During the morning rush hour in Anchorage, Alaska, the city of nearly 300,000 was rocked by a major earthquake. The epicenter was approximately 8 miles north of the city.
It appears the city received magnitude 6 to 6.5 shaking, which is enough to cause damage, but not catastrophic. Remember, a magnitude 7 is 10 times stronger than a magnitude 6.
Earthquake intensity is based on a base 10 logarithmic scale. This earthquake damage is like a storm surge.
During Hurricane Michael, the most severe damage was confined to Mexico Beach, Florida. The damage along the remainder of the Panhandle was bad, but not catastrophic.
Thankfully, this earthquake was not directly underneath Anchorage.
Alaska is no stranger to earthquakes, but remember, much of the state is uninhabited. This earthquake, unfortunately, rocked the most populated part of the state.
Alaska, on average, sees one “great” magnitude 8.0 or high earthquake every 13 years, one magnitude 7-8 earthquake every year, and six magnitude 6-7 earthquakes per year.
Alaska is also home to the strongest earthquake in US history – a 9.2 quake back in 1964.
This part of Alaska sits on the edge of the North American Plate and the Pacific Plate. The North American Plate is moving west and the Pacific Plate is moving northwest.
Friction builds between the moving plates and eventually, they slip causing an earthquake. Horizontal movement of the plates causes a column of water to be displaced and that heightens the threat for a tsunami.
Although the epicenter of the quake was north of the city, there was still relatively significant damage and that’s because it was shallow. The more shallow the earthquake, typically the worse the damage.