November 17, 2011
Double Whammy Wiped Out Dinosaurs
But the second phase of the Deccan Traps volcanic eruptions did more to wipe out dinos and other species than the Chicxulub volcanic eruption.
A cosmic one-two punch of colossal volcanic eruptions and meteorite strikes likely caused the mass-extinction event at the end of the Cretaceous period that is famous for killing the dinosaurs 65 million years ago, according to two Princeton University reports that reject the prevailing theory that the extinction was caused by a single large meteorite.
Princeton-led researchers found that a trail of dead plankton spanning half a million years provides a timeline that links the mass extinction to large-scale eruptions of the Deccan Traps, a primeval volcanic range in western India that was once three-times larger than France. A second Princeton-based group uncovered traces of a meteorite close to the Deccan Traps that may have been one of a series to strike the Earth around the time of the mass extinction, possibly wiping out the few species that remained after thousands of years of volcanic activity.
Researchers led by Princeton Professor of Geosciences Gerta Keller report this month in the Journal of the Geological Society of India that marine sediments from Deccan lava flows show that the population of a plankton species widely used to gauge the fallout of prehistoric catastrophes plummeted nearly 100 percent in the thousands of years leading up to the mass extinction. This eradication occurred in sync with the largest eruption phase of the Deccan Traps — the second of three — when the volcanoes pumped the atmosphere full of climate-altering carbon dioxide and sulfur dioxide, the researchers report. The less severe third phase of Deccan activity kept the Earth nearly uninhabitable for the next 500,000 years, the researchers report. A substantially weaker first phase occurred roughly 2.5 million years before the second-phase eruptions.
Imagine something on the order of the Deccan Traps eruptions occurred today. Would there be any way to do climate engineering to partially ameliorate the effects? I suspect we could not command enough energy in a short enough period of time to do fundamental alterations on the scale necessary.
But suppose we had 100 years to prepare. What could we do? If we had a sufficient amount of nuclear fusion power we could move civilization underground and use the fusion energy to power the synthesis of artificial foods or underground farms. But what could we do on the surface to take the carbon and sulfur out of the atmosphere as fast as a massive volcano would inject it? How to clean the atmosphere?
Hydrogen Sulfide is far more toxic than CO2, lethal in as little as 200 ppm while CO2 toxicity doesn't set in until above 10,000 ppm (>1%).
Enclosed habitations would be cheaper than going underground, but we don't have enough experience with enclosing large spaces, and these would have to resist exceptionally corrosive conditions, severe storms, and be slightly over pressured. We don't have fusion, yet, but we do have fission, and already significant reserves of thorium and uranium. And the Japanese already have one technique for extracting uranium from seawater. We'd need to set up desalinization plants anyway, since the rain would be contaminated.
The residence time of H2S under natural conditions seems to vary between 18 hours and three days, so cleaning it from the atmosphere doesn't look like an issue.
I second the enclosed habitation option. More research needs to go into this and self-sufficient facilities. Nuclear fission should offer a suitable energy source for survival provided the habitat technology is there.
So, nuclear power (fission or fusion, whatever we actually have).
Fuel for same, uranium, deuterium and boron are all extractable from seawater, in principal. The Japanese have a technique for uranium (somewhat more expensive than mining ore, at the moment), and are working on another. Fusion will want either deuterium or boron-11.
Atmosphere filtering technology (like Bujold's Komarr, the air inside will be made from the air outside). Over pressure slightly so any minor leaks are from inside to outside.
Enclosure technology, not up to scale yet. Lots of people are thinking about this, arcologies, cities 2.0.
Deccan Traps ( from wikipedia ) was caused by movement of plates.
somehow it looks like deep underground nuclear explosions migh ease the pressure which causes geo activity.
So if the things start to be bad ( series of huge volcanic eruptions ) and the cause ( sliding of plates is very well understood ) series of explosions migh ease the situation somewhat.
Looking at the Wikipedia article the worst of the deccan traps erruptions happened over perhaps 30,000 years, so humans would no difficulty in ameliorating the effects. The deccan trap erruptions resulted in global cooling and the warming caused by our greenhouse gas emissions are far in excess of what would be required to counter the average rate of cooling. But to avoid damage to the oceans and other negative effects we should cut back on CO2 emissions and instead a few chemical plants could manufacture and release various super greenhouse gases as required. Of course we should eliminate our own sulfur emissions and may need to dump ash or lime in some fresh water lakes to counter the effects of acid rain caused by volcanic gases.
Going totally underground is probably more expensive than just having a hardened underground shelter that can be used as a retreat, while still spending a lot of time on the surface. It's really hard to compete with free sunshine (even attenuated by volcanic emissions) and water that just falls from the sky.
