One thing strikes me about the world's history of huge volcanic eruptions: Another one is probably inevitable. 93 million years ago a volcanic eruption might have caused a worldwide massive depletion of oceanic oxygen. All those fish that get oxygen from water would have died in massive numbers.
University of Alberta scientists contend they have the answer to mass extinction of animals and plants 93 million years ago. The answer, research has uncovered, has been found at the bottom of the sea floor where lava fountains erupted, altering the chemistry of the sea and possibly of the atmosphere.
Earth and Atmospheric Science researchers Steven Turgeon and Robert Creaser found specific isotope levels of the element osmium, an indicator of volcanism in seawater, in black shale—rocks containing high amounts of organic matter—drilled off the coast of South America and in the mountains of central Italy.
According to their research, the eruptions preceded the mass extinction by a geological blink of the eye. The event occurred within 23 thousand years and the underwater volcanic eruption had two consequences: first, nutrients were released, which allowed mass feeding and growth of plants and animals. When these organisms died, their decomposition and fall towards the sea floor caused further oxygen depletion, thereby compounding the effects of the volcanic eruption and release of clouds of carbon dioxide in to the oceans and atmosphere. The result was a global oceanic anoxic event, where the ocean is completely depleted of oxygen, Anoxic events—while extremely rare—occur in periods of very warm climate, which means that this research could not only help prove a mass-extinction theory, but also help scientists studying the effects of global warming.
If we manage to develop rejuvenation therapies and also to avoid extinction at the hands of robots and nano-goo then many of us will live to see massive volcanic eruptions. I'm thinking that perpetually youthful people who have thousands of years to prepare will want to build underground bunkers for the day when some big volcano on the scale of the Toba eruption (called VEI-8 events) finally goes off.
We won't get wiped out by an asteroid unless one comes in the next few decades. At some point in this century we should possess the technologies needed to detect and deflect any big asteroid. But volcanoes are much tougher. Will we ever possess technology needed to scale down the size of volcanic eruptions? Will we at least gain the capability to predict them in advance?
The next big earthquake in California might not come until after the singularity or the robot take-over. So we might not still be around to deal with it.
The odds of avoiding a major quake in the next 30 years are about the same as flipping a coin and having it come up heads six times straight: almost nil, according to a new study.
The study, released April 14 in simultaneous news conferences at USC and in the San Francisco Bay area, finds a greater than 99 percent chance that a quake as big or bigger than the 1994 Northridge will hit somewhere in California by 2037.
But it could happen a lot sooner, according to the study. The chance of a big quake within five years is 50-50. The 10-year probability is about 75 percent.
Odds of a 7.5 quake are almost 50:50.
The 30-year probability of an even more damaging, magnitude 7.5 quake – nearly 30 times stronger than Northridge – is almost 50 percent, USC University Professor Thomas Jordan said at the news conference.
Last night Santa Barbara was rattled by a 3.2 earthquake. It was just strong enough to make one wonder if a much bigger one was about to start. Luckily it was weak enough that internet access kept working. After a really big quake it might make sense to move out of state until communications and electric power get restored.
I am more worried about Peak Oil than I am about the next big earthquake. Declining oil production will cost us far more than an 8.0 earthquake even if that earthquake hits a major city.
Michael Storey at Roskilde University in Denmark and colleagues have found evidence that a huge volcanic eruption, 55 million years ago, unleashed so much greenhouse gas into the atmosphere that world temperatures rose by as much as 8°C – with the Arctic ocean reaching a toasty 25°C.
So then did polar bears evolve since then? Ditto for some of the other North American and Northern Russian cold weather animals?
Massive volcanic eruptions are a much bigger threat to humanity than asteroids. For the asteroid threat we could (if we were wiser) develop excellent systems for detecting and deflecting asteroids. But I doubt that we can do much to prevent massive eruptions (though if anyone has any ideas on that please post in the comments).
If geological scientists could predict a massive volcanic eruption on some part of the Earth I would take that prediction as an argument for a massive nuclear reactor construction project in other parts of the globe. In the early stages of eruption light from the sun would get blocked out. So solar panels would become worthless and the planet would become really cold. Later the planet might go through a big warming as Michael Storey thinks happened before. But first we'd need to survive the very cold and dark period. Nukes would help on that score.
The farther out a volcanic eruption prediction could be made the more we could do to reduce the loss of life. We could stockpile food and medicine, move people away from the eruption area, build cold weather shelters, and build nuclear power plants.
