Queen Charlotte Fault
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The Queen Charlotte Fault is an active transform fault, located between the North American Plate and the Pacific Plate, Canada's equivalent of the San Andreas Fault. The Queen Charlotte Fault forms a triple junction on its south with the Cascadia subduction zone and the Explorer Ridge (the Queen Charlotte Triple Junction). The fault is named for Queen Charlotte Island which lies just north of the triple junction. The Queen Charlotte Fault continues northward along the Alaskan coast where it is called the Fairweather Fault. The two segments are collectively called the Queen Charlotte-Fairweather Fault System.
The fault has been the focus of large earthquakes. The study of the Queen Charlotte Fault affords further important information applicable to other similar faults throughout the world. [1]
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[edit] Significant earthquakes along the fault
Three large earthquakes have occurred along the Queen Charlotte Fault during the 20th century: a magnitude 7 event in 1929, a magnitude 8.1 occurred in 1949 (Canada's largest recorded earthquake since the 1700 Cascadia earthquake) and a magnitude 7.4 in 1970. The P nodal focal mechanism for the 1949 earthquake indicates virtually pure strike-slip movement with a northwest striking nodal plane corresponding to the strike of the fault, whilst the 1970 earthquake shows a similar strike-slip movement with a small but significant thrust component, consistent with relative plate motion. The 1949 earthquake was larger than the 1906 San Francisco earthquake, causing nearly a 500 kilometer long segment of the Queen Charlotte Fault to break.
A pair of 6.5 magnitude quakes occurred on January 5, 2008 near the southern triple junction, although they do not appear to have occurred directly on the Queen Charlotte Fault.[2]
| Year | Moment Magnitude | Casualties |
|---|---|---|
| 1929 | 7 | |
| 1949 | 8.1 | |
| 1970 | 7.4 | |
| 1990 | 5.3 | |
| 2001 | 6.3 | |
| 2004 | 6.8 | |
| 2008 | 6.5 |
