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!



Wednesday, 25 March 2020

DOWN TO EARTH EXTRA - April 2020


DOWN TO EARTH EXTRA - April 2020


You can get the latest edition HERE




At this Moment of Crisis........

At this Moment of Crisis........

Several correspondents have brought the following to my notice.


I think it originated on EPOD, which contains much of interest.

Diamonds Make a Craton Bigger

Baffin Island Kimberlites and the North Atlantic Craton

A correspondent has brought THIS ARTICLE to my attention. Researchers working on kimberlites in southern Baffin Island found that wall rocks brought to the surface by the kimberlites bore evidence that they were part of the North Atlantic Craton. 

This increases the craton's size by 10%. You can find more from HERE, and for the truly dedicated HERE. If you are dedicated and solvent and want to investigate further look HERE

Geologists studying rock samples from Baffin Island find lost fragment of continent. Photo: istock.

Saturday, 21 March 2020

23rd to 29th March 2020


NEXT WEEKS EVENTS


23rd to 29th March 2020


THE FOLLOWING IS AN EXTRACT FROM BRISTOL AND WEST COUNTRY GEOLOGY CALENDARS


MORE DETAILS CAN BE FOUND IN THE BRISTOL AND THE WEST COUNTRY CALENDARS AND ON THE WEB SITES OF THE RELEVANT SOCIETY OR ORGANISATION.


Nothing Happening!

Blame the Virus
and wash your hands!


If you know of any events, let me know.



Saturday, 14 March 2020

16th to 22nd March 2020



NEXT WEEKS EVENTS

16th to 22nd March 2020


THE FOLLOWING IS AN EXTRACT FROM BRISTOL AND WEST COUNTRY GEOLOGY CALENDARS

MORE DETAILS CAN BE FOUND IN THE BRISTOL AND THE WEST COUNTRY CALENDARS AND ON THE WEB SITES OF THE RELEVANT SOCIETY OR ORGANISATION.


MONDAY 16TH

Geostudies Lecture Course - Germany
When
Mon, 16 March, 19:30 – 21:30
Where
Wynstones School, Stroud Road, Whaddon, Gloucester (map)
Description
The Geology of Germany 

 Monday 13th for 10 weeks (not 17th Feb) until 23rd  March. Held at Wynstones School, Stroud Road, Whaddon, Gloucester from 7.30 - 9.30pm on Mondays. 

Like Britain, Germany consists of a number of exotic Terranes, derived from different continents and amalgamated together by plate tectonic collisions. Northern Germany is part of Avalonia, which amalgamated with the East European Craton (Baltica) along the Tornquist suture in the east. A great deal of this area is plastered by thick Quaternary glacial sediments. 

Central Germany is part of Armorica, which collided with the north during the Variscan orogeny. There is, in places, thick Mesozoic unconformable cover. The extreme south is part of the Alpine orogeny, but its effects were transmitted northwards to affect and reactivate older structures. There was extensive volcanic activity during the Tertiary, and some famous asteroid impact sites. 

Cost £75
-----------------------------------------------

Teme Valley G S - Lecture
When
Mon, 16 March, 19:30 – 21:00
Where
Martley Memorial Hall B4197 by Sports Ground (map)
Description
Richard Edwards, The Japanese Island Arc:Perspectives on the Malvern Complex and Warren House Formation  

tuesday 17th


wednesday 18th


thursday 19th

Thornbury Geology Group, 7.30pm, The Chantry, Thornbury
When
Thu, 19 March, 19:00 – 21:30
Description
Thornbury Geology Group, 7.30pm at The Chantry, Thornbury, and every 3rd Thursday in the month.  

friday 20th


saturday 21st

South Wales G A - Lecture and AGM
When
Sat, 21 March, 10:30 – 12:30
Where
Lectures at University of Wales Swansea are held in the department of Geography in the Wallace building. We meet on the landing area inside the main entrance to the building for refreshments with lectures in the main lecture theatre. (map)
Description
AGM and retiring President's Address


sunday 22nd



Friday, 13 March 2020

Nine Years Ago..............Terrifying Tsunami

If You Wonder What a Tsunami Looks Like ....

I came across THIS ARTICLE for the first time today and watched the video. The video was recorded nine years ago in Kesennuma city, on the banks of the Okawa river. 

