… Sergeant Pepper taught the band to play …
by Steve Goddard
I remember May 18, 1980 like it was yesterday. I was skiing behind Taos Ski Valley in ten foot deep snow, up to the base of Wheeler Peak.
At the time, I was working as a volcano researcher for the US Government, studying the nature of explosive volcanic eruptions. When we got back to Taos, we turned on the TV and saw amazing pictures of Mt. St. Helens, which had literally blown it’s top.
Mt. St. Helens had previously been a dependable source of snow and ice all summer, and the K2 ski team (including Phil Mahre) used to train up there in the summer. It no longer is tall enough for summer skiing.
The mechanism of the eruption is well understood, thanks to an amazing video reconstruction.
As the magma chamber rose up in the volcano (magma is less dense than rock) it did several things. First, it melted the snow and ice and turned the soil into mud. Second, it made the north slope of the volcano steeper and less stable. Third, groundwater from melted snow and ice seeped down into the magma chamber and added to the steam pressure. At 8:32 am, a large earthquake further liquified the soil on the north slope, and caused a massive mud slide. The weight of the overburden quickly became less than the steam pressure inside, and the volcano blew it’s top. A massive amount of ash and trees poured down into the Toutle River wiping out everything in it’s path.
A reminder that explosive volcanic eruptions dump a lot of steam, ash and gas into the atmosphere.
In June 1783 the Laki volcano close to Katla erupted for several months with clouds of poisonous gas that killed 9,000 people in Iceland. But the eruption also created a cold fog that spread across much of Europe and North America, in some places causing the coldest summer for 500 years as the Sun’s warmth was blotted out.
“The summer of the year 1783 was an amazing and portentous one, and full of horrible phenomena,” wrote the naturalist Gilbert White in Hampshire. “The country people look with a kind of superstitious awe at the red louring aspect of the sun thro’ the fog.” The climate across the northern hemisphere was sent into upheaval, even weakening the monsoon rains in Africa and India, leading to famine in Egypt and India.
A few days ago, the Met Office forecast that the ash cloud would move to the northeast out of British airspace by May 19th. Their forecast for May 18th (today) appears to have been very accurate.
Below is their current forecast for the next five days.
Will Katla erupt? What do readers think?