Coulomb stress change in the neighboring region and faults imparted by Anchorage Mw7.0 earthquake in Alaska

The Anchorage Mw7.0 earthquake on November 30, 2018, was the most extensively felt event in the region since the 1964 Alaska Mw9.2 earthquake. Based on published data of source fault model, we performed a preliminary analysis on the Coulomb stress change produced by Anchorage earthquake in the neighboring region and faults. The results show that the mainshock has triggered subsequent aftershocks, most of which are located in stress-increased region. The Anchorage earthquake also imparts Coulomb stress change on the Castle Mountain fault, with different fault segment ranging from − 2 × 105 to 3.27 bar. Similarly, on the Border Range fault, this stress ranges from − 0.71 to 3.31 bar despite being inactive fault on present knowledge. Furthermore, on nodal planes I and II of the Anchorage Mw7.0 earthquake, the Coulomb stress change imparted by the 1964 Mw9.2 earthquake ranges from 2.490 to 3.968 bar and from 3.283 to 5.140 bar, respectively. These results indicate that the 1964 Mw9.2 earthquake produces a large amount of Coulomb stress on the seismogenic fault plane of the Anchorage Mw7.0 earthquake and promote it more closer to failure. These results contribute to our understanding of the seismic hazard in the region and on fault segments where the Coulomb stress has been sharply changed.