why does this island have a web page
I mean if the last news item on said page is two decades old, does it really need one?
Although I do admit, I like .aq
One of Australia's two active volcanoes seems to be erupting. We say seems because the volcano in question, on Heard Island, is located in the southern reaches of the Indian Ocean, 2000km north of Antarctica and closer to Africa than to Australia. That's about as close to the middle of nowhere as it is possible to be. Heard …
This Kiwi says Russell Crowe is DEFINITELY Aussie - along with Joh-Bjelke Petersen (showing my age there) and Derryn Hinch. John Clark on the other hand, is a true Trans-Tasman icon, happy to let you share him since your guy Dawe makes a good team with him. Also, if you want volcanoes (or mountains bigger than fleabites), come over this side of the ditch, we've got plenty.
Heard Island's remote location means any eruptions are unlikely to bother anyone
You hope (assuming that the island has not been the subject of the same sort of detailed study by vulcanologists that, say, mount Vesuvius has been)
Some volcanoes go with a very big bang. The fallout can have regional or even global consequences. Krakatoa. Katla. Tambora.
Sorry to be the bringer of bad news - it's not going to go bang, it's the wrong sort of volcano.
You're looking for andesitic and rhyolitic volcanoes found in continental interiors and on island arcs. Basically you want lots of silica to make the magma sticky and lots of water and carbon dioxide to provide the 'umph!'
Unfortunately, Heard Island is fed by the Kerguelen hotspot which brings very low silica, volatile poor magma from deep inside the Mantle. The volcanoes in the hot spot are basaltic, producing lava flows, very little ash and even the occasional lava lake - something like Hawaii - but with penguins.
I'd say given the fact that it is already believed to be erupting the statement is more true than your rebuttal. As I recall, none of the events associated with those volcanoes was associated with an active lava eruption. They were instances in which the relatively quieter lava eruptions weren't possible and the pressure simply continued to build until there was an Earth Shattering Kamboom.
I believe that at Krakatoa, what happened wasn't much dependant on the lava type. The ocean got into a (half-?) empty magma reservoir, and the result was possibly the biggest steam explosion that humanity has ever seen. (Unless Santorini was bigger).
True, if it's the highly fluid lava they get on Hawaii, the chances of the ocean finding its way into a large empy magma chamber are lessened.
Katla also isn't particularly explosive. Just high enough in toxic fluorides to poison cattle in Ireland, and acid enough to cause severe respiratory distress in London. It also upsets the climate, though not as badly as Tambora did. EjaFyallawhatever was a small forewarning of what's long overdue from Katla.
Why omit Toba, some 75,000 yrs ago, which reduced Homo Sapiens to a miserable few thousands and carpeted the Indian sub-continent with a few meters of ash?
Still , the blast did make a beautiful lake, where I swam naked in the moonlight back in my hippie days...
And the gourmet delights of Ati Anjing at the Pago-Pago cafe! Apologies to canine readers.
Ah, the good ol' days.
'This would mean a new vent. Am I looking at it wrong?'
I can't tell either. But it's not impossible - almost all volcanoes have parasitic cones and fissures low on their flanks - the pressure of pushing a column of magma into the vent is often greater than that required to open a vent on the side.
In contrast to what the article points out, the website mentions:
"Heard Island is about 4,100 kilometres south west of Perth in Western Australia. The McDonald Islands are about 43 km further west. That puts them in the middle of the vast Southern Ocean, about 1000 kilometres north of the Antarctic continent and still about 4,700 kilometres from South Africa to the north west."
I thought that the official middle of nowhere was more or less the corresponding location in the South Pacific, marked by a lack of islands and any other reason to be there. It's also not even on the way to anywhere much.
Rumour has it that the middle of nowhere is the default target for the major nuclear powers' missiles, so that should one ever get armed and launched by mistake, as little harm as possible is done. (Unless you are a blue whale, of course. )
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