On December 6, a 7.0-magnitude earthquake occurred in the remote area east of Alaska, near the Canada border. The location far from residential areas helps limit damage, but its intensity is still considered enough to cause great damage if it occurs near cities.
Just 2 days later, on December 8, a 7.6-magnitude earthquake rocked northern Japan. This strong earthquake prompted a Tsunami warning, forcing tens of thousands of people to evacuate and at least 30 injured before the warning was lifted.
Both areas continue to record many aftershocks. Japan has warned that another stronger earthquake could hit within a week, requiring people from Hokkaido to Chiba to remain on high alert.
According to statistics from the US Geological Survey (USGS), the world records an average of 16 major earthquakes each year: 15 of which are at 7.0 degrees richter or higher and 1 of which is at 8.0 degrees or higher. In the past 4 to 5 decades, this number has exceeded the average many times.
However, experts say that the two strong earthquakes that occurred close together in time were not too unusual.
Dr. Lucy Jones, a seismologist at CalTech, emphasized: In fact, we average one earthquake of 7.0 richter per month worldwide. The two earthquakes in Alaska and Japan with such intensity appearing close together for several days is something that can happen every few years.
Ms. Lucy Jones also said that there is no scientific evidence that Alaska and Japan are seismically linked, as the aftershocks only occurred near the center of the earthquake, and the two sites were thousands of kilometers apart.
Despite no direct connection, two consecutive earthquakes still remind us of an unacceptable truth: science cannot predict the time of the earthquake.
The USGS frankly said: No one can predict the exact earthquake. We can only assess the likelihood of future disruptions based on the history and structure of the disruptions.
After each earthquake, there is always a 5% chance of a stronger match appearing nearby in a few days. The proportion is small but much larger than the basic level, and this is why Japan has to continuously warn.
A typical example is the 2019 in Ridgecrest (California, USA), a 6.4-magnitude richter hit on July 4, and just one day later, a 7.1magnitude match - the largest in southern California in 20 years - appeared.
According to the USGS, 37 US states have recorded earthquakes of 5.0 degrees or more in the past 200 years, the most dangerous of which is the West Coast and southern Alaska - where large tectonic boundary areas are concentrated.
The most concern area is currently the Cascadia subduction zone, which stretches from northern California to Canada. This is where a 9.0-magnitude earthquake occurred in 1700. Oregon's emergency management agency said there is a 37% chance of a 7.1-magnitude or more earthquake in Cascadia in the next 50 years.
Experts warn that a super earthquake (The Big One) could happen at any time, or not for centuries.
