Thursday 30 April 2020

Down to Earth Extra - May 2020

Down to Earth Extra - May 2020

The latest edition was sent to me in 2 parts. Get Part 1 HERE and Part 2 HERE.

I have combined the parts and you can get the complete version HERE.

Or you can read it below.

Tuesday 28 April 2020

Geologic Map of the Moon

Geologic Map of the Moon

A frequent correspondent has sent me THIS LINK. It introduces a newly released Geologic Map of the Moon produced by NASA. 

NASA introduces it HERE. The download is a little slow but you can get it, in all its glory, HERE. Also, below.

Monday 20 April 2020

Dinosaurs on Selsey Common!

Dinosaurs on Selsey Common!

Another correspondent has brought this interesting sight near Stroud to my attention. The pictures speak for themselves.

This post has created some controversy. Yet another correspondent writes:-
I love getting the updates and I like seeing art and science promoted but I have to say I am incensed by the latest offering 

Placing stones on grass seems set to become a craze and publicising it without a severe rebuke is unacceptable and can only fuel this act of utter thoughtless vandalism and conservation evil.

Environmental gems such as fescue and bent grasslands have taken millennia to establish and one thoughtless  (mindless) act will destroy the delicate grasses forever - eliminating the wild flowers which many butterflies depend upon as well as other less obvious problems. Tourists will exacerbate the problem as their footprints compact the soil making it impossible for these delicate grasses to survive. Not to mention the animals and plants living on or under the stones which will also lose their homes or die. 

I have seen stones placed onto heathland and downland before but never on this scale.  Please please let try to nip this illegal and damaging stupidity asap.

At the very least make it clear anyone making such art has a duty to restore nature, after a few minutes  - ensuring the stones are replaced EXACTLY where they were found and right way up Like the sand beach artists washed by the tide

I am sorry I am not a kill joy but the stupidity of our species knows no bounds. 
I have received a reply from the original correspondent.
I’m always amazed at the comments made by the narrower minded ‘conservationists’ who are only concerned with their own interest and point of view.   Totally ignoring the impact that all animals make on the planet - including homo sapiens!    Their comments give much cause for amusement though so they are not all bad...

Bearing in mind that this is in an old (human made) quarry where the locals for generations have created pictures and written their names in stone I can’t see the problem.     Especially as the quarry is surrounded by plenty of ‘natural’ grassland.

Keep up your good work of informing us all of events.
This blog is not the place for continuing this controversy, so it is now closed.

Saturday 18 April 2020

Iceland Volcanoes - all the information

Information on Iceland's Volcanoes

A correspondent has sent me THIS LINK. It is a catalogue of all of Iceland's volcanoes and the amount of information is astonishing. Well worth a browse!

Thursday 16 April 2020

Dinosaurs Overhead Underground

Dinosaurs Overhead Underground

500 metres below the Causse Méjean karst plateau, in the Castelbouc cave on the River Tarn, a scientist on a caving trip spotted dinosaur footprints on the roof of a rather large cavity. 

A scientist on a caving trip happened to spot dinosaur tracks in the ceiling of Castelbouc Cave in France. Credit: Jean-David Moreau et al./J. Vertebr. Paleontol.
The result is THIS ARTICLE based on THIS JOURNAL ARTICLE (you need to pay to see more than the abstract, unfortunately).

It seems that access is difficult and not for the likes of me, but it is reported that the tracks were made by some very large beastie, presumed to be titanosauriforms. Indeed the authors erect the new ichnogenus and ichnospecies Occitanopodus gandi, igen. et isp. nov. I suppose all the abbreviations mean something to the people professionally concerned with the matter.

Tuesday 14 April 2020

A (Virtual) Geological Trip to the Karoo

A (Virtual) Geological Trip to the Karoo

Yet another correspondent forwarded me THIS LINK to a very interesting article mostly about Karoo dolerites and included three of her own photos. 

The Karoo is the "Fly Over" part of South Africa, between Cape Town and Johannesburg. Much of it is flat and boring but there are occasional spectacular, flat topped mountains and these are the result of intrusions of dolerite sills and dykes.

