6 meters per year on average.

“Broadly speaking, plants are moving up mountains,” said Anderson. But different regions are responding differently, she added. (And while similar results have been previously noted in the Himalayas, not all plant life everywhere is moving up—recent research has shown that some tree lines are in fact moving downslope.)

A Climatic Culprit?

“People neglect the little plants.”

To investigate the potential drivers behind these changes, the team studied correlations with three climatic parameters: temperature, total precipitation, and snow depth. These data came from the European Centre for Medium-Range Weather Forecasts reanalysis dataset, which has a spatial resolution of roughly 30 kilometers.

Leng and her collaborators found that their site with the fastest-changing vegetation line also recorded the most rapid increase in snow depth over time. These two changes might therefore be linked, but more work is needed, Anderson admitted. “We haven’t addressed the causal link here. We’ve simply looked for patterns.”

There’s also a significant mismatch in the spatial resolution of the team’s meteorological data and their Landsat data, said Trevor Keenan, an ecosystem scientist at the University of California, Berkeley not involved in the research. Such a discrepancy can be particularly problematic in complex landscapes like mountain ranges because the coarse meteorological data might not be capturing the true microclimates that are bound to persist in such places, he said. “With heterogenous terrain and large elevational gradients, you really need that microclimate information.”

Sagarmatha National Park in Nepal, home to Mount Everest, is also host to rhododendron forests like this one. Credit: Peter Prokosch, CC BY-NC-SA 2.0

Anderson knows the geographical complexity of the Himalayas firsthand—in 2017 and 2022, she and other scientists conducted fieldwork in Nepal that informed this research. Those trips were a special opportunity to see plants like dwarf rhododendron thriving in tough conditions, she said. And it was a good lesson in appreciating some of the most diminutive members of the plant kingdom, Anderson added. “People neglect the little plants.”

—Katherine Kornei (@KatherineKornei), Science Writer

Citation: Kornei, K. (2026), Vegetation moves upslope across the Himalayas, Eos, 107, https://doi.org/10.1029/2026EO260149. Published on 14 May 2026. 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.

Editors’ Vox is a blog from AGU’s Publications Department.

Often times when we think “scientist,” we picture a white lab coat, a pipette. Or, a marine biologist covered in seaweed samples. A geologist with dusty knees and hands full of rock fragments. Endless blue gloves. What we may not always picture is our favorite professors, colleagues, or even students advocating for science to policy makers.

Federal policy decisions have a direct impact on science funding, research priorities, and the role of science in society.

Federal policy decisions have a direct impact on science funding, research priorities, and the role of science in society, and the AGU community has a critical role to play in those conversations. Each year, AGU’s Science Policy and Government Relations (SPGR) team organizes and hosts Congressional Visit Days to connect Earth and space scientists to their elected officials. As a member of AGU’s scientific publications team, I joined the April 21-22 Days of Action to learn about the bills currently impacting our workforce and research, how to craft messages that both speak to our personal experiences, and to ask our elected officials to advocate with and for us.

As a D.C. native, I grew up in close proximity to the power of science, the alphabet agencies, NOAA, NASA, NIH, and USDA. Institutions where the best and brightest were given the resources and support to learn, record, and disseminate knowledge on behalf of our country. In my current role with AGU as a non-profit publisher, I took to the Hill to share my experiences on the publishing and academic peer-review landscape. My role allows me to see first-hand how budget cuts and shifting attitudes have impacted critical programs at the agencies named above. This Days of Action event brought together 58 participants with one goal: to share personal stories that related to four bills:

1. The RESEARCHER Act (H.R. 3054, S.1664)- addresses graduate student financial instability.
2. KEEP STEM Talent Act (H.R. 2627, S.1233)- strengthens the U.S. scientific workforce by making it easier for skilled international STEM graduates from U.S. universities to stay in the U.S.
3. Protect America’s Workforce Act (H.R.2550 passed House, S.2837)- seeks to protect the U.S. federal scientific workforce by restoring collective bargaining (union) rights.
4. Scientific Integrity Act (H.R.1106)- protects the rights of U.S. federal scientists and researchers by safeguarding scientific integrity in federal research and decision-making.

Two participants spoke on their experiences meeting with elected representatives and uniquely captured just how closely the Earth and spaces sciences touch all of our lives.

Sheila Baber, an early career scientist with The University of Maryland, felt compelled to join due to “the uncertain future for myself, my peers, and the American scientific enterprise.” She noted, “It has been especially difficult to witness the deteriorating relationship between scientists, decision makers, and the public. This past year, with its rapidly changing federal landscape, has been a wakeup call to re-engage and remind the public of how science research gives back to the community.”

