There are several hundred craters in the area the study looked at. Over one hundred of them are up to 1,000 meters wide…

K. Andreassen/CAGE: “…if you watch this happening, you would see a huge mound suddenly release an enormous amount of gas, then collapse. The resulting craters we see today are between 1,000 and 3,200 feet in diameter.

The process, Andreassen says, is thought to be similar to what scientists are recording on Siberia’s Yamal Peninsula today. Over the last few decades, huge craters have been appearing. Researchers believe they are formed by thawing permafrost causing the buildup of methane below ground, eventually resulting in an explosive collapse.”

http://www.newsweek.com/hundreds-craters-methane-explosions…