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Scientists Discover 91 Unknown Volcanoes Beneath Ice Sheet in Antarctica Options
Daemon
Posted: Friday, August 18, 2017 5:00:00 AM
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Scientists Discover 91 Unknown Volcanoes Beneath Ice Sheet in Antarctica

Scientists have identified 91 volcanoes beneath an ice sheet covering Antarctica's west coast, a study shows. The volcanoes covered in ice stand nearly 3 miles along West Antarctica, possibly making the region denser than east Africa where Mount ... More...
Tovarish
Posted: Friday, August 18, 2017 2:20:49 AM

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Lets hope they stay buried.
thar
Posted: Friday, August 18, 2017 4:33:40 PM

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Well, it is a trade-off. Losing the ice sheet makes them more likely to erupt.
But in terms of safety, you are better off with them exposed.Whistle
A volcano can do a limited amount of damage. Instantly melted icecap does a heck of a lot more damage!


From an eruption, there is normally some warning to stay away. Lava and ash only goes a certain distance. But floods will get you and there is no place to run! Course in Antland there's nobody in the path. Interesting if the water surge could reach all the way to Oz? I suppose not. Too far away. And wrong side, anyway.

The core is stable, volcanoes are in the island arc, the archipelago side, which is where the ice sheet is disappearing fastest. That icecap is going to disappear in time...





Offload the ice, pop the volcano. Like taking the top off a shaken fizz bottle!
The worst danger would be when enough ice has gone to release the pressure, but enough is still there. Eruptions under ice are the worst!
Tovarish
Posted: Friday, August 18, 2017 10:49:09 PM

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Thar, this is a subject that is way, way above my knowledge base, however (love that word) with volcanoes in South America rotating around the world three times, emitting

carbon and stopping air traffic for weeks, was it Greenland that had similar disturbances in the Northern Hemisphere?
thar
Posted: Saturday, August 19, 2017 4:16:43 AM

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No volcanoes in Greenland. It is ancient shield, like the centre of Australia.

There was an eruotion in Iceland a few years ago that produced a lot of ash and disrupted air travel.





The effectdepends on where you are compared to atmospheric circulation.
Only volcs near the equator, like Tambora, effect both hemispheres.
Australia gets effected by eruptions in the Andes.



A lot of the coverage of the Icelandic ash cloud seemed to take it as a personal insult.Whistle

Most Icelandic volcanoes don't make that much as, because they are hot, primitive rick from the mantle. Zones where continental crust is melted, like the Andes, tended to be more explosive.
Eyjafjallajökull was a relatively small eruption but it happened under the ice cap. It generated a lot of ash and grounded much of European airspace for a while.

Now, there are a few media outlets that get hysterical now, every time Iceland raises the alert level on one of its volcs. The thing is, that happens pretty regularly. No big deal.


Aircraft are right to be careful though.
Many years ago nobody realised there was a problem. Then a British Airways flight over Indonesia experienced some odd things. St Elmo's fire (electrical glow), burning smell and smoke in the cabin - then all four engines cut out.
You probably heard about it. Best bloody bit of plane captaincy and crewing you can imagine.

Quote:
Shortly after 13:40 UTC (20:40 Jakarta time) above the Indian Ocean, south of Java, the flight crew (consisting of 32-year-old Senior First Officer Roger Greaves and 40-year-old Senior Engineer Officer Barry Townley-Freeman while 41-year-old Captain Eric Moody was in the lavatory) first noted an effect on the windscreen similar to St. Elmo's fire.[1] The phenomenon persisted after Moody returned from the lavatory. Despite the weather radar showing clear skies, the crew switched on engine anti-ice and the passenger seat belt signs as a precaution.

As the flight progressed, smoke began to accumulate in the passenger cabin of the aircraft; it was first assumed to be cigarette smoke. However, it soon began to grow thicker and had an ominous odour of sulfur. Passengers who had a view of the aircraft's engines through the window noted that they were unusually bright blue, with light shining forward through the fan blades and producing a stroboscopic effect.[3]

At approximately 13:42 UTC (20:42 Jakarta time), the number four Rolls-Royce RB211 engine began surging and soon flamed out. The flight crew immediately performed the engine shutdown drill, quickly cutting off fuel supply and arming the fire extinguishers. Less than a minute later, at 13:43 UTC (20:43 Jakarta time), engine two surged and flamed out. Within seconds, and almost simultaneously, engines one and three flamed out, prompting the flight engineer to exclaim, "I don't believe it—all four engines have failed!"[3]

Without engine thrust, a 747-200 has a glide ratio of approximately 15:1, meaning it can glide forward 15 kilometres for every kilometre it drops. The flight crew quickly determined that the aircraft was capable of gliding for 23 minutes and covering 91 nautical miles (169 km) from its flight level of 37,000 feet (11,000 m).[3] At 13:44 UTC (20:44 Jakarta time), Greaves declared an emergency to the local air traffic control authority, stating that all four engines had failed. However, Jakarta Area Control misunderstood the message, interpreting the call as meaning that only engine number four had shut down. After a nearby Garuda Indonesia flight relayed the message to them, air traffic control correctly understood the urgent message. Despite the crew "squawking" the emergency transponder setting of 7700, air traffic control could not locate the 747 on their radar screens.

