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A lengthy (and auto-reloading multipart) press conference about a Laurentide comet strike which killed off NorthAmerican megafauna and the Clovis culture as well as triggering the YoungerDryas.
It's one thing to contemplate extinction events occuring in terms of tens-of-millions-of-years timescale, and another altogether thinking of them in terms of tens-of-thousands-of-years.
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Tstorm, experts say the next eruption of the Yellowstone supervolcanoe is long overdue. And since there is constant geothermal and volcano-related events, including many changes in recent years, Yellowstone is classed as an "active volcano," and is constantly monitored. Note:
quote:Yellowstone Volcano Observatory (YVO) has developed a monitoring plan for the period 2006-2015 to increase our ability to provide timely information during seismic, volcanic, and hydrothermal crises and to anticipate hazardous events before they occur.
quote:Possible future violent events in the active hydrothermal, magmatic, and tectonic system of Yellowstone National Park pose potential hazards to park visitors and infrastructure. Most of the national park and vicinity are sparsely populated, but significant numbers of people as well as park resources could nevertheless be at risk from these hazards. Depending on the nature and magnitude of a particular hazardous event and the particular time and season when it might occur, 70,000 to more than 100,000 persons could be affected; the most violent events could affect a broader region or even continent-wide areas.
quote:In 2003, changes at the Norris Geyser Basin resulted in the temporary closure of some trails in the basin. New fumaroles were observed, and several geysers showed enhanced activity and increasing water temperatures. Several geysers became so hot that they were transformed into purely steaming features; the water had become superheated and they could no longer erupt normally.
Read the section in the above article on "Geology" for a description of the three major past eruptions, and their devastating effect on the entire continent and on global weather, and their role in extinctions of many species. One eruption is said to have been 1,000 times greater than the 1980 eruption of Mt. St. Helens, and ejected 240 cubic miles of ash, rock, and pyroclastic materials. The most powerful eruption released 588 cubic miles of volcanic materials.
Who says that another super-eruption could not be triggered by a powerful meteroric impact? They could go together.
Posts: 3742 | Registered: Dec 2001
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The important point about asteroid impacts is that they're preventable. So far, we don't have any way at all of preventing volcanic activity, no matter what the relative risk may be. Asteroid impacts are easily preventable, if we would spend comparable amounts on that risk as we do on, say, air travel safety. That's why it's so important that we get something going along those lines, so we don't wait too late and end up all dying of something stupid that we could have stopped if we'd been paying attention and doing reasonable things toward mitigating the risk.
Posts: 6246 | Registered: Aug 2004
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Nighthawk, we need two things to prevent major asteroid impacts:
(1) The means for early detection.
(2) The ability to intercept them with sufficient firepower to give them a nudge great enough to alter their course so they miss earth. If intercepted early enough, only a slight nudge would be needed.
They would still need to be monitored after that for undesireable changes of course after they go around the sun. The ideal solution would be to put them into a stable orbit around the earth, so we could go up and mine their useful materials (such as Titanium, Iridium, etc.). Or to be safest we could redirect them to collide with the sun.
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But it's quite doable within a reasonable budget and time frame. Say we start with the amount we spend on air traffic safety. The reason I want to start now is that we have no guarantee how long we have before the next impact, nor how severe it will be. Why wait until after it's too late? We did that with Katrina and New Orleans. If we're going to survive we have to start preparing for these clear and imminent threats before they happen.
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What could we have done about Katrina and the inundation of New Orleans? We could have had sense enough not to build a city on the seacoast that is below sea level. We could at least have had the sense not to rebuild the city there after it is mostly washed away. But even so, how do we stop a hurricane?
Perhaps it would help if we sent a fleet of tankers containing liquified CO2 into the path of the hurricane, so they could lay down a blanket of super cold CO2, which would hopefully stop any more heat from the warm ocean waters from rising ino the air to fuel the hurricane. Would that work--or make matters worse?
