Saturday, February 8, 2014

GLOBAL VOLCANISM: Global Volcano Report For February 8, 2014 - Terrifying Sinabung Volcano Eruption Spawns Amazing Towering Tornado-Like Twisters In Indonesia; Large Explosion At Kamchatka's Shiveluch Volcano; Increased Strombolian Activity And Lava Flow At Italy's Mount Etna; Summit Lava Lake Rises At Hawaii's Kilauea Volcano; Scientists Monitor Alaska's Shishaldin Volcano For Signs Of Eruption! [PHOTOS+VIDEO]

February 08, 2014 - WORLDWIDE VOLCANOES - The following constitutes the new activity, unrest and ongoing reports of volcanoes across the globe.

Sinabung (Indonesia): The Indonesian volcano Sinabung was dormant until pretty recently. In 2010 it kicked into action, but in January 2014, it switched to high gear, blasting out massive amounts of ash high into the atmosphere (see picture below). Then a lava dome collapse on Feb. 1 created a pyroclastic flow, a rapid wave of hot gas and rock that thundered downslope.

The Sinabung volcano started erupting violently again in January 2014. This shot, from Jan. 7, shows the
huge ash plume blasting into the sky.  Photo by Sutanta Aditya/AFP/Getty Images

These flows are incredibly dangerous (15 people were killed by Sinabung’s flows when they ventured inside the 5-kilometer exclusion zone) and are for my money one of the most terrifying events on Earth.

And now I find out they can create tornado-like vortices! And they’ve been caught on camera.

Towering twisters of ash spawned by a pyroclastic flow from a volcano explosion, because why not.
Photo by Photovolcanica, from the video

Now technically these aren’t tornadoes, even if they look like it. Tornadoes are when a funnel cloud is connected to the ground at its bottom and the base of a cumulonimbus cloud at its top. They form from the top down, dropping from the cloud base.

In this case, though, the phenomena are built from the ground up. The pyroclastic flow heats the air over the ground, causing it to rise. Air from the sides then rushes in to fill the partial vacuum. This creates swirls, eddies of turbulence, which can get amplified into the vortices seen in the video (and also in fire tornadoes which are also seriously a thing). This makes these events more like a dust devil than proper tornadoes. Or, I suppose, an ash devil. But still, yeesh.

WATCH:  Pyroclastic Flow followed by series of Tornadoes.

Sinabung’s eruption has been very dangerous and has caused the evacuation of over 30,000 people from nearby villages. When I saw the picture above of one of the eruptions, my instinct was to curl up into a tight little ball and scream into my own belly. Remember, that’s not just smoke you’re seeing; it’s vaporized rock, millions of tons of it! And it’s superheated to glowing, which can then flow downhill at hundreds of kilometers per hour, laying waste to whatever it touches.

Like I said, terrifying. Amazingly, though, volcanologists are getting better at predicting these. Magma moving underground can cause tremors that indicate an explosive eruption is imminent, allowing people to be evacuated. We can’t save everyone from volcanoes—they’re ubiquitous, and sometimes very close to dense population centers—but science is letting us understand what happens deep underground, which then informs us of what might happen closer to home.

There is a terrible beauty to volcano eruptions (much like hurricanes seen from space) that belies their destructive power. But one of the beauties of science is that it gives us the potential to save lives, and cut that threat down.

Shiveluch (Kamchatka): A phase of intense activity has been taking place at the volcano over the past few days. On 6 Feb afternoon (or early morning 7 Feb in Kamchatka), a large eruption occurred. VAAC Tokyo spotted an ash plume drifting at approx. 27,000 ft (9 km) altitude more than 300 km northwest. The ash plume reached the Sea of Okhotsk and ash fall occurred in the village Sedanka at more than 200 km distance from the volcano.

Bright glow from the active lava dome of Shiveluch this morning

View of Shiveluch at the time of the eruption on 6 Feb - bright glow is visible, but cloud
cover doesn't allows further details

Unfortunately, webcam images do not allow to determine whether this eruption had been caused by an explosion liberating accumulated pressure, or whether a major collapse of the actively growing viscous lava dome had taken place, producing pyroclastic flows and related co-ignimbrite ash plumes. It is possible if not likely that it was the result of a combination of both.

Etna (Sicily, Italy): So far, the latest (still ongoing) eruptive episode has been significantly weaker than all previous ones. Explosive (strombolian) and effusive (lava flow) activity from the New SE crater (NSEC) increased yesterday afternoon, but then dropped almost completely later in the evening, and seems to have picked up, at least temporarily, a bit this morning again, but bad weather prevents detailed observations.

View of strombolian activity and the lava flow from Etna's NSEC last evening
Photo: Emanuela / VolcanoDiscovery Italia

The lava flow and strombolian activity at Etna's NSEC
(Monte Cagliato thermal webcam INGV Catania)

February 7, 2014: The lava flow and strombolian activity at the New SE crater have continued and activity has been increasing. The corresponding tremor signal is rising as well with a pronounced upwards trend over the past hours. It looks as if Etna is in for another paroxysm in the very near future.

Kilauea (Hawai'i): Per HVO, Kilauea's summit lava lake rose by 20m/66ft in the past week, just another 15m/49ft until it's visible from the Jaggar Overlook!

Halemaumau Thermal Image of Lava Lake on Feb 7, 2014

Shishaldin (Alaska): Scientists at the Alaska Volcano Observatory are going to be keeping a close eye on Shishaldin Volcano over the weekend.

An AVO webcam shows Shishaldin Volcano steaming on Jan. 28, 2014. /Credit: Janet Schaefer, AVO/USGS

The volcano emitted a small ash cloud that was identified early Friday morning. AVO geologist Chris Waythomas says the cloud drifted south of the volcano and dissipated.

"However, Shishaldin is a very frequently active volcano, and this could mean that we’re heading into an eruptive period," he says. "It may not necessarily, but it wouldn’t surprise us if the volcano started getting more active."

Shishaldin was upgraded to a yellow alert level last week after abnormal behavior began. Waythomas says this ash cloud seems to have come from a combination of magma close to the surface, and increased steaming and temperatures in the crater.

Some of the seismic monitoring stations that track Shishaldin are still out of order. Waythomas says they’re relying on two functioning stations to look for earthquakes inside the volcano and other changes that could foretell an eruption.

"It can be explosive, and it could put ash clouds up to flight levels," he says. "That would not be unusual for this volcano to do that."

Shishaldin’s eruption in 1999 sent ash plumes as high as 45,000 feet above sea level. It last erupted in 2004, and the last time it showed unrest like this was in 2009.

Shishaldin is the highest peak in the Aleutians. It’s also the world’s most symmetrical glacier-covered, conical volcano.

Waythomas says the two other yellow-alert volcanoes in the Aleutians -- Cleveland and Veniaminof -- are mostly quiet right now.

Complete Earthquake list (worldwide) for February 8, 2014.

SOURCES: Volcano Discovery | Slate | KUCB.

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