2. The 1964 Alaskan earthquake…
…also known as the Great Alaskan Earthquake, the
Portage Earthquake and the Good Friday Earthquake,
lasted nearly four minutes on Good Friday, March 27,
1964. This megathrust earthquake attacked south-central
Alaska and caused ground fissures, collapsing structures,
and tsunamis.
It was the most powerful recorded earthquake in U.S. and
North American history, at a shocking magnitude of 9.2,
and the second most powerful in the entire world, only to
the horrible1960 Valdivia earthquake, also known as the
Great Chilean Earthquake.
3. Wikipedia states…
“The powerful earthquake
produced earthquake liquefaction
in the region. Ground fissures and
failures caused major structural
damage in several communities,
much damage to property and
several landslides. Anchorage (my
hometown) sustained great
destruction or damage to many
inadequately engineered houses,
buildings, and infrastructure (paved
streets, sidewalks, water and sewer
mains, electrical systems, and other
man-made equipment), particularly
in the several landslide zones along
Knik Arm. Two hundred miles
southwest, some areas near Kodiak
were permanently raised by 30 feet
(9.1 m). Southeast of Anchorage,
areas around the head of
Turnagain Arm near Girdwood and
Portage dropped as much as 8 feet
(2.4 m), requiring reconstruction
and fill to raise the Seward Highway
above the new high tide mark.”
5. The damage…
Most damage occurred in
Anchorage, 75 miles northwest of the
epicenter. Luckily, Anchorage was
not hit by tsunamis. But downtown
Anchorage was still severely
damaged, and parts of the city built
on sandy bluffs overlying "Bootlegger
Cove clay" near Cook Inlet, most
notably the Turnagain neighborhood,
suffered landslide damage.
The neighborhood lost a total of 75
houses in the landslide, and the
destroyed area has since been
turned into Earthquake Park.
The Government Hill school was left in
two jagged, broken pieces due to a
landslide. Land overlooking the Ship
Creek valley near the Alaska Railroad
yards also slid, destroying many acres
of buildings and city blocks in
downtown Anchorage.
Most other areas of the city were
only moderately damaged. The 60-
foot concrete control tower at
Anchorage International Airport was
not engineered to withstand
earthquake activity and actually
collapsed, killing one employee.
7. Interesting tidbits…
Valdez, AK was not totally destroyed, but after three years,
the town relocated to higher ground 7 km (4 mi) west of its
original site
The earthquake caused the Cold-War era ballistic missile
detection radar of Clear Air Force Station to go offline for six
minutes, the only unscheduled interruption in its operational
history
Near Cordova, the Million Dollar Bridge crossing the Copper
River also collapsed
Other towns along the U.S. Pacific Northwest and Hawaii
were damaged
Minor damage to boats reached as far south as Los
Angeles
Several fishing boats were sunk in Louisiana, and water
sloshed in wells in Africa
8. Aftershocks…
There were literally
thousands of aftershocks
for three weeks,
following the major, life-
shattering earthquake.
On the first day alone,
eleven scary aftershocks
were recorded with a
magnitude greater than
6.2. Nine more ensued
over the next three
weeks.
More than a year later,
the aftershocks stopped.
