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grinner
08-09-2004, 09:36 PM
Nature 'mankind's gravest threat'
We are making good progress in reducing the threat of asteroid impacts
Giant tsunamis, super volcanoes and earthquakes could pose a greater threat than terrorism, scientists claim.

Global Geophysical Events, or "Gee Gee's", as they are nick-named, are not being taken seriously enough, they say.

The global community needs to monitor these risks, and develop strategies to cope in the face of a catastrophe.

However, we are making good progress in reducing the threat of asteroid impacts, the researchers said during a briefing at the Royal Institution, UK.

Battening down

Since 9/11 we have become acutely aware of the threat of terrorism. Governments worldwide are battening down the hatches and ratcheting up the security.

But, in terms of grave threats, are we really looking in the right direction?

Giant walls of water that can devastate coastal cities, volcanoes so big that their ash crushes houses 1,500km (932 miles) away, giant earthquakes and asteroid impacts. These are very rare events and, if we are lucky, nothing like them will happen in our lifetimes.

But in the longer term, Gee Gee's may be our undoing if we do not take action. According to researchers, careful preparation could potentially save thousands of lives.


We need to raise awareness, identify threats and improve surveillance
Bill McGuire, Benfield Grieg Hazard Research Centre
"In any one year the chances of one of these things happening is probably much less than 1%," said Bill McGuire, director of the Benfield Grieg Hazard Research Centre. "But in the longer term it is 100%.

"We need to raise awareness, identify threats and improve surveillance.

"We need to plan what we will do if these things happen."

Super eruption

Volcanoes and earthquakes are relatively common occurrences, but Gee Gee's are on an altogether different scale.

The last "super volcanic eruption" was back in April 1815, when Tambora in Indonesia exploded violently, in what was the largest eruption in historic time.

The eruption column reached a height of about 44 km (28 miles), ash fell as far as 1,300 km (800 miles) from the volcano - and an estimated 92,000 people were killed.

Rare though they are, events this catastrophic need to be taken very seriously.

The potential threat that scientists currently have their eye on is an insecure rock - the size of the Isle of Man - in the Canary Island of La Palma.

The rock is in the process of slipping into the sea and Professor McGuire fears that when it finally collapses, the resulting tsunami will cause massive destruction along the coasts of countries like the USA, UK and many on the African continent, within a matter of hours.

The global community needs to monitor the risk posed by Gee Gee's, scientists claim
"Eventually the whole rock will collapse into the water, and the collapse - when it happens - will devastate the Atlantic margin," said Professor McGuire.

The triggering factor could be the eruption of the volcano on La Palma, called Cumbre Vieja, which could feasibly blow "anytime", according to Professor McGuire.

Many researchers working in the field of Gee Gee's would like better monitoring of Cumbre Vieja, so that advance warning can be given for the possible collapse of the rock.

"We need to be out there now looking at when an eruption is likely to happen," said Professor McGuire. "Otherwise there will be no time to evacuate major cities."

Cosmic threat

Global governments are not entirely ignoring the threat of Gee Gee's, however.

Work funded by the US government is swiftly tackling the threat posed by asteroids
The greatest danger to humanity comes from asteroids, but work funded largely by the US government is swiftly tackling this threat.

The European Space Agency (Esa) and Nasa are planning missions to test how the course of asteroids and comets can be altered by an impact.

Esa's mission Don Quijote will send a spacecraft crashing into the surface of a space rock to measure the effects. In 2005, Nasa's Deep Impact will monitor the outcome of blowing a hole in comet Tempel 1.

Scientists hope this will help them learn how to destroy or deflect an asteroid on a collision course with Earth.

According to Benny Peiser, of John Moores University, UK, the threat of cosmic mega disasters will be essentially "abolished within 30 years".

"A quiet and largely unnoticed technological revolution is dramatically accelerating the rate at which near-Earth asteroids (NEAs) are discovered," he said.

In 1995 we knew about 300 NEAs, today we know about 3000 - and within 20 years we could be aware of 90% of all nearby space rocks, he says.

