2013 Craig, Alaska earthquake

The Queen Charlotte Fault is a major right-lateral (dextral) strike-slip and transform fault running off the coast of British Columbia and into Southern Alaska, through the Saint Elias Range for more than 700 miles. Its southernmost section joins a spreading ridge of the Gorda plate and the Cascadia subduction zone while the northern termination section joins the a thrust fault where the Yakutat terrane plows into the North American plate. It has been the source of several large earthquakes in the 20th century, and appears that much of its length has ruptured in these events. In 1949, it produced a magnitude 8.1 earthquake off the west coast of Haida Gwaii, then in 1958, a magnitude 7.8 earthquake generated a megatsunami more than 500 meters tall, killing five people. Other earthquakes in the region include a 7.6 near Sitka, and the 2012 event. The Queen Charlotte Fault bears a similar resemblance with California's San Andreas Fault, another transform fault to the south. ==Earthquake==

The rupture zone is situated on a seismic gap between fault segments which ruptured in 1972 to its north, and the other to the south in 1949. The largest earthquake prior to the 7.5 quake along this gap was a magnitude 6.8 to the south of the 2013 epicenter. The 2013 earthquake ruptured for a length of 150 km (93 mi), 322 km (200 mi) north of the 2012 event. The Craig earthquake, on the other hand, was a near pure strike-slip event which was probably in response to stress transfer from the quake four months ago. The rupture propagated northwards, away from the epicenter, with an initial rupture velocity of 3.0 km. Aftershocks More than 290 aftershocks greater than magnitude 2.5 were recorded in the aftermath of the earthquake from 2013 to 2020. Most of them were along other fault structures away from the main fault. This is also commonly seen in other supershear earthquakes. ==Impact==

A maximum intensity of V (Moderate) was felt in Craig, Hydaburg, Klawock and Hyder without damage, A tsunami warning was broadcast from Cape Fairweather, Alaska to northern Vancouver Island, while a tsunami advisory was issued to the coast of Washington. It was later canceled after no large waves were observed. The shock frightened many who fled to higher grounds to avoid the tsunami. Tsunami Because the earthquake was of almost pure strike-slip mechanism, only small waves were produced without damage. These waves were up to 14 cm high. Seiches up to 1.5 meters high were also recorded at Deer Lake, Alaska, north of Port Alexander. The small waves however, were not detected by Ocean Networks Canada. ==See also==