Earth ChangesS


Info

How landslides can be the key to ignition of wildfires

Kate Ravilious
Science Daily
Mon, 01 Dec 2008 17:12 UTC
Can a landslide spontaneously combust? It can, if it contains the right kind of rock.

In August 2004, fire crews attending a wildfire near Santa Barbara, California, traced the source of the blaze to a recent landslide, but they had no idea how the fire got started.

A few weeks later, Robert Mariner of the US Geological Survey in Menlo Park, California, and his colleagues visited the site. They found that the temperature of the rocks in the landslide must have reached just over 300 °C - hot enough to start a fire.
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Meteor

How Many Meteorites Have Landed In Western Canada? Prospects For The Missing Holocene Impact Record


Science Daily
Mon, 01 Dec 2008 16:59 UTC
Based on the amount and frequency of meteorite falls and the formation of impact craters on the Earth, there should be over 20 impact craters in the <100 m size range that formed within the past 10,000 years, yet only five such craters are known worldwide.

Herd et al. report the discovery of a 36-m-diameter impact crater located in a forested area near the town of Whitecourt, Alberta, Canada. Although too overgrown to be seen in air photos or satellite images, the crater is revealed using a bare-Earth digital elevation model obtained through airborne Light Detection and Ranging (LiDAR).

The crater formed in deglacial sediments, with impact ejecta burying a soil with a radiocarbon age of ~1100 years. Seventy-four iron meteorites (0.1-1196 g) have been recovered, most having an angular, shrapnel-like shape.
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Fish

Want Sustainable Fishing? Keep Only Small Fish, And Let The Big Ones Go


Science Daily
Mon, 01 Dec 2008 16:39 UTC
Scientists at the University of Toronto analysed Canadian fisheries data to determine the effect of the "keep the large ones" policy that is typical of fisheries. What they found is that the effect of this policy is an unsustainable fishery.
Large mouth bass in a lake
© iStockphoto/Judy LedbetterLarge mouth bass in a lake. A fish population will produce more young -- and therefore sustain more fishing -- if it is made up of big, old fish.

In fact, the opposite policy (keep the small young ones and throw back the large old ones) would result in a more sustainable fishery. In short -- a big fish in the water is worth two in the net.
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Info

2008 Atlantic Hurricane Season Sets Records


Science Daily
Mon, 01 Dec 2008 16:33 UTC
The 2008 Atlantic Hurricane Season officially comes to a close on November 30, marking the end of a season that produced a record number of consecutive storms to strike the United States and ranks as one of the more active seasons in the 64 years since comprehensive records began.
Image
© NOAAA total of 16 named storms formed this season, based on an operational estimate by NOAA's National Hurricane Center. The storms included eight hurricanes, five of which were major hurricanes at Category 3 strength or higher.

A total of 16 named storms formed this season, based on an operational estimate by NOAA's National Hurricane Center. The storms included eight hurricanes, five of which were major hurricanes at Category 3 strength or higher. These numbers fall within the ranges predicted in NOAA's pre- and mid-season outlooks issued in May and August. The August outlook called for 14 to 18 named storms, seven to 10 hurricanes and three to six major hurricanes. An average season has 11 named storms, six hurricanes and two major hurricanes.

"This year's hurricane season continues the current active hurricane era and is the tenth season to produce above-normal activity in the past 14 years," said Gerry Bell, Ph.D., lead seasonal hurricane forecaster at NOAA's Climate Prediction Center.
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Bug

Farming And Chemical Warfare: A Day In The Life Of An Ant


Science Daily
Mon, 01 Dec 2008 16:27 UTC
One of the most important developments in human civilisation was the practice of sustainable agriculture. But we were not the first - ants have been doing it for over 50 million years. Just as farming helped humans become a dominant species, it has also helped leaf-cutter ants become dominant herbivores, and one of the most successful social insects in nature.

