Geology news

Fresh water

http://tamino.wordpress.com  January 3rd 2009 ... a blog with the title Open Mind that reported a year ago on the Firestone et al (2008) claim that a comet was responsible for the YD boundary event - a sudden reversion to cold almost glacial conditions in high latitudes of the northern hemisphere. However, the cooling episode does not appear in Antarctic ice cores (at Byrd station for example).

Antarctic Impact

http://cosmictusk.com ... the BBC reported from the 'lunar and Planetary Conference' in Texas by saying, 'a large space rock may have exploded over Antarctica thousands of years ago, showering a large area with debris. The evidence comes from tiny meteoritic particles and a layer of extraterrestrial dust found in Antarctic ice cores. The event would have been similar to the 1908 Tunguska event' they said. Looks like another one - they are coming thick and fast.

Toba Super Volcano

www.dailygalaxy.com March 4th ... the Toba super volcano appears to have been overhyped. It is said to have blown around 74,000 years ago and was responsible for a 1000 year cooling episode - but quite how these things are measured from so long ago must leave root for alternative explanations. At one point scientists were saying that humans became almost extinct at this time - until somebody pointed out that Neanderthals appear to have thrived and the Hobbit persisted in fairly close proximity to the Toba eruption.

K/T Boundary

www.physorg.com March 4th ... the asteroid impact at the K/T boundary left a clear band between light coloured Cretaceous sediments and dark coloured Palaeocene sediments (a picture of the geology is provided online), recovered from the sea floor off South America. The abrupt shift in colour reflects an instantaneous drop in ocean biological productivity. There is also an online video (including an audio interview and animated graph) of the asteroid impact, with Dr Joanna Morgan of Imperial College explaining the science.

Ocean Vents and El Ninos

www.physorg.com March 3rd ... the Earth Institute at Columbia University has posted evidence of hydrothermal vents on the seafloor near Antarctica. These vents spew volcanically heated seawater from the underwater mountain ranges where lava erupts and new crust forms (mid ocean ridges). Chemicals dissolved in the vents help sustain a complex web of organisms (Geophysical Research Letters).

Asteroid strike at K/T boundary

Science Daily March 1st (www.sciencedaily.com id100301102805) an asteroid strike at the K/T boundary may account for geographic uneveness of the extinctions and recovery according to research by Penn State University geoscientists. At the Cretaceous-Paleogene boundary 93 per cent of nanno plankton became extinct - and these are basic to the ocean food chain. The highest rate of extinction was in the northern hemisphere with decreasing levels in the southern hemisphere.

Volcanic Lightning, ice on the moon, and ice on Mars.

www.dailygalaxy.com March 2nd ... Daily Galaxy often have an 'image of the day' - on this post it is volcanic lightning (from a volcano that erupted in southern Chile in 2008). Electrical storms directly above erupting volcanoes are well documented phenomena but scientists can't agree on what causes them. There are three images that can be downloaded to your computer - and the source of the phots is given as http://www.thunderbolts.info (2005)

The River Eem

The Herholz Centre for Environmental Research (see http://www.alphagalileo.org ) March 3rd ... the Eemian Interglacial between 126,000 and 115,000 years ago is named after the river Eem in the Netherlands. It was followed by a glacial period that came to an end 15,000 years ago, known as the Weichselian after the Polish river Weichsel. At it's peak some 21,000 years ago it's glaciers stretched as far south as Berlin (or nearly so). Researchers have studied lake sediments to reconstruct the climate history of the Eemian.

YD Boundary Event Updates

New Scientist 204-2734 November 14th 2009 page 10 ... Kate Revilous claimed a mud core from the bottom of Lough Monreagh in western Ireland shows that the Younger Dryas event was so quick that very cold conditions set in within less than a year - possibly within weeks.

Underwater Waves

www.physorg.com id186252841 February 25th ... Oceanography scientists from the University of Rhode Island have been looking at what it might be that generates huge underwater waves that occur between layers of warm and cold ocean water in coastal regions. These can reach heights of 150m in the South China Sea and the effects of them can actually be viewed from space (cameras in satellites). The existence of a huge continental shelf system off the coast f East Asia is one factor but a deep ocean basin is also located in the South China Sea.