The article should have read 700 gigatons of TNT.
I'm afraid it didn't ... it said 700 one megaton bombs ... do you claim it should have said 700 one gigaton bombs ... no such thing ...
Do you wish to retract your claims until you've had a chance to find the error in the article? ...
Here is the published paper.
https://www.researchgate.net/public...neath_Hiawatha_Glacier_in_northwest_Greenland
Here is an excerpt from the published paper.
"...The diameter of an impact crater constrains the kinetic energy of the impactor. The formation of a 31-km-wide impact crater in crystalline target rock requires ~3 × 10 ^21 J of energy (17)."
Here is the reference which was cited for the calculation.
17. G. S. Collins, H. J. Melosh, R. A. Marcus, Earth Impact Effects Program: A Web-based computer program for calculating he regional environmental consequence of a meteoroid impact on Earth. Meteorit. Planet. Sci. 40, 817–840 (2005)
How much of this energy was use to create the 31 km diameter crater? ... if none, we still only see 1,100 gigatons of ice vaporizing, but then we won't have found the crater ... now would we have? ... you got to do better in light of the
very serious mistake noted above ... let's see hard numbers excavating that much Earth ...
The bottom line is that there is a massive crater in the polar region which would have resulted in a global climatic change which was a sudden event which released massive amounts of water vapor in the atmosphere which would have come down as rain. Glad to see you missed the forest for the trees.
It would take a long while for this water vapor to condense and rain down ... we have the other half of the conservation laws, where does the energy go once the water vapor condenses? ... we can't just destroy it, we have to radiate out again and that will take some time ... water vapor is a greenhouse gas, outbound energy transfer is inhibited ...
You've missed the ocean ... sea level's dropped 4 km ... that's going to play hell on Earth's energy budget ...