An hour after the Indian Ocean quake that triggered the Southeast Asian tsunami, seismologists at the University of Alaska Fairbanks "could actually detect the entire state of Alaska undulating up and down, rising and falling an inch or more every 30 seconds for several minutes." It also "triggered a second earthquake beneath Mount Wrangell, a 14,000-foot volcano about 50 miles east of Glennallen.... The phenomenon of one earthquake triggering another earthquake at a distance of 6,000 miles – a quarter of the circumference of the Earth – has never been seen before. Now that it has happened, scientists are hoping it will provide insight into volcanic activity in Alaska and elsewhere. Gaining clues as to when volcanoes may become active again could be an important tool in saving lives." [Link]