Anyway, I don't think it's possible for something as big as the Deccan Traps to sneak up on us. It may not even be possible for such an event to recur - after all, the Earth's volcanic activity *is* gradually decreasing. If I had to place bets on which supervolcano is most likely to hose us, it would be Uturuncu. It couldn't cause an apocalypse like the Deccan Traps, but it might still kill a billion people through crop failure and starvation.
No easy way out. Going underground for housing and factories is more expensive, but the shelter lasts longer so is the better buy. Death rate among humans pushing 98%, effective extinction. Plant die off very high. Human habitats would have to keep zoos in order to keep some sort of genetic diversity for after, and be spread far apart to minimize war and raiding. Massive social change. New cultures would make the Japanese look like staunch individualists. Being underground would be the new norm, and most of the influentual neo-trogs would resist anything that made the surface more habitable as an "unnecessary expense while we have so many social ills plaguing our society" etc. (meaning "I can't find a way to steal the goodies if you insist on spending on that").
Just like Roseanne Roseannadanna used to say: "Well, Jane, it just goes to show you, it's always something--if it ain't one thing, it's another."
I thought the Chicxulub meteor was settled science. Don't those guys know that once something is settled, you can't go against the consensus.
BTW: Good news LarryD. You can smell HS long before it kills you. CO2 is colorless and odorless, that is why it is so insidious.
Check up on HS. It's mostly harmless so long as you can smell it, but it numbs the sense of smell on the way up to lethal levels. "Did I stop smelling it because I'm clear, or did I stop smelling it because I'm gonna die?"
CO2 produces physiological reactions. It is oderless, but the body reacts anyhow; usually a panic reaction.
The Deccan Traps were flood eruptions, very quiet. One such eruption occured around 1905 about 25 miles NE of Juneau Alaska, and the exact date is not known because no one knew it was happenning. It shows up on some of the USGS maps of the area, but I've never found it on the net.
Uturuncu (never heard of it before, thanks for mentioning it) sounds like it would be a short event. Nasty, but short. Grandkids of anyone who survived would be able to live a fairly normal life, if impoverished by our standards.
The human race /could/ survive massive eruptions. We have the technology and resources to create enclaves that /could/ work, but what mitigates against human survival is human nature. Even if someone came up with a way to save every single person on the planet, some would refuse to make the changes they would need to stay alive, others would try to profit off allowing people to survive, and many would die in the panic and disruption. Between one thing and another, the means to survive would be destroyed, if it was not protected some how. The few level headed enough to actually be productive would have to fight the masses for the resources and to protect the resources. A few powerful individuals would try to have shelters built, but they are not going to hold enough people to survive short term (decades), much less the thousands of years for a flood basalt eruption.
Make a great science fiction series, though.
What are the long term health effects of exposure to carbon dioxide gas?
Several studies have monitored workers repeatedly exposed to elevated levels of CO2 gas. Exposure to 1-1.5% for 42-44 days caused a reversible acid-base imbalance in the blood and an increased volume of air inhaled/minute (minute volume). In another study, harmful effects were not observed in 19 brewery cellar workers repeatedly exposed to average concentrations of 1.1% CO2, with levels occasionally up to 8% for a few moments. Submarine occupants exposed to 3% CO2, 16 hours/day for several weeks experienced flushing of the skin, an impaired response of the circulatory system to exercise, a fall in blood pressure, decreased oxygen consumption, and impaired attentiveness. Adaptation to some of the effects of long-term exposure to CO2 has been reported.
Paleological atmospheric reconstructions show extensive periods when CO2 was in the 1,000s of ppm, even if you stick with the low end of the error bars. (http://www.geocraft.com/WVFossils/Reference_Docs/Geocarb_III-Berner.pdf)
Sunlight may be free, but concentrating/collecting it is expensive, and compensating for its variability is also. (http://bravenewclimate.com/2009/03/18/the-solar-fraud/)
What's interesting is that the Chicxulub impact occurred at the exact opposite side of the earth from the Deccan Traps, and the impact coincided with the largest of the Deccan Traps eruptions.
Regards the risk that the means to survive would be destroyed: If there is not enough resources go keep everyone alive then lots of desperate people will fight each other for remaining resources. But there are two ways that smaller numbers will survive:
- Militaries will protect some key facilities. For example, Cheyenne Mountain will get protected by people with guns.
- Some facilities will survive due to stealth.
How it would all play out would depend on how rapidly things went very wrong. A very slow decline would give more opportunity for extended fighting over limited resources. A sudden severe change (darkness 24 hours per day with very cold temperatures) would limit mobility. Therefore more remote facilities would face fewer external challenges.
I don't think it is reasonable to expect wise behavior by the masses.
I would be very curious to know what the US military has done to prepare for very extreme scenarios. How many can they protect underground for how long?
My guess is that no facility exists that can power itself and grow crops underground for years. So long term survival without sunlight would be unlikely. Maybe such a facility could be built near a geothermal energy plant.