Archive for October 27, 2013

Huge ancient monument found in Sweden   Leave a comment

The red lines on the map at left designate where the rows of posts have stood. The kilometre-long strip with post holes is seen at right. Gamle Uppsala – Old Uppsala – is about 60 km north of Stockholm. (Photo: Swedish National Heritage Board /www.flygfoto.com)

Archaeologists in Sweden have found two long rows of wooden post holes at nearly right angles to each other. One of the rows is a kilometre long and consists of 144 post holes. The other extends at least 500 metres. The holes are spaced every six metres and the rows are 500 metres apart.

“We think the wooden poles were high, perhaps over eight to ten metres. They have been easily spotted from a distance,” says the project leader of the dig, Lena Beronius-Jörpeland, an archaeologist with the Swedish National Heritage Board.

A newer version of such rows is found in Denmark, from the Viking era. But there it served as a defensive wall.

Archaeologists at work on what was once a row of tall posts, nearly a kilometre long. (Photo: Swedish National Heritage Board)

“As this is such a large tract of land, we don’t think these rows of posts would work well as protection. In those days they had castles which served that function, but they were much smaller. Maybe this monument had multiple functions,” said Beronius-Jörpeland to the Swedish newspaper Dagens Nyheter.

Connection with the royal burial mounds

The site is just a few hundred metres from a well-known landmark, the Royal Mounds [Kungshögarna]. These are from the decades around 600 AD and had significant functions for religion and trade.

The researchers are speculating about links between the monumental linear structures and the burial mounds. The area they are in is one of the most important known from the Swedish Iron Age.

Archaeologist Fredrik Thölin takes a breather by the foundation of one the 1,500-year-old posts, preserved in the clay soil. (Photo: Uppland Museum)

“We know there was some sort of judicial court associated with the kings who are buried in the mounds. It’s tempting to speculate that this had something to do with the newly discovered monument. Maybe it was intended as a visual manifestation of power,” says Beronius-Jörpeland.

Inspiration from abroad

The excavation has revealed animal bones in some of the holes where pillars once stood. A puppy skeleton was dug out of one, which indicates that it was sacrificed when the post was erected or the construction was completed.

The excavation of the extensive monumental structure will continue as researchers seek information on possible similar constructions elsewhere in Europe or skirting the Mediterranean. The idea is to find out whether mighty leaders who ordered the construction in  Gamla Uppsala got their inspiration from abroad.

The skeleton of a puppy was found in one of the excavated holes. (Photo: Swedish National Heritage Board)

Posted October 27, 2013 by kitokinimi in Uncategorized

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Biggest Meteor Strikes In History   Leave a comment

 

 

 

Our beloved blue planet gets pelted with debris from space all the time but, since most of it burns up or break apart in the atmosphere, it’s usually not a problem. Even when one does make it to the ground, they are rarely much larger than a small rock, minimizing the damage they’re capable of inflicting.

 

Then, of course, there is that once-in-an-eon occasion  where something very very large makes it through intact, and this can really do some damage. Fortunately, such hits are extremely rare, but they are worth noting, if only to serve as reminders of the power of the stars to undo the normal routine here on Earth, with little more than a few minutes’ warning. So where — and when — did these monsters hit? Let’s take a look at the geological records, and see.

 Barringer Crater, Arizona, USA

Barringer-Crater

Already the home of the Grand Canyon, around 50,000 years ago Arizona decided to add yet another tourist attraction, when a 160-foot diameter meteorite landed in the northern desert, leaving an impact crater nearly a mile wide and 600 feet deep. Scientists believe the meteorite that caused the crater was traveling at over 28,000 miles per hour when it struck, causing an explosion about 150 times more powerful than the Hiroshima atomic bomb. Some scientists initially rejected the idea that the crater was caused by a meteor when no meteorite was found, but the modern consensus is that the rock melted in the explosion, spreading a mist of molten nickel and iron across the surrounding landscape.

Though at a mile across, the crater is not all that large, the lack of erosion makes it an especially impressive site. In fact, it’s one of the few meteor craters that actually looks like what it is, making it a first-class tourist attraction — precisely as the Universe intended.

Lake Bosumtwi Crater, Ghana

Lake-Bosumtwi-Crater

When one stumbles upon a natural lake that is almost perfectly round, that’s a little suspicious. Such is the case with Lake Bosumtwi, a five-mile diameter body of water that lies some twenty miles southeast of Kumasi, Ghana. This was created when a 500-foot diameter meteorite hit the region some 1.3 million years ago. Efforts to study the crater closer have been complicated by the fact that the lake is difficult to get to, because of the thick rainforest that surrounds it, and the fact that the local Ashanti people consider it to be sacred (they consider it forbidden to touch the water with iron or use metal boats, making drilling for nickel on the bottom problematic.) Still, it remains one of the best-preserved craters on the planet today, and an example of the destructive power of megarocks from the stars.

Mistastin Lake, Labrador, Canada

Mistastin-crater

At a “mere” 38 million years old, the Mistastin crater from Labrador, Canada, is an impressive eleven-by-seven mile hole in the ground which, due to erosion from the many glaciers that has scoured that part of Canada over millions of years, was likely originally far larger than it is today. What’s unique about this crater is that, unlike most meteor impacts, this one is elliptical in nature rather than circular, suggesting that the rock hit at a shallow angle, rather than straight on like most big impacts. Even more unusual is that there is a small island in the middle of the lake which could be the central uplift of a complex crater structure, making it even cooler.

