The End of the Dinosaurs

THIS ARTICLE in The Conversation gives a minute by minute account of what happened when the asteroid struck. And it tells how the impact led to the death of the dinosaurs and the rise of the mammals. And it is co-written by Mike Benton and Monica Grady, so it is most probably correct! (At least at the time of writing.)

The article is well worth reading. If you are content with a summary, below is Google Gemini's.

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The Immediate Aftermath (T+0 to 5 Minutes)

The asteroid, traveling faster than the speed of sound, hit the Yucatán Peninsula with the force of billions of Hiroshima bombs. If you were within 1,000 miles, you didn't hear the impact; you were vaporized by the thermal radiation before the sound waves could even reach you.

Within minutes, supersonic winds—stronger than any Category 5 hurricane—flattened entire forests. The atmosphere briefly turned into an oven, reaching temperatures of over 200°C (400°F).

The Environmental Collapse (T+1 Hour to 1 Week)

As the crust rebounded from the impact, it formed a crater 30 kilometres deep, launching molten rock into space. This material rained back down as "impact spherules," igniting global wildfires.

Then came the "stinky" phase. The asteroid hit a region rich in sulphur, blasting massive amounts of it into the sky. Combined with the smoke from burning forests and decaying carcasses, the entire planet likely smelled like rotting vegetables and acrid smoke.

The Long Winter

The soot and sulphur created a global shroud, blocking the sun for years. Photosynthesis stopped. The oceans became acidic from nitrogen oxides, and the planet plunged into a deep freeze.

It is a humbling reminder of our planet’s fragility. While this Armageddon wiped out the giants, it left a tiny opening for small, burrowing mammals—our ancestors—to survive. Without that terrible Tuesday, humans might never have had the chance to walk the Earth.

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A Visualisation by Google Gemini

This visualization focuses on the global environmental shift. The sky is no longer blue but choked with thick, black soot and sulphate aerosols. This dense layer blocks the sun, plunging the planet into darkness. The illustration visualizes the "smell" described in the research by depicting the air itself as a visual fog of acid rain, illuminated by the low, dim, hellish glow of widespread global wildfires.

 Volcanic Items of Interest

Various items have come to my notice lately so here they are in no particular order.

• Can volcanic eruptions be forecast, like the weather? The origin of this was THIS ARTICLE and the answer is no but we are getting better at it. What controls volcanism is not easily visible and is not active all the time, unlike weather which is visible and happening constantly. The article covers many aspects of volcanism and has some spectacular photographs.
  
  
• Is the Campi Flegrei in Naples going to erupt? The Campi Flegrei to the west of downtown Naples is used to low grade volcanic activity - earthquake swarms, ground uplift and subsidence - there is a state of emergency but not yet at a level which would trigger mass evacuation. 
  
  
  Earthquakes detected in Campi Flegrei area, Italy from February 15 - 18, 2025. Credit: INGV
  
  
  
  
  
  
• Are Extinct Volcanoes actually Dormant? This comes from THIS ARTICLE. And the evidence for this comes from the "extinct" Methana volcano not far from Athens. It seems that zircon crystals formed throughout the volcanoes history, including during long periods of quiescence. Are they still forming now?
  
  

  

  
  

  The Southern Aegean Volcanic Arc, showing Methana on the left and Santorini at the bottom. (Giorgostr/Wikimedia Commons)
  
  

  
  
• Lots of magma under Tuscany. Tuscany is not known for volcanism but recent seismological studies have indicate that Yellowstone volumes of magma lie 10km under the surface. The academic paper detailing this is HERE. 

 Would You be Scared of this Giant Octopus?

Generally octopuses don't fossilise - they are essentially bags of water. But their beaks are preserved and someone has found some big ones in Cretaceous rocks. And using present day beak sizes and octopus sizes has come to the conclusion that their beaks belonged to an octopus 7 to 19 metres in length!

Cretaceous marine predators (at maximum estimated size) with a scuba diver for scale. Credit: After Ikegami et al. Fig. 4, and Jacobs 2026.

Was the octopus a top predator or was it an extra large food source for a Mosasaurus? It is certainly a very good focus for speculation. Proving anything might be a difficult task.

You can read all about it HERE, based on THIS PAPER

 Some New (but Old) Cambrian Fossils

A correspondent sent me THIS LINK (but I had spotted it my self!). It concerns a recently discovered Lagerstätte in Southern China, called the Huayuan biota.

It has an added importance as being just after the first mass extinction of the Phanerozoic. It contains some old favourites from the Burgess Shale but many new species have been identified.