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New Orleans was built *before* it was under sea level. Over a period of three centuries, the outlet of the Mississippi river deposits silt and sediment along its course until the level of the banks causes the entire river to wash over the land. This was known for many many years preceding Katrina, and many people predicted a similar scenario and said it was inevitable. The thing was, New Orleans should have been uninhabitable decades ago.
As for your post about Yellowstone. If that volcano erupts in a fashion similar to (pre)historical eruptions, it will be the end of human life, or at the very outside, the end of all economic and industrial activity on Earth, following the death of 99.9% of humanity.
But the term "overdue," is needlessly alarmist. There is no schedule for eruptions, and there is very concrete evidence showing that the periods between eruptions fluctuates widely. There can be an eruption there ever 100,000 years, but half a million years or more can pass without an eruption. It could go off tomorrow, or it might sit and gurgle for a million years. There is no way to know.
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Yellowstone supervolcano, asteriod... On a lighter note, did you all miss that top ten end-of-the-world program that aired this past year? (Yeah, it was so significant that I can't remember the actual name or the station on which it aired.) Global warming has the #1 spot.
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We could have spent $14B to build up the levees, redirect the outflow of the river indirectly rebuilding the barrier islands and so on. Then the hurricane wouldn't have flooded the city. There was an article in 1992 in Scientific American saying the next big hurricane that hits New Orleans is going to flood it, and here's what we need to do to prevent that.
Instead we spent at least $30B in the aftermath, and aren't ready yet for the next one, nor did we prevent all the human suffering that could have been prevented. So, yeah, we were dumb on that one. Let's do better with the asteroid thing.
Posts: 6246 | Registered: Aug 2004
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We can build a $14B levee that will stop an asteroid? Cool!
Actually, I'm stunned that, in light of the fact that not much was done to prevent the same thing in the future, people are back to living in New Orleans. I figured it'd be a ghost town by now.
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PRESS RELEASE FROM YellowstoneVolcanoObservatory PARTNER UNIVERSITY OF UTAH SEISMOGRAPH STATIONS "The largest of the earthquakes was a magnitude 3.9 (revised from magnitude 3.8) at 10:15 pm MST on Dec. 27. The sequence has included nine events of magnitude 3 to 3.9 and approximately 24 of magnitude 2 to 3 at the time of this release. A total of more than 250 events large enough to be located have occurred in this swarm.....Earthquakes are a common occurrence in the Yellowstone National Park area, averaging 1,000 to 2,000 earthquakes a year."
Posts: 8501 | Registered: Jul 2001
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Missed it by that* much.....Would you believe... "...an asteroid or small comet similar in size to 2009 DD45 exploded over Tunguska, a remote region of Siberia, with the force of up to 15 million tons of TNT, flattening trees for more than 1,000 square miles around."
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A 40,000 mile miss! I hadn't been aware it came that close! Most of them that we hear about pass beyond the orbit of the moon, some 250,000 miles out. I think we dodged a bullet, just barely that time.
Posts: 3742 | Registered: Dec 2001
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quote:Originally posted by Tatiana: We could have spent $14B to build up the levees, redirect the outflow of the river indirectly rebuilding the barrier islands and so on. Then the hurricane wouldn't have flooded the city. There was an article in 1992 in Scientific American saying the next big hurricane that hits New Orleans is going to flood it, and here's what we need to do to prevent that.
Instead we spent at least $30B in the aftermath, and aren't ready yet for the next one, nor did we prevent all the human suffering that could have been prevented. So, yeah, we were dumb on that one.
