Mississippi River valley and Yellowstone Park region among the regions susceptible to shaking damage
Six decades ago, the largest city in Alaska became Ground Zero for the most powerful earthquake in North American history.
The 1964 seismic catastrophe, which registered a shocking 9.2 magnitude, sent tsunamis crashing into coastal towns as far away as Hawaii and Japan. Waves at the Alaskan port town of Valdez rose to 220 feet high. Some 131 people died, including four in Oregon and 12 in California. Property damage to buildings, streets, and other infrastructure totaled about $9.5 billion, adjusted to 2024 inflation.
Recent studies by the U.S. Geological Survey and other entities conclude that another major quake impacting a significant number of people again is not a question of if, but when. While Alaska, California, and other far Western states are generally the most common targets of seismic activity, other areas, including around the Mississippi River valley and Yellowstone National Park region, are susceptible, according to a new map released by the federal agency.
The color-coded USGS map pinpoints where damaging earthquakes are most likely to occur based on seismic studies and other data. The areas in red and dark red on the map are most likely to be hit with major earthquakes in the near future. Those areas include not just much of Alaska, California, and the Seattle region, but parts of Nevada, Wyoming, Idaho, Montana, Missouri, Arkansas, Tennessee, and Kentucky.
"Nearly 75 percent of the U.S. could experience potentially damaging earthquakes and intense ground shaking, putting hundreds of millions of people at risk," USGS officials recently said.
The last significant earthquake in the U.S. happened in July 2023 about 66 miles south of Sand Point, a village on Popof Island off the Alaskan Peninsula. The quake registered a magnitude of 7.2 . There were no injuries, though some reported the ground shaking in numerous communities on the Alaska Peninsula and eastern Aleutian Islands, according to the University of Alaska-Fairbanks' Earthquake Center.
In December 2022, an earthquake measuring 6.4 magnitude struck the coast of Humboldt County in northern California, leading to two deaths of seniors who had medical emergencies and couldn't get services in time. Another 17 people were injured. Many reported damaged homes and buildings, as well as power outages.
Predicting future quakes
Seismologists say that earthquakes can't be accurately predicted, but they can give some guidelines on the most dangerous areas.
"Earthquakes are difficult to forecast, but we’ve made great strides with this new model," Mark Peterson, USGS geophysicist and lead author of the study, said in a statement. "The update includes more faults, better-characterized land surfaces, and computational advancements in modeling that provide the most detailed view ever of the earthquake risks we face."
The latest process identified nearly 500 additional faults that could produce a damaging quake from previous versions. Those new faults included some in the Midwest just north of Memphis, Tenn., as well as along the central and northeastern Atlantic Coastal corridor.
In 2020, a 5.1-magnitude quake centered in the northwestern North Carolina town of Sparta caused building damage, including 60 with major damage. One person was injured when a large picture frame fell on him.
Oklahoma, which is known for tornadoes, is another state that has reported more seismic events than many might think. Between 2010 and 2015, the state experienced more quakes with a magnitude of at least 3.0 than any other except Alaska. In 2016, a 5.8-magnitude one near the northern Oklahoma town of Pawnee resulted in severe building damage. A man was injured by a falling chimney as he sheltered a child.
Most seismic activity in the Northeast is relatively mild, though a 5.8-magnitude quake centered in Virginia caused much damage in 2011, including to the Washington Monument. In mid-March, quakes occurred in several northeastern states, including New Jersey, New York, and Maine. A 2.2-magnitude one in New Jersey on March 14 resulted in numerous people reporting movement, along with a loud noise.
Anchorage still feeling shock effects six decades later
The earthquake that hit around 5:36 p.m. on March 27, 1964, had its epicenter about 80 miles east of Anchorage. But its effect to Alaska's largest city and other areas of the state was immediate.
Anchorage, which had about 46,000 residents in 1964 and has grown sixfold since then, saw some 30 blocks of homes and commercial buildings destroyed in its downtown area. The shaking occurred for more than four minutes. Sidewalks, water mains, and streets collapsed in landslides. Homes slid for one-third of a mile. The airport traffic control tower collapsed.
Mary "Tay" Thomas, a writer and Anchorage School Board member from 1968 to 1974 whose husband was a lieutenant governor, wrote in National Geographic, "Our whole lawn broke up into chunks of dirt, rock, snow and ice. We were left on a wildly bucking slab; suddenly it tilted sharply, and we had to hang on to keep from slipping into a yawning chasm."
Bob Pate, a salesman for radio station KHAR in Anchorage, recorded his thoughts as he sat in his shaking one-story, wood-frame house. While cabinet doors swung open and dishes, pictures, and furniture fell, his home was among the fortunate ones with little damage. "I was falling all over the place here," he excitedly said. "It started as a real low rumble, and then all of a sudden, it built up in intensity and the whole place was shaking. The doors of the cabinets were open.....The lamps fell over....Everything in the bathroom is in shambles. Glass fell off the cabinets."
Rebuilding efforts were led by the U.S. Army Corps of Engineers, costing some $110 million. A state emergency services department and tsunami warning center were developed. Workers installed a network of instruments in the downtown Robert Atwood Building, the second tallest building in Alaska at 20 stories, to monitor seismic activity and how much it sways during quakes.
Probably the most apparent effect of the 1964 disaster these days is the sharp land drop-off and rippling hills surronding Earthquake Park, which includes a monument, interpretive displays, and trails. Some areas were lifted permanently by as much as 30 feet, while others declined by some eight feet.
Numerous events are slated in Anchorage to commemorate the disaster. Among those is a film scheduled for March 30 at the Alaska State Library.
Most powerful U.S. quakes
Alaska, being close to the place where the Pacific tectonic plate converges with the North American plate and causes havoc, has seen most of the ten most powerful earthquakes in the U.S. since 1905. More than 1,000 quakes with a magnitude of at least 3.0 occur in Alaska each year, much more than any other state.
Location .... Date ..... Magnitude ..... Deaths
1. Anchorage, Ak. .... March 27, 1964 .... 9.2 .... 131
2. Rat Islands, Ak. .... Feb. 4, 1965..... 8.7 .... 0
3. Aleutian Islands, Ak. .... April 1, 1946 .... 8.6 .... 165
3. Andreanof Islands, Ak. .... March 9, 1957 .... 8.6 .... 0
5. Aleutian Is., Ak. .... Aug. 17, 1906 .... 8.4 .... 0
6. Alaska Peninsula, Ak. ... Nov. 10, 1938 ... 8.2 ... 0
6. Chignik, Ak. .... July 29, 2021 .... 8.2 ....0
8. Aleutian Is., Ak. ... May 7, 1986 .... 8.0 .... 0
9. San Francisco, Ca. .... April 18, 1906 .... 7.9 .... 3,000
9. Gulf of Alaska .... Jan. 23, 2018 .... 7.9 .... 0
9. Aleutian Is., Ak. .... June 23, 2014 .... 7.9 .... 0
9. Denali, Ak. .... Nov. 3, 2002 ... 7.9 .... 0
9. Andreanof Is., Ak. .... June 10, 1996 .... 7.9 .... 0
9. Gulf of Alaska .... Nov. 30, 1987 ... 7.9 .... 0
Sources: USGS, NOAA
State .... Quakes 3.0M+, 2010-2015
Alaska .... 9,020
Oklahoma .... 1,714
California .... 1,545
Nevada .... 513
Wyoming .... 508
Hawaii .... 200
Kansas .... 104
Idaho .... 95
Source: USGS
Comments / 234