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DOT&PF Construction is starting repair work to the buckled asphalt on the New SewardHighway between Tudor Road and 36th Avenue. Use Trunk Road detour via the Parks Highway to access Palmer. If you are traveling in the Anchorage area today, please watch out for our bridge inspectors. They will have lights and reflective vests and are in the process of conducting technical bridge inspections.
The Matanuska-Susitna Borough School District reported that Houston Middle School, located in the town of Houston, was severely damaged, and students were forced to merge with their high school for the remainder of the year. Colony Middle School students were the last to return to learning. Severe damage to several buildings and a highway overpass near Ted Stevens Anchorage International Airport was reported. There were no fatalities, but at least 117 people were injured, mostly for minor injuries such as cuts, bruises or anxiety.
Anchorage earthquake left crumbling buildings, collapsed roofs and damaged roads
Where these two plates meet, the dense oceanic rocks of the Pacific thrust under the more buoyant continental rocks of Alaska. The quake was a type that usually produces less vertical motion, which means less chance for waves to build for a tsunami, said Paul Earle, a seismologist with the U.S. That was somewhat unusual, because quakes in the area usually are a type that cause more vertical motion and increase the chance for a tsunami, he said.
She told CNN that students were evacuated after the first main aftershock. ANCHORAGE — Tomasz Sulczynski had been driving for nearly four hours through rural Alaska on Friday when the biggest earthquake to hit the state in half a century began twisting the road beneath him. The airport terminal buildings sustained minor damage to light fixtures, water pipes, and windows. The DOT&PF Division of Facilities Services is conducting building assessments of state-owned buildings in the areas affected by the earthquake. Facilities staff will be working through the night and the weekend to assess damage and prepare for recovery. All DOT&PF Bridge inspectors are now in Southcentral Alaska and are conducting technical bridge inspections this morning.
Damage
As the EarthScope Transportable Array project added new seismic stations in previously unmonitored areas, we noticed an upward trend of detectable earthquakes from around the state. The westernmost Aleutians megathrust earthquake followed a year later on February 4, 1965. This M8.7 Rat Islands earthquake was characterized by roughly 600 km of rupture. Although this event is quite large, damage was low owing to the region's remote and sparsely inhabited location. A relatively small tsunami was recorded throughout the Pacific Ocean with run-up heights up to 10.7 m on Shemya Island and flooding on Amchitka Island.
They have some damage and flights may be impacted, travelers should call their individual carriers. Bridges and roadways north of Talkeetna have been reviewed and are clear. Roads in the Anchorage area and some leading to the airport are impassible.
Tsunami Hazard Map Tool
In the Anchorage community of Eagle River, at least one home collapsed during the earthquake. One man in the home, whose spouse was at work, was able to escape with several pets. DOT&PF Maintenance and Construction crews are now actively working the eight major damage sites. Aftershocks are continuing to contribute to settling and additional cracking. After this earthquake, we will need to make repairs to some bridges to ensure they are safe for the traveling public.
DOT&PF and DOA continue to work together to ensure all workplaces are safe for employees and the public to return and are working to limit traffic on the Glenn Highway. Please report property damage to your department Administrative Service Director directly. ASDs are creating comprehensive lists of damage to be forwarded on to SSOA and Risk Management. We have some additional work in the SB today, but will open up to three lanes as soon as we can. Employees are expected to verify if their regular work site has been inspected and cleared. Please note that the following lists are being actively updated.
Earthquake
While these models are relatively simple, initial reports support these conclusions. This photo provided by David Harper shows merchandise that fell off the shelves during an earthquake at a store in Anchorage, Alaska, on Friday, Nov. 30, 2018. Near the location of the January 23 earthquake, the Pacific Plate is moving to the north-northwest, toward the North American Plate at a rate of approximately 59 mm/year .
A tsunami warning was initially activated for the Cook Inlet area and Southern Kenai Peninsula, according to the National Oceanic and Atmospheric Administration, but it was lifted about 90 minutes after the initial shock. The Volcano Observatory combines these with other observations, including geology, satellite imagery, ground deformation and local observations to assess volcano hazards. The vigor of these faults, and our knowledge of them, generally decreases toward the north, although the impact of this compression can be traced all the way into the Arctic Ocean. Meanwhile, this northwest motion of the Pacific Plate exerts tremendous force on Alaska, compressing the land in a north-south direction and shearing or tugging southern Alaska to the west.
Examples of this type of earthquake include the 1964 magnitude 9.2 Good Friday Earthquake and the 1965 magnitude 8.7 Rat Islands Earthquake, the second and eighth largest earthquakes ever recorded worldwide. It prompted the warning across thousands of miles of Alaska's southern coast, from Attu in the Aleutian Islands to Canada's border with Washington state. Kodiak is about 200 miles south of Anchorage, the state's largest city, which was not under a tsunami threat. "Earthquake-damaged Mat-Su school to remain closed the rest of the school year". Over 80 aftershocks of various magnitudes were recorded throughout the day, with at least three having magnitudes greater than 5.0.
DOT&PF has documented over 40 damage sites on transportation infrastructure. DOT&PF has documented approximately 50 sites of potential damage sites. Northbound Briggs Bridge on Eagle River Loop Road is now closed. If a bridge is determined to be unsafe to travel over , we will close the area to travel. If the bridge is determined to be structurally sound, it will remain open.
This is a different mechanism than megathrust faults in the region, which do occur on the plate boundary itself. This faulting in the Pacific Plate is caused by downward bending while the plate is being forced under Alaska. Southern Alaska lies at the eastern end of the Aleutian Trench, where the Pacific Plate is subducting beneath the North American Plate. Near Anchorage, the plates are converging at a rate of 57 mm per year. The region has experienced severe earthquakes in the past, including several megathrust earthquakes. The 1964 earthquake, with a magnitude of 9.2, was the largest earthquake in American history and the second largest to ever be recorded anywhere in the world.
In addition, Matanuska Electric Association reported that 46,000 customers were left without electricity immediately after the earthquake. The earthquake had a magnitude of 7.1 on the moment magnitude scale using a centroid moment tensor inversion of the W-phase. The focal mechanism shows that the earthquake was a result of normal faulting.
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