Manchester Sink Hole

Reported in the news last Friday, a large hole opened up in the road in Mancunian Way, Manchester last Friday (14th August 2015).



www.bbc.co.uk/news/uk-england-manchester-33929490

The hole is stated to be up to 12m deep and 4.5 m wide, although it has grown in size over the weekend. The hole opened up following a period of heavy rain.  Collapse of a sewer pipe has been quoted as a possible cause although the Highways Agency, Manchester City Council and utility companies are still investigating.  Repairs could take over 2 weeks to complete because there are stability concerns about the area around the hole, which is making it difficult to safely investigate the feature. 

Sewer or culvert collapses are one cause of sink holes.  The collapse of the pipe / culvert allows soil over and around the structure undermining the road surface which eventually collapses.  Over time the hole can progressively enlarge until the pipe / culvert is repaired and the hole backfilled. 

If the cause is a broken sewer / culvert then following repairs it is likely that the hole will be filled up with concrete, as was done for a sink hole which opened up under the corner of a house in Walters Ash near High Wycombe in February 2014.  After the Walters Ash hole opened up a small car fell into it. which apparently was left there and the concrete poured round it.  In this case a natural cause formed the hole (solution feature in the top of the Chalk).

Mind you both are tiddlers compared to the massive hole that opened up in Guatemala City in May 2010 which was around 100 m deep and 20 m wide!  Another massive sink hole opened up in Tampa Florida in 2013 which killed an occupant of a house below which the hole opened up. 

Seminar 16 - Glacial Geology (Part 1)

The blog has been live for a week now and the first of the seminar recordings has been available for much of that time.  Any comments on the blog and the recordings as they are posted will be welcomed with the aim of improving standards, both in terms of content of the presentations and the quality of presenting delivered.

As the post title hints, Seminar 16 is one of two planned on the subject of Glacial Geology.  Part 1 covers an introduction to Ice Ages and their causes before focusing on the Quaternary Glaciation and then glacial periods which geologists know have occurred at intervals during geological history dating all the way back to the Precambrian.  I then look at glaciers and glacial processes.  Part 2 (the presentation for which is still being worked on) will look at glacial deposits, primarily those found in the UK.

As usual the presentation is based on my university notes and published material including on-line sources.  A key reference source was the Geological Society's publication "The Geology of England and Wales" edited by Patrick Brenchley and Peter Rawson.  The current version is the 2nd Edition, published in 2006.  Images used in the presentation are credited as noted on the slide in question.

Starting at the Beginning (or not)

Ah, when checking back through the recordings for past presentations, I find I have not got a recording for Seminar 1 - Doh!!  The earliest one I have is for Seminar 2, but in MP4 format no wmv, so the file is to big to publish.

In the way of background, I did not start recording the Seminars until No. 15 in 2014, although numbers 2 to 5 have been recorded when the seminars have been given again to different audiences, in this case Graduates in the 2014 / 2015 intakes. 

The presentations have been little altered for "second time around" so until I get round to delivering and recording Seminars 1,  6 to 14 there will be a bit of a gap in sequence.

First time round the presentations were delivered under the strapline of "How the Earth Was Made - An Introduction to Geology for All".  I cannot claim the credit for coming up with this, which was down to a colleague (thanks Gill) but it works so I still use it. 

Having a look at the poster slide I produced for the first seminar I see the date was 17th April 2012, so I started this process over 3 years ago.  Seminar 1 was delivered again to a an audience of Graduates on 9th October 2014, so only 18 months later....

Today I have delivered Seminar 17 on the Dinosaurs which seems to have been well received.  I also kept to time (just about) in only marginally exceeding the 1 hour allowed for the talk.  When I get the file prepared it will be posted.

To start the ball rolling (and until I can find a way to compress MP4 files to get them below 100 MB), the recording for Seminar 15 on Earthquakes is attached.  It even includes a short section of video feed to demonstrate primary and secondary seismic waves.
 

Enjoy.

Mark.

Not another blog!

After being a viewer of selected blogs for the last few years I have decided to take the plunge and set up my own blog with the aim of making accessible to a wider audience a series of geology talks (seminars) I have given to audiences within the company I work for. 

 

As a graduate in Geology from the University of Oxford and a Chartered Geologist this series of lunch-time talks on geological topics has been produced to inform or interest an audience made up largely of civil / structural engineers, but anyone with an interest in geology will have no trouble in following the subject matter.  The talks certainly do not require a geological background or any past experience of geology. 

 

The seminars are based around a set of Microsoft PowerPoint presentation slides and the talks have been recorded using Microsoft Lync.  Over time I will add seminar recordings as and when they are produced so don't expect the blog to be updated on a daily basis!  Equally the seminars will not be posted in order of sequence, generally as and when a recording file becomes available.

 

Viewers should note that I am not a professional presenter and I am certainly not being paid to produce these seminars so I hope that if the quality of the recordings falls below par I will be forgiven.  The list of seminars I have produced to date (August 2015) is as follows: 

1. An Introduction to Geology for All.  
2. Geology and Time. 
3. Sedimentary Rocks. 
4. Igneous Rocks. 
5. Volcanoes. 
6. Metamorphic Rocks. 
7. Palaeontology (Fossils) (1) – Introduction to Palaeontology.  
8. Palaeontology (Fossils) (2) – Trilobites. 
9. Palaeontology (Fossils) (3) – Molluscs Part 1. 
10. Geological Structures. 
11. Palaeontology (Fossils) (4) – Molluscs Part 2. 
12. Geological Maps. 
13. Palaeontology (Fossils) (5) – Graptolites. 
14. Plate Tectonics. 
15. Earthquakes. 
16. Glacial Geology (Part 1).

Hopefully that should whet the appetite. 

In terms of material source, the presentations have largely been put together using my university

notes combined with on-line material and published works.  Sources will be referenced as required. 

All images used have been acknowledged, where source is known.

Mark.