Tag Archives: AEC

Denali Fault Quake

Photo credit: Daily News-Miner

This week is the 17 year anniversary of the 2002 Denali Earthquake. At a magnitude of 7.9, to date, it is the largest quake I have personally experienced.

On 23 October 2002, the Denali Fault released a magnitude 6.7 quake. That would be a foreshock of what was to come on November 3.

Highway Shift; Richardson Highway, circa 2002

After the 6.7, I remember the Alaska Earthquake Center saying that the Denali Fault was capable of producing an 8.0. Sure enough, the fault came very close.

I was at an intersection in my ’66 Chevy C-20. All of a sudden, the truck was lurching all over the place, and I found it hard to stay on the brake pedal. There were two university students in the next lane, the passenger rolled down his window and asked what the hell was happening. I said, “Earthquake”. He then promptly hit the driver on the arm and said, “I told you it was an earthquake”.

The light changed, I drove on, but had to stop at the next light. The earth was still shaking. An elderly couple had been walking on the sidewalk, and the wife fell to the concrete, the husband was struggling to stay upright by hugging a signpost. Then the shaking was over. I rolled down the other window, to see if the couple was all right. They were, and I headed home to see if there was any damage.

The quake had ruptured 205 miles of earth along three different, yet connected faults in Interior Alaska. It was the largest ever recorded in Alaska’s Interior. It was the largest inland quake North America had seen in almost 150 years.

Both the Parks & Richardson Highways saw major damage. The Trans-Alaska Pipeline moved sideways 18 feet, and rose 5 feet. The engineers had designed for the fault, and the pipeline behaved exactly as it was designed to behave. Although, it did come within two feet of its sideways movement limit.

The Denali Earthquake was felt as far away as Louisiana.

Previously, the largest earthquake Fairbanks had experienced was a magnitude 7.3 in 1937.


How’s it shaking?


Sensor monitor reading at University of Alaska

Interior Alaskans felt the Earth move a bit on Tuesday morning. It wasn’t a big earthquake, at only magnitude 4.6, but it was widely felt at 7:18am. It’s note worthy, mainly because it has been a couple of years since I felt one pass through.

On Sunday morning, Kaktovik, which is located on the Beaufort Sea coast, woke up to a 6.4 magnitude quake. It was the largest earthquake ever recorded on Alaska’s North Slope.

Earthquakes in Alaska are far from unusual. An earthquake is detected once every 15 minutes, on average, within the state. In 2014, Alaska set a record with over 40,000 shakes. Over the past five years, the Alaska Earthquake Center has reported over 150,000 earthquakes. Of those, 31 had a magnitude over 6.0. and four went over 7.0. Seventy-five percent of all earthquakes over 5.0 within the United States happen in Alaska.

The 7.9 magnitude quake, that hit us in 2002 when the Denali Fault ruptured, is the largest I have experience. The 1964 Good Friday Earthquake was a magnitude 9.2, and it is still the second largest earthquake ever recorded anywhere on the globe.

Graph and stats credit: Alaska Earthquake Center