Surface Rupture of the 2002 Denali Fault, Alaska, Earthquake and Comparison with Other Strike‐Slip Ruptures

On 3 November 2002, an M7.9 earthquake produced 340 km of surface rupture on the Denali and two related faults in Alaska. The rupture proceeded from west to east and began with a 40‐km‐long break on a previously unknown thrust fault. Estimates of surface slip on this thrust are 3–6 m. Next came the principal surface break along ∼218 km of the Denali fault. Right‐lateral offsets averaged around 5 m and increased eastward to a maximum of nearly 9 m. The fault also ruptured beneath the trans‐Alaska oil pipeline, which withstood almost 6 m of lateral offset. Finally, slip turned southeastward onto the Totschunda fault. Right‐lateral offsets are up to 3 m, and the surface rupture is about 76 km long. This three‐part rupture ranks among the longest strike‐slip events of the past two centuries. The earthquake is typical when compared to other large earthquakes on major intracontinental strike‐slip faults.