Showing posts with label earthquake. Show all posts
Showing posts with label earthquake. Show all posts

Wednesday, April 14, 2010

More on Earthquakes

http://www.examiner.com/x-/x-28964-Anchorage-Conservative-Examiner~y2010m1d24-Alaska-Earthquakes-Volcanoes-and-Tsunamis

Alaska: Earthquakes, Volcanoes, and Tsunamis

January 24, 12:26 PMAnchorage Conservative ExaminerFranke Schein
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1964 Alaska Earthquake
1964 Alaska Earthquake
Photo: www.infoplease.com/

In the wake of the severe earthquake that savaged Haiti, one must remember that Alaska faced a similar catastrophe in 1964.


Lasting nearly five minutes, it was the most powerful recorded earthquake in U.S. and North American history, and the second most powerful ever measured by seismograph. It had a magnitude of 9.2, at the time making it the second largest earthquake in the recorded history of the world.

131 people lost their lives in the earthquake, and thousands were left devastated throughout much of the areas hardest hit.

A large tsunami that reached 70 feet high, and travelling at 450 miles an hour slammed into Alaska’s coastline—flooding much of the areas and creating rockslides that resulted in massive property damages. Vertical displacement of the land rose to approximately 38 feet.
Girdwood and Turnagain Arm, were destroyed by subsidence and subsequent tidal action, and 20 miles of the Seward Highway sank below the high-water mark of Turnagain Arm effectively cutting off the southern road system.

[ Alaska Earthquake March 27, 1964. Earthquake-demolished home in Turnagain Heights in Anchorage. 1964. Image file: /htmllib/batch75/batch75j/batch75z/ake00368.jpg ]

Following the initial earthquake there were approximately 10,000 aftershocks. Eleven major aftershocks were recorded on the first day alone with a magnitude of 6.0, and nine more occurred over the next three days. The earthquake’s aftershocks continued for another eighteen months.
The question that one must ask is will it happen again?

In a book titled “We are the earthquake generation” written in 1978 by Jeffrey Goodman, PHD; details startling facts that point to several distinct phenomena that could trigger another Alaska earthquake.

In one of the hypotheses Goodman concludes that the earth has a bulge along its equator. The circumference of the earth is 27 miles greater around the equator than around the poles. It’s thought that a large accumulation of ice on either pole would be enough to destabilize the earth’s spin, and unbalance it enough to cause the massive tectonic plates to shift—thereby resulting in mega-earthquakes and tsunamis, as well as eruption of several volcanoes within the region.
He also points to other causes that contribute to earthquakes—such as off shore drilling, nuclear weapons discharges, volcanic eruptions, and lowered water levels in the ground that could be the catalysis for future earthquakes.
Considering that Anchorage is the central hub where all of the cargo and supplies are distributed throughout Alaska, the ramifications of another severe earthquake would have potentially devastating effects on the rest of the state.
During the 2009 Mt. Redoubt eruption, most of the air traffic into and out of Anchorage was cancelled because of the volcanic ash threat it posed to commercial aviation. Alaskan’s were stranded in Seattle and Portland awaiting flights to Anchorage, some waited for days until a flight to Fairbanks brought them closer to home.
Alaska is one of the most active volcanic areas on the globe. The Aleutian islands have more active and dormant volcanoes than any other place in the world—and they are prone to earthquake activities.
Should another large earthquake shake the region, it’s possible that one or more volcanoes might erupt. Tidal waves, ash filled skies, and destroyed roadways would wreak havoc on Alaska’s ability to respond to a catastrophe of this nature.
Alaska is one of the most isolate states in the country. Nearly everything that is needed for consumption is either flown in, or brought in by trucks or barges. Any disruption of these vital supply routes will have instantaneous results on critical infrastructure such as fuel distribution, food, and other consumer goods.
Having the foresight to stockpile emergency supplies is almost critical to Alaska’s families. Should another earthquake strike alaska, like it did in 1964, the consequences could be devastating.

Photo: http://pixdaus.com/single.php?id=40289 Downtown Anchorage after the 1964 Earthquake

In a future article I will discuss the Pole Shift theory; another phenomena that could trigger earthquakes and volcanic eruptions.
Associated Press - January 24, 2010 4:54 AM Earthquake rattles near several towns

Tuesday, April 6, 2010

Quakes near Anchorage

ANCHORAGE, Alaska — A swarm of small earthquakes began Monday at a volcano near Anchorage in what scientists said was a warning that Mount Redoubt could be waking from its slumber.

"It is reminding us that it is an active volcano," said Rick Wessels, a geophysicist with the U.S. Geological Survey in Anchorage.

The swarm of small quakes started early in the day near the summit of Mount Redoubt, about 100 miles southwest of Anchorage, with a regular pattern often seen when magma is moving inside a volcano, Wessels said.

Researchers plan to fly through the steam plume of the volcano later this week and take measurements of three chemical compounds linked to volcanic activity — sulfur dioxide, carbon dioxide and hydrogen sulfide.

Scientists do not know if the earthquakes will lead to the volcano again becoming explosive, but they said that was a heightened possibility.

Last year, the volcano rumbled and grumbled for months before exploding on Jan. 26, at times producing huge ash plumes and sending mud flows down its flanks. It finally quieted in late September, but there was a similar episode of increased seismic activity in December.

Then came Monday.

"We were going along quietly and all of a sudden, boom, we started getting these small earthquakes," said Steve McNutt, a University of Alaska Fairbanks research professor.

Mount Redoubt is monitored by seven seismometers.

Last year, Mount Redoubt awoke after a magnitude-5.7 earthquake at the mouth of Cook Inlet.

The volcano followed that period of unrest with 19 significant eruptions over several weeks in March and April in which it sent ash plumes as high as 65,000 feet and cloaked parts of south-central Alaska in up to a half-inch of ash.

Residents donned face masks and covered their cars and trucks to keep the ash off the finish and out of the engines.

Mount Redoubt also erupted in 1989 and 1990.

Wessels said the current earthquakes were not connected to Sunday's magnitude-7.2 quake in Mexico just south of the U.S. border.

"We wouldn't expect there to be any connection given the distances," he said.

Alaska is the most seismically active state in the country. In 1964, it experienced a magnitude-9.2 earthquake near Anchorage, the strongest earthquake ever recorded in North America.

Sunday, February 21, 2010

Earthquake in Alaska




USGS reports small earthquake in Southern Alaska

Associated Press - February 21, 2010 12:24 PM ET

ANCHORAGE, Alaska (AP) - A minor earthquake has struck north of Anchorage, but no injuries or damages have been reported.

The U.S. Geological Survey says the quake, with a 3.0 magnitude, hit at 7:28 a.m. Sunday, and it was centered 24 miles north of Anchorage and 1 mile outside the town of Big Lake.

The USGS also says people in Eagle River and Chugiak have reported feeling the quake.

Copyright 2010 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
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