Earthquakes happen fairly frequently, though you might not notice. This is because most of them are not that powerful – less than 4.0 on the Richter Scale. But we all know what more powerful earthquakes and undersea quakes can do. One example is the Indian Ocean quake of December 26, 2004 which resulted in a massive tsunami that killed over 230,000 people in 14 countries. Just a few days ago, an earthquake near the Iran-Iraq border killed hundreds of people. Earthquakes have caused massive damage and heavy loss of life in recent years in our region and beyond.
We have also heard of the fact that one cannot predict earthquakes with any accuracy, even with the most modern equipment. This kind of technology may be developed in the future, but right now, scientists can only give predictions about the aftermath of a quake – whether it will cause a tsunami or landslide, for instance.
However, geologists and scientists are constantly monitoring the Earth’s movements. The Earth consists of a few tectonic plates and friction between them can cause earthquakes. By analyzing these movements, scientists can roughly guess which areas may be prone to earthquakes. There are also earthquake patterns in some areas – say, an earthquake could strike Area X roughly every 70 years. Scientists also say that the Earth’s rotation patterns and even the Moon’s pull could lead to Earthquakes.
Spin
In fact, since 2011, our planet has been rotating at a pace a few thousandths of a second slower than usual. Our planetary spin cycle changes constantly — ocean currents and atmospheric changes have an impact, as do the mantle and molten core under them. But, the current pattern has geologists worried about earthquakes. Professors Roger Bilham and Rebecca Bendick in the US say that this could lead to more than twice as many 7-plus-magnitude quakes in 2018. They found a curious correlation between clusters of certain earthquakes and periodic fluctuations in the Earth’s rotation. By examining the historical earthquake record and monitoring those fluctuations, scientists might be able to forecast years when earthquakes are more likely to occur, they suggest.
Bilham, who studies earthquakes at the University of Colorado, told the media that when the Earth’s pace lags for years at a time, its middle contracts. That shrinks the equator, but it is hard for the tectonic plates that form Earth’s outer shell to adjust accordingly. Instead of falling in line with the slimmer waistline, the edges of those plates get squeezed together. After five years without many high-intensity quakes, we are approaching the moment when the effects of this squeeze could be felt around the globe.
The last 117 years of earthquake records suggest quakes are especially sensitive to a ten-year rotational slowdown like the one we seem to be experiencing now. The slower spin adds more stress and pressure to some of the earthquakes that were already in the pipeline. That pushes the disasters to happen more quickly, especially, in earthquake-prone zones around the globe. The effect may be felt the most in the Tropics, near the Equator which is the general area where Sri Lanka is.
Bilham estimates the planet could see, on average, 20 high-magnitude earthquakes for each of the next four years which could ultimately affect one billion people. By comparison, just seven earthquakes have registered above a 7.0 so far this year. We already know that Earthquakes happen in our region.
We are no longer safe from Earthquakes, though we are not in a so-called “Ring of Fire”. This is why it is important to take precautions against this type of scenario, even if it may not happen next year itself.
The researchers hope that city planners and politicians in earthquake-prone zones will heed their latest warning and work quickly to retrofit buildings or update emergency plans. Sri Lanka’s National Building Research Organisation (NBRO) and the Geological Survey and Mines Bureau must take the lead in this regard.
While claims in the tabloid press of an impending “earthquake boom” are mostly sensationalism, it is always better to be safe than sorry. Besides, their conclusion is not set in stone. It has not been demonstrated in the lab or confirmed by follow-up studies. Several scientists say they are not yet convinced by Bendick’s and Bilham’s research.
But their efforts show one thing – that scientists are trying to understand earthquake patterns and predict a general time period and/or region of earthquake occurrence. On their part, Bendick and Bilham added a new number to their analysis: the “renewal interval,” or the amount of time a given earthquake zone requires to build up potential energy for a really big quake.
The field of earthquake forecasting has seen some particularly outlandish claims. Scientists and even laymen have tried to predict quakes based on the behaviour of animals, gas emissions from rocks, low-frequency electric signals rippling through the Earth — all without success. After all, getting a prediction right can mean the difference between life and death for countless people. Even a warning of 15 minutes could potentially save thousands of lives. Scientists hope that identifying any patterns might help public officials and disaster planners to prepare in advance for a period in which quakes are more likely and subsequently, for any preparedness measures.
Earthquake
Fears have already been expressed that a “Big One” could be coming to California soon. Experts claim to have found proof a major earthquake and a massive Tsunami is due to strike California. Researchers say the Cascadia Subduction Zone (a 1,000km “megathrust” fault line that stretches from Northern Vancouver Island to Cape Mendocino California) generates a major event every 200 to 530 years - and last experienced a quake in the 1700s. Apart from Earthquakes, there are fears that a super volcano such as Yellowstone could erupt soon, leading to a global catastrophe.
There is another fear – that a rogue state or terror group could trigger an artificial earthquake that could devastate an entire region.
Technologies that can cause minor tremors already exist and there are concerns that these could be developed further. A powerful underground nuclear explosion can also lead to an earthquake. The world must be on guard against these possibilities.
It is time that we in Sri Lanka took earthquakes more seriously, given recent events and new “predictions” about earthquakes in our region.
We are already well prepared for any tsunami – by extension, we should have a response mechanism for an earthquake (sometimes referred to as an inland tsunami) as well. Earthquakes cannot be prevented per se, but there still are certain steps that can be taken to minimize their deadly impact.