Or: Why can’t science solve our most critical problems?
To some extent, we can predict weather: a hurricane land-fall up to five days out, a tornado up to two hours out. There are two consequences to this relatively new, science-driven ability: (1) these predictions have gone a long way towards saving human lives, and (2) there has been no discernable change in where people buy their homes and choose to live. What about earthquakes? If we could predict earthquakes, would it dramatically change our lives?
Go back and read the previous two observations.
There are about 60 scientists in the US Geological Survey, including one of us, who volunteered to reply on their own time to questions that came to us via Ask-a-Geologist. This WAS a place on the USGS website where anyone could ask a question and get an answer from a geoscientist. Almost half the questions were spam. (Surprisingly, many of these seem to be in Portuguese, and, no, we don’t understand that either, but we’re getting better at filtering them out. About a quarter of the questions were from school children trying to get someone else to do their homework assignment for them. These were pretty obvious, and by policy we were asked not to encourage this.) The rest tended to be really interesting questions from people as young as 3.
Here is an interesting question I received one day; I share it here because I hope my answer will shed light on some of the questions that, from my reading of the daily newspapers, are floating out there:
Question:
“Hello. I was just wondering first if the increased number of earthquakes is a sign of something bigger to come and since the earthquake in Japan knocked our earth off of its axis a few feet is that the reason for the severe weather we have had lately like all the floods in the south and tornados and severe storms?”
–No name given
My Reply:
The Earth’s axial tilt moved about 10 cm during the 2011 Great Tohoku earthquake – that’s about 4 inches. It requires some very sophisticated GPS equipment and a lot of measurement time to arrive at that tiny amount of offset.
While there is evidence that continents were at hugely different latitudes in ages past (e.g., freshwater aquatic dinosaur fossils discovered in Antarctica; see for instance Smith et al., 2011), a 10-cm tilt-change will not cause any effect that can be sensed by a human being. A long and slow tilt change in the Earth’s axis has been documented over time and can be explained by simple orbital mechanics (something called nutation, that you can see in a spinning top), but the operative word here is “slow” – we’re talking many thousands of years slow – the precession of the equinoxes takes about 25,770 years to complete a cycle. There is also the added complication that the continental plates have been moving around at the same time.
What fixed point do you reference against? Since we didn’t have observers using sextants to track where Polaris was 25,000 years ago, these things are understandably hard to sort out. The pole star 5,000 years ago, when the Egyptians were building the pyramids and aligning them, was Thuban, anyway, and not Polaris (Kallinger, et al., 2005). And 25 million years ago, it would have been Vega.
Let’s consider another issue. There is an ongoing discussion within the seismic community about earthquakes triggering other earthquakes. Large earthquakes have been shown to “light up” volcanic areas like Yellowstone and Long Valley with short-term clusters of increased micro-earthquakes. Note that italic: these are very small consequences. However, the current scientific consensus, culled from literally petabytes of data (i.e. multiple libraries’ worth) collected over the past 50 years, is that distant earthquakes do not have any effect on faults not part of that earthquake’s own fault system. In other words, the monster earthquake in Chile during the spring of 2010 did not trigger the huge earthquake in New Zealand later in the fall, and that one didn’t trigger the ginormous Tohoku earthquake in March 2011 east of Sendai, Japan. Among other things, there were months separating each event. Also, an earthquake’s energy falls off as approximately distance squared, so if YOU didn’t feel these, then neither did the other distant subduction faults that broke loose later on. Researchers have studied syzygy (Coyle, 2014), the effects of Sun and Moon tides on earthquakes, and have found no statistical correlation.
All THAT said, there is a measurable, undeniable, and steady increase in the carbon dioxide content of the Earth’s atmosphere over the last several centuries. Carbon dioxide (CO2) has a measurable greenhouse effect on atmospheric temperatures, and in 2015 CO2 levels in Earth’s atmosphere reached and crossed the 400 ppm level. Methane, however, has far more of a greenhouse effect for the same number of molecules released (it’s 37 times more potent, and we’re not talking odor here). There are far more cattle now than a century ago because there are far more people feeling they deserve beef steak. Virtually all scientists (except those paid to say otherwise) will readily acknowledge that there is a large anthropogenic component to this increase. This means that humans burning hydrocarbons, destroying forests, raising flatulent cows, etc., are mostly responsible for these increased gases in our atmosphere. How are they so sure? For starts, the levels of 14C are dropping – in other words, the new CO2 entering the atmosphere is coming from fossil carbon. Also, if you haven’t ridden a horse or milked a cow recently, you might not believe how much methane a grass-chewing critter can produce. Hooo.
It’s still being argued – mainly through increasingly sophisticated mathematical models – just how much all this increase in greenhouse gas emissions has actually changed our weather. There are certain undeniable influences on weather (the Solar flux and the great ocean currents like the Gulf Stream, for instance). There are a huge number of variables involved, so one model may disagree with another in detail – but not in gross conclusions. As the cartoon character Pogo famously said, “We has met the enemy, and he is us.”
You and I may not remember huge hurricanes and tornado clusters from our childhood, but that may just be our imperfect memory. The apparent increase in wild weather events over the past few decades may also be an artifact of how records have become increasingly more detailed and complete over time. Keep in mind that earthquakes – and probably to some extent anomalous weather events – are to varying degrees random things. They don’t come on the hour, nor on Friday the 13th, but often have gaps and then appear in clusters – and we remember the most recent cluster best. That’s called the Recency Effect or Recency Bias, and is an artifact of the human mind (and why scientists must carefully record their data). Using a statistically more reliable approach – averaging and comparing hurricanes and their strengths for say, the 19th Century against the 20th Century – we are also hamstrung by the fact that there were far fewer recording observers 150 years ago… and correspondingly fewer and sparser records kept then.
Bottom line(s):
- Climate change is here, is human-caused, and it is clearly accelerating.
- Earthquakes are random and essentially not predictable*.
- Neither one affects the other.
However, this is just what science knows today. In 3 Ne 8:6 we find these words:
“And there was also a great and terrible tempest; and there was terrible thunder, insomuch that it did shake the whole earth as if it was about to divide asunder.”
This and subsequent verses make it clear that an earthquake and a coincident volcanic cataclysm are being described here. The timing – coincident with the death of Jesus Christ in the eastern hemisphere – implies that earthquakes can in fact be triggered, or at least understood (and thus predicted), though not yet by modern science.
To us, this suggests how far science has NOT yet gotten in the past century, and just further reinforces the idea that there is more than one path to the truth.
* Recent studies suggest that a cluster of earthquakes on a major fault may increase the immediate likelihood of a significant earthquake nearby by a few percent (http://www.latimes.com/local/lanow/la-me-earthquake-probability-20161019-snap-story.html), however this is still controversial in the geoscience world as we write this.