The earth's crust tends to crack whenever there is a sudden change in the pressures affecting it. Severe earthquakes are generally caused by cracking of the earth's crust near the earthquake site. Asteroid impacts, which did occur at the end of the Ice Age, generally cause severe earthquakes. Evidence of severe earthquakes around the time of the end of the Ice Age can be found in parts of northern Canada.
According to current geological theory, the melting of ice at the end of the Ice Age significantly reduced the weight pressing on parts of the earth' s crust. As a result, lasting cracks in the earth' s crust appeared in some of those parts under the stress of pressure from below. At the end of the Ice Age Sweden was racked by severe earthquakes. Ttherefore, it is likely that the melting of the ice contributed to these earthquakes.
Which one of the following, if true, most strengthens the argument above?