Many passengers, fearing for their lives, wrote notes to relatives. One such passenger was Charles Capewell, who scrawled "Ma. In trouble. Plane going down. Will do best for boys. We love you. Sorry. Pa XXX" on the cover of his ticket wallet.[2]

Owing to the high Indonesian mountains on the south coast of the island of Java, an altitude of at least 11,500 feet (3,500 m) was required to cross the coast safely. The crew decided that if the aircraft was unable to maintain altitude by the time they reached 12,000 feet (3,700 m) they would turn back out to sea and attempt to ditch into the Indian Ocean. The crew began engine restart drills, despite being well outside the recommended maximum engine in-flight start envelope altitude of 28,000 feet (8,500 m). The restart attempts failed.

Despite the lack of time, Moody made an announcement to the passengers that has been described as "a masterpiece of understatement":[3]

Ladies and gentlemen, this is your captain speaking. We have a small problem. All four engines have stopped. We are doing our damnedest to get them going again. I trust you are not in too much distress.[3][4][5]

As pressure within the cabin fell, oxygen masks dropped from the ceiling – an automatic emergency measure to make up for the lack of air. On the flight deck, however, Greaves's mask was broken; the delivery tube had detached from the rest of the mask. Moody swiftly decided to descend at 1,800 m per minute to an altitude where there was enough pressure in the outside atmosphere to breathe almost normally.

At 13,500 feet (4,100 m), the crew was approaching the altitude at which they would have to turn over the ocean and attempt a risky ditching. Although there were guidelines for the water landing procedure, no one had ever tried it in a Boeing 747. As they performed the engine restart procedure, engine number four finally started, and at 13:56 UTC (20:56 Jakarta time), Moody used its power to reduce the rate of descent. Shortly thereafter, engine three restarted, allowing him to climb slowly. Shortly after that, engines one and two successfully restarted as well.[6] The crew subsequently requested and expedited an increase in altitude to clear the high mountains of Indonesia.[7]

As the aircraft approached its target altitude, the St. Elmo's fire effect on the windscreen returned. Moody throttled back; however, engine number two surged again and was shut down. The crew immediately descended and held 12,000 feet (3,700 m).

As Flight 9 approached Jakarta, the crew found it difficult to see anything through the windscreen, and made the approach almost entirely on instruments, despite reports of good visibility. The crew decided to fly the instrument landing system (ILS); however, the vertical guidance system was inoperative, so they were forced to fly with only the lateral guidance as the first officer monitored the airport's distance measuring equipment (DME). He then called out how high they should be at each DME step along the final approach to the runway, creating a virtual glide slope for them to follow. It was, in Moody's words, "a bit like negotiating one's way up a badger's arse."[1] Although the runway lights could be made out through a small strip of the windscreen, the landing lights on the aircraft seemed to be inoperable. After landing, the flight crew found it impossible to taxi, due to glare from apron floodlights which made the already sandblasted windscreen opaque.


They found it had flown through an as cloud, invisible to its weather radar. Sticky molten ash clogged the insides of all the engines. As they fell, with the engines off, it cooled and cracked off clean!
When they landed they saw the plane, and its windows, had been completely sandblasted.


In Iceland (as eksewhere) the volcs are all very carefully monitored. Weather service shows the status constantly updated.


All green!


The ones under the icecaps are a worry.
Recently including Katla, Grímsvötn, Bárðarbunga.

The aeroplanes are the ones that have to worry. And anybody downstream from the glaciers - floods from subglacial eruptions regularly take out the main road and cut off parts of tge island. But apart from that, you can't worry too much, or you would never do anything. Whistle


The reaction abroad:
Quote:
The Icelandic volcano that experts fear could erupt and cause significant disruption to air travel was hit by the largest earthquake since tremors began 10 days ago, the country's Meteorological Office said on Tuesday.

Intense seismic activity at Bardarbunga volcano has raised worries that an eruption could cause another ash cloud like that from the Eyjafjallajokull volcano in 2010, which shut down much of Europe's airspace for six days.

“There was one event during the night ... it was a magnitude 5.7 (quake), the largest in this series,” Palni Erlendsson, a geologist at the Met Office said.

“Activity is still deep and we see no signs of anything close to the surface.”

On Sunday, Iceland lowered its warning code for possible volcanic disruption to the aviation industry to orange from red, the highest level on the country's five-point alert system, after concluding that seismic activity had not led to a volcanic eruption under the glacier.



