Down to Earth Extra October 2026

The October 2026 edition of Down to Earth Extra has been published, You can download it HERE or you can read it below.

The Handedness of Forams

I learned a new word today - chirality - which is defined as - The property of handedness or asymmetry that is not superimposable on its mirror image.

And I learned this from THIS ARTICLE, sent to me by a correspondent. The article discusses, at some length and with nice illustrations, the phenomena that some species of forams coil in a clockwise or anti-clockwise style. And in any one species the coiling is almost always in one direction or the other. Even more mysteriously the direction of coiling flips to the other direction - and this occurs all over the world and - as far as stratigraphers are concerned - instantaneously!

These fossils from the extinct foram Globorotalia limbata, which lived 11 million to 2 million years ago, illustrate right- and left-handed chirality in shell coiling.

Read the article and you will find that it comes to the conclusion that an advantageous mutation in a small subpopulation of forams occurs, and it has the different coiling direction. It outcompetes its forbears and rapidly spreads across the world. Which sounds very ordinary and not at all miraculous!

The article is very readable, but if you are pressed for time, here isa summary produced by Google Gemini.

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For millions of years, tiny single-celled ocean organisms called foraminifera (forams) have built microscopic, snail-like coiled shells. In many species, nearly the entire population coils its shell in the same direction—either left or right. However, the fossil record reveals a bizarre mystery: every few thousand years, entire global populations of certain foram species suddenly flip their shell direction all at once, only to flip back again millennia later.

For decades, scientists believed environmental factors caused these flips. A popular theory suggested that water temperature dictated coiling direction, with cold ice-age waters favoring left-handed spirals and warmer periods favoring right-handed ones.

However, recent genetic discoveries and comprehensive global studies led by micropaleontologists like Bridget Wade have disproven the simple temperature theory. Researchers found that these shell flips occurred simultaneously across completely different ocean environments, latitudes, and climate zones worldwide, ruling out local environmental changes as the cause.

Instead, scientists now propose that the flipping motion is not a direct adaptation to climate, but rather an accidental evolutionary footprint. Ocean populations often harbor "cryptic species"—microorganisms that look identical under a microscope but are genetically distinct. The new hypothesis suggests that a advantageous mutation arises in a small subpopulation of forams that happens to coil in the opposite direction. As this new genetic group outcompetes others and rapidly spreads across the world's ocean basins, its coiling preference quickly becomes the new global standard.

Ultimately, these mysterious shell flips provide paleobiologists with a rare visual window into how hidden genetic traits and new species can sweep across the planet over geological time.
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 Update on the Oblate Spheroid

A correspondent sent me a link to THIS MAGAZINE ARTICLE. This, in turn, is based on THIS ACADEMIC PAPER. The articles are concerned with the shape of the Earth and the changes which are taking place to it.

When I went to University I was much interested in this and was amused to find that the north to south flowing Mississippi had its source closer to the centre of the Earth than its mouth, so it was flowing uphill!

But the author of the scientific paper has gone rather further into the problem than I did and has found that global warming is the cause - and it is accelerating. Ice has been removed from the poles so the Earths surface has risen. Meanwhile the melt water has moved to lower latitudes and depressed the Earth's surface. The rocky spheroid is becoming less oblate.

But the affect on the Earth's gravity is the opposite. Moving mass (water) to the equator makes the gravitational geoid more oblate!

I found this difficult to comprehend so used Google Gemini to summarise the academic paper - (this is long and very dense) - and it came up with this:-

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Summary of Mapping Global GNSS Vertical Velocities to Solid Earth Figure Change (Kotsakis, 2026)

A 2026 study published in the Journal of Geophysical Research: Solid Earth reveals that the physical shape of our planet is changing at an accelerating pace.

Earth is not a perfect sphere; it bulges slightly at the equator due to its rotation. However, using precise Global Navigation Satellite System (GNSS) tracking stations, geologist Christopher Kotsakis analyzed movement across Earth’s crust between 1997 and 2015. The findings show a clear global pattern: the polar landmasses are rising (uplift), while regions near the equator are sinking (subsidence). This ongoing movement means the solid surface of the Earth is gradually becoming slightly rounder and less flattened at the poles.