The tsunami followed an earthquake which damaged a nuclear power station, on the coast north of Tokyo. I was in Hawaii at the time, living in a house on the coast and we had to evacuate because of fears of a tsunami. In Hawaii it was barely measurable, but in Kesennuma it was rather different.

Nothing much happens for the first couple of minutes, then the river starts flowing the wrong way. At 7 minutes the videographer retreats up the stairs of a block of flats. At 9 to 10 minutes debris starts appearing in the river and then it gets worse - a lot worse. The unrelenting power of the water is what struck me. That and the slow realisation that something horrible is happening. At what stage would I have realised that I had to get someplace safe - and what was safe?



Saturday, 7 March 2020

9th to 15th March 2020


NEXT WEEKS EVENTS

9th to 15th March 2020


THE FOLLOWING IS AN EXTRACT FROM BRISTOL AND WEST COUNTRY GEOLOGY CALENDARS

MORE DETAILS CAN BE FOUND IN THE BRISTOL AND THE WEST COUNTRY CALENDARS AND ON THE WEB SITES OF THE RELEVANT SOCIETY OR ORGANISATION.


MONDAY 9th

Geostudies Lecture Course - Germany
When
Mon, 9 March, 19:30 – 21:30
Where
Wynstones School, Stroud Road, Whaddon, Gloucester (map)
Description
The Geology of Germany 

 Monday 13th for 10 weeks (not 17th Feb) until 23rd  March. Held at Wynstones School, Stroud Road, Whaddon, Gloucester from 7.30 - 9.30pm on Mondays. 

Like Britain, Germany consists of a number of exotic Terranes, derived from different continents and amalgamated together by plate tectonic collisions. Northern Germany is part of Avalonia, which amalgamated with the East European Craton (Baltica) along the Tornquist suture in the east. A great deal of this area is plastered by thick Quaternary glacial sediments. 

Central Germany is part of Armorica, which collided with the north during the Variscan orogeny. There is, in places, thick Mesozoic unconformable cover. The extreme south is part of the Alpine orogeny, but its effects were transmitted northwards to affect and reactivate older structures. There was extensive volcanic activity during the Tertiary, and some famous asteroid impact sites. 

Cost £75

tuesday 10th

Cardiff University Lecture - Volcanoes—all you need to know!
When
Tue, 10 March, 18:30 – 20:00
Where
School of Earth and Ocean Sciences will be held in the Wallace Lecture Theatre (0.13), Main Building, Cardiff University, Park Place, Cardiff CF10 3AT (map)
Description
The precious diamondiferous cargo of volcanoes.    Wolfgang Maier, Cardiff

The 2019-2020 monthly Tuesday evening lecture series in the School of Earth and Ocean Sciences will be held in the Wallace Lecture Theatre (0.13), Main Building, Cardiff University, Park Place,
 Cardiff CF10 3AT.  Lectures begin at 18.30.  Booking is not needed.  Should you require the Q&A sessions to be in Welsh, please email edwardsd2@cardiff.ac.uk at least two weeks before the event.

Did you know that the majority of volcanic eruptions – maybe even 90% – occur under water and of which we are largely unaware? There remains a very great deal we don't know about volcanoes, but many exciting new insights are emerging from ongoing research. This lecture series will encompass the diversity of volcanoes, their functioning and products, together with the nature of eruptions and their attendant problems of predictions plus their ensuing past and present environmental and biological impacts.
--------------------------------------

WEGA - Presidential Address
When
Tue, 10 March, 19:30 – 21:00
Where
Earth Sciences Lecture Theatre, Wills Memorial Building, Queens Road, Bristol, BS8 1RJ (map)
Description
Prof Brian Williams: Presidential Address - "Continental Sedimentation" - Details to follow.

wednesday 11th


thursday 12th

Geostudies Lecture - Uniformitarianism
When
Thu, 12 March, 19:30 – 21:30
Where
The Chantry, Thornbury (map)
Description

The Limits of Uniformitarianism.


