Wednesday, July 22, 2020

Multiple Aftershocks Follow 7.8 Quake: 20 Between 2.8 and 6.1 Magnitude

Jason Hanna and Madeline Holcombe

An earthquake with a magnitude of 7.8 struck off southern Alaska's coast late Tuesday, shaking the Alaska Peninsula and briefly sparking tsunami concerns before officials said no destructive waves were coming.
The earthquake was centered in the Pacific Ocean about 60 miles southeast of Perryville on the sparsely populated Alaska Peninsula, striking around 10:12 p.m. local time (2:12 a.m. Wednesday ET).
The Alaska Peninsula protrudes from mainland Alaska and is flanked to the southwest by the Aleutian Islands. 
Reports of significant damage, if any, weren't immediately available. A tsunami warning initially was issued for south Alaska and the Alaska Peninsula, but was canceled by early Wednesday, according to the National Oceanic and Atmospheric Administration.
The warning sent people to higher ground in cities like Sand Point, an island community of about 1,000 people off the peninsula, the Anchorage Daily News reported.

Strong shaking was reported on the peninsula, the USGS said. Light to weak shaking was reported around Kodiak, about 300 miles northeast of the quake's center, and in Anchorage, some 530 miles from the center, according to the USGS.

In Kodiak, a city of about 6,000 people, a long line of cars headed up a mountain after residents learned of the tsunami warning late Tuesday, John Cannon told KTUU.

Police were "trying to clear the lower areas down by the harbor," he said.
"You (could) hear the tsunami alarms. It's rather eerie," he told KTUU.
This quake's depth was 28 kilometers, or 17 miles, the USGS said -- relatively shallow.
    "Anything below 70 kilometers is considered a shallow quake," CNN meteorologist Allison Chinchar said. "That's important, because shallow earthquakes often cause the most damage, compared to the ones that are deeper, regardless of the strength."
    More than 20 aftershocks followed the quake late Tuesday to early Wednesday, ranging from magnitudes of 2.8 to 6.1.


    A 6.5 magnitude earthquake struck off the coast of Fiji this morning, the US Geological Survey says.

    The quake occurred just before 9.30am and was centred 42km east-north-east of Fiji’s Ndoi Island, and 423km south-east of the capital Suva and 336km west-north-west of Tonga’s capital Nuku’alofa.

    The quake struck at a depth of 349 miles.No tsunami warning has been issued.

    Deeper quakes are less noticeable while a shallow quake–in the 0 to 40 mile depth range–can feel much stronger than their actual reported magnitude. Quakes just below the earth’s surface, in the 0 to 10 miles range, can cause even more damage at lower magnitudes.

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