Ryan Haupt, long-time AGU member and the Executive Director at National Youth Science Academy, with a 10-year track record of geoscience advocacy, emphasized the importance of building relationships with elected officials. “Regardless of party affiliation, I want those staffers to know that when they meet with me or any other AGU member, they will get honest and informed feedback from folks who are truly passionate about our fields,” Ryan told me. “[Experts who can speak to how current bills] impact issues like improved financial support for graduate students, helping international students stay in the US to join the STEM workforce, and protecting funding for federal science agencies and the folks who work for them.”

As a participant myself, I joined the Maryland group to meet with Senator Chris Van Hollen’s office. Van Hollen and I met briefly at the Stand Up for Science March in 2025. His voting track record indicates a long-standing commitment to the scientific community, and he champions bills that support funding federal agencies like NOAA.

(left to right) The Maryland group, McKay Porter, Andrew Inglis, Nour Rawafi, Stephen Jascourt, and Emille Beller met with Senator Chris Van Hollen’s staffer, Leo Confalone. Credit: Beth Bagley, AGU

Finding and discovering the best and the brightest means funding, protecting, and supporting the best and the brightest.

Working in scientific publishing has allowed me to peer behind lab doors, into research vessels sailing through the Arctic, and into the entire ecosystem that is peer-reviewed research. A system that relies on incoming eager students, federal grant funding, consortium agreements between the biggest institutional libraries and the biggest publishing houses in the country, scientific integrity, and future, stable career opportunities. Finding and discovering the best and the brightest means funding, protecting, and supporting the best and the brightest.

Open, accessible science builds and supports both public trust and future scientific advancements. As the world widens and we are all met with increased access to studies, content, and news, scientific storytelling and literacy have never been more important for ensuring public trust. Transparency from the lab and from the field to published output allows for data to be discussed, fact-checked, and reused to support future scientific discovery. Days of Action demonstrates that we have a unique role to play in supporting the health, safety, and future of our country. If you feel called to get involved, please see resources available from SPGR.

Ryan reminds us, “There are lots of ways to participate in our democracy… find where you can best serve as a leader…don’t try to do it all, but try to do something.”

—Emille Beller (ebeller@agu.org, 0009-0009-7274-0706), Senior Program Coordinator, AGU Publications

Citation: Beller, E. (2026), The impact of advocacy: American Geophysical Union’s Days of Action, Eos, 107, https://doi.org/10.1029/2026EO265020. Published on 14 May 2026. This article does not represent the opinion of AGU, Eos, or any of its affiliates. It is solely the opinion of the author(s). 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.

Author(s): Jordan Lee, Peter Norreys, Robert Paddock, Matthew Oliver, Pawala Ariyathilaka, Christopher Spindloe, Donna Wyatt, Samuel Irving, Ben Fisher, Nigel Woolsey, Stavros Bakandreas, Bruno Albertazzi, Michel Koenig, Piotr Rączka, Takayoshi Sano, Alexis Amouretti, Naoki Yamagata, Kai Taketoshi, Kosuke Nishitani, and Norimasa Ozaki

Low-density foams are of significant interest in inertial confinement fusion (ICF), with potential applications as fuel carriers, ablation layers, or as a hohlraum filling material. Despite their potential, the shock response of these materials remains poorly characterized, limiting the accuracy of …

[Phys. Rev. E 113, 055210] Published Thu May 14, 2026

Author(s): F. Massimo, I. Moulanier, A. Guerente, O. Khomyshyn, M. Masckala, T. L. Steyn, U. Schramm, A. Irman, and B. Cros

High-accuracy modeling of laser-plasma interactions at high intensity requires precise knowledge of the laser field, including its asymmetries. However, the experimental characterization of such lasers is often limited to fluence measurements in transverse planes, which creates the need for a reliab…

[Phys. Rev. E 113, 055211] Published Thu May 14, 2026

An international team of scientists has discovered that methane hydrates beneath the northwest Greenland continental shelf became rapidly destabilized by meltwater, releasing large stores of methane during ice-sheet retreat across the continental shelf.

New evidence from the Natural Hazards Commission – Toka Tū Ake (NHC) shows that landslides are now New Zealand’s most costly natural hazard.

New Zealand is a country that is prone to a range of natural hazards. Located on a series of major fault systems, earthquakes cause high levels of loss. The country is also volcanically active, with occasional tragedies. Heavy rainfall brings floods.

