On April 15, Japan was struck by a 7.0-magnitude earthquake. Just one day later, Ecuador was hit by a quake of 7.8 magnitude.
The natural disasters caused widespread destruction in both countries, with the death toll in Ecuador reportedly reaching 600. The quake in Japan struck the island of Kyushu, killing 40 and injuring over 200.
The events that took place just hours apart have caused many people around the world to speculate whether the two earthquakes are related and if they are a sign of an upcoming major quake.
That said, earthquake specialists are keen to dismiss any alarmist theories that are doing the rounds on the web.
“Earthquake occurrence is a probabilistic process, not a deterministic one. It’s possible that the probability of a large earthquake is somewhat higher than normal now, but not by enough to worry about,” Robert J. Geller, seismologist at Tokyo University, told Metro.
“But the idea that one earthquake can be definitely identified in advance as a fore shock is incorrect. Many people have tried to see if events that could retrospectively be called fore shocks had any distinguishing characteristics that would allow them to be identified as such in advance, and the answer has always been ‘no’".
Similarly, figures collected by specialist earthquake agencies reveal that there is no sustained or significant increase in the frequency of high magnitude earthquakes.
Data from the U.S. Geological Survey suggests that the average number of quakes per year is consistent. For example, earthquakes between magnitudes of 7.0 and 7.9 have occurred roughly between 10 to 20 times a year, with the average being 15. That’s over an earthquake a month.
Indeed, along with tsunamis, earthquakes account for nearly 750,000 deaths over the last 20 years and cause significant economic losses, according to the United Nations.
It is still impossible to know for sure when an earthquake is going to happen, but what it is possible to predict is where a big quake could take place.
“There are only limited places on Earth where you can get monster earthquakes above magnitude 9," Roger Musson, seismologist at the British Geological Survey, said. "Such events need a big area of fault slip so they can only occur where you have a particular tectonic environment, where one plate is sliding under another at a gentle angle and where the plate boundary is straight enough that a long segment can slip at once. The classic example is Chile (9.5 in 1960) but Japan, Indonesia, Alaska and North India are other possible locations.”
As science advances to the point where earthquakes can be accurately predicted, the authorities must work on improving infrastructure in earthquake zones to avoid the preventable loss of life.
As Robert Glasser, a U.N. special representative for disaster risk reduction, said after the earthquake in Ecuador: “It is buildings and damaged infrastructure which kill people when an earthquake strikes.”
- By Daniel Casillas