In Ankorizhy 1964, in Alaska, the earthquake and tsunami occurred tsunami without warning on Good Friday, March 27.
It was a quiet spring day in Ankorizh, holiday. The air temperature was moderate, with the average number of snow on the ground. The children had the day off from school, and the movement of customers in the shops in the center was small. Many residents were preparing or enjoying dinner at home. At 5:36 pm a major earthquake began to shake the earth, and the earth under the South Central Alaska moved in waves for the next four minutes long.
Parents and children slipped, stumbled and fell to the floor in panic shift efforts to go out, to avoid broken windows. Two inch cracks with & # 39 appeared in the ground in many places. Roads wrinkled and split and Fourth Avenue in downtown Anchorage broke collapsed 10 feet or more. Elementary School Government Hill curled up, moved, and in an instant became unusable. The outer wall of JC Penney building crashed to the street. In a residential neighborhood Turnagen land razrezhvalasya how calm, slipped and swallowed 75 or more houses.
Four minutes of the earthquake released energy equivalent to approximately 10 million power of the atomic bomb. The mass of the earth and ocean absorbed most of the force, but man-made structure in the area could not absorb the rest of the force without suffering massive damage. Total property damage was estimated at $ 500 million.
The fortress was crippled when gas and water were drastically broken. Residents turn to melting snow for water, waiting for repair. Four days later, the students returned to available schools as life in Anchorage began to recover.
Earthquake Center in Alaska, was about 75 miles east of Anchorage and about 55 miles west of Valdez. It began in the depths of the earth's crust 14-16 miles, a relatively shallow depth, where the Pacific plate sinks beneath the North American plate. Huge subduktsyi zone situated at the northern end of the fire ring and zemlyatrusnay semicircle volcanic activity, defining the Pacific rim.
Earthquake fault, more precisely, the irritation that caused the earthquake Good Friday, raspastsirylasya 750 miles from the Alaskan Islands to Valdez. Pacific plate that day moved an estimated 25 to 30 feet to the north, sinking beneath the North American plate. Resurfacing of two massive tectonic plates caused an earthquake in Alaska and was 8.4 on the Richter scale. In subsequent years, the measurement of the earthquake in Alaska was raised to 9.2 by MW, or the magnitude of the time, since the Richter scale was determined by the inaccuracy in the measurement of very large earthquakes above 8.0. On the day of the initial big earthquake 11 more tremors of 6.0 and a shake already nervous population. In fact, tremor lasted almost a year.
The earthquake led to the fact that the earth has moved up 25 feet on several alyaskanskih islands and by nearly 3 feet upward at the city of Valdez. In other parts of the earth has moved down by as much as 9 feet, for example, in the town of Portage.
An earthquake in Alaska on Good Friday was the strongest earthquake recorded in North America. It was the second most powerful in the world, which was recorded as a result of the earthquake of 9.5 MW in Chile 22, my 1960. In December, 26 December 2004 earthquake off the coast of the Indonesian island of Sumatra was 9.0 MW. The deadliest earthquake occurred in Shensi Province, China, in 1556, killing more than 830 000 inhabitants.
tsunami – This device is a Japanese word that means "wave port", a reference to the fact that the danger and destructive power of the waves only become apparent when approaching the shore.
During an earthquake in Alaska in 1964 the North American plate released upward vytsyasnivshy huge on & # 39; The volume of ocean water and causing a seismic wave, a tsunami, stand out. Waves traveling approximately 450 miles per hour in the deep ocean at a wavelength of almost imperceptible height.
If a tsunami wave passed over the continental shelf and approached shore its length was reduced, its velocity decreases and height increases when a massive & # 39; the volume and weight of the water getting ready to release an incredible energy on anything in its path.
On a shallow inlet Valdez wave reached a maximum height of almost 200 feet. Further, in the old town Valdez 30-foot wall of water struck and destroyed all the buildings. Twenty eight Valdez residents died when the tsunami crashed ashore. Later, Valdes was rebuilt at a higher elevation and farther away from the waterfront.
In Seward, Alaska, the earthquake caused part of the bay. Slide caused a local tsunami which devastated Seward's port and the city center, both of them were eventually restored. Twelve residents perished in Seward.
The small town of Portage was erected its own local tsunami and never moved and restored. Another local tsunami struck the small port of one's, who was killed 12 residents.
Original tsunami was about 8400 miles. It caused damage in Hawaii, along the coast of Oregon and California. A wave of 20 feet struck the Krestsent City, California, and killed 10 people. The tsunami caused the deaths of 16 people in Oregon and California.
The three states of the tsunami killed 122 people. For comparison, the earthquake resulted in 9 deaths.
It has been over 40 years since the earthquake and tsunami in Alaska. At the same time, building materials and construction practices are used to produce structures that can survive strong earthquakes. In addition, the population of Alaska's vulnerable areas has increased considerably.
Smaller earthquake zones along subduktsyi Alaska and other broke occur daily, presumably, removing the internal pressure, which could otherwise lead to another massive earthquake.
However, no one knows with certainty when, where, or another huge and destructive earthquake will strike Alaska.