Bob CollinsIf last evening’s meteor in Siberia has you yearning to take a look at what happens when a meteorite hits earth, you can save yourself some time and just head up north in Minnesota.
On the Gunflint Trail a few years ago, geologist Mark Jirsa of the Minnesota Geological Survey found debris from a meteorite that hit Sudbury, Ontario. The impact created a crater 150 miles wide, and scattered rock over a million square miles.
The “impact layer” is a mix of fragments that were broken from the iron and cemented together by the effect of the impact.
Mr. Jirsa said the Gunflint was probably a shallow sea when the meteorite hit, setting off a tsunami that ripped up the sea bottom, and mixed them with rocks that fell from the sky.
Only to eventually become part of the fireplace at Gunflint Lodge. Oh, and Minnesota itself.
When the meteorite hit, the temperature is estimated to have reached 10,000 degrees.
A timetable in his report says that 13 seconds after the meteorite hit Sudbury (500 miles away), the fireball erupted at Gunflint Lake. The airborne rain of rocks hit 5 to 10 minutes later, and 40 minutes after that, wind speeds hit 1,400 mph.
Here’s his entire report with pictures.
“I think the excitement for the people of Minnesota is that we are one place in the world where you can see evidence of an ancient meteorite impact,” University of Minnesota geology professor emeritus Paul Weiblen said of the report, which he co-authored.