The science of geology is heavily dependent on the principle of uniformitarianism – the idea  that geological conditions and processes have remained substantially unchanged through geological time, meaning that we can interpret the past on the basis of our understanding of the geological present. But how accurate is this principle? To what extent were conditions and processes different in the past? Are present conditions and processes typical? How well do we understand present processes? And there are also spatial features to consider; A casual examination of a modern sedimentary or volcanic environment reveals rapid and wide-ranging changes in facies over a small area. Our evidence of past environments is largely based on small, possibly unrepresentative, exposures of tiny fractions of those past environments. Are we justified in using evidence from the past to interpret the present and future, such as climate change?  Held at The Chantry, Thornbury, in the Hanover Room.  First meeting 7.30 – 9.30, Thurs 16th  January until April 2nd  (not Thurs 20th Feb or 19th March). Cost £75


Programme

What do we mean by Uniformitarianism? Origin of the term and the historical context in which it arose and developed as a counter to “Old” Catastrophism.

What are the main problems with Uniformitarianism? The rise of “New” Catastrophism in the later part of the 20th century. Problems of direction, cyclicity, punctuation, gradualism in the following fields of geology:

Uniformitarianism and sedimentation. Have conditions changed over geological time? How representative in terms of coverage and completeness is the sedimentary record?

Uniformitarianism and volcanicity, earthquakes, intrusion and landslides

Uniformitarianism and the solar system – external processes affecting earth geology

Uniformitarianism and major environmental change (such as climate and sea level changes)

Uniformitarianism, evolution and mass extinction  

Uniformitarianism and tectonics – was plate tectonics a relatively young development? Is the Wilson (supercontinent) Cycle real?

Geomorphology and Uniformitarianism

Is the present the key to the past? (or in reverse?)


friday 13th

Cheltenham Mineral and Geological Society - Lecture
When
Fri, 13 March, 19:00 – 21:00
Where
Shurdington at The Century Hall (map)
Description
  AGM and Annual Competition

saturday 14th


sunday 15th



Much More About the Seismometer on Mars

Much More About the Seismometer on Mars

Nature has LOTS about the InSight lander on Mars. Read all about it HERE. I did not realise how much the Mars seismometer was recording the Martian weather!

The detail is great and the number of authors is vast including people from Bristol. Much of it is beyond me but it is fascinating stuff.

The seismometer on the surface of Mars

TWO articles from the Landslide blog

TWO articles from the Landslide blog

One of my favourite blogs - "The Landslide Blog" - has two articles which attracted my attention. 

THE FIRST ONE is nothing to do with landslides but has a couple of great photos of the pillow lavas at Wadi Jizzi.


And THE SECOND ONE reports a landslide which derailed a TGV train in Eastern France. The best report is HERE - a translated version of THIS original. The video works in the original version.

Tuesday, 3 March 2020

Saturday, 29 February 2020

3rd to 9th March 2020


NEXT WEEKS EVENTS

2nd to 8th March 2020


THE FOLLOWING IS AN EXTRACT FROM BRISTOL AND WEST COUNTRY GEOLOGY CALENDARS

MORE DETAILS CAN BE FOUND IN THE BRISTOL AND THE WEST COUNTRY CALENDARS AND ON THE WEB SITES OF THE RELEVANT SOCIETY OR ORGANISATION.


MONDAY 3rd

Geostudies Lecture Course - Germany
When
Mon, 3 February, 19:30 – 21:30
Where
Wynstones School, Stroud Road, Whaddon, Gloucester (map)
Description
The Geology of Germany 

 Monday 13th for 10 weeks (not 17th Feb) until 23rd  March. Held at Wynstones School, Stroud Road, Whaddon, Gloucester from 7.30 - 9.30pm on Mondays. 

Like Britain, Germany consists of a number of exotic Terranes, derived from different continents and amalgamated together by plate tectonic collisions. Northern Germany is part of Avalonia, which amalgamated with the East European Craton (Baltica) along the Tornquist suture in the east. A great deal of this area is plastered by thick Quaternary glacial sediments. 

Central Germany is part of Armorica, which collided with the north during the Variscan orogeny. There is, in places, thick Mesozoic unconformable cover. The extreme south is part of the Alpine orogeny, but its effects were transmitted northwards to affect and reactivate older structures. There was extensive volcanic activity during the Tertiary, and some famous asteroid impact sites. 

