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Earth’s crust is recycled into oceanic lava

Sicily’s Mount Etna erupts with lava flowing through a fracture in the volcano, near the city of Catania, Nov. 17, 2006.


Earth recycles itself

"U.S. researchers say evidence suggests material contained in oceanic lava flows is 'recycled,' having originated in Earth's ancient crust billions of years ago," reports United Press International. "Scientists at the Scripps Institution of Oceanography at the University of California, San Diego, say the findings support the theory that much of the Earth's original crust has been recycled by the process of subduction, helping to explain how the Earth has formed and changed over time. Subduction takes place when one of the Earth's tectonic plates moves under another plate and sinks into the mantle as the plates converge."

Two-fisted memorizing

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"New research suggests making a fist … is not necessarily a sign of exasperation, rather a memory recall method," says Psych Central. "Investigators also discovered a differential between upper extremities such as squeezing your right fist may help form a stronger memory of an event or action, and clenching your left may help you recollect the memory later." The study, by Ruth Propper and colleagues from Montclair State University, is published in the open-access journal PLoS ONE.

Oceans heat our hemisphere

"It contains most of the world's land and 90 per cent of its people, but that is not why the Northern Hemisphere is consistently hotter than its southern counterpart," says the New Scientist. "It turns out that ocean circulation is to blame. The temperature disparity was first recorded by early 16th-century explorers who noticed icebergs floating in the Southern Hemisphere at latitudes where they wouldn't have been in the north. The Northern Hemisphere is currently 1.5 C warmer on average than the Southern Hemisphere." To find out what is going on, scientists at Germany's Potsdam Institute for Climate Impact Research used climate models to simulate what would happen if the North Atlantic heat pump, a northward-moving mass of warm water, was turned off. Having controlled for other factors such as land mass, they found that the temperature gap almost disappeared.

Prehistoric runways

The biggest airborne dinosaurs flew with great difficulty, says BBC Focus magazine. "The largest pterosaurs (which aren't actually classified as dinosaurs) were much bigger than even the largest flightless birds alive today. Quetzlcoatlus, for example, was the size of a giraffe. The highest estimates of its weight are 200 to 250 kilograms, and at that weight there is no plausible mechanism for Queztlcoatlus to get airborne. … But for body weights of 70 to 80 kilograms, a simulation at Texas Tech University showed, the beast may have used slopes at the edges of lakes as runways. It would begin by running on all fours with its huge wings folded. It would then shift onto its back legs and begin flapping. Finally, it lunged forward and lifted its back legs off the ground. Once aloft, Queztlcoatlus was capable of efficient, soaring flight."

Right out of fairyland

Scientists have discovered a new species of tiny insect, a minuscule wasp known as a fairyfly, that lives in the forests of Costa Rica, reports the Christian Science Monitor. "Named Tinkerbella nana after the Peter Pan character, the species measures no more than 250 micrometres in length. By comparison, the average human hair is about 100 micrometres wide. … As small as Tinkerbella is, it's not the smallest flying insect. That distinction goes to Kikiki huna, a fairyfly native to the Hawaiian islands that measures just 150 micrometres. The Canadian

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Forestry Service's John Huber, the primary author on the Tinkerbella paper, was also the principal discoverer, in 2000, of Kikiki."

Thought du jour

"The surroundings householders crave are glorified autobiographies."

T.H. Robsjohn-Gibbings, British-born architect and furniture designer (1905-76)

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