Are you sure? You have to consider the probabilities here. What was the probability of Katrina hitting New Orleans in the way that it did? More generally, what is the probability of such a storm in a given year? Suppose it is 1%, to make up a number. Then if you spend 14 billion, over 100 years there is roughly a one-third chance you wasted that money. (100 years is actually rather longer than it's worth considering these things; how much infrastructure from 1908 is still around?) So there is a one-third chance you wasted 14 billion, and a two-thirds chance you saved (30 billion minus 14 billion = 16 billion), for a net expected value of 5.2 billion. On the other hand if you had invested that 14 billion somewhere else, at a very moderate 1% real interest, then at the end of 100 years you would have 37 billion. So with these numbers, building levees is a pretty bad investment. And notice I chose a long time period and a very low rate of return on the other investment.
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The probability of a big hurricane hitting New Orleans eventually is pretty close to 100%. If you live on the Gulf, it happens to you eventually. It's not a whether but rather a when.
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Apophis will come with in 22,000 miles in 2029... and may hit us 7 years later in 2036. This is a 237 meter wide asteroid, big enough to wipe out France! Yikes! I didn't realize we knew of any that big that are likely to hit us.
As for the one that just missed us by 40,000 miles -- we only noticed it 8 days before it swept by. And that was one as big as the Tunguska event. Eight days warning! We've gotta get better at asteroid spotting or we're going to regret it.
Posts: 3295 | Registered: Jun 2004
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quote:Originally posted by Tatiana: The probability of a big hurricane hitting New Orleans eventually is pretty close to 100%. If you live on the Gulf, it happens to you eventually. It's not a whether but rather a when.
That is not the relevant calculation, however. The question is,do you best prepare for this disaster by building levees, which prevent damage, or by investing in other things, which generate wealth that can be used to repair the damage?
Posts: 10645 | Registered: Jul 2004
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When significant numbers of lives are at risk, you spend the extra money to prevent that rather than investing is to make a profit on cleaning up the damage. Also, when have you known the US gov't to make a decision like what you're suggesting?
Do you advocate not buying homeowner's insurance if the cost-benefit estimates come out for it being a bad investment?
Posts: 5462 | Registered: Apr 2005
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quote:When significant numbers of lives are at risk, you spend the extra money to prevent that rather than investing is to make a profit on cleaning up the damage.
This is not generally true. In general we are willing to spend about five million to save a life, as a rough average. So if you have some estimate of how many lives would have been saved by the levees, by all means multiply by five million and add that to the 30 billion property damage. But this does not alter the fundamental nature of the calculation.
Now, you may be about to go off saying that it is immoral to calculate the cost of lives in this manner. Before you do, consider that if ten million are spent saving one life frm he next hurricane, then that's two times five million that cannot be spent saving two lives from some disaster that's easier to guard against. Nature does not except you from opportunity costs just because you have good intentions.
Also, I did not say anything about 'making profit on cleanup'. You make the profit investing in other stuff before the disaster. Then you spend some of the profit cleaning up. This is a pure loss from the point of view of society, even though it is a gain for the cleanup contractors. Building levees is a gain for the levee-building contractors, too, but I don't see you objecting to their profit. The question is what is the best overall use of resources, not who stands to gain.
Please notice: I do not own stock in either housing contractors or cement factories; I really have no economic stake in which preparations are done.
quote:Also, when have you known the US gov't to make a decision like what you're suggesting?
Every day. Highway speed limits, for example, are set based on some sort of calculation of convenience versus traffic deaths versus a dozen other considerations.
Posts: 10645 | Registered: Jul 2004
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quote:Don't worry, Apophis will miss the keyhole. [Smile]
The first time 'round sure, but what if it gets aerobraked into it for the second time around? There's definitely enough atmosphere up there to do some serious aerobraking for an asteroid that big...
Ps. Your linky is broken.
Posts: 3295 | Registered: Jun 2004
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It would have been less expensive to give each&every displaced NewOrleanean a new home from existing housing stock already on sale before Katrina hit than to rebuild the flood walls.
