Juneau, Alaska (KINY) Researchers from NOAA, the U.S. Geological Survey and their partners have completed the first high-resolution, comprehensive mapping of one of the fastest moving underwater tectonic faults in the world, located in southeastern Alaska.
This information will help communities in coastal Alaska and Canada to better understand and prepare for the risks from earthquakes and tsunamis that can occur when faults suddenly move.
Since 2015, scientists have been gathering data on the Queen Charlotte-Fairweather fault system, a 746-mile long strike-slip fault line that extends from offshore of Vancouver Island, Canada, to the Fairweather Range of southeast Alaska. The team has gathered high-resolution bathymetric data through multibeam sonar across 5,792 square miles of the ocean bottom.
Scientist Peter Haeussler said the goals of the project is to better understand the location and the structure of the fault system. He called it the main plate boundary fault between America's west coast and southeast Alaska.
He said many think of the fault as the San Andreas fault, "We know that fault is on land, the Queen Charlotte fault is mostly offshore and under water."
Haeussler said until now they really didn't know where the fault was. He described it as a gouge in the ocean bottom, "The last piece was the southern most part of the fault off shore in US waters north to noise canyon."
He said it will help authorities researchers realize where an earthquake ruptures might end and also the magnitude of earthquakes. "If there were submarine landslide hazards with earth quake ruptures, we were concerned about it in noise canyon. We wanted to know if a big earthquake triggered an underwater landslide."
He noted the fault system has made really large earthquakes in the past. In 1949 magnitude 8.1 earthquake struck west of Juneau. The most famous earth quake was the July, 9,1958 quake that started off shore in Lituya Bay near Elfin Bay and Glacier Bay National Park. A 1,720 feet tsunami occurred and led to the deaths of five people. Damage was reported as far away as Pelican and Sitka.