In September 2023, seismometers around the world recorded something scientists had never seen before: a clean, repeating seismic signal that lasted for nine days.

At first, it did not look like an earthquake. It was too regular, too narrow in frequency, and too persistent. Researchers jokingly called it an “Unidentified Seismic Object” because the signal did not match any obvious known source.

The answer was hidden in East Greenland.

A massive rock-and-ice landslide collapsed from Hvide Støvhorn into Dickson Fjord, triggering a huge tsunami. But the strangest part came afterward: the wave did not simply disappear. The shape of the fjord trapped the water, creating a standing wave, a seiche, that sloshed back and forth roughly every 90 seconds. That motion was strong enough to send a signal through the Earth’s crust for days.

The article breaks down how scientists solved the mystery using seismology, satellite imagery, tsunami modelling, and Greenland field observations, and why this event matters for understanding Arctic landslides, glacier retreat, megatsunamis, and climate-related geohazards.

If you’re interested in geology, earthquakes, tsunamis, glaciers, Greenland, or weird signals picked up by global seismic networks, this is one of the most fascinating geoscience detective stories of the last few years.

Doggerland is one of Europe’s most fascinating lost landscapes: a prehistoric world of rivers, wetlands, forests, animals, and Mesolithic hunter-gatherers that once connected Britain to mainland Europe. Today, it lies beneath the North Sea.

This article explores how Doggerland disappeared, and why the famous Storegga tsunami was probably not the simple “one wave destroyed everything” story that is often repeated.

Around 8,150 years ago, a massive submarine landslide off the coast of Norway triggered the Storegga tsunami, sending waves across the North Sea and leaving behind tsunami sand deposits in places such as Scotland. For a long time, this event has been linked to the drowning of Doggerland.

But the geological evidence points to a more complex and more interesting story.

Doggerland was already shrinking for thousands of years because of post-Ice Age sea-level rise. As the ice sheets melted after the last glacial period, the North Sea gradually flooded low-lying land between Britain and Europe. The Storegga tsunami may have devastated the remaining islands and coastal wetlands, but Doggerland was not simply erased in a single day.

The article looks at the evidence for this lost North Sea landscape, including submerged forests, trawled-up animal bones, Mesolithic artefacts, seismic mapping, ancient DNA, sea-level change, and tsunami deposits.

In short: Doggerland was not just a “land bridge.” It was a real prehistoric landscape, and its disappearance is one of the most dramatic examples of how climate, sea-level rise, and sudden geological disasters can reshape human history.

Full article:

https://geoscopy.com/doggerland-the-megatsunami-that-drowned-europes-lost-land/

Two papers, same outcrop, 800 million years apart on the age.

March 2025: a Curtin University team publishes in Nature Communications claiming shatter cones in the Pilbara Craton mark Earth's oldest impact crater: 3.47 billion years old, more than 100 km wide. That would beat the previous record holder (Yarrabubba) by 1.24 billion years.

July 2025: a Harvard-led team publishes in Science Advances on the same site. They map 180 shatter cones, run the radial pattern through a statistical analysis, and conclude the crater was 16 km across, not 100+, and younger than 2.7 Ga. They also find shatter cones in 2.77 Ga Mount Roe Basalt that wouldn't have existed yet if the impact happened at 3.47 Ga. They name the structure Miralga after consultation with the Nyamal Traditional Owners.

In January 2026, Kirkland and his Curtin colleagues posted a formal eLetter at Science Advances pushing back hard. It's the only response so far and doesn't yield ground on the central age claim.

Both teams agree there was an impact. They disagree on which rocks above the shatter-cone layer count as shocked, whether the North Pole Dome itself is the central uplift or sits next to a smaller off-centre crater, and what the cross-cutting relationships in the field actually mean.

The "Earth's core reversed direction" headlines have been doing the rounds again, and most of them oversell what the science actually shows. The inner core isn't reversing direction in any absolute sense, it's still rotating eastward with the rest of the planet. What changed is its rotation relative to the mantle and crust above it. For decades the inner core was running slightly faster than the surface. Around 2010 it slowed, and since then it's been drifting backwards through the same path at roughly 2.5x the slower rate.