"For the first time in the history of evolution we are closing this window of vulnerability."link (http://news.bbc.co.uk/2/hi/science/nature/3549812.stm)

bubblez
08-09-2004, 09:42 PM
hahahahaha

do what you will: build walls, dams, etc..., but you can't beat water. And, aren't we sitting on a super-volcano via Yellowstone National Park?

You can have your "protective" shelters... but, given the time this erupts give me a lawn chair and a pair of sunglasses.

JadedLegend3
08-09-2004, 09:42 PM
Is there no safe place to live?

Lord Loser
08-09-2004, 09:46 PM
Jeez. I'm starting to think I should just stay in bed from now on. I won't be any safer, but I'll at least be more comfortable...

BrowderChick
08-09-2004, 10:02 PM
I know. Sheesh.... :dunno:

Kurt_eh
08-09-2004, 10:04 PM
Geology at work, my friends, geology at work! :D

JadedLegend3
08-09-2004, 10:05 PM
Well, fix it, Kurt! You're the geologist! :P :)

Kurt_eh
08-09-2004, 10:30 PM
Unfortunately, unlike a dog, the Earth doesn't stop peeing in the corner when you get it "fixed" ;)

AgentSun
08-09-2004, 10:38 PM
does the universe have a corner?

Saajak
08-09-2004, 10:46 PM
Hmmm...let's worry about something over which we have absolutely no control. Heck, the sun'll go supernova in a few million years. Better start buying that property on Mars.

Frellster
08-10-2004, 01:30 AM
Which is only fair as mankind is Nature's greatest threat!

TheBladeRoden
08-10-2004, 01:46 AM
Nature's had it easy for far too long!

mfa96
08-10-2004, 08:46 AM
Athol Fugard to Spalding Gray:

"The sea's a lovely lady. The sea's a lovely lady when you play in her, but if you play with her, she's a bitch. Don't ever play with the sea. You're lucky to be here. You're lucky to be alive." -Swimming to Cambodia

stellar
08-10-2004, 09:00 AM
There is something that can be done about the rock about to fall into the sea. Hydrogen Bomb. When the first H-bomb was tested in 1952 on Elugelab Island , the resulting 10+Mton explosion vaporized the island and left a 200ft crater in the seabed, 1-mile in diameter.

That ought to take care of the rock.

NebariNookiee
08-10-2004, 09:13 AM
And risk turning one falling rock into many.

stellar
08-10-2004, 09:14 AM
We can bomb those rocks too.

Teraad
08-10-2004, 03:58 PM
Hmmm...let's worry about something over which we have absolutely no control. Heck, the sun'll go supernova in a few million years. Better start buying that property on Mars.

Just a quick aside. The sun will never go super nova. It's not massive enough. Once the sun finishes fusing all of its hydrogen, it will expand into a red giant, expanding past the orbit of Mars. So even Mars will be charred to a crisp inside the sun. The timeline for this is about 5 billion years.

More massive stars that do go super nova will go through this red giant phase, but then helium will be fused, once that runs out, another (smaller) red giant phase, then repeat with other elements up until iron is reached. Since fusing iron is endothermic (requires energy instead of giving it off), the fusion process stops. The star then implodes.

stellar
08-10-2004, 04:01 PM
A massive enough star will either go Supernova or Black Hole. If it goes Supernova, I'll betcha that will take care of the rock that's about to fall into the ocean. :)

AgentSun
08-10-2004, 04:09 PM
and if it goes black hole, it'll just suck up the rock? i hope it doesn't turn into a white hole afterwards :eek:

stellar
08-10-2004, 04:24 PM
Or White Snake.

grinner
08-10-2004, 04:25 PM
I think Mr. Coverdale would have something to say about that

Teraad
08-10-2004, 04:28 PM
Well technically even to become a black hole, a star has to go super nova first. The remnant of the star after the implosion sheds off most of the material will either be a neutron star or a black hole. It's the mass of the star that determines the eventual state of the star.

