“Textbook Classic” Surtseyan Explosions


For those among you who think the world is coming to an end and we are witnessing something unusual with the eruption of Eyjafjallajökull, well, guess again.

If things continue, the Royal Navy is going to do the rescue thing and bring Brits stranded in airports home!

Please pardon The Pink Flamingo for continuing my volcano junkie indulgences. This is just way much fun!

There is one ash model where it could be over   Scotia by Monday.  With the high ash cloud will come some incredible sunsets, even here in the US by the end of the week – just beautiful sunsets.

The real problem is the fact that every time Eyjafjallajökull erupts, sister volcano Katla erupts.  If this happens, it gets a little interesting.  We’re not talking the Pacific Ring of Fire here, but the fact that Iceland is sitting on top of a seam in the earth’s crust.  There are idiots who want you think globalwarming is the cause of this, as they think everything is because of global warming, but this is getting so old, Al Gore and his ilk are becoming like the chicken littles who cried wolf.

The real chicken little is Yellowstone!

So far something like 750tons/second of material is being ejected.  According to sources the action was not as great on Sunday.  Another source suggested the volcano was sending “mixed signals”.

“…Iceland’s Meterological Office said tremors from the volcano had grown more intense but that the column of ash rising from the volcano had eased back to 4-5 km (2.5-3 miles) from as high as 11 km when it started erupting earlier this week. “We are seeing mixed signals. There are some hints that the eruption will be decreasing, and others that show it is not decreasing,” said Einar Kjartansson, a geophysicist at the Meteorological Office. The eruption is taking place under Iceland’s Eyjafjallajokull glacier, normally a popular hiking ground about 120 km (75 miles) southeast of the capital Reykjavik. Kjartansson believes the volcano has melted about 10 percent of the glacier, but melting might have slowed in recent hours. However, that does not mean Europe will see any great relief from the plume of ash that is choking the upper atmosphere with tiny particles of glass and pulverised rock, threatening jet engines and airframes.

The glacier on top of the volcano is about 200 metres (650 ft) thick — thinner than many glaciers atop other volcanoes that have erupted in recent times. That means there is less ice, and water, to suffocate the eruptions and resulting steam. “It might mean more intense ash production,” Kjartansson said….”

According to Eruption, Eyjafjallajökull is proving to be a classic example of a Hydrovolcanic Eruption.

“….Hydrovolcanic eruptions are generated by the intereaction of magma with either groundwater or surface water. Explosive hydrovolcanic eruptions of basaltic lava are sometimes called Surtseyan, after the eruption off Iceland in 1963. Surtseyan eruptions are considered to be the “wet” equivalents of Strombolian-type eruptions, although they are much more explosive. This high explosivity is a hallmark of hydrovolcanic activity. As the water is heated, it flashes to steam and expands explosively, thus fragmenting the magma into exceptionally fine-grained ash. When the volcanic island of Surtsey was born in the Atlantic, the initial hydrovolcanic eruptions were spectacularly explosive. As the volcano grew, however, the rising lava in the central vent interacted with water to a lesser degree, so that the waning stages of the eruption became more Strombolian in character.

Hydrovolcanic eruptions are not restricted to the underwater development of oceanic islands. Many explosive Surtseyan events are generated on land by rising conduits (diapirs) of basaltic magma that interact with water-bearing strata (e.g., aquifers) at shallow levels beneath the surface. The two examples are shown here are from Ukinrek in Alaska and Capelinhos in the Azores….”