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Posts Tagged ‘alaska’

Clues Sought for Sea Star Die-Off

December 18, 2013 Comments off

scientificamerican.com

Dermasterias imbricata: Biologists are searching for the cause of a mysterious and unprecedented die-off of sea stars along the Pacific coast of North America. Image: Ed Bierman/Flickr

 

In their waterproof orange overalls, Hannah Perlkin and Emily Tucker look like commercial fishermen or storm-ready sailors. But they are biologists on their way to tide pools along a remote stretch of northern California coast. There they are searching for the cause of a mysterious and unprecedented die-off of sea stars along North America’s Pacific shores.

The syndrome took marine scientists by surprise this summer, when sick and dying sea stars — also known as starfish — appeared in a host of locations between Alaska and southern California. Predatory species were the first to succumb, but now the mysterious ailment is appearing in species once thought to be resistant to its effects.

The progression is predictable: white lesions appear on an animal and become infected. Within hours or days the sea star becomes limp, and its arms may fall off. Necrosis Read more…

More than 1,000 fish killed by Alaska summer heat wave

August 3, 2013 1 comment
Rainbow Trouts [Wikipedia Commons]

By Yereth Rosen

ANCHORAGE, Alaska (Reuters) – Alaska’s summer heat wave has been pleasant for humans but punitive for some of its fish.

Overheated water has been blamed for large die-offs of hatchery trout and salmon stocks in at least two parts of the state as hot, dry weather has set in, according to the Alaska Department of Fish and Game.

Hundreds of grayling and rainbow trout died in June after being placed in a Fairbanks lake, the department reported. An unusually cold spring caused lake ice to linger much longer than normal, before the water quickly became too warm, department biologist April Behr said.

Surface temperatures in the lake rose to about 76 degrees Fahrenheit (24 degrees Celsius), she said. The precise number of dead fish was not yet known. “We picked up several hundred,” she said.

A similar incident occurred in Read more…

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7.5-magnitude earthquake strikes southeast of Alaska

January 5, 2013 Comments off

earthsky.org

The U.S. Geological Survey (USGS) said that a strong 7.5-magnitude earthquake struck off the southeastern coast of Alaska just before midnight local time last night (January 4-5, 2013).  A local tsunami warning was issued for parts of southern Alaska and coastal Canada, and it has now been withdrawn.  The warning area extened for about 475 miles and included coastal areas from about 75 miles southeast of Cordova, Alaska, to the north tip of Vancouver Island, Canada, the Alaska Tsunami Warning Center said.  There were no initial reports of damage from the earthquake.

Here are the details of the quake from USGS:

Date-Time  Saturday, January 05, 2013 at Read more…

Mount Cleveland Lava Dome Grows 25%

February 15, 2012 2 comments

accuweather.com

The lava dome covering Mt. Cleveland volcano in Alaska has grown by 25 percent since last week. The dome was reported to be 40 meters across on Monday Feb. 6., and has now increased to 50 meters in size, according to the Alaska Volcano Observatory (AVO).

“We got indications from satellite data that the dome had grown slightly,” Alaska Volcano Observatory Research Geologist Matt Haney said. “The recent expansion shows that growth has not ceased.”

The current lava dome is much smaller than the dome was before the last eruption of Mt. Cleveland.

“The previous lava dome that was removed by explosive activity on Dec. 25 and Dec. 29 covered most of the 200-meter-diameter summit crater. So, indeed it was larger than the current dome,” said Haney.

Given that the current lava dome is still significantly smaller than the dome in December, does that mean the explosion would be smaller if it happened from this smaller lava dome?

“No, a larger dome doesn’t necessarily mean a larger yield from the explosion,” said Haney. “We’re still expecting the same type of altitude for the ash cloud. It should interrupt Trans-Pacific Read more…

Magnitude 5.1 – FOX ISLANDS, ALEUTIAN ISLANDS, ALASKA

January 24, 2012 1 comment

usgs

Map showing earthquakes

Alaska Earthquake, No Tsunami Expected

September 14, 2011 Comments off

mauinow

Map showing earthquakes

A 6.1 earthquake was reported in the Aleutian Islands near Alaska.  The quake was reported at 8:10 a.m. HST (9:10 a.m. near the epicenter) on Wednesday, September 14, 2011.

