By now many of the readers of this blog have likely seen this video by Prime Minister Julia Gillard that the end of the world is nigh. While Triple J’s prediction of the end of the world on December 7th did not come true, I think the consensus was that it was supposed to happen on the 21st of December anyways. Despite the fact that Mayans themselves assert that the end of their ancient calendar doesn’t mean the end of the world, this has become the date when a lot of people believe Armageddon will happen. So what are some of the possibilities of the end of the world? I look into it.
The largest earthquake ever recorded since the advent of seismometers was the 1960 Valdivia earthquake, which struck off the coast of Chile in South America. At magnitude 9.5, it was quite a bit stronger than last year’s Tohoku earthquake, and the 2004 Sumatra earthquake (it is estimated that one earthquake accounted for 25% of the total energy of all earthquakes in the past century). Earthquakes of this magnitude happen in offshore subduction zones, so while they are massive, they aren’t necessarily the most destructive. These are localized disasters that might make it seem like the end of the world for those affected, but certainly it is not global in nature, a requirement for the apocalypse.
Tsunami’s have the potential to cause widespread damage and death, however only in coastal regions. In a large megathrust earthquake event (i.e. greater than magnitude 9), the tsunami can cause more death and destruction than the earthquake itself (which was the case in the Tohoku earthquake last year). I remember back in 2004, watching the devastation of the Indian Ocean tsunami. It was very sobering. A large tsunami is something that can happen very quickly, but it is also not global in nature, so it cannot be the cause of the end of the world.
I’ve talked about this at length in a previous post, so I won’t elaborate. I’ll just add that a magnetic reversal happening in the course of a day is ridiculous, and even if it did, it would not cause an instant catastrophe. Yet it is one of the most cited as a potential cause of the apocalypse.
Even more ridiculous is the idea that the entire earth flips over in some sort of huge adjustment to the Earth’s rotational axis. Yet there are people who believe this. I actually listened to part of that video, it is both kind of funny and sad there are people who make this stuff up. It happens when someone reads a bunch of scientific information, but doesn’t really understand the actual physics behind it and is more willing to believe in crazy conspiracy theories.
The earth’s rotational axis does actually move secularly, known as the Chandler Wobble. This is a very small change in the rotational axis, only a few metres, possibly caused by motion of water in the ocean. This is something that is easily measured. If the Earth was set to have a large change in its rotational axis, you can be sure that we would be measuring it by now. Large earthquakes also change the location of the axis by just a few centimetres. Long term changes in the Earth’s rotational axis happen due to changes in the distribution of the mass of the planet, caused by continental drift.
A volcanic eruption could have the potential to be an apocalyptic event, as it can affect global climate, and it would happen very suddenly. The Mount Pinatubo eruption in 1991, for example, caused a temporary fall of global temperature by nearly a half degree. In the year 1816, dubbed the “Year without a Summer“, a volcanic eruption (or series of coincident eruptions), blanketed the atmosphere with ash, leading to unusually cold conditions during the summer. The poor growing conditions led to food shortages. A volcanic eruption may have been the trigger for the Little Ice Age, something I wrote about earlier this year.
The Lake Toba eruption, which happened about 70,000 years ago, is possibly the largest single volcanic eruption in the past 25 million years. The caldera left by the eruption is 100 km wide, and would have been extremely devastating. Some archaeologists hypothesize that this event caused a bottleneck in the human population. So far, evidence of widespread decline in fauna during that time is limited, and it may not have had a long term impact on climate.
No doubt, if an eruption the size of Toba were to happen, it would have a devastating impact on the entire Earth. Crops would fail worldwide, and in all likelihood civilization would be thrown into chaos. Of all the events that could happen in an instant, this is probably the most likely. We can’t really predict when large volcanic eruptions happen, and the chances of it happening on a particular day is low. Though as I was told by my fellow students, the total effect of the eruption would take several months to affect the whole world.
Large Igneous Provinces!
