From good 'ol Wikipedia:
And for good measure:
Someone on FR once posted that "normal is Chicago under a mile of ice." That's certainly been true recently. For example, for the last 500,000 years:
From good 'ol Wikipedia:
And for good measure:
Someone on FR once posted that "normal is Chicago under a mile of ice." That's certainly been true recently. For example, for the last 500,000 years:
Note the abrupt temp. drop at the Eocene Oligocene boundry 34 million years ago. Almost certainly caused by the Chesapeake Meteor with 60 mile diameter crater, the Popogai (sp?) meteor crater in Siberia, and the 10 mile diameter Toms River crater off NJ all of which fell about the same time.