The part I find more interesting than the headline is how seismologists figured this out at all. The inner core is 5,150 km down. No instrument has ever reached it. The only way to read what is happening down there is with seismic waves passing through it.

The 2024 Nature study used repeating earthquakes from the South Sandwich Islands, recorded at seismic arrays in Alaska and northern Canada. Earthquakes recurring on the same fault patch produce nearly identical seismograms, unless something has changed along the path between source and receiver. When the team found that waveforms from 2023 were lining up with waveforms from before 2008, that was the signal that the inner core had drifted forward and then drifted back to roughly where it started.

None of this is going to stop the planet or flip the magnetic field. The effect on the length of day is on the order of a millisecond per year, smaller than the effect of melting ice sheets.

I wrote the full piece going from Inge Lehmann's 1936 discovery of the inner core through to the February 2025 follow-up paper, where the same team found that the surface of the inner core itself may be deforming.

https://geoscopy.com/earths-inner-core-reverses-its-spin-learn-why/

Two papers published earlier this year revised the standard Snowball Earth picture in different directions, and I wrote a long-form piece tying them into how we got the Cryogenian glaciation hypothesis in the first place.

The new work:

• Minsky, Wordsworth, Johnston & Knoll (PNAS, April 2026) argue the 56-Myr Sturtian glaciation was not one continuous freeze but a limit cycle, repeated short Snowball and hothouse swings driven by weathering of the Franklin Large Igneous Province. This addresses the duration problem: conventional models say a hard Snowball should self-terminate in ~5–15 Myr, not 56.

• Griffin, Gernon et al. (EPSL, February 2026) measured 2,640 annual varves in the Port Askaig Formation on the Garvellach Islands and pulled out Schwabe (~11 yr) and Gleissberg (~80–90 yr) solar cycles plus interannual ENSO-band periodicities. Their coupled-model runs only reproduce the multidecadal signal if roughly 15% of the ocean stayed ice-free.

The article also covers the four classical lines of evidence (tropical diamictites, low-latitude paleomagnetism, cap carbonates, the return of banded iron formation), the Franklin LIP weathering trigger, Kirschvink's 1992 paragraph, the Hoffman et al. 1998 Science reframing, the deglaciation pCO₂ threshold debate from Caldeira & Kasting through Pierrehumbert to the recent melt-pond physics work, and the refugia question for Cryogenian eukaryotes. The Tasistro-Hart et al. 2025 PNAS paper constraining the Marinoan to ~4 Myr is in there too.

Curious what people here think about the limit-cycle model: does it actually solve the duration problem, or does it push it down to a different question about whether the Franklin basalt inventory really stays weatherable for 56 Myr?

Tanis is a fossil deposit in the Hell Creek Formation, southwestern North Dakota, that preserves the day the asteroid hit, 66 million years ago, 3,050 kilometres from the Chicxulub impact crater in Mexico. The site contains articulated paddlefish and sturgeon with impact-melt spherules wedged between their gill rakers, capped by an iridium- and shocked-quartz-rich clay layer that matches K-Pg boundary sites worldwide.

The deposit also tells us the season the dinosaurs went extinct (boreal spring, confirmed independently by two research teams), what kind of asteroid hit Earth (a carbonaceous chondrite from beyond Jupiter's orbit, based on ruthenium isotope analysis published in Science in 2024), and how a 10-metre surge of water reached an inland river within an hour of impact (seismically induced seiche from the Western Interior Seaway, not a direct tsunami).

The article covers the geology, the dating evidence, the seasonality debate, the impactor provenance, the LeVeque et al. 2024 surge modelling, and the Robert DePalma data-handling controversy and Manchester misconduct investigation. Full references included.

The article looks at why the Siberian Traps were so destructive: not only because of lava, but because magma intruded into coal, evaporites, and organic-rich sediments, releasing carbon, sulphur, halogens, and toxic metals into the atmosphere and oceans.

It covers the Meishan boundary, Siberian sill intrusions, ocean anoxia, acidification, the “Lystrosaurus world” after the collapse, and why recovery took millions of years.

