Geology news

Earthquake clustering

www.sciencedaily.com/releases/2010/06/100602193429.htm is a post on earthquakes triggering other earthquakes, causing clusters of them - which involves the synchronisation of faults in the crust. The synchronisation of earhquakes - clusters of ruptures of several faults followed by phases of quiescence has apparently been found in palaeo-seismic records (or proxy data). It reflects the common observation that large earthquakes can trigger others on nearby fault lines.

Himalayan Smack

At www.physorg.com/print194263023.html May 28th ... geologists have found evidence that when India collided with Asia 90 million years ago the crust of the Indian tectonic plate was forced beneath the larger Asian plate and sank into the mantle of the earth to a depth of at least 200km. This is double that of previous estimates.

Timor Sea Crater

At www.physorg.com/print193556580.html ... Australian scientists have found a crater at the bottom of the Timor Sea and this has been dated (how?) contemporary with a heavy bombardment event some 35 million years ago. Archaeologist Andrew Glikson said the identification of microstructural and chemical features in drill fragment revealed further evidence of impact saying it was a 50km wide scar.

Fish Extinctions

At www.sciencedaily.com/releases/2010/05/100517152518.htm it is claimed a mass extinction of fish some 360 million years ago reset the button on earth's life forms triggering modern vertabrae biodiversity. The mass extinction event, it is theorised, scrambled the species pool near the juncture when the first vertebrae were crawling out of the water on to the land.

Layering of Loess

At http://calderup.wordpress.com Nigel Calder has a post on the 1960s discovery by Czech geologist George Kukla, who counted the layers of loess, each separated by darker bands of material thought to be left over from warm interglacial periods. Kukla found too many layers of loess - and this did not fit into current thinking. Until then everyone had been thinking in terms of just four Ice Ages.

Blobs of crust that excite

www.newscientist.com/article/dn18877-dents-in-earths-gravitational-field-due-to-plumes.html?full=true&print=true May 9th ... old pieces of continental crust that are thought to fall to the bottom of earth's mantle region are being blamed for mysterious dents in the planet's gravitational field. At some points on  the globe, such as the middle of the Indian Ocean, the NE Pacific, and the Ross Sea, earth's gravitational field is weaker.

Floods of Water at the end of the Ice Age

At www.physorg.com/print191683663.html April 28th ... a paper that can be accessed in full (or abstract) at http://bit.ly/9VKpln on research that shows part of Alaska was inundated by a massive flooding event - 17,000 years ago. I am assuming this coincides with the end of the Ice Age but the dating differs from other studies. It is being described as a mega-flood event which formed dunes in the ground over 110 feet high and spread half a mile apart

Asphalt Domes

At www.physorg.com/print191397828.html April 25th ... in 700 feet deep water off Santa Barbara in California is a series of asphalt domes that it is thought derive from flows of petroleum deposited by an underwater volcano 35,000 years ago. The deposits hardened into asphalt domes (see Nature Geoscience April 25th). The domes were discovered by a deep submersible vehicle and were teeming with life - like an artificial reef.

The Origin of Water on Earth

At http://wattsupwiththat.com April 18th ... we have a post by Steven Goddard, 'Volcanoes and Water' ... with a series of stunning images. Water vapour is consistently the most abundant of volcanic gases - normally comprising some 60 per cent of total emissions. C02 accounts for between 10 to 40 per cent. Around 70 per cent of the surface of the earth is covered with water - but where did all that water come from?

Gulf dry and wide

At www.gulf-times.com April 11th there is a story in which a team of archaeologists from Birmingham University (who pioneered research on the North Sea bottom) have been in Qatar and looking at the sea floor of the Gulf (in conjunction with the Qatar Natural History Museum). They have been able to demonstrate how the Gulf has changed during the last ten thousand years as a result of sea level rise. During the Ice Age the peninsular of Qatar was part of a huge plain stretching all the way across to Iran - broken just by a couple of fresh water lakes.