Within Alaska are 86 active volcanoes.
Of these, three are erupting right now.
In additional to the Semisopochnoi volcano, and the Great Sitkin volcano, a third volcano
known as Pavlof is also erupting.
This is not too unusual, as it’s the single most active volcano in all of Alaska.
Since 1900, the longest it has gone without an eruption was only 7 years.
Regardless, Pavlof is a beautiful towering volcano which contains shades of red, gray,
and some white due to the ice near its summit.
This video will cover this volcano, it’s ongoing eruption, and mention what it’s
future hazards are.
Mount Pavlof is located in the far southwest of mainland Alaska where it lies on the Aleutian
Peninsula.
Specifically, this volcano is 29 miles north-northeast of the closest city, King Cove.
This beautiful stratovolcano stands at 8,179 feet or 2,493 meters above sea level.
The reason why its edifice is much more colorful than a typical gray stratovolcano relates
to its composition.
Unlike the majority of stratovolcanoes, it does not erupt gray andesite.
Rather, it primarily erupts both basalt and basaltic andesite, which give its summit a
red color.
Similar reddish hues are seen at some cinder cones and Mount Fuji, which reflect the low
silica content found at these volcanoes.
The story of Mount Pavlof began with a different volcano to the southwest.
If we zoom out, we can notice a large lake.
Surrounding this lake is a massive caldera known as the Emmons Lake Caldera.
This 11 mile wide caldera formed in a catastrophic eruption approximately 26,000 years ago.
This eruption created a 160,000 foot high ash plume, and ejected 12 cubic miles of volcanic
rock.
It was 50 times the size of the 1980 eruption of Mount Saint Helens, and caused a massive
area to sink 1500 feet into the ground.
It was in the aftermath of this caldera collapse that Mount Pavlof began to form.
Before I continue, I must note that a similarly named but different active volcano known as
Pavlof Sister is found to the northeast.
Approximately 15,000 years ago, a volume of low silica basaltic andesite magma reached
the surface just outside the northeastern edge of the Emmons Lake Caldera.
As this magma interacted with a volume of ice, it generated a series of violent explosions.
After the nearby ice had melted, the new volcano began erupting with far less explosiveness.
Soon, intermittent explosions of lava and ash began, which ejected bombs of lava in
a several mile radius.
Flows of lava eventually came out of the new vent, and as the related ash settled it began
forming a new volcanic cone.
Due to the near constant eruptions of this volcano, it did not take long to reach a height
of several hundred feet.
Within a few dozen more years it reached a height of 1,000 feet tall.
Since then, this volcano has been consistently erupting about one third of the time.
Its eruptions were mainly what is called a strombolian style eruption.
However, on occasion it produces larger eruptions which produce short distance pyroclastic flows
called "vulcanian" eruptions.
Eventually, some of the underlying magma traveled 1.5 miles to the southwest.
It too eventually erupted, and over time built a satellite volcanic cone of Mount Pavlof
which is known as Little Pavlof.
Since the formation of this volcanic cone, Pavlof has not truly produced a large eruption
with a long term sustained eruption column or an eruption rated on the volcanic explosivity
index as larger than a 3.
Since records of this volcano began in 1790, it has erupted on 47 separate occasions.
The largest of these eruptions occurred in 1911, when a large fissure opened on its northern
flank.
The current eruption of Pavlof began on August 5th of 2021, and is still ongoing as of the
writing of this video.
Although Mount Pavlof can produce both pyroclastic flows and lahars, no towns are located close
enough to be effected by these.
With this being said, this volcano is located within a major commercial airplane route.
Thus, its frequent eruptions are a common cause of flight delays or cancellations.
Any ash emitted into the atmosphere can make it impossible to fly as these particles damage
airplane engines.
This hazard is significant enough that instruments have been placed around the volcano which
monitor it in real-time.
Based on these hazards, the US Geological Survey designated Mount Pavlof as a high threat
volcano.
I hope that you enjoyed this video!
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