Editorial

(From 'Charnia' Newsletter, Autumn 2003)

Having finished reading ‘Architects of eternity’, I made the very pleasant discovery of Michael Benton’s book, ‘When life nearly died: The Greatest Mass Extinction of all time’ (Thames & Hudson, ISBN 0-500-05116-X.). Both books have historical geology as a common thread, the latter being a superbly readable account of the slow dawning of the magnitude of the end-Permian mass extinction. I wanted to relate extensively on the content of this book, though I shall resist the temptation. Take it from me, once you start reading you won’t be able to put this book down; it will appeal to both the professional geologist and lay amateurs alike. What Benton’s book perhaps shows more than anything is the rapid evolution of the subject of geology itself; as such this book provides an entertaining means by which to update your geological knowledge.

Late Permian rocks in the UK: the coastline near South Shields, Tyne and Wear

   One topic mentioned by Benton concerned fossilized spores and plant life. In mid-September Charles Wellman and colleagues of Sheffield University announced in ‘Nature’ that they had found evidence for terrestrial plants dating back to 443-496 million years ago. Previously, spores of the type studied by Wellman’s group had been interpreted as algal and therefore of aquatic origin. Wellman’s interpretation suggests that the fossils are more akin to present-day liverworts.

   Some time ago I wrote about ‘extremophile’ organisms and the origin of life. Until recently, the record holder for high temperature survival was held by Pyrolobus fumarii, whose normal environment is water at 100 Celsius. P. fumarii can survive temperatures up to 113 degrees Celsius. Now the new record holder is a micro-organism dubbed ‘Strain 121’. Researchers Derek Lovley and Kazem Kashefi of the University of Massachusetts found that this ‘new’ bug lives quite happily at 121 degrees Celsius and is killed when the temperature rises to 130 degrees Celsius. As you may have guessed, Strain 121 was collected at great depth adjacent to a submarine ‘smoker’. In this case it was 2.4km below the waves on the Juan de Fuca ridge in the Pacific. It is thus reasonable to suppose that primitive life forms evolved with a higher temperature tolerance than previously thought and therefore that life could have evolved earlier than currently thought?

   At the other end of the scale - and returning to the opening theme of this Editorial - there are sizeable fragments of rock in the Solar System which could obliterate life on Earth in very short order. The latest of a number of these scares is Asteroid 2003 QQ47 - a 2.6 billion tonne rock originally calculated to intersect the Earth’s orbit on March 21st, 2014. Not to panic though, the latest calculations show that QQ47 has a 1 in 909 000 chance of hitting us. However, there are another 523 similar objects in space posing comparable threats to our planet. Perhaps we can draw comfort from the fact that the UK Near-Earth Object Information Centre is here in Leicester at the National Space Centre. The most recent near-miss was on August 16th. this year, though that object whizzed past us at an astronomical whisker’s breadth - 2.4 million miles. Having said this, do any of you know anything about an event occurring in Siberia, where a fireball and earth-tremors were experienced? No, I don’t mean the Tunguska event of June 30th., 1908 - this happened on September 25th., 2002. It seems very strange that the event wasn’t widely reported in the UK, if indeed reported at all. Whatever impacted destroyed 100 square kilometres of forest in the drainage basin of the River Vitim. It seems that one or two large meteorite fragments exploded 30km above the surface, releasing energy equivalent to 200 tons of TNT. This certainly aroused my curiosity and entering ‘Vitim meteorite’ into my computer’s search-engine, it soon came up with a report at the ‘Far Shores’ website (http://www.100megsfree4.com/farshores/n03met7.htm). You can imagine the energy that would be derived from Asteroid 2003 QQ47 if it slammed into us at thirteen miles a second… Perhaps the end-Holocene mass extinction? If you’re feeling inclined you could calculate how many joules of energy might be derived from this impact. All you need to do is convert the mass of QQ47 to kilograms and its velocity into metres per second. The formula ‘half times the mass in kg times (the velocity in metres per second) squared’ should give you a very big number. If you wish to convert this figure to ‘tons (imperial) TNT equivalent’, you’ll need to know that one ton of TNT = 4.184 megajoules.

Graham Stocks