Last August, one of the tallest tsunamis ever recorded on Earth happened in Alaska — and almost nobody noticed. That's not a metaphor. The wave was real, it was enormous, and the reason you didn't hear about it is simply that it struck an uninhabited fjord before most people were awake.
At 5:26 a.m. on August 10, 2025, a chunk of mountainside roughly the size of 25 Empire State Buildings' worth of rock broke loose above Alaska's Tracy Arm fjord. The collapse sent that rock plunging into the water at the base of the South Sawyer Glacier, displacing enough water to generate a breaking wave nearly 100 meters high. When that wave slammed into the opposite shore, it surged up the rock face to a height of 481 meters above sea level — the second tallest tsunami runup ever measured anywhere on the planet.
The only reason this isn't a disaster story is timing and geography. No one was there. The fjord is remote, the hour was early, and the wave had no population to hit. Researchers are now calling it a near-miss event, and they're not subtle about what that means: we got lucky, and we may not next time.
A new study published in Science reconstructed exactly what happened and, more importantly, why. The culprit isn't seismic activity or some random geological quirk. It's climate change, working slowly and then all at once.
For centuries, the steep rock face above Tracy Arm was essentially held in place by the South Sawyer Glacier. The ice acted as a structural brace, pressing against the slope and keeping it stable despite its extreme angle. But South Sawyer has been retreating for decades, thinning as regional temperatures have climbed. Between 2013 and 2022 alone, the glacier ice supporting the failure site lost between 100 and 130 meters of thickness. That's not a rounding error — that's the difference between a stable slope and a catastrophic one.
Researchers traced local summer temperatures back to around 1875 and found a 1.1 degree Celsius increase over that period. That warming pushed snowlines nearly 170 meters higher in elevation and steadily ate away at the ice. By July 2025, just weeks before the collapse, the glacier had retreated far enough that the rock face was essentially unsupported. The mountain was waiting to fall.
Landslide tsunamis behave differently from the earthquake-generated waves most people imagine when they hear the word tsunami. They're more localized, but they hit harder and faster. When millions of tons of rock drop into a narrow, confined fjord, the water has nowhere to go but up. Scientists have catalogued 27 such events since 1925 with runups exceeding 50 meters. The 1958 Lituya Bay event in Alaska still holds the record at 530 meters.
Tracy Arm is now second on that list. And the forces that caused it — retreating glaciers, warming temperatures, destabilized slopes — are not confined to one fjord. They describe conditions that exist across Alaska, Greenland, Patagonia, and the Alps. The researchers aren't predicting where the next one happens. They're noting that the ingredients are being assembled in a lot of places at once.
SCIENCE
Fathers May Pass Life Experiences to Children Through RNA
Here's something that should make you rethink how inheritance works: mice whose fathers ran on treadmills before conception grew up to be measurably better athletes — even though they never trained a day in their lives and share the same DNA as mice whose dads were sedentary. The fitness didn't come from genes. It appears to have traveled in RNA.
Researchers at Nanjing University in China set up a straightforward but quietly radical experiment. They had male mice exercise regularly, then analyzed the molecules inside their sperm. What they found was an elevated presence of tiny RNA fragments called microRNAs — molecules that don't carry genetic code the way DNA does, but can influence how genes get expressed. When the team injected those specific microRNAs into unrelated embryos, the resulting offspring ran farther and built up less lactic acid than control animals. The fitness trait transferred without a single shared gene.
The lead researcher said he was genuinely surprised when he first saw the data. That's a notable admission in a field where scientists are trained to be measured. But the findings are hard to dismiss.
This study sits at the growing edge of a field called epigenetic inheritance — the idea that what a parent experiences during their lifetime can shape their children's biology through mechanisms that have nothing to do with DNA sequence. The concept has been building quietly for about two decades, largely through animal studies. Exercise, diet, chronic stress, childhood trauma, alcohol exposure, pesticide contact — all of these have been shown to alter RNA fragment levels in sperm, and offspring of affected males have shown corresponding changes in metabolism, development, and even rates of depression.
The leap from correlation to causation has been the hard part. A lot of early studies showed these associations without being able to prove the RNA was actually doing the work. Critics pointed out that lab experiments often used RNA concentrations far higher than what naturally exists in sperm, raising questions about whether the effect was even biologically realistic.
Recent research has started closing that gap. Scientists have now confirmed that paternal RNA fragments do transfer into fertilized eggs, and that they can produce measurable changes in offspring at concentrations that actually match what's found in real sperm. That's a meaningful upgrade from suggestive to credible.
The implications run in uncomfortable directions if you follow them far enough. It would mean that a father's habits — how much he exercises, what he eats, how much stress he carries, what he's exposed to — can shape his children's biology before those children even exist. Not through conscious choices or parenting behaviors, but through molecular signals written into sperm.
Researchers are cautious about overstating this for humans. Controlled experiments are much harder to run on people, and the field still has open questions about exactly how these RNA signals survive fertilization and influence development. But fluctuations in sperm RNA have already been documented in men based on exercise habits, diet, smoking, and trauma history. The mouse data has a way of not staying in the mouse cage for long.
Source: Ars Technica
Researchers at Nanjing University in China set up a straightforward but quietly radical experiment. They had male mice exercise regularly, then analyzed the molecules inside their sperm. What they found was an elevated presence of tiny RNA fragments called microRNAs — molecules that don't carry genetic code the way DNA does, but can influence how genes get expressed. When the team injected those specific microRNAs into unrelated embryos, the resulting offspring ran farther and built up less lactic acid than control animals. The fitness trait transferred without a single shared gene.
The lead researcher said he was genuinely surprised when he first saw the data. That's a notable admission in a field where scientists are trained to be measured. But the findings are hard to dismiss.
This study sits at the growing edge of a field called epigenetic inheritance — the idea that what a parent experiences during their lifetime can shape their children's biology through mechanisms that have nothing to do with DNA sequence. The concept has been building quietly for about two decades, largely through animal studies. Exercise, diet, chronic stress, childhood trauma, alcohol exposure, pesticide contact — all of these have been shown to alter RNA fragment levels in sperm, and offspring of affected males have shown corresponding changes in metabolism, development, and even rates of depression.
The leap from correlation to causation has been the hard part. A lot of early studies showed these associations without being able to prove the RNA was actually doing the work. Critics pointed out that lab experiments often used RNA concentrations far higher than what naturally exists in sperm, raising questions about whether the effect was even biologically realistic.
Recent research has started closing that gap. Scientists have now confirmed that paternal RNA fragments do transfer into fertilized eggs, and that they can produce measurable changes in offspring at concentrations that actually match what's found in real sperm. That's a meaningful upgrade from suggestive to credible.
The implications run in uncomfortable directions if you follow them far enough. It would mean that a father's habits — how much he exercises, what he eats, how much stress he carries, what he's exposed to — can shape his children's biology before those children even exist. Not through conscious choices or parenting behaviors, but through molecular signals written into sperm.
Researchers are cautious about overstating this for humans. Controlled experiments are much harder to run on people, and the field still has open questions about exactly how these RNA signals survive fertilization and influence development. But fluctuations in sperm RNA have already been documented in men based on exercise habits, diet, smoking, and trauma history. The mouse data has a way of not staying in the mouse cage for long.
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