A particular emphasis of the article is the hope that dolerite intrusion has reduced the attractiveness of the area for companies looking to exploit shale gas. 

But my correspondents photos are the best for appreciating the dolerites of the Karoo.

Thaba Thabo, near Fouriesburg in the Freestate, near the Lesotho border.  A vertical dyke in sandstones has weathered out more than the baked margins - the hornfels.  Note that this is close to the contact with the overlying Drakensberg lavas, so it may have been a feeder dyke.
A thick dolerite body, which is climbing up section but nearer to a sill than a dyke., capping a hill near Harrismith in the North-east Freestate.

Top is a sill and another intrusion which not quite a dyke or a sill, which appears to have displaced the sandstone layers and bent them downwards, at the right.  There is a small dyklet feeding in to it along the fracture. On the road from Beaufort West to Calvinia in the Northern Cape.

Ordnance Survey - Things to do at home

Ordnance Survey - Things to do at Home

Another correspondent suggested this might be useful.

Thank goodness the step up challenge is over!

Severn Bore

Drone on the Severn Bore

A correspondent directed me to watch this footage of the Severn Bore as there were no surfers present! It was filmed from a drone and you can see it HERE or below. The reason there are no surfers is because of the Coronavirus lockdown. I suppose that is a positive.

Saturday 11 April 2020

Oxford Geoheritage Virtual Conference

Oxford Geoheritage Virtual Conference

I know a lot of you are interested in our geoheritage in one form or another. Because of COVID-19 many conferences on the subject have been cancelled or postponed. So, of course, the answer is to have a virtual conference. This has many disadvantages - you cannot have face to face conversation or travel to exotic locations - but at least the conference can take place and you do not need to get out of bed! (or your preferred place for being online.)

You can read all about one being organised by Oxford Museum of Natural History HERE. If you want to submit a paper the abstract has to be in by 29th April. If you want to attend (virtually) you have to register by 18th May. And the conference starts on 25th May.

This sounds very good for the person with a casual interest - no cost for travel, accommodation, food etc.

Monday 6 April 2020

Coronavirus - Seismologists Notice Something

Coronavirus - Seismologists Notice Something

A correspondent brought THIS and THIS to my attention. They both record that lockdowns imposed as a result of the Coronavirus outbreak have reduced the amount of seismic noise which reduces the sensitivity of seismometers located in urban areas. Obviously not earth shaking news but still very interesting!

Saturday 4 April 2020

Footnotes in a Time of Virus

Footnotes in a Time of Virus

The Wessex Group of the OUGS is one of the most active and this continues in the present lockdown. 

For all of you looking for something geological to do they have produced a special edition of Footnotes, their rather well produced Newsletter.

You can get it HERE, or read it below.

Wednesday 1 April 2020

Slow Earthquakes

Slow Earthquakes

I had heard of such things but did not know much about them, so I was interested in reading THIS ARTICLE. After reading the article I realise that calling them earthquakes is dramatising something with no drama at all! 

An earthquake releases a lot of energy very quickly. A "slow earthquake" can release the same amount of energy but over a period of months or even longer. Is a slow earthquake somewhere between rocks moving steadily and moving in earthquakes? Can a slow earthquake trigger a catastrophic one nearby?

What makes an area have slow earthquakes rather than a catastrophic one? The author (from Cardiff) has been working in New Zealand where the Hikurangi subduction zone off the south eastern coast of the North Island demonstrates slow earth earthquakes in a conveniently shallow and accessible place. 

He hypothesises that the very variable seafloor rocks and sediments may have something to do with it. Also the presence of seamounts, pressurised fluids decreasing frictional resistance, seafloor roughness and other things might be involved. Obviously we are in a phase of looking for a cause.

Out and About - on Mars

Out and About - on Mars

A correspondent emailed me THIS LINK and it is wonderful. I make a lot of panoramas with my photos but they pale in comparison (on at least two levels - quality and location!) with this one. Look on it and wonder!