Between 1997 and 2000, polar regions were rising at a rate of roughly 0.5 millimeters per year. By 2015, that speed had doubled to about 1 millimeter per year, demonstrating an overall acceleration in surface deformation.

The primary driver behind this shift is the redistribution of water mass across the planet, largely fueled by climate change. As ice sheets and glaciers in places like Greenland and Antarctica melt, the immense weight pressing down on the polar crust lightens. Consequently, the rocky ground underneath springs back up (elastic rebound).

At the same time, all that melted ice flows into the global ocean network, adding heavy water weight to lower latitudes and causing the seafloor and equatorial regions to sink under the new load.

Interestingly, this creates a subtle paradox between Earth's physical ground and its gravitational field. While the rocky crust itself is becoming slightly rounder, the mass of water collecting around lower latitudes causes the planet's gravitational field to remain flattened. Overall, the study highlights how dynamic Earth's solid surface is in response to shifting climate and ocean dynamics.

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 Geol Soc Nightschool

Want to find all about dinosaurs? Then go to THIS WEBSITE and let Mike Benton tell you all he knows - or at least quite a lot!

This a new venture by the Geol Soc. It will be live at 17:30 on the 21st October and will last for about 2 hours. It will not be recorded so you need to be online.

If you go to the link above you will find not only Mike Benton but lots of other educators teaching lots of geological topics. This should fill up your calendar until almost Christmas!

Deep Down, Its Complicated

A correspondent forwarded THIS LINK which is based on THIS JOURNAL ARTICLE. It concerns seismic waves created by the French nuclear tests in the South Pacific between 1977 and 1995. The records used were recorded in Kazakhstan. 

One would think that seismic waves created in one spot and recorded in another would be the same over time. After all they are travelling through the same stuff!

But no! Using waves which reflected inside the (liquid) outer core, the travel times varied over time. This leads to the conclusion that the outer core is dynamically changing. 

This is important as the outer core is responsible for generating the Earths magnetic field.

Both articles are quite complex but Google Gemini is able to give a fairly simple version of the papers. Here it is:-

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A research study published in the Journal of Geophysical Research: Solid Earth (doi: 10.1029/2026JB033798) reveals that the deep interior of our planet is far more dynamic than long believed, challenging the traditional view that Earth’s outer core is a uniform, static ocean of liquid metal.

Led by Virginia Tech geophysicist Ying Zhou, researchers analyzed seismic data recorded during underground nuclear tests conducted by France at Moruroa Atoll in French Polynesia between 1977 and 1995. Subterranean nuclear explosions provide a unique advantage over natural earthquakes for geoscientists: because test detonations occurred at precisely known, nearly identical locations, they generated consistent seismic wave pathways through Earth’s deep interior. By analyzing 112 pairs of historic explosions, the team tracked microscopic variations in how long it took specific waves (known as PKrKP waves, which reflect within the outer core) to travel through the planet over several decades.

The findings indicate that the travel times of these deep-reaching waves changed measurably between test events. This shift points to a massive, previously unrecognized structure drifting within the molten outer core beneath the southern Pacific Ocean. Estimated to stretch roughly 700 kilometers across and 100 kilometers thick, this feature may consist of solid material suspended inside the churning liquid metal or localized density variations drifting as the core circulates.

These rapid, decade-scale shifts are significant because movement within the liquid outer core powers the geodynamo—the planet-wide engine responsible for generating Earth’s protective magnetic field. Understanding that massive structures can shift deep underground over just a few decades offers scientists a dynamic new model for how Earth’s core behaves, while demonstrating how legacy Cold War-era nuclear records can serve as unexpected time capsules for planetary science.

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 Down to Earth Extra September 2026

The September 2026 edition of Down to Earth Extra has been published. You can download it HERE or you can read it below.

 Down to Earth Extra August 2026

The august 2026 edition of Down to Earth Extra has been published. You can down load it HERE or you can read it below.