Large igneous provinces are the slow flowing equivalent of a supervolcano, generally erupting basaltic lavas over a large area. The sheer volume of material that comes out of large igneous province dwarfs the supervolcanoes, and they have been implicated in some of the largest mass extinctions the Earth has ever seen. The last large igneous province to erupt on land was the Columbia River flood basalts, which erupted between 17.5 and 6 million years ago, though the majority of the eruptions happened during the first 2 million years of that period. Flood basalts not only affect the world climate through the release of volcanic gases, but also burn off plant material, coal, and methane hydrates. However, even if a large igneous province eruption were to start tomorrow, it would take thousands of years to have any large effect on the Earth, and there is little evidence of one starting up. This would not be a cause of the apocalypse.
If a large (i.e. > 1 km) meteor were to strike the Earth, it would be devastating, and would immediately impact the Earth. We’ve all seen movies like Armageddon and Deep Impact, so this is a widespread idea for end of the world hypotheses. If a meteor the size of the ones featured in those movies were to be on a collision course with the earth, there indeed would be little that could be done about it (the amount of energy required to split the meteors apart is far beyond any weapon humans have created).
NASA actually has a website with the risk of impact of various known meteors that come within the vicinity of Earth. The Torino hazard scale was developed to assess the risk to Earth. A 10 on the scale would cause a collapse of society. The objects on the list vary on the scale of less than zero to zero in terms of hazard. An object large enough to cause widespread damage to earth would have been detected by now, so this is not going to be a cause of the apocalypse.
It is interesting to note that earlier this year, the DA14 asteroid (which is about 45 m wide) caused a panic amongst the catastrophe crowd. It will pass within 3.5 Earth radii on February 15 next year, though it will not collide with the Earth. Even if it did, the impact of a 45 m wide object would not likely cause widespread damage. By comparison, the Tunguska event was estimated to have been caused by a meteor about 100 m wide. Meteor Crater, the famous crater caused by an impact 50,000 years ago, was caused by an approximately 50 m wide iron-nickel meteor. An impact by such a small body would be fairly localized.
I remember an episode of The Outer Limits that dealt with this. A large solar flare hits the Earth, heating up the land and oceans on one side of the planet, and causing a flood event on the other side. The largest solar storm ever observed happened in 1859, and if one of this magnitude happened now, it would likely cause disruptions of the power grid. A geomagnetic storm in 1989 knocked out the power grid in the Canadian province of Quebec.
The current solar magnetic cycle is not expected to peak until late next year or in 2014, so the chances of a large flare happening this week is likely low to moderate. The current solar cycle has also been quiet compared to those during the past 100 years. Though because of how quickly a solar flare could hit, it is one of the most widely cited causes of the apocalypse. Here is a great video by a scientist at NASA who explains the pure impossibility of a solar flare causing the end of the world. Certainly, a solar flare will not cause the oceans to boil off, as suggested by the TV episode.
At any rate, it takes three days for a solar storm to reach Earth, so if one hasn’t happened by the time this article is posted, then the chances of one hitting Earth on December 21st is zero.
Climate change can be very rapid. Just look at the Younger Dryas event, where temperatures across the globe (likely) plunged rapidly. However, climate change is not really something that happens rapidly on the time scale of a human life. And certainly, there won’t be some sort of step function to it that will suddenly cause catastrophe. Global warming is a threat in the future, but not tomorrow.
Big Freaking Storms!
Snowstorms, hurricanes/cyclones/typhoons, tornadoes, etc! They are all weather events, and only affect small areas of the globe. A big storm could be catastrophic to a small area, but definitely not a sign of the end of the world. Something like Hurricane Sandy causes widespread damage, but it is not going to end civilization.
The interaction of the Earth with some planet with an enormously elliptic orbit is always a popular idea when it comes to doomsday predictions. The fact is, if there was a planet of any significant size orbiting the Sun, we would know about it by now due to the gravitational effects it would have on other planets. Considering scientists are able to detect planets that are 100 light years away, not even orbiting other stars, you can imagine that they should be able to detect Planet X. Not happening.