Met Office scientists believe the earthquakes are a result of magma flowing out from under the crater of the volcano, causing a change in pressure.

The migration of magma — estimated at around 300 million cubic metres (10.6 billion cubic feet) along a 35 kilometre (21 miles) dyke by Icelandic scientists on Monday — could stop. That should lead to a gradual reduction in seismic activity.


But the magma could also reach the surface away from the glacier. This would probably lead to an eruption, but with limited explosive, ash-producing activity, scientists said.

If the magma reaches the surface under the glacier, that would lead to flooding and possibly an explosive eruption and ash production, they added. An eruption inside the Bardarbunga caldera is also possible, but scientists say less likely than the other scenarios.
"We still can't say whether it will cease, continue like this for a while or erupt. It's impossible to say,” Erlendsson said.

There have been thousands of smaller quakes over the past week at Bardarbunga. Areas around the volcano, in the centre of the North Atlantic island nation, have been evacuated.

Bardarbunga is in a different range to Eyjafjallajokull.


Reaction locally:


Whistle




Tovarish
Posted: Sunday, August 20, 2017 1:36:45 AM

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Thats the one Thar, thank you for the maps they are fascinating.

The news report said when speaking about the Antarctic volcanoes it was second to the proliferation off Africa?.
thar
Posted: Sunday, August 20, 2017 4:23:22 AM

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Not off Africa. In it. Africa is breaking apart, so there is a rift, but not yet an ocean.
Lots of volcanoes and some lava plains.




Because it is a rift, not a collision, the volcanoes are not that explosive. More bubbling away. So they don't make the news.

But they do erupt, lava and ash.





The whole area of East Africa has bulged. That was one of the theories as to why East African runners are so good - they live at altitude. Other athletes have to go to mountains to achieve the same physiological response. But I think that was debunked.

There are proper cone volcanoes, as well. Kilimanjaro,



And some with some really freaky chemistry.



It is also how the soil in Central Africa stays fertile - normally in equatorial regions the high rainfall leaches nutrients from soil and it is quite poor. But volcanoes in places like Rwanda and Congo keep it rich, able to support a dense population - and vulnerable to both natural and human disaster.





Tovarish
Posted: Monday, August 21, 2017 10:03:07 PM

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Oh dear, Mother Nature is never dormant.

I took the report to be under the ocean, it certainly is a hot spot.
thar
Posted: Tuesday, August 22, 2017 9:59:52 AM

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Nah, nothing really happening off the coast of Africa. It split away from South America, Australia, Antarctica and India, so it is surrounded by spreading ridges - but it did it a long time ago so they are a long way from the continent by now. Lots of activity there, but only a few places where islands reach the surface - eg St Helena in the South Atlantic, Maldives in the Indian Ocean.



But Africa mostly just sits there. Apart from that active rift in the east, of course.
It did crash into Europe a while ago, producing the Alps. It didn't effect Africa that much, it appears. The Atlas mountains were already there, from a earlier collision with America (the Alleghenies). Africa is pretty solid! It looks like in future Europe will begin to subduct under Africa (not for a while, thoughWhistle )

Of course, the Earth stays the same size. The spreading centres in the Atlantic and Indian Oceans are only being pulled apart because crust is subducting elsewhere and pulling it apart - the active volcanically places, like Indonesia and all around the Pacific. But Africa mostly just sits there, like it always has. Much like AustraliaWhistle







If you can keep your head when all about you are losing theirs....




Whistle
Tovarish
Posted: Wednesday, August 23, 2017 9:46:02 PM

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Thankfully Gondwanaland missed most of the volcanic clusters.

Thar has there ever been a comparison between volcanic emissions to people based emissions to the carbon footprint?

My understanding is that emissions directly related to people is around 4% of the total emissions, is there any substance to that?
thar
Posted: Thursday, August 24, 2017 3:54:36 AM

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Volcanoes release
water vapour - the most important greenhouse gas, and the one we can do nothing about

Carbon dioxide -currently all the world's volcanoes (most of which are along the mid-ocean ridges, underwater)release about 100 - 300 million tones each year, which is only 1% compared to human fossil fuel burning alone. And that is only part of the human effect.

Sulphur dioxide and ash - these both have a temporary cooling effect as they reflect sunlight and stop it reaching the Earth ( eg the year without summer in 1816, when the northern hemisphere starved, Mary Shelley wrote dystopian Frankenstein amid all the thunderstorms, Turner painted spectacular sunsets, a German invented the bicycle because there was no food for the horses, a lot of people thought the world was punishing them and invented new religiins, and a few others decided life was unfair and wrote about a 'communist' system that must must replace it. Mostly due to eruption of Tambora in the Dutch East Indies, although there were a few other eruptions as well.)


