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Bizarre, nine-day seismic signal caused by epic landslide in Greenland

Ice calving from a glacier

Enlarge (credit: Jason Edwards via Getty)

Earthquake scientists detected an unusual signal on monitoring stations used to detect seismic activity during September 2023. We saw it on sensors everywhere, from the Arctic to Antarctica.

We were baffled—the signal was unlike any previously recorded. Instead of the frequency-rich rumble typical of earthquakes, this was a monotonous hum, containing only a single vibration frequency. Even more puzzling was that the signal kept going for nine days.

Initially classified as a “USO”—an unidentified seismic object—the source of the signal was eventually traced back to a massive landslide in Greenland’s remote Dickson Fjord. A staggering volume of rock and ice, enough to fill 10,000 Olympic-sized swimming pools, plunged into the fjord, triggering a 200-meter-high mega-tsunami and a phenomenon known as a seiche: a wave in the icy fjord that continued to slosh back and forth, some 10,000 times over nine days.

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The DNA secrets of a medieval cave-dwelling community

View of cave site

Enlarge / View of the Las Gobas cave site. (credit: Miguel Sotomayor via Getty)

In a new study, we have sequenced DNA from a Christian community in medieval Spain that lived in artificial caves carved into a rocky outcrop.

This is one of several medieval cave communities known to have lived on the Iberian Peninsula—which includes both Portugal and Spain. Why these groups favored caves over more conventional village dwellings is a subject of longstanding debate for archaeologists. While it may be tempting to speculate about hermits or religious groups, there’s scant evidence to support such theories.

Our study, published in Science Advances, explores the possibilities, adding genetic analysis to what we know about the physical remains of people from the site’s cemetery. DNA was able to shed light on the ancestry of this community, their relationships to each other and the diseases that afflicted them.

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How accurate are wearable fitness trackers? Less than you might think

How accurate are wearable fitness trackers? Less than you might think

Enlarge (credit: Corey Gaskin)

Back in 2010, Gary Wolf, then the editor of Wired magazine, delivered a TED talk in Cannes called “the quantified self.” It was about what he termed a “new fad” among tech enthusiasts. These early adopters were using gadgets to monitor everything from their physiological data to their mood and even the number of nappies their children used.

Wolf acknowledged that these people were outliers—tech geeks fascinated by data—but their behavior has since permeated mainstream culture.

From the smartwatches that track our steps and heart rate, to the fitness bands that log sleep patterns and calories burned, these gadgets are now ubiquitous. Their popularity is emblematic of a modern obsession with quantification—the idea that if something isn’t logged, it doesn’t count.

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The climate is changing so fast that we haven’t seen how bad extreme weather could get

The climate is changing so fast that we haven’t seen how bad extreme weather could get

Enlarge (credit: Peter Zelei Images via Getty Images)

Extreme weather is, by definition, rare on our planet. Ferocious storms, searing heatwaves, and biting cold snaps illustrate what the climate is capable of at its worst. However, since Earth’s climate is rapidly warming, predominantly due to fossil fuel burning, the range of possible weather conditions, including extremes, is changing.

Scientists define “climate” as the distribution of possible weather events observed over a length of time, such as the range of temperatures, rainfall totals, or hours of sunshine. From this, they construct statistical measures, such as the average (or normal) temperature. Weather varies on several timescales—from seconds to decades—so the longer the period over which the climate is analyzed, the more accurately these analyses capture the infinite range of possible configurations of the atmosphere.

Typically, meteorologists and climate scientists use a 30-year period to represent the climate, which is updated every 10 years. The most recent climate period is 1991–2020. The difference between each successive 30-year climate period serves as a very literal record of climate change.

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A chemist explains the chemistry behind decaf coffee

Close-up of coffee beans with roasted beans on table

Enlarge (credit: matusgajdos17 / 500px via Getty Images)

For many people, the aroma of freshly brewed coffee is the start of a great day. But caffeine can cause headaches and jitters in others. That’s why many people reach for a decaffeinated cup instead.

I’m a chemistry professor who has taught lectures on why chemicals dissolve in some liquids but not in others. The processes of decaffeination offer great real-life examples of these chemistry concepts. Even the best decaffeination method, however, does not remove all of the caffeine—about 7 milligrams of caffeine usually remain in an 8-ounce cup.

Producers decaffeinating their coffee want to remove the caffeine while retaining all—or at least most—of the other chemical aroma and flavor compounds. Decaffeination has a rich history, and now almost all coffee producers use one of three common methods.

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Alaska’s top-heavy glaciers are approaching an irreversible tipping point

Taku Glacier is one of many that begin in the Juneau Icefield.

Enlarge / Taku Glacier is one of many that begin in the Juneau Icefield. (credit: Mauricio Handler / Getty Images)

The melting of one of North America’s largest ice fields has accelerated and could soon reach an irreversible tipping point. That’s the conclusion of new research colleagues and I have published on the Juneau Icefield, which straddles the Alaska-Canada border near the Alaskan capital of Juneau.

In the summer of 2022, I skied across the flat, smooth, and white plateau of the icefield, accompanied by other researchers, sliding in the tracks of the person in front of me under a hot sun. From that plateau, around 40 huge, interconnected glaciers descend towards the sea, with hundreds of smaller glaciers on the mountain peaks all around.

Our work, now published in Nature Communications, has shown that Juneau is an example of a climate “feedback” in action: as temperatures are rising, less and less snow is remaining through the summer (technically: the “end-of-summer snowline” is rising). This in turn leads to ice being exposed to sunshine and higher temperatures, which means more melt, less snow, and so on.

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The dangers of sneezing—from ejected bowels to torn windpipes

Picture shows a woman about to sneeze holding a handkerchief in her hand.

Enlarge (credit: Getty | Bettmann)

If you were to envision the kind of accident that would cause a person’s bowels to explode out of their body, you might imagine some sort of gruesome stabbing or grisly car accident. You’d probably never imagine that something as commonplace and harmless as a sneeze would cause this kind of ghastly injury—but that’s exactly what happened to a Florida man earlier this month.

The man had recently had abdominal surgery and was suffering from wound dehiscence—where his surgical scar wasn’t healing properly. While eating breakfast, the man first sneezed, then began coughing. He noticed pain and a wet sensation on his lower abdomen—only to discover several loops of his bowel had burst through his unhealed wound.

The man was rushed to hospital for emergency surgery where his bowels were returned to his abdomen.

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Searching for a female partner for the world’s “loneliest” plant

Map from drone mission search for the Encephalartos Woodii in the Ngoye Forest in South Africa.

Enlarge / Map from drone mission search for the Encephalartos Woodii in the Ngoye Forest in South Africa. (credit: CC BY-NC)

“Surely this is the most solitary organism in the world,” wrote paleontologist Richard Fortey in his book about the evolution of life.

He was talking about Encephalartos woodii (E. woodii), a plant from South Africa. E. woodii is a member of the cycad family, heavy plants with thick trunks and large stiff leaves that form a majestic crown. These resilient survivors have outlasted dinosaurs and multiple mass extinctions. Once widespread, they are today one of the most threatened species on the planet.

The only known wild E. Woodii was discovered in 1895 by the botanist John Medley Wood while he was on a botanical expedition in the Ngoye Forest in South Africa. He searched the vicinity for others, but none could be found. Over the next couple of decades, botanists removed stems and offshoots and cultivated them in gardens.

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