The Earth’s orbital parameters are always in flux. Orbital variability, or Milankovitch Cycles, are one of the most dominant factors that affected Earth’s climate during the past 2 million years, at least. These cycles are very slow, on the order of tens of thousands of years. They are not going to cause an instant cataclysm on December 21st, or at any time. In the absence of any other forcings, orbital variability would likely lead the Earth into the next glaciation, but that would be tens of thousands of years away.
Distant galactic event!
Supernovas! Stellar collisions! These things happen very far away. The most recent supernova of note was observed in the year 1054, and was responsible for creating the Crab Nebula. That star was about 6500 light years away from the Earth. One of the best known stars on the verge of supernova and relatively close to the Earth is Betelgeuse. It is apparently a common source of doomsday scenarios. Scientists say that when it does go supernova, it will appear as bright as the Moon in the sky, but it certainly isn’t going to cause any noticeable affects on the world, aside from being an amazing story.
When word got out that the CERN Large Hadron Collider produced particles that were analogous to black holes, people panicked to the point where CERN had to put out an release saying that there was no threat to the world. If a black hole were on a collision course with the Earth, we would not be able to directly observe it. However, something with large enough gravity to destroy the earth probably would have been indirectly observed by now, due to its effects on other celestial bodies. Certainly, there is no way that human activities could ever produce a black hole that could actually damage the earth. The only way black holes can form are by the collapse of large bodies, such as stars.
Here are some non-geological and geophysical possibilities. Plague caused a substantial portion of Europe’s population to die off during the Black Death. The plague was exacerbated by poor sanitation, something that isn’t really an issue now a days. Although plague still exists, large outbreaks are not that common.
Epidemics from other diseases can also cause widespread death, such as the Spanish Flu back in 1918. The Spanish Flu killed as much as 3% of the world’s population. That epidemic was likely spread so widely due to the end of World War 1. With the world as interconnected as it is now, it is possible that a major disease could spread everywhere quickly. Even with a mortality rate as high as the 1918 flu, the survival rate is still so high that it is unlikely to cause society to collapse.
Of all doomsday scenarios, the most likely would be one caused by humans themselves. If a substantial amount of nuclear weapons were detonated over a short period of time, it would not only devastate infrastructure, but it would cause a fallout of radioactive material that would affect all fauna. It should be noted that it would take a hell of a lot of nuclear explosions to completely destroy civilization – I’m talking Dr. Strangelove amounts. The vast majority of the radioactive elements created during a nuclear blast decay within a few weeks of the explosion, so it would take a lot of blasts to blanket the earth.
This is another common theme in apocalyptic predictions. One has to wonder, if aliens were intelligent enough to create technology to reach Earth, that they might be enlightened enough to not blow it up. At present, we don’t really have any evidence that life exists on other worlds (though fellow blogger Adi is on the lookout!).
The most problematic part of an alien invasion is how would they would get here. The latest research on warp drives indicates that stopping a ship going warp speed would in all likelihood destroy everything in the neighbourhood of the it. I suppose if it was the aliens’ first attempt at warp speed, and their target was the solar system, it would be the end of us as we know it. Warp drives are implausible for this reason (in addition to requiring more energy than is known to exist in the universe to propel a ship-sized vessel).
If aliens were coming at a speed that was less than the speed of light, we would probably be able to detect them before they arrived. We have to assume the spacecraft was large enough to contain weapons that could obliterate the Earth, or an army large enough to subjugate humans. A ship large enough to to hold these things, as well as contain fuel to reach the solar system from another star, would be sufficiently large to be detected by regular telescopes as it approached Earth. I would also assume they would need time to slow down, so we would have many days warning. If aliens are to be responsible for the end of the world, it isn’t happening tomorrow.
What would happen if the dead rose up and started eating everyone’s brains? According to mathematical models, virtually everyone would be infected within a few days. This would be the quickest way that civilization would collapse, beating out nuclear annihilation, meteors, solar flares and volcanoes. So really, if we are to prepare for an end of the world scenario, it should be a zombie apocalypse.