Ice core records from the Arctic show that Alaska’s Okmok Volcano had a massive eruption in 43 BCE. Following the eruption, there was an abrupt cooling globally, which led to crop failures, famine, disease, and eventually, social unrest. The Mediterranean region was no exception to this.
Such a shift in climate, coming a year after the assassination of Caesar, would have put great pressure on local powers. Strain was also felt in Egypt.
Okmok has a very active history. At one time, it had a 150 meter deep lake in its crater. A notch in the rim eventually drained the lake, although some small remnant lakes remain near cones B & D.
The eruptions of Okmok 8300 and 2050 years ago earn a Volcanic Explosivity Index rating of 6, which puts it on par with Novarupta and Krakatoa.
On 12 July 2008, Okmok erupted without warning, sending ash 50,000 feet into the air. It erupted continuously for almost six full days, causing transportation problems in the air and on the water for the region. That eruption was ranked a 4 VEI, which is considered “cataclysmic”.
Okmok Volcano; Photo credit: AVO/Burke Mees
Back to 43 BCE. The decade following the eruption was one of the coldest in a millennia, with 43 and 42 BCE being some of the coldest years. It is believed that a temperature drop of 7C from normal was a result of the volcanic eruption on the other side of the globe.
There is a cluster of volcanic islands in the Aleutian Chain that scientists have recently been asking a rather provocative question: Could they all be a part of one giant super volcano, similar to the Yellowstone Caldera?
This tight grouping of islands is home to six stratovolcanoes: Carlisle, Cleveland, Herbert, Kagamil, Tana and Uliaga. Mount Cleveland has been one of the most active volcanoes in North America over the past 20 years.
Most stratovolcanoes tend to have modest sized reservoirs of magma. Although that doesn’t mean they can’t have explosive eruptions, but they are dwarfed by caldera forming eruptions. A caldera is formed by tapping a huge reservoir of magma in the earth’s crust. A caldera forming eruption releases a massive amount of lava and ash, and they are catastrophic, often causing world-wide effects.*
Field work continues, although there is nothing easy about doing research in the Aleutians.
Mount Cleveland
Photo and map credit: USGS, *University of Alaska – Fairbanks
St Lawrence Island; Photo credit: KNOM/Laura Kraegel
Lost in the excitement and drama of Fat Bear Week, was the story of how two Russian nationals crossed the Bering Sea in a boat, landed on St Lawrence Island, and turned themselves in to authorities in Gambell, Alaska. The two men were seeking asylum in order to escape Putin’s War in Ukraine.
Gambell, Alaska, population 600, is actually much closer to the coast of Russia, than it is to Nome, which is 200 miles away. The two Russian men were flown to Anchorage.
The incident adds to the drama going on between Alaska and Russia. Russian military aircraft have been veering into Alaska airspace for several years now, and recently, the USCG followed a flotilla of Chinese and Russian naval ships out of the Aleutian Islands.
A smoke jumper spotter watches the Round Island fire from the air; Photo credit: BLM Alaska Fire Service
A wildfire started up on Round Island out in the Aleutians. The fire was started by staff from a Fish & Game campsite, when they used a burn barrel. The dry grass caught quickly, and spread from there. The Alaska Division of Forestry sent an air tanker and six smoke jumpers from Fairbanks to contain the blaze. By the time the fire was contained, approximately 40 acres of the 720 acre island had burned.
Walrus beachcombers of Round Island
Round Island is one of four major pull out locations for Pacific walrus in Alaska, and the island is a part of the Walrus Islands State Game Sanctuary. As many as 14,000 male walruses haul out on Round Island in a given day.
Like Brooks Falls, the folks at explore.org have a Walrus Cam on Round Island. The soothing sound of waves can be experienced, with the constant baritone grunts of the male walruses jockeying for the most comfortable spot on the beach.
Fred Machetanz first came to Alaska in 1935, spending two years in Unalakleet. He left for New York, only to request service with the U.S. Navy in the Aleutians, returning to Alaska in 1942.
“Spring Fever”; 1987
After WWII, Machetanz returned to Unalakleet in 1946. Eventually, he settled in the farming community of Palmer, where he died at the age of 94, in 2002.
A swarm of earthquakes and aftershocks hit the Aleutian Chain, just past Unalaska, on Tuesday. A couple of foreshocks were detected, then a 6.8 magnitude earthquake – which was the largest of the swarm, followed by a whole series of aftershocks. A dozen of the aftershocks came it at a 4.4 or higher, with one 6.6 magnitude shaker.
According to the Alaska Earthquake Center, the event was a “very unusual, very energetic swarm of earthquakes.”
No major damage was reported, and the earthquakes did not generate any tsunamis.
Fairbanks hit 89F officially, which was the highest temperature for the Summer of 2021. Seeing 80’s on the North Slope is a bit of a WHOA moment. Not unprecedented, just whoa.
At this stage of the season, only the Aleutians have much of a chance at increasing their number. Fairbanks has already started showing yellow in the hills, and I’m not talking about gold dust.
The southern portion of Atka Island is older than the north, with some volcanic rock dating back 5 million years. The active northern part of the island once had one large cone, which was lost in a large eruption, and is now peppered with several smaller volcanos.
A volcanic complex can have several vents, and a widely varying composition of lava. Seismic activity within a complex can be difficult to pinpoint the source of the activity. Which vent is rumbling now? Some of those smaller vents have developed into stratovolcanoes.
Korovin Volcano has been very active in recent times, while Mount Kliuchef last erupted in 1812. The Atka Complex recently was elevated to a Level Yellow, due to seismic activity on the island. Interestingly, the swarm of activity is not near the known suspects, but several kilometers the the west and southwest, and approximately 10 miles from the community of Atka.
New Year’s Eve storm over the Aleutians; Image credit: CIRA/NOAA
The Aleutian Chain was rocked by an incredible storm over New Years. The wonderfully named Bomb Cyclone, set a record in Alaska for a low pressure system.
High and low-pressure systems form when air mass and temperature differences between the surface of the Earth, and the upper atmosphere, create vertical currents. In a low pressure system, the air currents flow upward, sucking air away from the earth’s surface like a giant Shop*Vac.
Eareckson Air Force Base on Shemya Island recorded the record low pressure at 924.8 millibars.
The record breaking low pressure system; Image credit: Tomer Burg
A sea buoy off of Amchitka Island, registered a wave at 58.1 feet. Winds at Shemya hit gusts of 83 mph. This was an impressive storm that pummeled the outer islands of the Aleutian Chain. From Atka to Adak, the islands were seeing 40-50 foot waves and hurricane force winds.
Graphic credit: National Weather Service – Fairbanks
St Lawrence Island and the Yukon Delta saw high winds and blizzard conditions when the storm hit Alaska’s mainland.
Unlike a hurricane, which extract heat from the ocean, as they grow in power, a maritime cyclone creates energy by drawing together warm and cold air masses. It’s the energy created when the warm air rises and the cold air sinks, that gives rise to the cyclone.
