Category: Science

Those of us who live outside circumpolar regions can watch the aurora borealis in Iceland here in real time, sometimes. If you don’t see much the first time you visit, cross your fingers and try again later.

Volcano Café has compiled a convenient list of the nine “New Decade Volcano Program” candidates announced thus far and invited speculation about the top spot on the list. A few weeks ago I wrote about Lake Kivu in the East African Rift, which is ominously close to Nyiragongo. I guessed then that a volcanic complex involving the lake would be first or second on the list, and I still think so. The most dangerous volcano on the planet, to the best of my (superficial) knowledge, is likely the Nyiragongo/Lake Kivu combination.

Continue reading “CO₂ and SO₂“

For the past week, ever since Campi Flegrei was awarded third place in the New Decade Volcano Program, I’ve wondered which volcanoes could possibly present a greater threat. Nothing that comes to mind meets the criteria. The Auckland volcanic field lies directly under the New Zealand city and could erupt at any time, but the magma involved is basaltic and not explosive; other north island volcanoes probably present a greater danger to the inhabitants than the one directly below them. There are plenty of dangerous mountains in Iceland, but the the total population is less than that of Wichita. Kamchatka is also sparsely populated. Islands in the South Pacific are generally too small to support millions of residents. And so on.

While reading the most recent post at Volcano Café, on how vulcanism affected the waters of Lake Tanganyika, it occurred to me that maybe I’m thinking too literally. Perhaps I should look for placid lakes, not fiery mountains. Lake Kivu, for instance.

In 1984, Lake Monoun in Cameroon experienced a “limnic eruption,” releasing an asphyxiating cloud of carbon dioxide that killed 37 people. Two years later at Lake Nyos, also in Cameroon, a similar event suffocated 1,700 more. Both lakes are “meromictic,” in which the water remains stratified throughout the year.

Lake Kivu is another meromictic lake, and its depths are saturated with carbon dioxide. It’s also 2,000 times larger than Lake Nyos, and there are over two million people along its shores. Nearby is Mount Nyiragongo, noted for its lava lake and its very fluid lava that could readily travel to the lake and trigger a limnic eruption. There is evidence that these eruptions occur there regularly. From Wikipedia:

Sample sediments from the lake were taken by professor Robert Hecky from the University of Michigan, which showed that an event caused living creatures in the lake to go extinct approximately every thousand years, and caused nearby vegetation to be swept back into the lake.

So, I am going to guess that the Lake Kivu/Nyiragongo complex is one of the two remaining NDVP volcanoes. We’ll find out if I’m right in one or three weeks if the café maintains its schedule.

Colima, a volcano west of Mexico City not far from the Pacific coast, is getting feisty. There’s a good view on the webcam here, ((when it works)) and when it’s cloudy you can watch time-lapse videos by clicking the icons below “El día en un minuto.”

Colima has been deemed a “decade volcano” by the International Association of Volcanology and Chemistry of the Earth’s Interior, one of sixteen worthy of special study because of capacity for dangerous eruptions and proximity to populated areas. Some of the denizens of Volcano Café find the IAVCEI list unsatisfactory and are currently announcing their own, one volcano at a time each Friday. ((usually if they feel like it)) Theirs is based on the pleasant notion of “million death expectancy” possible within the next century or so. Of the five listed thus far, I anticipated two (Kelud and Mayon), was not surprised by two of the others, but did not expect #7 at all. There are five more to go. I hesitate to make any predictions, but I’m pretty sure that Yellowstone is not on the list.

Tambora, a volcano on the island of Sumbawa and at that time one of the tallest mountains in Indonesia, erupted violently, propelling a Plinian eruption column up over 18 miles high. Spectacular though it was, the April 5 event was just the warm-up for the main show five days later, when Tambora uncorked the largest eruption observed in historical times, vastly larger than the Pinatubo, Katmai/Novarupta or Krakatau eruptions. Mount St. Helens in 1980 was a mere hiccup in comparison. The top of the mountain was replaced by a caldera four miles across, and the injection of dust and sulphur dioxide into the atmosphere led to the “year without a summer.”

Update: Just how big was the Tambora eruption?

Comet C/2014 Q2 (Lovejoy).

Comet C/2014 Q2 Lovejoy 29th December from Phil Hart on Vimeo.

Courtesy of Sakurajima.

Holuhraun Volcano, Iceland, November 2014 from Jon Gustafsson on Vimeo.

The eruption in the Holuhraun lava field between Bárðarbunga and Askja continues unabated.

Again, in slow motion:

There are good live views of the action here and here when the weather in Iceland cooperates.