As is, there is only a miniscule chance that the rebuilt flood walls will protect NewOrleans from being flooded by even a strong Category2 hurricane, let alone the Cat.3 that they're "designed for". Discounting rising sea-levels from GlobalWarming entirely, the Louisiana coastline is sinking into the Gulf of Mexico at a rate of ~3feet/~1metre per century. Faster in some areas, eg NewOrleans is expected to drop a metre in ~50years. So the flood walls would hafta be at least 3feet higher to bear the brunt of the next expectable Cat.3 hurricane...unless hurricanes start making landfall upon NewOrleans on a more frequent basis than in the past.
At a minimum, the flooded sections should have been bought out under eminent domain and filled to the top of preKatrina floodwalls with soil pumped from a shipping canal dredged through LakePontchetrain to BatonRouge, which will be the natural MississippiRiver seaport for the end of this century. Then it would have made at least some sense to rebuild&preserve NewOrleans as a tourist destination by putting in new floodwalls.
quote:Originally posted by aspectre: It would have been less expensive to give each&every displaced NewOrleanean a new home from existing housing stock already on sale before Katrina hit than to rebuild the flood walls.
Ah, but think how much cheaper still it would be now, at 2008 prices! Posts: 10645 | Registered: Jul 2004
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"A 40,000 mile miss! I hadn't been aware it came that close! ...I think we dodged a bullet, just barely that time."
It came within 0.00047AstronomicalUnits or 70,311kilometres of Earth's center, or ~63,940km/~39,730miles of surface impact. Using Earth's orbital speed of 107,218 km/hour, 2009 DD45 missed by ~35minutes47seconds.
On the other hand, "1,000 square miles" is contained within a radius of only 18miles.
posted
The impact cross-section is a bit larger than the geometric cross-section, due to gravity and whatnot, so you can likely shave some seconds off that estimate.
Posts: 10645 | Registered: Jul 2004
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Yeah, but I'm cheating already by assuming that the asteroid passed through the tubular-ring cross-section formed by Earth's travel along Earth's orbit, even though the plane of 2009 DD45's orbit is inclined relative to the plane of Earth's orbit.
The slides on the bottom and right of the screen change the orientation of your viewpoint. The |< and >| buttons change the time-viewed backwards and forwards respectively. You can also change the view in a manner such that Earth is at the center of the screen, then zoom in using the labeled slide.
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Here's a follow up on that Winnebago-sized chunk that hit North Africa a few months ago. It seems that they were able to find meteorites that made it all the way to the ground, and they're very unusual. The findings are Nature's cover story this month.
Posts: 6246 | Registered: Aug 2004
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Oh, something just occurred to me relative to an argument some people way back in the first few pages brought up. They said no big impact has ever happened in recorded history. Setting aside the fact that recorded history is very short, and significant impacts have definitely occurred during that time, e.g. Tunguska, I had an idea that sort of negates their argument.
If a really big impact DOES occur, one of the certain-extinction size that I'm most worried about, then there won't be any way for it to be part of anyone's recorded history because recorded history will end at that point.
Perhaps in a few hundred million years someone else, some non-human species, could be around once again to record their own history. But perhaps not. We really don't know anything about the likelihood of species-who-write evolving on planets like the earth. So far we only know of just the one.
Posts: 968 | Registered: Sep 2003
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I've just been reading about Zion's camp, an episode in the history of The Church of Jesus Christ of Latter-day Saints, otherwise known as the Mormons. The church at that time was concentrated mostly in Kirtland, OH and Independence, MO. When the Saints in Independence were being harrassed, mobbed, murdered, raped, etc. and their homes and stores and properties were being destroyed by the locals trying to run the Mormons out, Joseph Smith, Jr. and a few hundred men from the Kirtland area rode to the rescue in a semi-military group known as Zion's Camp.
The expedition suffered through great hardships and difficulties to reach Missouri, at which time the government forces they'd counted on to back them up never materialized, and God, speaking through revelations to Joseph, withheld his permission for them to attack the local mobbers. Apparently self-defense was allowed but not all-out war, and the Saints were urged to proclaim peace. In the meantime, Zion's camp came down with cholera, and most were very sick, and many died. The Camp was forced to disband and make their way home piecemeal as best they could, their numbers sorely depleted. It seemed a terrible defeat.