In the geological past, in times of greater volcanic activity, there have been much higher levels of atmospheric CO2 and warmer climate. Warm swamps at the poles. But the fact is, at the moment there is very little volcanic activity compared with most of geological time. It is really at an extremely low level.

But the main difference is timescale. Geological change happens over tens of millions of years. Organisms adapt, evolve. The difference now is that anthropogenic CO2 is rising so fast, nothing can adapt in time,- including humans living in low-lying settlements or trying to grow food. d'oh!
The actual levels are a mere blip, on a geological scale - but the effect in terms of climate change, sea level rise, extreme weather, is immense to our overpopulated, interdependent, fragile human settlement.


The argument for volcanic emissions is sometimes brought up by climate change deniers but it is a red herring. It is tiny compared to fuel burning. And, more importantly, you can't do anything about it, so as an excuse to do nothing about fossil fuel, it is a playground- level cop-out.




The figure if 4% carbon dioxide comes from the fact that by far the most important greenhouse gas is water - and since the Earth is mostly ocean and the atmosphere is always going to have water vapour in it, that is also a red herring. Oil companies pull out that figure as a 'what about them!' Defence. But the fact is, water vapour is always there. It is carbon dioxide that humans are pumping out.
There is also a postive feedback loop. The more CO2 we pump out, the warmer it gets, the more water turns to vapour (and the more ice melts, the less heat is reflected, the more is absorbed), so the warmer it gets...




Water vapor is there, but get too much and it falls as rain. It is self-limiting. But carbon dioxide just keeps accumulating.
Tovarish
Posted: Thursday, August 24, 2017 9:50:56 PM

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Thar, I am having trouble understanding the last graph, is it the year 2000, where is the comparison to 1750?

Please forgive my ignorance but to have plants grow we need CO2, also I hear on the radio if all of the Paris Accord was adopted the reduction in emission would be less

than .5% by the end of this century.

No wonder 300 million years ago the period was called Carboniferous.
thar
Posted: Monday, August 28, 2017 3:38:01 AM

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Yes, sorry, not a great diag. The baseline - zero, is the preindustrial figure and the bars above or below that are the situation now.

The accords are trying to limit the rate of increase because at current rates the level will rise more and more rapidly. At the moment a lot is being absorbed into the oceans (making it acidic, killing reefs) but that sink is reaching capacity - after that, it all gets to accumulate in the atmosphere. A big increase in such a short time has a big effect on certain things like sea level that effect millions. The emission reduction accords are a 'change the things you can change' solution.

A lot if CO2 was 'taken out of service' many millions of years ago by being buried as coal and oil. Burning that produces vast amoopunts of CO2. Also in limestone - when you make cement you release the CO2 from that, so that is a major contributor as well in certain countries with booming construction.
You could say it is natural to put it back into the atmosphere where it cameo from - but in terms of the effect on sea level, weather and subsequently on humans, that is a terrible result.

Vegetation naturally sequesters CO2. When a tree dies it returns to the atmosphere, but another growing tree is taking it back out again. Deforestation means it is put back in the atmosphere and stays there.


Even if emissions can be reduced, there will still be a temperature increase because the level has risen. The intention is to limit that temperature increase. It doesn't sound like a lot, but the fact is several systems are at tipping point, ready to tip into runaway ice melt, for example. The more ice melts, the less heat it reflects, the more heat the sea and land absorbs, the more ice melts...
Similarly, the more desertification, the fewer trees removing CO2, the more in atmosphere, the more warming,the more desertification...

It may be 'unfair' that a small increase in temperature has such widespread effects - at another time in Earth history, the story would be different. But that is how it is.


This is global temperature rise - business as usual versus reduction targets:



This is CO2 emissions from various reduction targets - even reductions still produce temp increases:



And a few effects. Tgjey depend on the rate of increase:
Tovarish
Posted: Friday, September 01, 2017 12:58:38 AM

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We are bombarded down here by the deniers and the anti coal, climate change groups.

Australia is gifted with copious quantities of uranium, coal, natural gas and of course sunshine.

Successive Governments have made appalling deals with international companies to buy and export these assets and in case of the gas, we can

buy our own gas from Asia cheaper than the cost of gas here.

States seem to be divided by politics, Labor is attempting a 50% renewable electricity load causing electricity to sky rocket where the elderly and low income homes opting

to go without essentials just to keep warm or cool as maybe.

South Australia that relies on Wind Turbine generation had an episode of particularly bad weather with very strong winds, the turbines shut down because of the high winds

and the State had a 24 hr blackout, hospitals were most effected, SA has the most expensive electricity in the world, and is subsidised by the Federal Government.

Queensland is still using base load from coal generators that are past their use by date so now the debate is on between relatively clean coal or renewables and we the

people are stuck in the middle paying for the experiments and ideologies.
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