Land Level Rises - What is the Cause?

A correspondent sent me THIS LINK. It is based on THIS ACADEMIC PAPER. The reason for the papers is the measured rise in land level in South Africa. The rise is not much - 6mm in the period 2012 to 2021. The rise could be measured because of the extensive GPS network in the country.

But what is the cause of the rise? For several years the reason was thought to be the mantle plume beneath the region. But the research described in the papers suggests that the real cause is drought! If you think of the soil as a sponge, taking the water out will cause the sponge to expand. Therefore land level rises.

All very interesting but the research suggests that the GPS system can be used as a means of measuring the severity of drought and planning to mitigate the consequences of predicted water shortages.

 An Unsurprising Discovery

A correspondent sent me THIS LINK. It is based on this ACADEMIC PAPER in Nature. The Nature paper concentrates on the history of the breakup of the ice shelves which fringed the British-Irish Ice Sheet (BIIS). The BBC article concentrates on the scratches the icebergs breaking off from the ice shelves left on the sea floor. 

It has always seemed to me that such scratches would inevitably be found some time; - there was an ice sheet; icebergs would be spawned; icebergs would leave sea bed scratches. So it is nice that there presence has been proved.

The paper in Nature uses the scratches to detail how the BIIS retreated and uses the data to model how the Antarctic Ice Sheet might break up.

Icebergs calved in the Witch Ground Basin would drift eastwards towards the Norwegian Channel before being routed northwards towards the continental shelf edge. The isostatically-corrected bathymetry of the central North Sea at 20 ka is from Bradley et al. 60, with bathymetric depth contours displayed every 25 m. Colored stippled lines represent the modeled ice margins of the last British-Irish (BIIS) and Fennoscandian (FIS) ice sheets at timeslices between 20 ka and 18 ka from Clark et al. 40. NCIS—Norwegian Channel Ice Stream.

 Petrification: Fossils & the Revelation of Deep Time

News has come to me of this free exhibition at the Bath Royal Literary & Scientific Institution and it sounds very interesting. It runs until Saturday 11th October.

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What makes fossils so special? Fossils provide the evidence that there was life on earth before humans and this year Bath Royal Literary and Scientific Institution is displaying a selection of the best from the depths of our amazing collections. Petrification is BRLSI’s latest exhibition and in it you will discover fossils from across 505 million years of the history of life. The BRLSI’s earliest fossil is a trilobite from the Cambrian geological period!

Our exhibition begins by encouraging visitors to follow a Deep Timeline, starting out at a meteorite which represents the formation of both the Solar System and planet Earth 4.567 billion years ago!

Crossing the gallery, the timeline leads visitors through the Precambrian era, when only single-celled life existed, all the way through to the Cambrian Explosion of life. The final ninth of the timeline, which is depicted in a scale running up the wall of the gallery, is where all the palaeontologic action happens.

This is where visitors get to experience trilobites and corals, dinosaurs, marine reptiles, mammoths and cave bears! Colour-coded exhibits in the room correspond to the timeline so that visitors always know where in Deep Time they are.

And that’s really just the start! Learn more about some of the amazing things you can hope to find in Petrification, and our accompanying activities for families and children here.

Come to BRLSI and discover the beautiful complexity of prehistoric life and Bath’s influential role in the birth of palaeontology.

Please note our opening hours are Monday to Saturday, 10am to 4pm (closed on Sundays).

We are open Good Friday (18 April) and Easter Monday (21 April).

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 Filling the Mediterranean - a Megaflood of Articles

It has probably not escaped your notice that there has been a plethora of articles in the last few days about the flooding of the Mediterranean when the barrier at Gibraltar was breached. It has been on YouTube HERE, HERE, HERE, HERE, HERE and many more; on various web sites such as HERE and HERE. It has also featured on my FAVOURITE PODCAST. I could go on but you get the picture.

All these eruptions of interest, except the podcast, are due to THIS PAPER which discusses, in some depth, the geomorphological results of the refilling of the Mediterranean, especially the part east of Sicily.

I first became aware of the drying of the Mediterranean when I read about the difficulty the builders of the Aswan Dam had in finding hard rock for the dams foundations. They discovered that there was a deep canyon along the Nile caused by the river eroding downwards to a base level far below the present Mediterranean. The canyon had been filled in with sediments deposited when the base level rose back to its present position. 

The interest in the refilling shows the publics interest in exciting stories and the stories don't get any more exciting than the Gibraltar waterfall!

 

 The Case of the Missing Niobium

A correspondent sent me THIS LINK. As he said, it is very interesting but I admit I found it rather difficult to understand. So, being a bit of a tech wizard, I decided to get some help from my pal Gemini, and asked it to summarise the article in less than 200 words. I reckon it did a good job and I understand it much more. Read and see if you agree.

I wish Gemini and its like had been around when I was at University!

Below is Gemini's summary.

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A new study challenges the long-held assumption that Earth's early crust was significantly different from today's continental crust. Researchers used mathematical models to simulate the formation of Earth's first protocrust during the Hadean eon (4 to 4.5 billion years ago). Their findings suggest that this early crust surprisingly exhibited a similar chemical fingerprint to modern continental crust, specifically a lack of the element niobium.

This niobium depletion was previously thought to be a hallmark of subduction zones, implying the existence of tectonic plates early on. However, the model indicates that niobium would have been drawn to Earth's core during its formation, explaining its absence in the early crust without the need for plate tectonics. This suggests that continental crust formation may have been an original part of Earth's layering process. The study offers a new perspective on Earth's early geological evolution and potentially the formation of continents on other planets.

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 Somerset Geology Group - 2025 Update

The Somerset Geology Group has published its update for spring 2025 and it contains much of interest. You can download it HERE and you can read it in this blog below.

They have a new website which you can see at https://somersetgeology.org.uk.

And they have update Hugh Prudden's Bibliography of Somerset Geology. You can download the updated version HERE, and compare it to the old version which you can get HERE.

As a result of the update I have changed a couple of web pages - https://westcountrygeology.com/somerset-papers/ and 

https://bristolgeology.com/somerset-papers/. Because incorporating pdf files into my web pages is not easy I have converted them to Word files but this entails a small loss of formatting.

 CARDIFF UNIVERSITY GEOLOGY FIELD COURSE FOR ADULTS

Nick Chidlaw has contacted me about a course he is running this summer in association with Cardiff University Lifelong Learning. The details are given below.

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I am offering to run a field course for 4 consecutive days in June this year.  This is organised by Lifelong Learning at Cardiff University and examines the geology at key locations in and between the Malvern Hills and the Cotswolds.  

Enrolees do not need to be students studying at Cardiff University - it is intended and available for the adult public.

Please see attachment for details, and for contacting Lifelong Learning. The course fee is £196.00, concessionary fee £157.00 .

The Attachment is HERE.

No prior knowledge of geology or the study area is assumed.

The course carries assessment, which is completed after the course is run and returned to the tutor within 14 days.  It is designed to be easily completed (ticking boxes, filling in words only) and in practise course attendees find the process enjoyable and useful for consolidating what they've learned. There is only a 'pass' or 'fail' grading: a pass is 40%.

Most course attendees score very highly - usually above 80%, with some getting scores in the high 90's.

Any queries you have about the course content, do contact me; enrolling and course payment is done through Lifelong Learning at Cardiff (contact details given in attached doc).

I hope you find this proposal of interest, that you're available and that you decide to enrol.

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You can read the attachment below. Nick is referring to the central item.