Deep within ancient chamber tombs where elite members of society in ancient Greece and Crete were once laid to rest, new evidence has emerged that these high-status individuals wore some out-of-this-world iron jewelry.

Among the most coveted jewelry worn in the Bronze Age Mediterranean world were rings that were likely made from extraterrestrial iron, according to a new study published in the Journal of Archaeological Science.

Researchers Matthieu Gounelle and Eleni Mantzourani used chemical analysis to examine more than 90 iron objects from the Bronze Age and Early Iron Age, uncovered from 33 archaeological sites, revealing that about one-third of the artifacts were likely crafted using iron that fell from space.

Although iron harvested from ancient meteorites accounted for at least 10 of the rings the researchers examined, another three “might deserve further examination,” the study’s authors say, in new observations that indicate these ancient extraterrestrial adornments “may have been popular power symbols among prominent individuals” that included the Mycenaean and Minoan palatial elite.

Yet despite their apparent significance, the otherworldly fashion trend involving these otherworldly rings seems to have mysteriously vanished by the 12th century BCE, for reasons that remain unclear to researchers.

Meteoritic Iron as a Status Symbol

Using portable X-ray fluorescence, or XRF, to assess these rare artifacts in various museums where they are kept, most of the objects were found to contain very little nickel, if any at all. This is consistent with iron produced using smelting processes from the periods in question, which relied on terrestrial ores.

However, 13 of the objects possessed elevated levels of nickel, which hinted at the likelihood that some of these ancient rings had been crafted with metal originating in meteorites, which contain far more nickel than smelted varieties of iron do.

Another intriguing discovery the researchers made was that each artifact suspected of being made from meteoritic iron was either a whole or fragmentary signet or bezel ring, combining the suspected meteoritic iron with gold, silver, or bronze. Most were also found in various chamber tombs alongside other luxury goods, adding to the likelihood that these unique artifacts may have been considered symbols of status or authority.

Where Did Ancient Greeks Obtain Extraterrestrial Iron?

However, another mystery involves the source of the meteoritic material, which remains uncertain since extraterrestrial iron was uncommon in ancient Greece. Because of this, the team suspects that one reason for this material’s role as a status symbol may have been not just its otherworldly nature, but also the fact that it was likely imported.

“Given the rarity of meteorites in Greece and the established trade networks during the Bronze Age, we propose that the source of the raw meteoritic material was Egypt,” the team writes, “where meteorites are numerous due to the abundance of deserts.”

Several famous examples of meteoritic iron have been recovered from Egypt, which include a dagger found among the items entombed with the Pharaoh Tutankhamun.

The abundance of rings made from this extraterrestrial metal contrasts with the more common iron objects that appear to have been made from smelted material. This suggests that ancient metalworkers recognized the distinction between the materials, and ascribed higher value to the far rarer meteoritic forms of iron.

An Otherworldly Fashion Trend Goes Missing

Curiously, the researchers also found that by around the 12th century BCE, this otherworldly fashion trend appears to have almost completely vanished, and for reasons that remain unclear.

Possible reasons for this may include interruptions to trade networks, political upheaval, or simply changes in trends from the period. However, one potential clue is that the ancient Greeks’ production of meteoritic iron rings seems to have ended coinciding with the collapse of the Mycenaean palace system.

“Such a development could be related to economic, social or political changes,” the team speculates, although they also acknowledge more mundane possibilities.

“It is also possible that the meteoritic finger ring fashion, almost exclusive to Minoan and Mycenaean Late Bronze Age, has ‘naturally’ faded away as does any fashion,” the researchers write.

The recent study, “Iron in Greece in the second millennium B.C.E.,” appeared in the Journal of Archaeological Science. 

Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. A longtime reporter on science, defense, and technology with a focus on space and astronomy, he can be reached at micah@thedebrief.org. Follow him on X @MicahHanks, and at micahhanks.com.

Globally, about 1 billion people live near glaciers and depend on glacial water. As temperatures continue to climb due to global warming, glaciers can become unstable and hazardous to nearby communities. These communities risk exposure to a series of linked processes, like ice collapse, flooding, and landslides, which could have life-threatening consequences. Scientists call these events catastrophic glacier hazard chains, or CGHC. So, a team of scientists in China sought to understand the driving forces behind these dangerous phenomena. 

The team focused on a CGHC event that occurred in 2018 at the Sedongpu Glacier, located in the Eastern Himalayas. During this event, the glacier obstructed the flow of 30 million square meters (more than 300 million square feet) of the Yarlung Tsanpo River, one of the main rivers within the region. 