To share the cost of these perils, following the 1942 Wairarapa earthquakes, the New Zealand government established the Earthquake Commission (EQC) in 1945, initially focusing on earthquakes and war damage, but subsquently expanded to cover other natural hazards.

In the subsequent years, the EQC has evolved into the Natural Hazards Commission – Toka Tū Ake (NHC), with a purpose “to reduce the impact of natural hazards on people, property, and the community”. Essentially it operates as a financial pool, with home owners paying a levy on top of their insurance to generate the fund. In the event of a loss, the fund pays for the rebuild costs up to a cap (currently NZ$300,000); the remainder is then covered by the property’s insurance. Claims are funded directly from the pool, with reinsurance cover and ultimately a government guarantee in place to ensure that there are sufficient funds.

In reality, NHC does much more than this, acting to manage and settle claims, and to understand the range of hazards to which New Zealand is prone.

In the last few days, a range of media outlets in New Zealand have been reporting new data from NHC about losses from natural hazards in New Zealand. This is the headline from 1News:

“Landslides are New Zealand’s most expensive natural hazard – and new data reveals a sharp rise in damage claims and growing risks to homes, infrastructure and communities.”

In total, since 2021 NHC has received 13,000 landslide claims and has paid out NZ$322 million (US$191 million). New Zealand is seeing an abrupt increase in landslide losses, driven primarily by increasingly frequent high magnitude rainfall events. NHC is urging property owners to undertake preventative maintenance and to be aware of the limitations of EQC cover.

Here be landslides – typical landslide-prone terrain in New Zealand.

In common with many other places, these landslide hazards represent a major challenge to New Zealand. The landscape has many dormant landslides that are being reactivated by these increased rainfall events, and many new failures are also occurring. But, generating reliable risk maps for landslides remains a major challenge. This needs to be a major research focus in the coming years. It will require better understanding of triggering events (rainfall and earthquakes primarily); of the initiation processes within the slope; of runout / debris mobility; and of vulnerability and consequent losses. It is probably true to say that in all of these areas, landslide research lags behind that of earthquakes and floods, primarily because of a lack of long term investment.

In many countries, landslides are not an insured risk for this reason. On its own, this will be a major challenge that must be addressed. For those countries in which landslides are insured, we need quickly to get up to speed.

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.

SummaryThe Wasatch Front Community Velocity Model (WFCVM) is the most complete and detailed Earth model for the Wasatch Front region in north-central Utah (USA). Until recently, it had not been well evaluated with strong ground motion observations due to a lack of local earthquakes with magnitude M5+. The 18 March 2020 Mw 5.7 Magna, Utah, earthquake generated excellent strong ground motion data at dozens of stations along the Wasatch Front, with peak ground accelerations up to 0.54 g. Here, we use the forward finite-difference code SW4 to simulate waveforms of the 2020 Magna mainshock in the WFCVM up to 3 Hz and compare its predictions to observations from 35 nearby stations at epicentral distances of 4–46 km. We use a finite fault source model with a semi-stochastic slip distribution and overlay stochastic velocity perturbations (S) and surface topography (T) on the WFCVM, which we refer to as the 3D+S+T model. Observed-predicted amplitude ratios and Goodness-of-Fit (GOF) scores for PGA, PGV, PGD, Arias intensity and duration, cumulative energy and duration are calculated. Our 3D+S+T model performed fairly, matching the general character of the observations with an average GOF score of 5.20 (out of a maximum of 10), slightly better than the unaltered WFCVM score (GOF=4.97). Stochastic velocity perturbations mostly affect peak ground motions at the closest sites (< 20 km), while surface topography improves durations for basin sites and generates more realistic signals at higher frequencies. Neither addition resolves underprediction of basin amplification in the eastern Salt Lake Basin and overprediction of ground motion at basin-edge sites, which likely reflect inaccurate representations of basin structure in the WFCVM. Based on these results, we recommend including stochastic velocity perturbations and topography in future simulations but conclude that updating deterministic models of basin structure will lead to the biggest improvement in forecasting ground motion for future large (M6.75+) earthquakes in the Wasatch Front region.

