Tag Archives: volcano

Katmai, Alaska; circa 1912

Katmai after the Novarupta Eruption; Photo was taken 9 weeks after the eruption

The eruption of Novarupta on 6 June 1912 was the largest of the 20th Century. The village of Katmai was destroyed in the eruption, buried under as much as 18 inches of volcanic ash.


Hunga Tonga Eruption

An undersea volcano erupted Saturday near the island of Tonga. The satellite imagery above is pretty intense, and the ash plume reached 20km above the earth.

Tsunami alerts were put out almost immediately, and the island of Tongatapu had waves flooding into the capital.

Courtesy of NWS/NOAA

The tsunami reached Alaska’s southern coast this morning, with King Cove recording the highest waves at 3.3 feet.

Air pressure change

That wasn’t the only wave to hit Alaska from the eruption. The shock wave of the event caused a drastic air pressure change over the state as well.

Courtesy of the NWS and NOAA

Can you hear a volcano erupt from almost 6000 miles away? It turns out that you can. Many people, who were up between 3:30-4:00 am on Saturday reported hearing a sonic boom. It’s telling that many Alaskans initially reported being awaken by a large boom, and most of them assumed it was a “moose on the porch”. Various infrasound recorders placed around the state by Alaska Volcano Observatory confirmed that the sound heard was the volcanic pressure wave, not a moose.

I find that absolutely fascinating.

A second eruption pressure wave traveled over Anchorage 19.3 hours after the first wave, traveling in the opposite direction.

As of this writing, details of the damage remained sketchy at best. It is known that waves entered Tonga’s capital, and that a thick layer of volcanic ash was dumped on the island. No deaths have been reported at this time, and it is not known how many islands have seen damage from tsunamis or ash fall. Tonga’s internet service, much like Alaska, is served via undersea cables. It is thought that those cables were damaged in the eruption.

New Zealand has sent military aircraft to Tonga to assess the damage.


Historic Ash

Kodiak Island just Southeast of Katmai

Kodiak Island had a somewhat unique Winter Warning on Thursday. Mixed in the fresh snow was some ancient volcanic ash. Ash from the Novarupta eruption of 1912 was carried across the Shelikof Strait due to some high winds, and the ash came down with the recent snowfall. The ash was not expected to climb above 7000 feet, but airlines were notified, and air quality on the island may have been diminished.

Ashfall, over a foot deep, on Kodiak Island; June 1912

The Novarupta eruption started on 6 June 1912, and lasted three days. The eruption was the most powerful of the 20th Century. The ash cloud is thought to have risen to over 100,000 feet, which is incredibly impressive. An estimated 3.6 cubic miles (15 cubic KMs) of magma erupted. That’s 30 times more than the Mount St Helens eruption. As much as 600 feet of ash was dumped on the region now known as The Valley of 10,000 Smokes.

The ash kick-up does happen from time to time, when winds hit the area just right, and carry loose ash over to Kodiak.

All seven volcanos in the Katmai region, including Novarupta, remain at Level Green.


Atka Volcanic Complex

Earthquake activity on Atka Island

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.

Source: AVO


Great Sitkin & other rumblings

The growing lava dome on Great Sitkin; Photo credit: AVO/Dave Ward (8/4/21)

I had to share this shot from the Alaska Volcano Observatory and photographer Dave Ward. Great Sitkin has been at Level Orange and the lava dome has been growing since mid-July. According to AVO, the dome is now 100 meters across. What are the odds of having such a clear day out on Great Sitkin Island? Wonderful shot by Mr Ward.

Great Sitkin has been active most of the summer, although that lava dome build up has occurred in the last couple of weeks.

The glow of Great Sitkin at night. Photo credit: AVO/Peggy Kruse

Both Pavlof and Semisopochnoi Volcanos are also at Level Orange. Pavlof is known to erupt with little to no warning, and it is showing elevated seismic activity, and at least one ash eruption. Explosions and elevated seismic activity on Semisopochnoi Island also continues. At least one ash eruption dissipated quickly, and sulfur dioxide emissions have been detected by satellite.

Cleveland Volcano rounds things out at a Level Yellow. Some seismic activity, but no reported ash eruptions.


Timing is everything

An eruption plume from the Great Sitkin volcano on the Aleutian Chain

Volcanos world-wide seem to be getting a bit anxious of late, and Alaska has three rumbling right now. The Great Sitkin volcano, which dominates the skyline of Great Sitkin Island, erupted on May 25. Lauren Flynn of the U.S. Fish & Wildlife Service captured this image as Great Sitkin erupted. Flynn was aboard the Research Vessel Tiglax at the time.

Great Sitkin Island was a fuel depot during WWII. The island lies between Adak and Atka, and is roughly 11 miles long by 10-1/2 miles wide. The Great Sitkin volcano rises to a height of 5710 feet above sea level.

Photo credit: Lauren Flynn/USF&WS/AVO


Wrangell-St Elias National Park and Preserve

National Park Week Day II; Today’s Park Theme: Volunteer Sunday

The Chitina River en route to McCarthy

Wrangell-St Elias may very well be my favorite road accessible park in Alaska. Denali is closer, and I visit it the most, but Wrangell-St Elias is a trip of its own. First off, it is the largest National Park at 13.2 million acres. It starts at sea level and rises all the way up to 18,008 feet with the summit of Mount St Elias, which is the second highest peak in the United States.