The find is of importance for many reasons but for me it is important for the wonderful photographs of the beasties. The source academic paper is HERE

non-bilaterian metazoans and deuterostomes from the Huayuan biota

 How and Why Etna is Unusual

A correspondent sent me THIS LINK. It is based on THIS ACADEMIC PAPER. Both links are quite complex and the best summary of them can be provided by Chat GPT.

The GA will visit Etna this June and I will be there! I look forward to hearing what degree of complexity we hear when we are on the slopes!

Here is ChatGPT's summary.

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The article explains how scientists may finally understand the unusual behaviour of Mount Etna, one of the world’s most active and puzzling volcanoes. Although Etna is over 500,000 years old and sits above a subduction zone where tectonic plates collide, its eruptions don’t match typical volcanic models. Instead of producing the kinds of magma expected in such settings, Etna frequently emits alkaline lava more typical of hotspot volcanoes like those in Hawaii—despite no hotspot being present nearby.

To solve this mystery, researchers analysed the chemistry of Etna’s lava over hundreds of thousands of years. They found that its composition has remained remarkably consistent, even as surrounding tectonic conditions changed. This suggests the magma feeding Etna is not newly formed each time, as in most volcanoes, but instead comes from a long-lasting, stable source deep underground.

The study proposes that Etna is fed by pockets of magma trapped about 80 kilometres beneath the Earth’s surface, in a region between the upper mantle and tectonic plates. As the African Plate moves beneath the Eurasian Plate, pressure squeezes this stored magma upward through cracks in the crust, much like water from a sponge.

This mechanism resembles that of so-called “petit-spot” volcanoes—small volcanic features usually found on the ocean floor. However, Etna is vastly larger, making it an unusual and possibly unique example of this process operating on a massive scale.

These findings reshape scientists’ understanding of how volcanoes can form and function, suggesting Etna may not fit into standard categories. The research also has practical importance, helping improve assessments of volcanic hazards in nearby populated areas such as Catania and Messina.

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 The Hunga-Tonga Eruption Hid its Effect

A correspondent sent me THIS LINK. It concerns the 1922 eruption of Hunga-Tonga. This occurred under water and this had the effect of disguising its impact. 

The release of sulphur dioxide (SO₂) is often used to measure the cooling affect of eruptions, but Hunga-Tonga released little SO₂ to the atmosphere. And therefore it was assumed that it had little affect on the climate. The SO₂ released reacted with sea water - I assume sulphuric acid will be somewhere in the reactants.

But the lack of SO₂ in the atmosphere does not mean that the eruption had little climactic affect. 3 billion tons of water vapour went into the atmosphere in 1 hour! And it went very high - into the stratosphere and mesosphere. And there it had complex climatic results.

Read the article to understand some of the complexities!

 Another Huge Eruption Sometime (Geologically) Soon

A correspondent has sent me THIS LINK concerning a volcano which produced the largest eruption of the Holocene. Recent research indicates that the magma chamber is slowly refilling.

When one considers the damage the Holocene eruption did to what was then a sparsely populated area - just south of Japan's southernmost large island, Kyushu - another similarly sized eruption today would be catastrophic. Population densities are rather higher nowadays!

The researchers have found that the magma refilling the magma chamber is new stuff - not the leftovers of the last eruption.

You can get a better idea of the article by reading a summary provided by ChatGPT.

The article describes new research into the Kikai Caldera, a largely submerged volcano Japan responsible for one of the most powerful eruptions in Earth’s recent geological history. Around 7,300 years ago, the volcano produced the Akahoya eruption—the largest known eruption of the Holocene—ejecting vast quantities of material, spreading ash across Japan and beyond, and likely devastating the ancient Jōmon population.

Although the volcano has remained relatively quiet since then, scientists have now discovered that its  magma chamber is slowly refilling. Using advanced seismic techniques, including air-gun pulses and ocean-bottom seismometers, researchers mapped the subsurface structure beneath the caldera. Their results reveal a large magma reservoir that appears to be the same system responsible for the ancient eruption. 

Importantly, the magma currently accumulating is not simply leftover material from the previous eruption. Chemical analysis shows it is newly injected magma, indicating an active replenishment process. This is supported by evidence of a lava dome forming within the caldera over the past several thousand years, suggesting continuous magmatic activity.

The findings provide insight into how giant caldera systems “recharge” over long timescales. Researchers propose a model in which fresh magma is gradually injected into shallow reservoirs, eventually rebuilding the conditions necessary for another large eruption. This mechanism may apply not only to Kikai but also to other major volcanic systems such as Yellowstone and Toba.

While there is no indication of an imminent eruption, the study highlights the importance of monitoring such systems. Given today’s dense populations, even a moderate eruption could have severe consequences. Ultimately, the research aims to improve understanding of volcanic cycles and enhance the ability to detect warning signs well before future catastrophic eruptions occur.