To reconstruct the event, the team observed satellite images of the Sedongpu glacier over time, using a process called remote sensing. They used the images to calculate ice volumes, glacier velocities, and glacier movement between 1961 and 2018, to determine the glacier’s long-term physical properties and how they changed over time. They found that from 1968 to 2013, the Sedongpu Glacier shrank, or retreated, by over 6 football fields. It also lost ice and water volume and increased its velocity.

The scientists also measured earthquake waves on the Earth’s surface, or seismicity, to characterize any downslope rock or debris movements caused by the glacial retreat. They measured seismicity across 11 different seismic stations within 580 kilometers (about 350 miles) of the glacier. Then, they used this data to identify 2 distinct phases of the CGHC event on Sedongpu Glacier: the ice-rock avalanche and the debris flow.

When the ice-rock avalanche occurred, the team detected noticeable increases in seismicity, suggesting it lasted over 30 seconds. During those 30 seconds, over 8 million cubic meters (more than 280 million cubic feet) of ice fell onto the main glacier. The team recorded even more increases in seismicity during the debris flow, which lasted nearly 5 minutes. The debris from the avalanche hit the main valley glacier at nearly 300 kilometers (200 miles) per hour.

The researchers combined these data to describe how the 2018 CGHC event unfolded. First, the backward movement and shrinkage of the glacier produced an unstable sheet of ice hanging over a cliff face. The steep slope and large cracks in the ice caused an ice-rock avalanche. Debris from the avalanche then accumulated on the main glacier, causing it to move faster. As the main valley glacier moved downslope, it picked up even more debris from the bottom and sides of the glacial valley. The melting ice also increased the glacier’s velocity, and its movement eventually transitioned into a debris flow, which obstructed the Yarlung Tsangpo River. 

In total, the CGHC event in the Sedongpu Glacier travelled over 10 kilometers (6 miles) and moved down in elevation for over 3 kilometers (about 2 miles) at a velocity of about 100 kilometers (about 70 miles) per hour. The glacier accumulated enough debris and ice to fill thousands of Olympic-sized swimming pools. Imagine what this could do to a nearby village!

It’s difficult for scientists to estimate when CGHC events will occur, but this team proposed several factors that could help predict them. These factors included the size of the ice-rock avalanche and the glacier velocity, as well as the occurrence of earthquakes, temperature changes, and the melting of the glacier’s underside. They stated that these factors can combine to create a domino effect that drives the CGHC process. They recommended consistent glacial monitoring as temperatures continue to climb, in the Himalayas and globally. 

The team concluded that understanding CGHC events can help scientists mitigate glacial hazards and keep people safe, especially in mountainous areas such as the Eastern Himalayas. They stated that their findings illustrate the dangerous processes behind glacial melting, but further research is needed to accurately assess those processes and ensure nearby communities remain safe.

The post Can melting ice increase glacial hazards? appeared first on Sciworthy.

Nearly 170 billion tons of ice melt off the Greenland Ice Sheet every year, but scientists don’t fully understand the process by which this melting occurs. Researchers in the past suggested that liquid water forms at the glacier’s surface, where warm air and sunlight melt the ice. This meltwater travels down through cracks in the glacier and along the bedrock beneath it and flows out to sea. 

However, some scientists view this model as too simple because it assumes water only flows downward and ignores how temperature affects water movement. They argue that an oversimplified melting model is unreliable for predicting how future ice sheets will behave.

One group of researchers tested this by investigating how water movement across Greenland is controlled by lakes beneath the ice sheet, called subglacial lakes. They monitored a newly discovered subglacial lake using high-resolution satellite images taken from 2012 to 2019 and 3D surface maps generated from the images. They focused on ice sheet changes from July 22 to August 1, 2014, during a suspected subglacial lake drainage event. A drainage event is like a water balloon that’s too full, bursting from excess pressure. 

They examined images of the Greenland ice sheet taken from Landsat-8, 3D surface maps from the Polar Geospatial Center, and data from ICESat and ICESat-2 taken in the summer of 2014. Based on these data, the researchers identified a 2-square-kilometer (0.8-square-mile) region of ice rising 10 to 15 meters (about 30 to 50 feet), forming a dome on the ice sheet’s surface. They suggested that this dome formed when a large, meltwater-fed lake developed on the bedrock beneath the ice sheet, pushing the ice upward. 

They also saw that on July 22, 2014, the dome began to collapse. Over the next 10 days, it dropped by 85 meters (about 280 feet), forming a basin. Using the dome’s dimensions, the researchers estimated that 90 million cubic meters, or about 3 billion cubic feet, of water drained from the lake at an average rate of 100 cubic meters, or about 3500 cubic feet, per second over the 10 days. This is roughly equivalent to 36,000 Olympic swimming pools draining at a rate of 1 pool every 25 seconds! 