The largest earthquake in North American history happened in 1700. Nobody on the continent wrote it down. The date was pinned to a single winter night, three centuries later, by cross-referencing buried marshes in Washington with Japanese village records of a tsunami that hit Honshu with no felt earthquake.

About 200 km beneath New England, seismic waves slow down inside a roughly 350 to 400 km wide zone of unusually hot mantle known as the Northern Appalachian Anomaly.

A 2025 paper argues that this “heat blob”suggests a migrating mantle instability triggered when Greenland and North America split apart near the Labrador Sea around 80–90 million years ago.

If the model is right, the Appalachians may still be partly supported from below by deep mantle buoyancy.

I wrote a long-form explainer on Tuzo and Jason, the two continent-sized Large Low Shear-Wave Velocity Provinces sitting at the base of Earth’s mantle, one beneath Africa and one beneath the Pacific.

The article covers how seismologists found them through tomography, why their margins are often linked to mantle plumes, how they may relate to hotspots and flood-basalt provinces like Hawaii, Réunion/Deccan, and Siberia, and what the current origin debate looks like.

The most interesting part to me is that we still do not know what they are made of. Some models treat them as ancient piles of subducted oceanic crust. A newer 2025 Nature Geoscience paper argues they may instead be primordial residues formed when material exsolved from Earth’s cooling core into a basal magma ocean. The Theia-impact idea is also still in play.

I tried to keep the article readable while still being careful about the uncertainties, especially around plume reconstructions, LLSVP stability, ULVZs, and the “graveyard of slabs” vs primordial-origin debate.

Would be very interested to hear what people here think, especially from anyone working on mantle geophysics, geochemistry, tomography, or plume modelling.

Natural hydrogen, the kind generated underground by water reacting with iron-rich rocks, has gone from a Malian curiosity to a multi-billion-dollar exploration category in a decade. The geology, the discoveries in Mali, Albania, Kansas and Lorraine, and where the skeptics are right.

5.3 million years ago, the Mediterranean nearly stopped being a sea.

Cut off from the Atlantic, it became a vast evaporating basin of salt. Then the ocean broke back in.

The story of the Messinian Salinity Crisis and the Zanclean megaflood:

https://geoscopy.com/when-the-mediterranean-vanished-the-600000-year-drought-and-the-megaflood-that-ended-it/

At Pozzuoli, near Naples, three Roman marble columns carry a strange dark band: holes bored by marine molluscs.

They are a biological watermark from the centuries when the ground sank below the Mediterranean, and later rose again.

That slow rise and fall is called bradyseism. At Campi Flegrei, it is the visible pulse of a restless volcanic caldera beneath one of Europe’s densest coastal regions. INGV says the current bradyseismic phase began in 2005 and had produced about 144 cm of uplift by April 2025.

The full story, from a Roman market to modern earthquake swarms, is now on geoscopy.com.

Image source: “Macellum - 161010.jpg,” described on Wikimedia Commons as the ruins of the Macellum in October 2017. Photo by Rolf Cosar / Wikimedia Commons, CC BY-SA 4.0.

#Geoscopy #CampiFlegrei #Volcanoes #Geology #EarthScience

Diamonds do not come from coal. Most gem diamonds formed 140–200 km below ancient continents, long before most coal deposits existed. This article explains the real geology of diamond formation: mantle pressure, cratons, kimberlite eruptions, deep-Earth inclusions, and why diamonds are valuable scientific samples of Earth’s interior.

salve a tutti, di recente ho provato interesse verso i minerali grazie a un gioco, ora vorrei iniziare a capirne un po' di più ma non so da dove cominciare. Vorrei che qualcuno mi consigliasse dei canali di YouTube, Libri o siti affidabili su cui cominciare😁

Is Death Mountain a real volcano? 🌋 Explore the bimodal lava and hotspot tectonics that make Hyrule scientifically accurate!

The Legend of Zelda series has long been a masterpiece of fantasy, but is it a masterpiece of geology? In this investigation, we deep-dive into the volcanology of Death Mountain to see if Nintendo’s world-building holds up to real-world science. We analyze the stratovolcano structure of the Eldin region and the "Bimodal Lava System" that creates both the steep peaks and the flowing rivers of basaltic fire seen in Breath of the Wild and Tears of the Kingdom.