"Extinct" Volcano Erupts in Kamchatka

"Extinct" Volcano Erupts in Kamchatka

On this day in 1956, Mount Bezymianny, a volcano considered to be extinct, unleashed its most destructive explosion in Russia’s Kamchatka Peninsula. According to some, it is considered the largest single volcanic eruption in the 20th century.

Much smaller in size than its behemoth neighbours, Mount Kamen and Mount Kliuchevskoi, Mount Bezymianny was formed about 4,700 years ago atop a late-Pleistocene-era lava-dome complex and an ancestral volcano that was formed some 11,000 to 7,000 years ago. It is a stratovolcano, also known as a composite volcano: a tall, conical volcano consisting of many layers of hardened lava, tephra, pumice, and volcanic ash. Stratavolcanoes, like the famous Mount Vesuvius, are known for their steep profiles and periodic, explosive eruptions.

Up until 1955, Mount Bezymianny (and its environs) enjoyed a peaceful 1000-year quiescence. That is, the Russian volcano hadn’t erupted for an entire 1000 years, prompting most scientists to believe it was extinct. Then, in October 1955 the supposed gentle giant began a period of explosive eruptions, which produced lava domes. The volcano continued erupting for months, then, on 20 March 1956, at 5:11 PM, it unleashed a monster eruption. Witnesses described a huge jet of fire ejecting from the mountain at a 30-degree angle, producing a 45-kilometre-high column of ash, filling the atmosphere with smoke and ash before the sky went black. Scientists later determined that the amount of ash ejected from Mount Bezymianny was enough to cover all of Paris 15 metres deep. Mount Bezymianny continued to erupt for a full year, from September 1955 to October 1956, leaving a large, horseshoe-shaped crater formed from the collapse of the summit.

Thankfully, the closest human settlement was 50 kilometres away, so no human deaths were reported. However, the eruption got some scientists considering the advantages of volcanoes, namely the incredible power they generate (it takes a volcano 40 trillion kilowatts of energy to eject 2.4 billion tons of debris). Today environmental engineers and volcanologists are studying ways to harness geothermal power from volcanoes, efforts already in practice in places like Hawaii and Iceland.

 

Image: Courtesy of Wikimedia Commons.