At the time it was tempting to believe God had abandoned the Saints altogether. The cholera was understood by some at the time to be a scourge sent from God to punish them for internal contention in the camp. Now, of course, we would attribute it to the poor standards of water hygeine. They probably didn't keep their latrines in an area that was downstream from their drinking water supply. Something simple like that might have prevented the disaster. As it was, the Saints ended up losing almost everything in Missouri and having to leave. What does that say about how we should understand the way God succors his people?
That thought was 'impacting' in my head this morning with the question of whether God would reach out and save us from an asteroid impact from which we had means but not sufficient motivation to save ourselves. I'm thinking that God didn't save his Saints from cholera when they didn't even realize yet what caused cholera, and how to save themselves from it. I don't think he's going to save us from an asteroid impact that we can clearly see coming, but are too apathetic to do anything about. I think it's up to us.
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I'm also thinking about the phenomenon of Cassandra. When I make these warnings, I feel like a Cassandra, someone who warns of disaster but nobody listens. It's interesting to realize that the original Cassandra of legend was right. She was Hector's sister in Troy, and predicted that disaster would come to their city, which of course it did in the Trojan War.
I see society as analogous to the body of a human or other animal. Each individual in a civilization is like a cell or other part of the body of society. Some of us are like feet, others like skin or hands, others are brains or bones.
The Cassandras of society are sort of like our eyes, because they see disasters that are headed our way, and they see how we can take steps to avoid them. But they are eyes without any nerve connections to the brain. They can see what's about to happen, but they don't have any way to hook in to the motor nerves and get them to step in another direction to avoid the danger.
What Cassandra needs is to develop some axons into the higher executive control functions of the body of civilization. That is what is lacking. I wonder how to go about doing that?
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The British were taking the threat a bit more seriously than anybody else, the last time I checked. That was a couple of years ago, though. I wonder what kind of progress they've been making in their plans in the intervening years?
Ana kata, what made you decide to switch from your Tatiana handle to this one?
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Ah, I forgot. In order to change the tagline on the topic header I have to change back to ana kata, or it won't let me edit that post. Then I forgot to change back until you mentioned it.
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How do you miss a 2to3kilometres-wide asteroid with a 3.4year orbit that came within 0.084AU* of Earth on 9Jan1999?
* According to Nasa's Horizon ephimerides calculator. It came within 0.0811AU according to the Orbital Simulator (link in my previous post above).
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Wow, that's a big one. Maybe with more viewings we'll find a somewhat different orbit farther away, or maybe not. I think we're still missing a lot of the earthgrazing objects.
How many miles is .084AU? 93,000,000 * .084 = about 900,000 miles. So would that be about 4 times as far as the moon? That's pretty darn close.
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~12,600,000kilometres/~7,800,000miles, or almost 33 times the average distance to the Moon. Due to the asteroid's orbital inclination, the closest it flys under Earth's orbit is ~3,500,000kilometres/~0.046AU/~2,170,000miles.
The writing mostly reminds me that science reporters were amongst the first fired during the downturn in newspaper subscriptions.
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How could that meteorite have been going that fast? Air resistance almost certainly should have slowed it to around 200-300 mph.
Posts: 684 | Registered: Jun 2002
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Yeah, Schoolboy survives direct hit by meteorite travelling at 30,000mph, does not survive flash vaporization
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Interesting articles. How would we cope now with something like this, I wonder? If most of North America burned and there were huge tsunamis on one coast? It would be a struggle to keep civilization going, I think. These things happen pretty frequently in our solar system. Witness the recent Jupiter impact, as well.
We need an asteroid defense, guys. Like, soon. This is entirely preventable. We have the technology to protect ourselves. If we don't use it, whose fault will it be if we get hit? I don't see how we can blame anyone but ourselves in that case.
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