How big can a volcanic eruption get? Tambora in 1815 spewed 100 times as much as Mt. St. Helens in 1980 but Toba about 71,000 years ago spewed 2800 times as much as Mt. St. Helens. Toba's 2800 sq. km. spew is not the biggest in history. Note that the Yellowstone Caldera could become a supervolcano again and the current US territory has been the site of other supervolcanoes, including one that spewed up 5000 sq. km. of stuff.
Update: The scientists who conducted this research see it as evidence that a big spike in CO2 and methane can cause global warming.
The Paleocene-Eocene thermal maximum, or PETM, was a period of intense warming that lasted roughly 220,000 years. In addition to the warming of sea surface waters, this event – characterized by scientists as a "planetary emergency" – also greatly increased the acidification of the world’s oceans and led to the extinction of numerous deep-sea species.
Warming periods in Earth’s history are of interest as analogs to today’s climate change, Duncan said.
The international science team was able to link the PETM with the breakup of Greenland from northern Europe through analyzing the ash layers deposited toward the end of the peak of the volcanic eruptions. Using chemical fingerprints and identical ages, they were able to positively match ash layers in east Greenland with those in marine sediments in the Atlantic Ocean.
"We think the first volcanic eruptions began about 61 million years ago and then it took another 5 million years for the mantle to weaken, the continent to thin and the molten material to rise to the surface," Duncan said. "It was like lifting a lid. The plate came apart and gave birth to the North Atlantic Ocean."
If the human race doesn't get wiped out by robots, nanotech replicators, or an invading alien species then at some point we are going to need to do large scale climate engineering to compensate for future periods of intense volcanic activity.
With Hurricane Katrina people had a couple of days notice that something highly destructive was coming their way. When the big quake comes to SoCal and LA gets wrecked we'll find out about it right when the big ride starts. The last really big SoCal earthquake was in 1690. The San Andreas Fault has been building up unreleased tension for at least 300 years.
A researcher investigating several facets of the San Andreas Fault has produced a new depiction of the earthquake potential of the fault's southern, highly populated section. The new study shows that the fault has been stressed to a level sufficient for the next "big one"—an earthquake of magnitude seven or greater—and the risk of a large earthquake in this region may be increasing faster than researchers had believed, according to Yuri Fialko of Scripps Institution of Oceanography at the University of California, San Diego.
Historical records show that the San Andreas Fault experienced massive earthquakes in 1857 at its central section and in 1906 at its northern segment (the San Francisco earthquake). The southern section of the fault, however, has not seen a similar rupture in at least 300 years.
Although seismologists have not been able to predict when a great earthquake will occur on the southern San Andreas, most believe such an event is inevitable. Fialko has produced the clearest evidence to date of the strain buildup that will ultimately result in a large earthquake along the southern San Andreas Fault, a 100-mile segment that cuts through Palm Springs and a number of other cities in San Bernardino, Riverside and Imperial counties. Such an event would be felt throughout much of Southern California, including densly populated areas of metropolitan Los Angeles and San Diego.
If you are a SoCal resident now might be the time to start thinking about a really extended trip to some other part of the world.
"All these data suggest that the fault is ready for the next big earthquake but exactly when the triggering will happen and when the earthquake will occur we cannot tell. It could be tomorrow or it could be 10 years or more from now," said Fialko.
Bonds have maturities measured in decades. Earthquakes are a substantial risk factor. Hey there bond investors, you might want to think twice before buying bonds of SoCal governments.
Fialko found evidence that the southern San Andreas is mostly locked and continues to accumulate significant amounts of strain. He calculated the rate at which the fault is moving and estimated the "fault slip rate," the pace of the plate movement at the fault, at about an inch per year. According to Fialko, this means that during the last 300 dormant years the fault has accumulated approximately six to eight meters of slip "deficit," which will be released in the future big earthquakes. If all inferred deficit is released in a single event, it would result in a magnitude eight earthquake, roughly the size of the 1906 San Francisco earthquake.
"In the earthquake business, the past is a key to understanding the present and by comparing data on the timing of past earthquakes on the fault with what we have measured over the last 10 years, we can say with some certainty that the fault is approaching the end of its loading period," said Fialko.
When it does rupture on the San Andreas, such a quake could be as deadly as the 1994 Northridge quake, which struck on an unsuspected hidden fault now called the Northridge or Pico and killed 51 people, injured 9,000 and caused $44 billion in damages.
If you are in a wood frame house that is not perched precariously on a hillside your odds of getting killed are quite low. But if you are on an elevated roadway or some old high building or downstream of some dogdy old dam filled with water then your risks go up. For myself personally I'm more worried about the economic disruption (e.g. the need for electricity and internet to do work).