Lighter massive stars (if that makes any sense) will collapse to neutron stars where the degenerage matter is neutrons. That is, the neutrons of all the atoms in the star are touching. In a more massive star, the gravity will force even the degenerate neutrons to collapse, making a much denser object we call a "gravitationally dense degenerate remnant star" or black hole for short (and it helps the coolness factor).

stellar
08-10-2004, 04:30 PM
But it would destroy an island-sized rock.

Teraad
08-10-2004, 04:33 PM
But it would destroy an island-sized rock.

Yeah, I guess. You might even say that it would destroy an Oort cloud's worth of island-sized rocks.


Edit: I can't spell.

stellar
08-10-2004, 04:40 PM
Interesting you would say that. If a Black Hole has a bigger Oort cloud than the original star, would the Supernova have cleared the path in such a way that the debris contained in the Oort cloud of a Black Hole is distinguishably fine and covers a distinguishable large expanse?

AgentSun
08-10-2004, 04:43 PM
it's like discovery channel death match in here. Stellar vs. Teraad...ROUND 1...FIIIGHT!

stellar
08-10-2004, 04:44 PM
No fighting. Collaboration. :)

Teraad
08-10-2004, 04:57 PM
Interesting question, Stellar. Without giving it too much thought (since I don't have much time right now), I'm not certain. Assuming the implosion and the resultant shockwave that throws off the stellar material is perfectly spherical (inaccurate but they do say, to make calculations simpler, assume a horse is spherical), the stellar material would be ejected in equal amounts in every direction.

I don't remember the theoretical average velocity of the ejected matter, so this is where it gets fuzzy. If the material is travelling fast enough, it could arrive at the Oort cloud without diffusing too much, so the material would be enough to destroy most of the proto-comets. If, on the other hand, it doesn't travel fast enough, it would diffuse and not destroy the whole cloud.

But in either case, I believe the passage of the stellar material would disrupt the orbits of the bodies in the Oort cloud enough to eventually send most of them into the remnant of the star or off into interstellar space.

I hope that was coherant enough and that I didn't forget too much of what I learned by having to deal with "how do rearrange v=d/t to solve for time". [Grade 12 students should already know how to rearrange equations before taking university prep physics courses. Sorry for the mini-rant there.]

stellar
08-10-2004, 05:01 PM
Just use a triangle, base side down, divided into thirds. Put the d in the top third and the v and t in the two bottom thirds. When you want to solve for t, circle t and look at the remainder in the triangle - d/v. Want d? Circle d, v*t. Even a monkey can understand a triangle.

Teraad
08-10-2004, 05:07 PM
Yeah, I use the triangle, works great for a lot of things. It helped with simple intereste when I was teaching the personal finance course. I = Prt, the I on top, the P,r and t on the bottom, etc.

But that's something that they should know from even grade 9. And it doesn't really help when it comes to slightly more complex equations like a = (v2-v1)/t for the average acceleration. Cross multiplying should be ingrained by then.

I can see how the triangle could be used for the average accel equation if you were only looking for delta v or t, but if you're looking for the initial velocity, it's useless. Yet I still get some of the brighter students sticking everything in triangles. Luckily I'm only going to be starting my second year of teaching, so I've got plenty of time to figure it out before I retire.

stellar
08-10-2004, 05:09 PM
Or become overwhelmingly cynical.

Teraad
08-10-2004, 05:12 PM
That's always an option.

I wonder if I'd be able to get away with giving students multiple choice questions where all the answers are A more easily if I'm cynical.

bubblez
08-10-2004, 09:36 PM
That's always an option.

I wonder if I'd be able to get away with giving students multiple choice questions where all the answers are A more easily if I'm cynical.

Perhaps being more cynical wouldn't be necessary. Watching the twisted, pained looks of confusion after 7 to 8 questions would surely do your heart good.

(inaccurate but they do say, to make calculations simpler, assume a horse is spherical),
so, it's not a bad thing when I say pi is about 3? :lol: *giggle snort snort*

Okay, bad. Back to the star talk.