From: Alaska Earthquake Information Center, UAF Geophysical Institute
Date: November 7, 2002
The magnitude Mw 7.9 earthquake of November 3, 2002 has given many Alaskans quite a jolt. This earthquake is the largest earthquake on Earth this year and is the largest earthquake to hit interior Alaska in recorded history. The earthquake ruptured a nearly 300 km long segment of the Denali fault from near Cantwell to the Canadian border, with offset ranging from a couple of meters to more that 10 meters. It is important to note that following a major earthquake of this kind we expect to have many aftershocks along the fault. These aftershocks occur most frequently directly after the main rupture and then gradually decrease in numbers over several weeks to months. It is normal to feel aftershocks for several weeks and reasonable precautions should be taken. Some of these aftershocks could be fairly large and could reach the high magnitude 6 to low magnitude 7 range. Those of you closer to the fault will feel the aftershocks for a longer period of time.
This event along with the magnitude Mw 6.7 earthquake of October 23, 2002, ruptured about one third of the total length of the Denali fault, leaving two areas of the fault in tact. One section extends from the Canadian border to the Alaskan panhandle and the other extends to the west, through Denali National Park. The area that ruptured during the November 3 event has probably released its stored energy and should not rupture again in a major event in the near future (except for the aftershocks discussed above). It is impossible to predict the entire effect of the November 3, 2002 event on these other sections of the Denali fault and other faults in the region. In Alaska there is a need to be continually aware of the possible hazards from earthquakes. Major faults can produce large earthquakes at any time, and since there are still segments of the Denali fault that did not rupture in the recent events, these may someday produce significant earthquakes. There are other faults, mapped and buried in other areas of Alaska (including the Fairbanks area) which can also produce significant events. Nevertheless, it has remained impossible to predict when and where these events might occur. Rumors of impending disasters or predictions of future earthquakes should not be taken seriously and are not based on the existing evidence. For more information about recent earthquakes or earthquakes in general, please visit the Alaska Earthquake Information Center (AEIC) Web page at http://www.aeic.alaska.edu/.