This time we actually got to see itall happening in its different phases. One is left with a truly vastrespect for the actual scale of what may happen with a volcano and anunderstanding of how a volcano sequences through the differentchambers.
I suspect that we need to go check of alot of volcanoes to determine if a similar sequence is apparent inthee assays. This will provide us a pile of new interpretive data. It certainly makes Mt St Helen look like a tame volcano and alsoshows us that any volcano has serious potential to hugely out performhistorical norms.
A string of chambers could sit sealedfor thousands of years while the closest to the surface eruptregularly. Think Santorini as a scary example. You can be surefrequent earlier eruptions made it all appear safe, just like all theother so popular volcanoes we know and love.
The take home for all is that novolcano is safe at all. The right conditions will trigger a cascadeof chambers releasing in series and bathing the countryside with ashover a long period of time. History is only a suggestion that failedin every major volcano which is why folks lived nearby.
The good news however, is that a multichamber blow out puts the volcano to sleep for a long time.
Iceland VolcanoEruption Caused By Chain Reaction
http://www.inquisitr.com/419705/iceland-volcano-eruption-caused-by-chain-reaction/#O2ygwHwltfBrtwSQ.99
November 30, 2012
According to NBCNews, after nearly two centuries of dormancy,Eyjafjallajökull (AYA-feeyapla-yurkul) erupted many times over thecourse of 10 weeks. The eruptions spewed a huge plume of ash thatcaused extraordinary lightning displays, colored sunsets a fiery redacross much of Europe, and forced widespread flight cancellations fordays.
The eruptions began in2010 when a fissure opened on the flank of Eyjafjallajökull inMarch, revealing that it was inflating with magma. An explosion thenburst from the volcano’s summit in April, and three more majorexplosions from Eyjafjallajökull rocked Iceland in May.
Analysis of materialspewed from the explosions suggests each explosion involved separatechambers loaded with magma of distinct ages and compositions.
To learn more aboutwhat caused this spate of eruptions, the researchers analyzed swarmsof microearthquakes during the outbursts. The data suggests that thefirst explosion was rooted in a magma chamber about 3 miles (5kilometers) below the surface, while the three later explosionsstemmed from magma chambers at depths of about 7 miles (11.5 km), 12miles (19 km) and 15 miles (24 km).
Interestingly, theresearchers found that microearthquakes apparently occurred atgreater depths with each outburst. Researchers now suggest that theseries of eruptions was due to a “decompression wave” thatessentially rippled downward, upsetting the volcano’s plumbing.
The initial explosionspewed a massive amount of magma and melted about 650 feet (200meters) of ice. The researchers suggest this relieved a great deal ofpressure exerted from Eyjafjallajökull’s summit on its innards.This drop in pressure from above caused a magma chamber slightlylower down to begin inflating. When this led to an explosion, thisliberated magma in another chamber slightly lower down, and created acascade through successively lower chambers.
Jon Tarasewicz, ageophysicist at the University of Cambridge in England said:
“It’s novel tohave been able to match the deep seismic observations to big changesin the eruption rate at the surface. In this case, it seems thevolcanic plumbing system at depth responded to changes near thesurface, rather than vice versa.”
Tarasewicz continuedby saying:
“There are severalexamples around the world of volcanoes that are thought to have morethan one magma chamber, stacked at different depths beneath thevolcano. Understanding the pressure linkage and feedback betweendifferent magma storage reservoirs may help us to understand whysome volcanoes like Eyjafjallajökull have prolonged eruptions withepisodic surges in eruption rate.”
Although this researchcould yield insights on the magma underlying a volcano and how itmight behave, Tarasewicz cautioned, “we are still not in a positionto be able to predict accurately in advance when, or if, a volcano isgoing to erupt.”
The scientistsdetailed their findings online October 13 in the journal GeophysicalResearch
http://www.inquisitr.com/419705/iceland-volcano-eruption-caused-by-chain-reaction/#O2ygwHwltfBrtwSQ.99
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