The researchers also found that during the collapse, 40-meter-high (130-foot) ice blocks were uprooted about 1 kilometer (0.6 mile) downstream from the basin, followed by 6 square kilometers (about 2 square miles) of smooth ice. The researchers hypothesized that these features formed when water burst through the ice, flowed along its surface, and then reentered the ice sheet.

Next, they used data from Landsat 5, Landsat 9, the National Snow and Ice Data Center, and the U.S. Geological Survey to demonstrate that the drainage event also affected the surrounding environment. When the water reentered the ice sheet, it flowed beneath the Harding Glacier downstream. This influx of fast-moving water reduced pressure at the glacier’s base, slowing its movement. Simultaneously, the increased drainage beneath the Harding Glacier caused 500 to 600 meters (about 1,600 to 2,000 feet) of ice to break off its end. 

In response to these changes, the researchers hypothesized that subglacial waters rose to the surface rather than sinking to the bedrock because the ice sheet was frozen to it. To test this, they simulated temperatures at the base of the ice sheet using computer-generated thermal models. They input a range of likely bedrock temperatures and ice thicknesses to simulate possible conditions under the ice sheet. They found that all the simulations predicted the glacier’s base would remain below -5°C (23°F). At such low temperatures, the ice would be frozen to the bedrock before subglacial water could drain out. Since water couldn’t flow under the glacier, it was forced to travel upward. 

The researchers used these findings to develop a new conceptual model of how glacial meltwater moves. First, surface ice melts and flows into a subglacial lake. As meltwater accumulates, pressure builds at the base of the ice sheet, forming a dome on the surface. A drainage event causes the dome to collapse. As water moves downward through the glacier, it is blocked from reaching the base because the ice is frozen to the bedrock. The water then moves upward, bursts through the surface, travels across it, and eventually reenters the glacier before draining to the ocean.

The team concluded that water movement above, through, and below glaciers is interconnected. Destructive upward flow of meltwater, followed by downward flow beneath glaciers, can weaken ice sheet structure and alter downstream glacier dynamics. Their work highlights the need for more scientists to consider the processes driving glacial ice loss.

The post How do ice sheets melt? appeared first on Sciworthy.

The Greenland Ice Sheet: An Unstoppable Catalyst of Global Sea-Level Rise

In the unfolding narrative of our planet’s climate crisis, the Greenland Ice Sheet stands as one of the most formidable agents of change. Since the dawn of satellite observations in 1992, this massive reservoir of ice has relinquished approximately 4,900 gigatons of ice, a staggering volume whose meltwater has contributed about 13 millimeters to the rise in global mean sea level. Such a figure, while already alarming, merely scratches the surface of potential long-term impacts. Even in a hypothetical future devoid of any additional warming, the Greenland Ice Sheet is effectively locked in to contribute an extra ~274 millimeters to global sea levels. This commitment underscores a sobering reality: the ice sheet’s decline is not simply a transient phenomenon but a geological-scale reordering, with the total potential of a 7-meter sea-level rise looming if complete melting ever unfolds.

To truly grasp the implications of the Greenland Ice Sheet’s evolution, scientists have undertaken comprehensive syntheses of its surface melt dynamics extending across centuries—from 1500 to projections as far ahead as 2200 CE. This historical and predictive vantage reveals a striking acceleration in surface melt beginning in the 1990s, characterized by a rapid increase of roughly 1 percent per year. This upsurge has not occurred in isolation. Rather, it is a direct consequence of amplified regional warming patterns coupled with notable alterations in atmospheric circulation dynamics. A phenomenon known as enhanced atmospheric blocking—where persistent high-pressure systems effectively stall weather patterns—has played a pivotal role in this rapid intensification of melt rates.

The consequences of these climate shifts manifest with increasing frequency and severity in extreme melt events. Since 2007, Greenland has experienced multiple unprecedented episodes where melting persists intensively over several consecutive days. These events reach apogees such as the extraordinary case of July 2012, during which almost the entirety of the ice sheet surface succumbed to thawing. Such extremes stress the limits of current predictive models and underscore the urgent need to understand the complex interplay of forcings driving these episodes.

Dominating the seasonal melt cycle is the absorption of shortwave solar radiation. Solar energy, pouring relentlessly onto the ice sheet’s surface during summer months, serves as the primary engine for surface melting. However, this process is far from straightforward or uniform. Turbulent heat fluxes—essentially the turbulent exchange of heat between the ice and atmosphere—alongside cloud cover dynamics and the critical feedback mechanism of albedo, significantly modulate the spatial and temporal variability of melt. Albedo effects refer to the reflectivity of the ice surface: as ice melts and dark patches or meltwater form, less sunlight is reflected back, and more is absorbed, accelerating melt rates in a self-reinforcing loop.