The earthquake occurred at a depth of 1 km, according to the USGS.

Location to nearby cities is as follows:  21 miles NNW of  Attu Station, Alaska; 596 miles E of Petropavlovsk-Kamchatskiy, Russia; and 2009 miles NE of Tokyo, Japan.

The NOAA West Coast & Alaska Tsunami Warning Center issued a statement this morning saying the magnitude is such that a tsunami IS NOT EXPECTED. However, in coastal areas of intense shaking, locally generated tsunamis can be triggered by underwater landslides.

7.1 Quake strikes off Alaskan coast

September 2, 2011 Comments off

cnn.com

An earthquake with a preliminary magnitude of 7.1 struck Friday off the coast of Alaska, the U.S. Geological Survey reported.

The quake was initially reported to have occurred a depth of 6.2 miles, but the Geological Survey later updated its reading to say it was 22 miles deep.

The earthquake occurred 120 miles east-southeast of Atka, Alaska, in a sparsely populated part of the Aleutian Islands known as the Fox Islands. The epicenter was 1,658 miles west southwest of Anchorage, the Geological Survey said.

It prompted a brief tsunami Read more…

North Korea poised for nuclear weapon test next year

August 15, 2011 Comments off

theaustralian

NORTH Korea will conduct another nuclear weapons test within 12 months, according to senior US sources with access to Washington’s intelligence assessments.

This will bring much closer the day when North Korean nuclear weapons could threaten Australia. And it could trigger explosive reactions in northeast Asia.

The senior US sources believe the test could come sooner rather than later, although next year is regarded as the most likely.

“2012 is an auspicious year from the North Korean point of view,” said one senior American.

“It’s an election year in the US and an election year in in South Korea. And the North Koreans have publicly declared their desire to be a fully functional nuclear weapons state by 2012.”

For most of the past decade, sources say, North Korea has been systematically involved in nuclear proliferation.

At a meeting in 2003, senior North Koreans told representatives of the Read more…

2011: Headed for Record Arctic Melt?

July 21, 2011 Comments off

ouramazingplanet

arctic-sea-ice-satellite-110720.jpgJuly 11, 2011: Arctic sea ice, seen by satellite. Credit: NASA.

This year could be well on its way toward earning a dubious spot in the record books.

Arctic sea ice has melted away with astonishing speed in the first half of July, at an average rate of about 46,000 square miles (120,000 square kilometers) per day, according to the National Snow and Ice Data Center (NSIDC) in Boulder, Colo.

That’s equivalent to an area roughly the size of Pennsylvania melting into the sea every 24 hours.

“That’s relatively fast,” said Julienne Stroeve, a research scientist at the NSIDC.

Already, sea ice extent — how far ice extends across the ocean — this year is below the extent for the same time in 2007, a year which, in September, saw the lowest sea ice coverage ever recorded.

As of July 17 this year, sea ice covered 2.92 million square miles (7.56 million square kilometers) of the frigid Arctic Ocean. That may sound like a lot, but it’s 865,000 square miles (2.24 million square kilometers) below the 1979 to 2000 average.

However, Stroeve said, much of what Read more…

Collapsing Coastlines

July 4, 2011 Comments off

sciencenews

access

Storms can ravage coastal permafrost, as shown near the village of Kaktovik, Alaska.© Accent Alaska.com/Alamy

Gray waves surged over miles and miles of open water, breaking against the bluffs underlying Kaktovik. The tiny village sits precariously on the Beaufort Sea, a frigid body of water bordering Alaska’s northeastern Arctic coast. As the choppy waters inundated vulnerable stretches of shoreline, the surf carved deep chasms into the tall bluffs.

Torre Jorgenson, a geomorphologist working near Kaktovik, watched the storm boil up, shaking homes and boats for nearly two days in July 2008. Dramatic erosion followed soon after. Blocks of graphite-colored earth, as much as 10 meters wide and several meters deep, toppled into the sea one by one like skyscrapers in a Japanese monster film.

“The locals had never seen that type of erosion,” says Jorgenson, also president of the U.S. Permafrost Association. “It was something new, a regime change.”

The erosion Jorgenson witnessed was a potent warning to Kaktovik’s residents of the instability of their coastal home. Seaside bluffs and beaches across the Arctic are Read more…

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