John Snow's Cholera Map.

John Snow was a nineteenth century London doctor, who is widely credited with the discovery of the transmission mechanism of Cholera, a severe and often fatal infection of the small intestine caused by the bacterium Vibrio cholerae. In Snow's time our understanding of microbiology was in its infancy, and Snow may not even have heard of the concepts of germs or bacteria, but he did, nevertheless, come up with the theory that Cholera was spread by a poison that was formed within the body of its victims and which then went on to infect other people. Prior to this the assumption had been that Cholera, like other diseases, was spread by 'bad air'.

Portrait of John Snow. National Library of Medicine.

A year after he published this theory a major Cholera epidemic hit London (sadly a common occurrence in the mid-nineteenth century), giving him the opportunity to put his theory to the test. Snow set about mapping the course of the outbreak, noting where people were infected, and where they got their water from (most people in London did not have domestic water supplies at the time, instead being dependent on public stand-pipes). Using this method Snow discovered that almost all of the victims got their water from a single company, the Southwark and Vauxhall Waterworks Company, who obtained there water from the lower reaches of the Thames, i.e. water that had passed through the city and had the opportunity to become infected. In particular Snow found that one pump, on the corner of Broad Street (since renamed Broadwick Street) and Cambridge Street, was at the center of a cluster of infections that had killed over 500 people in 10 days. Snows findings led to the removal of the handle of the Broad Street Pump, which reputedly still resides in a local pub, The John Snow, and to a major reworking of London's water supply.

John Snow's map was based upon the geological maps of Robert Mylne, and was eventually presented to the Geological Society of London by the pioneering hydrogeologist William Whitaker. It is featured in the June 2012 edition of Geoscientist, the magazine of the Society and copies if the map are available for purchase from the Society, priced £25 + VAT and postage for fellows of the Society and £35 + VAT and postage for non-fellows.

John Snow's Map of London.

See also Mapping Africa's groundwater resources and United States Geological Survey releases a geological map of Io.

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Geological Society of London to host a public meeting on Shale Gas extraction.

Shale Gas is naturally occurring gas trapped within shale (sine grained sedimentary rocks, typically mostly clay) formations. This is harder, and more expensive, to extract than other forms of Natural Gas, but is becoming increasingly attractive to hydrocarbons companies as other sources of gas start to dwindle. Typically Shale Gas is extracted using a technique called Hydraulic Fracturing, or Fracking, which involves blasting water, sand and chemicals into shale beds at high pressure in order to fracture the rocks and release the Gas.

Diagram of a Hydraulic Fractioning operation. geology.com

Shale Gas extraction has expanded rapidly in the US in recent years, and is expected to produce half of all the Natural Gas extracted in the US by the year 2020. It has, however, proved to be extremely unpopular with environmental groups, both within the US and in other countries, to the extent that some countries have altogether banned the practice.

There are four principle objections to Shale Gas extraction. One of these is that Natural Gas is a hydrocarbon, and potentially contributes to Global Warming; this is no different to the objections to the extraction of Natural Gas from other sources, excepting that extracting the gas from shale significantly increases the available reserves. The remaining objections are with the Fracking process, and are therefore specific to Shale Gas extraction.

Firstly the process causes Earthquakes. This is not in dispute, though the scale of the quakes the process can cause is hotly disputed between environmentalists and the industry. An Earthquake is shaking in the ground, regardless of the source; a large truck driving past your house does not merely feel like its causing an Earthquake, it actually is. Blasting water, sand and chemicals into buried sediments with the intention of fracturing the rock will certainly cause Earthquakes (if it did not it would not work). 

Industry experts do not expect the process to produce quakes larger than a magnitude of 1 on the Richter Scale, but areas where Fracking occurs in the US have seen an unexpected increase in quake activity, with some quakes exceeding magnitude 3. Since the Richter Scale is logarithmic this represents quakes more than a hundred times as large as predicted, leading the industry to claim that any connection is impossible, but not able to provide an alternative explanation (in some cases this is further confused by the employment of lobbyists who do not understand the process and who will offer blanket denials for even the most minor of quakes). In the UK the process has been linked to two small quakes near an experimental Fracking operation at Preese Hall in Lancashire, leading to a halt in operations.

Secondly the process has been linked to the contamination of aquifers; the chemicals used in the process are potentially toxic, and people do not like the idea of these getting into drinking water. Again industry models do not predict that the chemicals could escape the targeted deposits into other strata, but the chemicals have been found in the aquifers. A report into the industry in the US was unable to confidently say that the process had caused the contamination, but only because the chemical containment at the surface was so poor that contamination from ground-level sources could not be ruled out.

Thirdly the process uses large amounts of water, a matter of some concern in more arid parts of the US, where the industry is suspected of the using water that could be used for other purposes, notably agriculture.

In the UK a report commissioned by the Department of Energy and Climate Change was published last month (April 2012), recommending that the process should be allowed in the UK, subject to very tight environmental regulation, bringing the process back into the public eye.

On 18 June 2012 the Geological Society of London is hosting a public meeting to discuss Shale Gas Extraction, at Burlington House in London. The meeting will not seek to address whether the process should be used in the UK, but will seek to explain the geological science behind the process, and whether it can be undertaken safely. The meeting is not aimed at geologists, but rather at elected representatives (politicians), local and central government officials, regulators, NGOs, representatives of other industries likely to be affected (such as water companies) and other interested parties.