According to an article in the November issue of Microbiology Today, leaf-cutter ants have developed a system to try and keep their gardens pest-free; an impressive feat which has evaded even human agriculturalists.
Leaf-cutter ants transporting leaves
© Wikimedia CommonsLeaf-cutter ants transporting leaves.

Leaf-cutter ants put their freshly-cut leaves in gardens where they grow a special fungus that they eat. New material is continuously incorporated into the gardens to grow the fungus and old material is removed by the ants and placed in special refuse dumps away from the colony. The ants have also adopted the practice of weeding. When a microbial pest is detected by worker ants, there is an immediate flurry of activity as ants begin to comb through the garden. When they find the pathogenic 'weeds', the ants pull them out and discard them into their refuse dumps.
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Hourglass

Brazilian rainforest destruction on the up once more


New Scientist
Mon, 01 Dec 2008 16:16 UTC
Destruction of the Amazon forest in Brazil accelerated for the first time in four years, the Brazilian government has reported, as high commodity prices tempted farmers and ranchers to cut down more trees.

Satellite images showed nearly 12,000 sq km - an area nearly the size of the US state of Connecticut - were chopped down in the 12 months through to July, Brazil's National Institute for Space Research said. That is up from 11,224 sq km last year but down from a peak of 27,379 sq km in 2004.

"Today's figures are unacceptable but the long-term trend remains positive and they show that it is possible to do something about deforestation," said Paulo Moutinho, coordinator at the National Institute for Amazon Research.
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Alarm Clock

Update: 150 whales die in stranding off Australian coast

Anirban Nag
Reuters
Mon, 01 Dec 2008 14:02 UTC
SYDNEY - At least 150 whales have died in a mass stranding off Tasmania's west coast, Australian authorities said on Sunday, despite the efforts of rescuers who managed to shepherd a small number back to the ocean.

The state government said the number of long-finned pilot whales that had perished had climbed to 150 after a body count on Sunday, almost double the earlier estimate of 80.
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Sun

2008 in Top Five for Sunspotless Days in Last Century

Joseph D'Aleo,
IceCap
Sun, 30 Nov 2008 04:56 UTC
One of our loyal Canadian Icecap readers asked us to comment on the fact we are now at the end of November, in the top five years with the most sunspotless days the last century and heading towards a #3 or even #2 finish depending on how many spotless days we have in December. Here is a comparison of monthly spotless days in this cycle 23 minimum (red) versus the last cycle 22 minimum in the mid 1990s (blue).
Sunspots
© SolarCycle24.com
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Snowman

Cocking a snook at the experts - Snow in parts of Switzerland 12 times deeper than average


IceAgeNow
Sat, 29 Nov 2008 04:44 UTC
Ski resorts across Europe will open this weekend ahead of schedule after the biggest November snowfalls for at least a decade - in some places the biggest November snowfalls in more than 40 years - including 60cm (23in) of snow on Alpine slopes and even more in the Pyrenees.

"This is nature's way of cocking a snook at the experts," said Christian Rochette, the director of Ski France International, the tourist body for French resorts.

"We've got excellent conditions for this time of year and very cold temperatures, which means we can use the snow cannons to make artificial snow as well," he said.
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Frog

Sudden cold weather endangers sea turtles; many being rescued


Associated Press
Thu, 27 Nov 2008 04:39 UTC
Jacksonville - Recent cold weather caught sea turtles off-guard before they could reach warmer Gulf Stream waters, and that has led to nearly 25 rescues along the North Carolina coast in the past week.

Karen Beasley Sea Turtle Rescue and Rehabilitation Center on Topsail Island has rescued numerous cold-stunned sea turtles since Thursday, said Jean Beasley, the hospital's executive director.

"We're overwhelmed, this has never happened before -- at least not since the turtle hospital has been in existence," Beasley said. "We had 11 turtles come in last Thursday, 12 on Saturday and six (Sunday). We're frantically trying to make more space."
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