Tag Archives: volcano

Kodiak after Novarupta

Kodiak, Alaska in 1912


Photo courtesy of Katmai National Park & Preserve

The Alaskan community of Kodiak one day after the eruption of Novarupta in 1912. Over a foot of ash fell on the town, collapsing roofs and engulfing the area in near total darkness.


Novarupta: Revisited


Novarupta, still steaming in 1923, 11 years after its eruption. Photo courtesy: Katmai NP&P

On 6 June 1912, Novarupta, located in the Aleutian Range, erupted. The 60 hour eruption would end up being the most powerful volcanic event of the 20th Century.

The people in Juneau, Alaska, 750 miles away, heard the blast from the eruption an hour after it occurred. In the end, 30 cubic kilometers of ejecta blanketed the area. That was 30 times more than the 1980 eruption of Mount St Helens; 3 times more than the second largest eruption of the century from Mount Pinatubo; and more ejecta than all of Alaska’s historic eruptions combined. The ash fall was so heavy, that roofs on buildings on Kodiak island collapsed from the weight.

The pyroclastic flow from Novarupta, filled 20 km of the valley of Knife Creek, turning the v-shaped valley into a wide, flat plain. When it was over, the pyroclastic flow would solidify into an area 120 square kilometers at depths of over 200 meters.


Katmai Caldera, photo credit: USGS

So much magma was expended during the eruption, that the peak of Mount Katmai, which lies 6 miles from Novarupta, collapsed, leaving a two mile wide by 800 foot deep crater. Early investigations had Katmai as the source of the massive eruption.


Novarupta lava dome, photo credit: USGS

It wasn’t until the 1950’s, when investigators realized that Novarupta was responsible for the eruption, and not Katmai.

In 1916, the National Geographic Society sent an expedition to Alaska’s Katmai area. Led by Robert Griggs, it was Griggs who named the former valley of Knife Creek, “The Valley of 10,000 Smokes”.

“Having reached the summit of Katmai Pass, the Valley of Ten Thousand Smokes spreads out before one with no part of the view obstructed. My first thought was: We have reached the modern inferno. I was horrified, and yet, curiosity to see all at close range captivated me. Although sure that at almost every step I would sink beneath the earth’s crust into a chasm intensely hot, I pushed on as soon as I found myself safely over a particularly dangerous-appearing area. I didn’t like it, and yet I did.”
— James Hine, Zoologist, 1916 Griggs Expedition
*

* geology.com


Bogoslof


Bogoslof volcano, as seen from a satellite image, 18 minutes after the start of the eruption 5.28.17

Bogoslof once again went red on Monday morning at 10am. The ash plume extended to 32,000′. The ash cloud from the above photo, from a May eruption, rose to over 40,000′. Since December, Bogoslof has erupted 60 times.

Photo credit: AVO/Dave Schneider


Alaska Volcanoes

Bogoslof by USCG
Bogoslof’s eruption of 23 December 2016. Photo credit: Crew of USCG Cutter Alex Haley

With Bogoslof being as active as it has been recently, there has been an increase in interest regarding Alaska’s many volcanoes. Since mid December, Bogoslof has erupted ten times.

Bogoslof plume
Plume from the eruption of Bogoslof on 20 December. Photo credit: Paul Tuvman/AVO

According to Alaska Volcano Observatory, which is a joint program by the U.S. Geological Survey and the University of Alaska – Fairbanks, Alaska has 90 volcanoes that have erupted in the past 10,000 years – and could erupt again. Of those 90, 50 have erupted since records started being kept in 1760.

Unlike volcanoes in Hawaii, which tend to ooze lava, Alaska volcanoes usually explode, sending ash as high as 50,000 feet in the air. Airlines get anxious when ash gets above 20,000 feet, and Bogoslof has consistently sent plumes into the 35,000′ range.

FAA estimates that roughly 80,000 large aircraft fly downwind of the Aleutian volcanoes yearly, with 30,000 people doing so every day. When Redoubt erupted in 1989, a KLM jet, which was 150 miles away, flew through Redoubt’s ash path. The jet lost all four engines with 231 people on board. The aircraft had dropped two miles, down to just over 13,000 feet, when the crew managed to restart the engines, and safely land in Anchorage.

Bogoslof change
Changes in Bogoslof Island with the recent eruptions. Credit: USGS/AVO

Photos and statistics come courtesy of AVO and their website. A special shoutout to the USCG Cutter Alex Haley: Nice photo, I hope its inclusion in the post is acceptable.


Bogoslof erupts unexpectedly

bogoslof island
Bogoslof Island

The submarine volcano at Bogoslof Island in the Aleutian Chain has gone Red twice in two days. An ash plume was sent up 34,000 feet on Wednesday, causing some concern for passing aircraft.

Bogoslof Island was first mapped after it’s eruption in 1796. The 173 acre island has seen six eruptions since then, from various vents. The island rises to 490′ above sea level, but approximately 6000′ from the seabed.

Castle Rock
Castle Rock on Bogoslof Island; Photo credit: Ann Harding/AVO

“Castle Rock”, as seen above, is the eroded remnant of a dome from the 1796 eruption. Currently, AVO has downgraded the alert level to Orange.


Explosion under Cleveland 

Photo credit: AVO

An explosion was heard from the Cleveland Volcano by residents in the village of Nikolski.

The 5676′ active volcano is on Chuginadak Island, which lies 940 miles southwest of Anchorage. The alert level on Cleveland was subsequently raised from yellow to orange.

Cleveland, named after former U.S. President Grover Cleveland, is one of Alaska’s most active volcanos.

Meanwhile, in Ohio, the Cleveland Indians exploded for 6 runs in a shutout win over the Chicago Cubs.  Coincidence?


Katmai Bear Cam

Brooks Falls in Katmai
Brown bears fishing at Brooks Falls in Katmai National Park

The Katmai National Park Bear Cam is back up and running for the season. The camera overlooks Brooks Falls in the park, where the bears congregate to fish the salmon run.

The 6395 square mile park was established as a National Monument in 1918. Located on the Pacific side of the Alaska Peninsula, Katmai is home to approximately 2200 brown bears. It is considered to be one of the Seven Wildlife Wonders of the World.

The Bear Cam has once again been set up by explore.org. The link is below.

http://explore.org/live-cams/player/brown-bear-salmon-cam-brooks-falls