Yet, it is precisely the intricate and interlinked nature of these processes that confounds climate models. Even among today’s state-of-the-art regional climate models, there is a stark divergence in projections of Greenland’s surface melt and mass loss. When subjected to identical climate forcing scenarios, these models yield predictions differing by as much as a factor of two. This discrepancy highlights fundamental uncertainties inherent in simulating the nuanced physics of ice-atmosphere interactions, energy balance complexities, and meltwater behavior within the firn layers—densely packed snow that acts as a sponge holding meltwater before it refreezes or runs off.

A central challenge lies in the accurate representation and integration of these processes within numerical simulations. Extreme melt events, in particular, remain difficult to quantify and predict with confidence. The drivers behind these sporadic but increasingly frequent episodes are multifaceted, involving shifts in jet stream patterns, atmospheric blocking frequencies, and the enigmatic influence of cloud microphysics. Likewise, the fate of meltwater—whether it refreezes in the porous firn layers or contributes to runoff—critically influences the net mass balance of the ice sheet yet remains poorly constrained in many models.

Adding further layers of complexity, coupling between atmospheric forcing and the surface energy balance must accurately capture feedback loops and temporal variability. Discrepancies in these couplings propagate through simulations and exacerbate uncertainties in projections of future melt and associated sea-level rise contributions. Scientists recognize that overcoming these hurdles necessitates expanding observational networks across Greenland, leveraging advanced remote sensing methods combined with in situ monitoring to resolve fine-scale processes.

Furthermore, there is a burgeoning potential for integrating emerging data-driven approaches into this research frontier. Machine learning, artificial intelligence, and data assimilation techniques offer promising means to synthesize vast datasets, identify subtle patterns, and enhance the physical realism of model parameterizations. However, realizing these gains demands concerted efforts in model development, interdisciplinary collaboration, and continued investment in observational infrastructure.

The stakes could hardly be higher. Greenland’s meltwater contributions are a central element of global sea-level rise—one of the most significant threats to coastal communities worldwide. The unprecedented speed and scale of Greenland surface melt ask not only for scientific diligence but also for rapid climate mitigation and adaptation strategies. The Greenland Ice Sheet is both a harbinger and accelerator of change in Earth’s climate system, embodying losses that reverberate far beyond polar latitudes.

Looking to the centuries ahead, the trajectory of Greenland’s surface melt remains riddled with uncertainty but is unmistakably poised on an upward trend in response to continued warming. Understanding and predicting this trajectory with greater precision is not merely an academic endeavor; it is a prerequisite for global climate resilience planning. The Greenland Ice Sheet, with its vast store of frozen freshwater, is a sentinel of deep Earth system transformations, reminding humanity of the interconnectedness of climate, ice, and sea.

Our current epoch demands that we unravel the intricacies of ice sheet melting at a pace matching the climate forces reshaping our planet. The Greenland Ice Sheet’s story, as told from the past into the future, is both a cautionary tale and an invitation to innovate in climate science. Only through enhanced observational capabilities, refined models, and novel integrative approaches can we rise to this challenge. The fate of coastlines, ecosystems, and human settlements worldwide hinge on the answers we find in this colossal frozen archive.

As the Earth warms, the story of Greenland’s shrinking ice transforms from abstract projections into tangible realities. Extreme melt events once considered anomalies have become harbingers of a new normal, with implications cascading through global systems. The urgency of understanding this dynamic, the mechanisms underpinning it, and its future paths cannot be overstated. Greenland, in its ancient calm, increasingly pulses with restless change—bearing witness to and driving one of the most profound climate transformations of our era.

Subject of Research: Greenland Ice Sheet surface melt and its contributions to global sea-level rise.

Article Title: Past, present and future Greenland Ice Sheet surface melt, 1500–2200 CE.

Article References:
Hanna, E., Box, J.E., Fettweis, X. et al. Past, present and future Greenland Ice Sheet surface melt, 1500–2200 CE. Nat Rev Earth Environ (2026). https://doi.org/10.1038/s43017-026-00800-3

Image Credits: AI Generated

DOI: 10.1038/s43017-026-00800-3

Keywords: Greenland Ice Sheet, surface melt, sea-level rise, climate change, atmospheric circulation, atmospheric blocking, albedo feedback, turbulent heat fluxes, climate models, firn processes, meltwater retention, extreme melt events