Cost £75

tuesday 4th


wednesday 5th


thursday 6th

Bath Geol Soc - AGM and Lecture
When
Thu, 6 February, 19:00 – 21:00
Where
16 Queen Square, Bath at the kind invitation of the Bath Royal Literary and Scientfic Institution. (map)
Description
Annual General Meeting, 2019
AGM will start at 7.00 p.m. followed by the lecture at 7.30p.m. Please note that the AGM is for members only. Visitors are welcome to attend the evening's lecture.
Did Ocean Acidification kill off Calcifiers at the end of the Cretaceous?
Prof. Toby Tyrrell, University of Southampton
Ammonites went extinct at the time of the end-Cretaceous asteroid impact, as did more than 90% of species of calcium carbonate-shelled plankton (coccolithophores and foraminifera).Comparable groups not possessing calcium carbonate shells were less severely affected, raising the possibility that ocean acidification, as a side effect of the collision, might have been responsible for the apparent selectivity of the extinctions (calcium carbonate dissolves in even slightly acidic seawater). We investigated whether ocean acidification could have caused the disappearance of the calcifying organisms. I will describe the results of some modelling work we carried out. We simulated various scenarios for how the impact could have produced more acidic seawater (different possible mechanisms from impact to acidity). The results suggest that, although acidification was quite extreme in some scenarios, nevertheless it was probably not the primary reason why so many calcifiers went extinct.
------------------------------------------

Geostudies Lecture - Uniformitarianism
When
Thu, 6 February, 19:30 – 21:30
Where
The Chantry, Thornbury (map)
Description

The Limits of Uniformitarianism.


The science of geology is heavily dependent on the principle of uniformitarianism – the idea  that geological conditions and processes have remained substantially unchanged through geological time, meaning that we can interpret the past on the basis of our understanding of the geological present. But how accurate is this principle? To what extent were conditions and processes different in the past? Are present conditions and processes typical? How well do we understand present processes? And there are also spatial features to consider; A casual examination of a modern sedimentary or volcanic environment reveals rapid and wide-ranging changes in facies over a small area. Our evidence of past environments is largely based on small, possibly unrepresentative, exposures of tiny fractions of those past environments. Are we justified in using evidence from the past to interpret the present and future, such as climate change?  Held at The Chantry, Thornbury, in the Hanover Room.  First meeting 7.30 – 9.30, Thurs 16th  January until April 2nd  (not Thurs 20th Feb or 19th March). Cost £75


Programme

What do we mean by Uniformitarianism? Origin of the term and the historical context in which it arose and developed as a counter to “Old” Catastrophism.

What are the main problems with Uniformitarianism? The rise of “New” Catastrophism in the later part of the 20th century. Problems of direction, cyclicity, punctuation, gradualism in the following fields of geology:

Uniformitarianism and sedimentation. Have conditions changed over geological time? How representative in terms of coverage and completeness is the sedimentary record?

Uniformitarianism and volcanicity, earthquakes, intrusion and landslides

Uniformitarianism and the solar system – external processes affecting earth geology

Uniformitarianism and major environmental change (such as climate and sea level changes)

Uniformitarianism, evolution and mass extinction  

Uniformitarianism and tectonics – was plate tectonics a relatively young development? Is the Wilson (supercontinent) Cycle real?

Geomorphology and Uniformitarianism

Is the present the key to the past? (or in reverse?)


friday 7th


saturday 8th


sunday 9th

OUGS Severnside - AGM and Talks
When
Sun, 9 February, 10:00 – 16:00
Where
: Langstone Village Hall, Old Chepstow Road, Langstone, Newport NP18 2ND, South Wales (map)
Description

Branch Annual General Meeting

Branch AGM followed by a number of short talks from members.

This is a winter social event for our branch members.

Doors open at 10 am, and the AGM itself will start at 11 am. This will include a short presentation describing the various events we held during 2019.

Tea and coffee will be available throughout the day. A buffet lunch will be provided after the AGM, but you are welcome to bring your own packed lunch. Please note that there is no charge for this event.

After lunch we will have a number of short talks from members. We would love to hear from anyone who would like to give a talk about their own geology visits, for example while on holiday. There will be a projector available if you wish to show some photos or provide a short presentation (eg in Powerpoint), although a talk with some rock specimens only would be equally welcome. A talk can be quite brief and should not exceed 15-20 minutes. Please contact Norman (details below) if you would like to share your geological experiences with other members.

The branch library will be available throughout the day and you will be able to borrow geology-related books from its large collection, as well as return any books borrowed previously.

Please let Norman know if you plan to attend (details below) so that we can ensure sufficient food and drink are provided for everyone.