Friday Headlines, May 10, 2013
THE LATEST IN THE GEOSCIENCES
RUSSIAN RESEARCHER CLAIMS TO HAVE FOUND ROCKS FROM AN OBJECT THAT CAUSED THE TUNGUSKA EXPLOSION
In 1908, there was a tremendous explosion over Siberia, called the Tunguska explosion or event. This explosion occurred in the air near the Podkamennya Tunguska River, flattening forest for ~2100 square kilometers. It’s thought that it was an impact event that caused the explosion, but no remains of the impacting object, nor a crater, have ever been found.
Until now, perhaps.
Andrei Zlobin of the Russian Academy of Sciences believes he has found three pieces of the impacter.
http://cdn.physorg.com/newman/gfx/news/2013/76tgig.jpg
Zlobin sees melting and other features of the rocks that belie their extraterrestrial origin, but further testing is needed to prove this hypothesis.
You can read a draft of Zlobin’s paper here on arXiv:
Discovery of probably Tunguska meteorites at the bottom of Khushmo river’s shoal, arXiv:1304.8070 [physics.gen-ph] arxiv.org/abs/1304.8070
ANCIENT BONE-HEADED DINOSAUR FOUND
This was a happy birthday gift for me: A new species of dinosaur was revealed. Now, knowing how the science of paleontology works, this new species was known and described years ago, and it’s only now that the formal description has been published. But it was awfully nice of them to publish it on my birthday.
Pachycephalosaurs are called ‘bone-headed’ or ‘thick-skulled’ because the domed tops of their skulls are composed of very thick bones, presumably for head-butting behavior like bighorn sheep exhibit today.
This new species was approximately dog-sized, but I still wouldn’t want him to head-butt me!
One quandary we have today thinking about global warming and the end of ice ages is how exactly that happened and what triggers warming.
We already know that changes in the sun’s intensity on the Earth (due to regular shifts in the Earth’s orbit and rotation) is what causes glaciers to melt in the northern hemisphere, but warming seems to begin in the southern hemisphere.
Scientists, by studying deep ocean cores, now see that the melting of the glaciers in the northern hemisphere upset oceanic currents. This disruption caused the release of carbon dioxide from deeper waters, resulting in warming.
This disruption in ocean circulation due to melting glaciers is reminiscent of the movie “The Day After Tomorrow,” only that in the movie, the climate shifts to dramatically cooler weather rather than warmer. But it is only a movie, after all.
Penny Higgins - Storyteller • Artist • Scientist 