Mount Blackburn

Within Wrangell-St Elias is four mountain ranges: The Chugach, Wrangell, St Elias, and the eastern part of the Alaska Range. Mount Wrangell is one of the largest active volcanoes in North America, and nine of the sixteen tallest peaks in the U.S. are within the boundaries of Wrangell-St Elias.

If you prefer glaciers, Wrangell-St Elias has you covered with 60% of Alaska’s glacier ice within this park. It has the state’s longest tidewater glacier, North America’s largest piedmont glacier, and the world’s longest valley glacier.

The park offers an endless list of things to do. The hiking here is phenomenal, although established trails are few. The beating heart of this park is wilderness. I have seen the gamut of Alaska wildlife with Wrangell-St Elias.

The Kennecott Mine

The Edgerton Highway runs along the Copper River Valley to Chitina, where the McCarthy Road follows the old CR&NW Railway grade to the Kennicott River. For years, you had to stop there to take a tram across the river to the town of McCarthy and the mines of Kennecott. Today, the tram sits unused, and a walking bridge spans the river.

The Kennecott Mine and company town were named after the Kennicott Glacier, but they missed the spelling by a letter. It gets confusing trying to keep it straight. Copper ore was discovered here in 1900, and a rush soon started. Eventually, Kennecott would have five mines operating, but by 1938 operations had shut down. During that time span, the mines produced over 4.6 million tons of copper ore, and gross revenues of $200 million. I’m not sure what that dollar amount would add up to today. The Kennecott Mines are now a National Historic Landmark District.

McCarthy, Alaska in 1915
McCarthy Hardware in 2011

The population of McCarthy in 1920 was 127. By 2010 it had dropped to 28.

Some of the mines like Jumbo can be hiked to, and the green of copper ore can still be seen in the rocks around the area.

Fishing the Copper and Chitina Rivers is an Alaskan tradition, going back millenniums. Dipnetting for salmon is restricted to Alaska residents, but I can tell you that it is an adventure like no other.

If you want a park that you can disappear into, Wrangell-St Elias may just be the place for you. 2018 saw only 79,450 to the nation’s largest park. Like Alaska in general, that’s a lot of elbow room.

Find your Park!

Veniaminof goes Orange

Mount Veniaminof; Photo credit: AVO/Allan Lerner

Mount Veniaminof, which is located on the Alaska Peninsula, erupted last Thursday. The ash plume that exploded from the volcano did not reach 10,000 feet. Veniaminof last erupted in the fall of 2018.

Mount Veniaminof is a rather active stratovolcano, having erupted at least 14 times in the past 200 years. It is surrounded by a 25 square mile ice field. According to the National Park Service, the glacier is the only one known in North America with an active volcano at its center.

Image credit: AVO/Hannah Dietterich

As of 7 March, Veniaminof continued to show an ash plume via satellite imagery. Mount Veniaminof rarely shows itself for the camera. The volcano is visible only one or two days a year, the rest of the time, Veniaminof is shrouded in clouds and fog.


Mount Shishaldin

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The Shishaldin Volcano on Unimak Island; Photo credit: USGS

Mount Shishaldin, which is one of the most beautiful and perfectly cone-shaped volcanos on the Aleutian Chain, has been restless since July 2019, with several short burst eruptions.  At the end of December, temperature elevations were measured at its summit, and seismic activity had increased substantially.

This past Friday morning, Shishaldin erupted, sending ash five miles into the air.  Volcanic lightning, and the glow of lava near the summit, could be seen from Cold Bay.

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Shishaldin from high; Photo credit: AVO

At an elevation of 9373′, Mount Shishaldin is the highest peak in the Aleutians.  Shishaldin is relatively young, with its cone less than 10,000 years old, although remnants of an ancestral volcano can be found on Unimak.

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Mount Shishaldin, postcard image, circa 1910; Photo credit: J.E. Thwaites

The first known ascent of Shishaldin happened in 1932, when G. Peterson and two others, made the climb to the summit.  It is widely understood, that native Aleuts and visiting Russians certainly made the climb previously, but their ascents were not documented.

Local climbers are known to still make the climb to Shishaldin’s summit, then ski back  down its flank.


Mount Veniaminof


Mount Veniaminof letting off some steam, 25 September 2018; Photo credit: AVO/Mari Peterson

Mount Veniaminof, the glacier covered volcano on the Alaska Peninsula, has been erupting since early September. The Alaska Volcano Observatory reports that lava is still flowing from the caldera this week. The volcano last erupted in 2013.


ESA Sentinel-2 image of Veniaminof, showing lava flow on the south flank of the volcano. Photo credit: AVO/USGS

Veniaminof sent a plume of ash, 13,000′ into the air in late November, but that action has come to a stop, at least for now.

Currently joining Veniaminof on AVO’s Orange Alert List, is the seemingly always active Mount Cleveland.