1964 Anchorage, Alaska, earthquake and tsunami arrested without warning on Good Friday, March 27.
It was a quiet spring day in Anchorage, a holiday. Temperatures have been unseasonably mild to moderate amount of snow on the ground. Children had the day off from school, and customer traffic in the center of the store was light. Many residents were preparing or enjoying dinner at home. At 5:36 pm a major earthquake began to shake the earth, and the earth beneeth Southcentral Alaska moved in waves for the next four minutes long.
Parents and children slipped, stumbled and fell to the ground sliding panic in an effort to get outdoors, to avoid breaking the window. Two inches to the & # 39 cracks appeared in the ground in many places. Roads wrinkled and split and Fourth Avenue in downtown Anchorage broke and collapsed 10 feet or more. The Government Hill Elementary School twisted, shifted and became unusable at the moment. The outer wall of JC Penney building crashed to the street. In the Turnagain residential district the ground liquefied like a swimmer, slid, and swallowed up 75 or more homes.
Four minutes of the earthquake released energy equivalent to about 10 million times the forces of the atomic bomb. The mass of the earth and the oceans absorb much of the force, but man-made structures in the area may not absorb the rest of the force without suffering huge losses. The total material damage is estimated at $ 500 million.
Anchorage inoperative gas lines and water lines were severed abruptly. Residents turned to melting snow for water while waiting for repairs. Four days later students returned to available schools, life in Anchorage began to recover.
Earthquake Center in Alaska was located about 75 miles east of Anchorage and about 55 miles west of Valdez. It began 14 to 16 miles deep into the earth, and # 39; crust, a comparatively shallow depth, where the Pacific plate dives favor North American plate. The huge subduction zone is located in the north of Ring of Fire, a semicircle of volcanic and earthquake activity that defines the edge of the Pacific Ocean.
earthquake fault, more precisely advancing what caused the earthquake on Good Friday stretched 750 miles from Alaska & # 39; s Valdez Aleutian Islands. Pacific plate that day moved about 25 to 30 feet northward, diving beneath the North American plate. Grinding two massive tectonic plates caused the Alaska earthquake and measured 8.4 on the Richter scale. In subsequent years, the measurement of the earthquake in Alaska was raised to 9.2 to Mw, or moment magnitude, scale as the Richter scale was determined to be inaccurate when measuring very large earthquakes above 8.0. During the day, the initial major earthquake 11 more than a tremor of 6.0 or more to shake already nervous population. In fact, aftershocks continued for nearly a year.
The earthquake caused the ground to displace upward by as much as 25 feet on several islands in Alaska nearly 3 feet upward at the city of Valdez. In other areas, the soil is displaced downward as much as 9 feet, for example, in Portage city.
An earthquake in Alaska on Good Friday was the strongest earthquake ever recorded in North America. It was the second strongest ever recorded in the world, surpassed in strength of the earthquake at 9.5 MW in Chile, 22 in 1960, my recent December 26, 2004, an earthquake off the coast of the Indonesian island of Sumatra measured 9.0 MW. Death earthquake in Shaanxi Province, China, in 1556, killing more than 830 thousand inhabitants.
tsunami with & # 39 is an adapted Japanese word meaning "harbor wave", a reference to the fact that the wave of & # 39; s danger and destructive power only become evident as it approaches the shore.
During the 1964 earthquake in Alaska in North America plate released upward, displacing a huge on the & # 39; the volume of ocean water and causing a seismic wave, a tsunami, to travel outward. Wave traveled an estimated 450 miles per hour in the deeper ocean in a long wave of almost imperceptible height.
As the tsunami wave passed over the continental shelf and approached shore its length reduced, its velocity decreases and its height is increased by a massive on & # 39; the volume and mass of water prepared to release its incredible energy on anything in its path.
The shallow Valdez input wave reached a maximum height of about 200 feet. Further, in the Old Town Valdez, 30-foot wall of water was delayed and destroyed all the buildings. Twenty eight Valdez residents died when the tsunami dropped ashore. Valdez was later rebuilt to a higher altitude and farther away from the coastline.
In Seward, Alaska, the earthquake caused part of the bay to slide. Slide caused a local tsunami that devastated Seward & # 39; s port and downtown district, both of which were eventually rebuilt. Twelve residents perished in Seward.
The small town of Portage was bound by its own local tsunami and not relocated or rebuilt. Other local tsunamis small port of Whittier killing of 12 residents.
Original tsunami traveled about 8400 miles. It caused damage in Hawaii and along the coast of Oregon and California. A 20-foot wave of contract Crescent City, California, and killed 10 people. The tsunami was responsible for the deaths of 16 people in Oregon and California.
The tsunami killed a total of 122 people in three states. For comparison, the earthquake has caused 9 fatalities.
It took more than 40 years after the earthquake and tsunami in Alaska. At the same time, building materials and construction methods have been tougher to create structures capable of withstanding a powerful earthquake. In addition, at the same time, the population of Alaska and # 39, S vulnerable areas increased significantly.
Smaller earthquakes along Alaska & # 39 Speed subduction zone and other fault zones occur on a daily basis, presumably facilitating internal pressure that could produce another massive earthquake.
However, no one knows with certainty when, where, or another huge and destructive land hit Alaska.