(meteorobs) man google-earths crater in Outback

[belatrix]

wonder how many of these there are yet to be found?

http://www.smh.com.au/articles/2008/03/25/1206207065556.html


'Arthur Hickman's discovery on Google Earth of what is almost certainly 
a rare meteorite impact crater in remote Western Australia has earned 
him both bragging and naming rights.

Measuring 260 metres wide and up to 30 metres deep, the divot is 
thought to be between 10,000 and 100,000 years old and was stumbled 
upon in the rich, rust coloured landscape of the Hamersley Ranges in 
Western Australia's Pilbara region.

If confirmed, the Hickman Crater will become just the 30th 
officially-verified meteorite impact crater in Australia and the first 
such discovery since 2005.

According to the Earth Impact Database, a resource maintained by the 
Geological Survey of Canada and University of New Brunswick, only 173 
such impact craters have been discovered in the world.

The find will likely deliver a lifetime of peer group kudos to Dr 
Hickman, a government geologist with the Geological Survey of Western 
Australia.

"I wasn't looking for it," Dr Hickman recalled in a telephone 
interview. "I was high up in Google Earth [the free program that 
enables users to scour the Earth using stitched together aerial and 
satellite images] when I spotted this little circular structure which 
struck me as odd."

Dr Hickman, who heads his organisation's Pilbara Craton Mapping 
Project, says he made the discovery last July while he was looking for 
possible sites of channel iron deposits - highly sought after alluvial 
deposits from which the ore can be extracted very cheaply.

Although the crater is situated about 1000 kilometres north-east of 
Perth and more than 300 kilometres south-east of Port Headland, it is 
only 35 kilometres north of the mining town of Newman in an area that 
has been previously surveyed.

Dr Hickman referred his find to Dr Andrew Glikson, an impact crater 
expert who is a visiting fellow at the Australian National University's 
Research School of Earth Sciences.

Dr Glikson, who has been studying impact craters since 1968, visited 
the site in August and corroborated Dr Hickman's hypothesis.

"It's a little beauty," he said in a telephone interview. "It's an 
absolute gem in terms of youth and preservation."

He said the only other explanation for the formation - which is about 
the same size as the Melbourne Cricket Ground - is a volcanic eruption.

But after finding the surrounding area "chockers" with rock 
fragmentation consistent with a high velocity impact, he has ruled this 
out.

"No other process could have created this type of crater," said Dr 
Glikson, who estimates the meteorite was between 10 to 15 metres in 
diameter when it slammed into the Earth.

The two geologists - together with a third scientist - have written and 
submitted a paper on the discovery to the Australian Journal of Earth 
Sciences, where it will be subjected to peer review.

The next step in the process of formal identification involves 
returning to the site and trying to find shards of meteorite that have 
been left behind, or examples of terrestrial rocks that have been fused 
together with extraterrestrial matter as a result of the violent 
impact.

Dr Hickman, who hopes to visit the site for the first time in May, says 
the site is about half a day's drive north from the town of Newman 
following the privately-owned rail line to Port Headland, which is 
famous for its mile-long trains.

He said it was Dr Glikson's decision to name his find the Hickman 
Crater. "I'm not that conceited," he said modestly.

Dr Glikson, who also has another crater in Western Australia named 
after him, says he couldn't explain why the crater hadn't been found 
before.

"This one stands out like a sore thumb on Google Earth," he said.

The crater site can be seen on Google Maps (see embedded map, above 
right) and on Google Earth (requires download).'