The location of Burlington House.

The meeting will be addressed by Mike Stephenson of the British Geological Survey, who will discuss the nature and distribution of shale gas reserves in the UK, Richard Davies, of Durham University, who will discuss the Hydraulic Fractionation process, Peter Styles of Keele University (one of the authors of the Department of Energy and Climate Change report), who will discuss the safety of the process with regard to induced seismicity (i.e. causing Earthquakes). The meeting will also discuss the potential effects on groundwater, and the uses of water in the industry, as well as the regulatory framework for the industry in the UK, though the speakers on these subjects are yet to be confirmed.

The layout of Burlington House.

See also Report recommends Fracking should be allowed to continue in the UK, Protests against hydraulic fractionation across Bulgaria, Oklahoma shaken by Earthquake on Christmas Day, Earthquake in Texas attributed to fracking and Fracking linked to earthquakes in Lancashire, northeast England.

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Geology Today to hold online Minerals and Fossils Event.

Geology Today is published by Wiley Blackwell on behalf of the Geological Society of London (the UK's main professional body for geologists) and the Geologists' Association (the UK's main non-professional geological organization). It contains articles about current developments in the geological sciences written by experts for the general reader, as well as news about the geological community, and regular features on fossils, minerals etc.

From 5-16 March 2012 Geology Today is hosting an online Minerals and Fossils Explained event, which will enable students & members of the public to participate in a geosciences conference, without having to travel (scientific conferences within easy distance are a once in a lifetime event and not to be missed; the Palaeontological Association held one a mile from where I was living two years ago - and I spent the entire two weeks in bed with Swine Flu). The event will feature online discussions on common & interesting fossil groups hosted by experts in the field.

5 March will see an opening session, followed by online discussions on Taphonomy (the study of fossilization processes) and Fossil Lagerstätten (exceptionally well preserved and plentiful fossil deposits), followed by discussions on three particularly famous fossil assemblages; the Ediacaran Biota (well preserved, but enigmatic Precambrian Fossils that may, or may not, represent the earliest multicellular animals in the fossil record), the Burgess Shale (exceptionally well preserved Early Cambrian fossils from British Columbia, with many soft bodied animals) and the Lady Burn Starfish Beds, a site in Southeast Scotland noted for exceptionally well preserved Ordovician invertebrates, particularly trilobites and echinoderms. On the mineral side there will be discussions on alpha-quartz (or to the layman, quartz), Opel, Alkali Feldspar and Plagioclase Feldspar.

Echinoderm from the Lady Burn Starfish Beds. Huntarian Museum and Art Gallery.

7 March will see discussions on notable groups of Palaeozoic Invertebrates; Trilobites, Graptolites, Brachiopods, Crinoids and Eurypterids (water scorpions), and on the mineral side Olivine Group minerals, Amphiboles, Micas, Garnets and Kyanite.

Olivine, (Mg,Fe)₂SiO₄. School of Ocean and Earth Science, University of Southampton.

9 March will see discussions on prominent groups of Mesozoic Invertebrates; Belemnites, Nautiloids, Bivalves, Rudists (a group of reef-forming bivalves that went extinct at the end of the Cretaceous) and Sea Urchins. On the mineral side there will be discussions on Calcite, Dolomite, Baryite, Gypsum and Fluorite.

A preserved Late Cretaceous Rudist Bivalve Reef, near Isona in Spain. Paul Harnik, National Evolutionary Synthesis Center.

12 March will see discussions on Cenozoic Invertebrates, namely; Gastropods, Barnacles, Bryozoans, Benthic Forminifera and the Palaeontology of Amber. On the mineral side there will be discussions on Hematite, Galena, Sphalerite, Pyrite, Azurite and Malachite.

Malachite with Azurite crystals. Muséum national d'Histoire naturelle.

14 March will see discussions on Vertebrate groups, notably Anaspid (Jawless) Fish, Ichthyosaurs, Therapod Dinosaurs, Azhdarchid pterosaurs and Saber-toothed Cats. The mineral side will see discussions on naturally occurring pure elements, Graphite (carbon), Copper, Silver, Sulphur and Gold.

The event will close on 16 March.

The experts hosting the discussions will be:

Peter Doyle, palaeontologist and geologist, of University College London and the Department of Earth and Environmental Sciences at the University of Greenwich, the Editor in Chief of Geology Today and Lethaia, and a prolific author in the geosciences field.

Duncan Pirrie, mineralogist and geologist, of the Cambourne School of Mines at the University of Exeter, and deputy editor of Geology Today.

Craig Barrie, mineralogist and geochemist, of the Mineralogical Society of the UK and Ireland and a member of the editorial board at Geology Today.

Howard Falcon-Lang, palaeobotonist and palaeontologist, of Royal Holloway, University of London and the University of Munster, a member of the editorial board at Geology Today and science writer for BBC News Online.

Jamie Pringle, geophysicist and sedimentary geologist, of the Keele University and a member of the editorial board at Geology Today.

Colin Prosser, geologist and palaeontologist, of Natural England and a member of the editorial board at Geology Today.

Jon Radley, geologist, of Warwickshire Museum and the School of Geography, Earth and Environmental Sciences at the University of Birmingham and a member of the editorial board at Geology Today.

Hugh Rollinson, mineralogist, petrologist and geochemist, of the University of Derby and a member of the editorial board at Geology Today.

You can sign up for the event here.