SummarySpectral Induced Polarization (SIP) is a geophysical technique which measures the frequency dependent electrical properties of geologic materials which can, in turn, be linked to underlying petrophysical parameters. Four-electrode SIP measurements exhibit errors above 100 Hz related to parasitic capacitive coupling (PCC) inside of the instrumentation and to the impedance of the potential electrodes. These errors can easily mask the true sample response. Existing techniques to correct SIP data infected with these errors can be complex and prone to operational error. Here we present a simple procedure that utilizes joint two- and four-electrode measurements using the same sample holder to validate high frequency SIP data. We tested the practicality of this approach by performing a series of two electrode SIP measurements on a known NaCl solution using conventional coiled current electrodes composed of different metals. We compared this procedure with both theoretical values and against a four-electrode correction procedure (referred to as the Wang correction), which utilizes four impedance measurements to directly calculate high frequency phase errors in instruments with differential amplifiers. We found that two electrode measurements conducted with coiled Ag-AgCl electrodes performed well for resistive samples and for highly polarizable samples above 100 Hz, and for conductive samples above 1 kHz. The use of joint two- and four-electrode measurements on the same sample holder is simpler than existing correction techniques and presents a straightforward alternative to the validation of high-frequency four-electrode data.

SummaryMagnetization vector inversion is an effective method for analyzing magnetic anomaly data influenced by significant remanent magnetization. However, the multi-dimensional parameters of the magnetization vector increase both the non-uniqueness of the solutions and the computational burden. We propose a magnetization vector inversion method based on Gaussian radial basis function which the magnetization vector parameters are represented by the functional node parameters. By leveraging the inherent smoothness and local support characteristics of Gaussian radial basis function, the method suppresses spurious divergence in magnetization direction during the inversion process, thereby enhancing both the accuracy and computational efficiency of the inversion results. The proposed method is applied to interpret magnetic data in Xiangshan area for revealing the magnetization characteristics of magma-hydrothermal structures. The region of non-uniform magnetization vectors, which can be interpreted as lithological contacts and alteration fronts, may indicate multiple phases of magmatic intrusion. The distinct magnetization directions between shallow mineralized bodies and underlying magma conduits facilitates the identification of potential mineralized rocks and magma conduits that are undetectable by conventional magnetic intensity analysis. Drilling in the study area confirms the presence of Cu-Ni mineralization in the shallow mafic-ultramafic intrusions. Results demonstrate that the magnetization vector inversion could capture complex geological information, providing a promising tool for understanding volcanic and magmatic systems.

Buffalo's legendary snowfall totals are largely the result of one unlucky geographic reality: the city sits east of the Great Lakes instead of west. Anyone who has lived through a winter in Buffalo, Cleveland or any snowbelt city knows that prevailing westerly winds pick up moisture from the lakes and dump lake-effect snow on their eastern shores.

Grasslands, covering 40% of Earth's vegetated surface, play a crucial role in the global carbon balance but are increasingly threatened by climate-driven water scarcity. A new study published in Science Advances finds, however, that a widespread wind speed decline—a phenomenon known as "terrestrial stilling"—is enhancing the ability of global grasslands to absorb more carbon while minimizing water loss. This shift offers a crucial buffer for these water-limited biomes under climate change.

Artificial intelligence is beginning to transform climate science, not just by improving forecasts, but by helping researchers understand the physical forces shaping the planet's future.

It all began with a perfectly ordinary chat over coffee between four researchers. How many films featuring geologists can we think of? Quite quickly, the colleagues were able to come up with about 10 films. But then the scientific mind of one of them sprang into action.

Atmospheric methane levels have surged to record highs in recent years and are projected to increase by as much as 13% by 2030, according to a report from the Climate & Clean Air Coalition. As scientists work to better understand what is driving this rise, a new collaborative study published in Nature Communications used methane isotopologues to trace where recent emissions originate and how they are changing around the world.

Researchers at the University of Bristol have developed a new method which could help scientists perform large-scale climate simulations at a fraction of the cost and time needed compared to traditional climate models. The team, led by Dr. Charles Williams, Senior Lecturer in the School of Geographical Sciences, wanted to investigate factors influencing the way Earth's climate has repeatedly swung between cold glacial "ice ages" and warmer interglacial periods over the last 2.6 million years—known as the Quaternary period.

Every year in the West Pacific, as summer ends and September rolls around, typhoons are not far behind. Typhoons are the most impactful extreme weather events affecting Japan and East Asia, and due to climate change, extremely strong typhoons are becoming more frequent. In order to adapt critical infrastructure to these massive storms and protect coastal areas, accurate accounting for their future impact is essential.

In 2012, a wildfire ripped through 42 square kilometers of alpine moorland in Africa's Rwenzori Mountains, a range of glaciated peaks on the border of Uganda and the Democratic Republic of Congo. The blaze, which occurred at an elevation of over 13,000 feet, was shocking to those familiar with the mountains, as the climate had been assumed to be too cold and too wet for fire to spread.