Jane...not such a strange idea...melting of large volumes of ice decreases the vertical stress (the gravitational load) and makes it more likely to have a quake in areas of thrusting (of horizontal maximum stress and vertical miniumum stress). However, I don't think the area where most of the Alaska ice is, is likely to have a quake that large due to ice melt in the next couple of decades (although I don't know enough about the faults in SE Alaska to be confident in that statement...I think it becomes a right-lateral boundary there and British Columbia, but something is holding up the high mountains so there is probably also thrusting). There may have been thrust quakes in the NE North America as the last ice sheet melted...seems I've seen an article or 2 on this in the last decade or 2.
Chris