Gosses Bluff, Northern Territory, Australia

Gosses-Bluff

Equally impressive from both the ground and the air, this 142-million-year old, 15-mile diameter crater, near the center of Australia, was created when an asteroid, estimated to have been a good 15 miles in diameter, hit the surface at an impressive 40,000 MPH, gouging out a hole some 16,000 feet deep. That’s the energy equivalent to 22,000 megatons of TNT, suggesting that life on the continent likely had a difficult time in the immediate aftermath of this little incident. Now one of the most significant impact structures in the world, the highly eroded crater stands as a stark reminder of the power one big rock can have.

Clearwater Lakes, Quebec, Canada

clearwater-lakes

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It’s cool enough to find one meteor crater, but to find two of them side-by-side is twice as cool. This is exactly what happened when an asteroid split in two upon entering the Earth’s atmosphere some 290 million years ago, creating two monster impact craters on the eastern shore of Hudson Bay. Since then, erosion and glaciers have eroded much of the original craters away, but what remains is still impressive. One lake is some twenty miles in diameter and the other just under fourteen. Given the amount of erosion that has occurred over the last 290 million years, one can only speculate how much larger they must’ve been when first created.

The Tunguska Explosion, Siberia, Russia

Tunguska-crater

This one is a little controversial, as it didn’t leave any pieces of itself, making it a source of debate as to what exactly it was that hit this little corner of Siberia a mere 105 years ago. The only thing that’s known for certain is that something pretty big, and moving very fast, exploded near Russia’s Tunguska River in June of 1908, leaving over 800 square miles of forest flatter than a squirrel on the freeway at rush hour. So large was the explosion in fact, that it was detected on instruments as far away as Great Britain!

Since no bits of meteorite have ever been found, some believe the object may not have been a meteor at all, but a small chunk off a comet (which, if true, would account for the lack of meteoric material.) To further muddy the waters, there are also those who contend that what actually exploded was an alien spaceship. While completely unsubstantiated and totally speculative, we gotta admit it’s a pretty fun theory.

 Manicouagan Crater, Canada

Manicouagan-Crater

Manicouagan Reservoir, also known as the “eye of Quebec,” was created some 212 million years ago, when a 3-mile wide asteroid hit the Earth. The 62-mile-wide hole that it left has been worn away by the passing of glaciers and other erosive processes, but it remains impressive nonetheless. What’s especially unique about this particular crater is that, instead of just filling with water to become a near-perfect circular lake, this one is mostly dry land, ringed by a natural mote. That would make it a great place to build a castle, one might imagine.

Sudbury Basin, Ontario, Canada

Sudbury-Crater

What’s with Canada and impact craters? It appears that Alanis Morrisette’s beloved homeland has an inordinate number of meteor craters, with the one near Sudbury, Ontario being the largest of the bunch. 40 miles long, 16 miles wide, and 9 miles deep, this 1.85 billion year old crater is actually home to some 162,000 people and a number of mining companies, who discovered over a century ago that the bottom of the basin is super rich in nickel because of the asteroid. Rich enough, in fact, to provide about 10% of the world’s nickel supply!

Chicxulub Crater, Mexico

Chicxulub-Crater

This is the one that may have done in the dinosaurs, and is one of the largest meteor strikes in Earth’s history. The impact happened roughly 65 million years ago, when an asteroid the size of a small city crashed onto Earth with the destructive power of 100 teratons of TNT. That’s one billion kilotons for those of you keeping score. Compare that to the Hiroshima bomb, which released the equivalent of just 20 kilotons of TNT and you get the idea.

Not only did it leave a 105-mile diameter hole in the ground, but it created mega-tsunamis, earthquakes, and volcanic eruptions around the globe, that dramatically altered the environment and doomed our reptilian friends (along with a lot of other critters, it appears.) Buried beneath the Yucatán Peninsula in Mexico near the village of Chicxulub (after which it is named,) this vast crater can only be discerned from space, which is why it took so long for scientists to find it.

 Vredefort Dome, South Africa

Vredefort-Dome

While the Chicxulub Crater is better known, it’s a mere pothole compared to the 186-mile-wide Vredefort Dome in South Africa, which currently holds the record for being the largest impact crater on Earth. Fortunately, in hitting over two billion years ago, the meteor/asteroid (estimated to be about six miles in diameter) didn’t do a lot of damage to life on Earth, as there were no multi-cellular organisms around at the time, or things could have gotten dicey. No doubt it adversely affected Earth’s climate at the time — not that anyone noticed, of course.

Today, the original crater is mostly eroded away, but what remains is still impressive when seen from space, and serves as a graphic reminder of just how scary our little corner of the Universe can be.

via: http://www.toptenz.net

Posted October 27, 2013 by kitokinimi in Uncategorized

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Weapons Boeing CH-47 Chinook   Leave a comment

Boeing CH-47 Chinook

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Posted October 27, 2013 by kitokinimi in Uncategorized

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