Earthquakes
The Japaneese earthquake in 2011 and some thoughts about its prediction
On 11-th of March 2011, there was a huge earthquake near Japan. Its magnitude was 9.0 and it summoned a destructive tsunami higher than 10 meters in some places. The aftermath was catastrophic. Many people were killed and many buildings were destroyed. But the most interesting thing was that Japaneese were ready to it as much as possible. 90 seconds before the main push on Tokio there was an alert via TV and mobile phones. It saved many lives. There was also an alert of tsunami 10-30 minutes before the actual flood and people climbed to higher places and went away from the shore. It became possible because of the very good alerting system connected with the net of sensors located near the shore. The speed of light is faster than speed of seismic waves running at speed of 4 km/s.
Some days before the main shock there were some foreshocks (small earthquakes) on 9-th of March with magnitude 7.2 and 6.0. Scientists had expected the strong earthquake in that region with magnitude of 8.0, but not 9. As food for thought, an earthquake with every next level of magnitude is 10 times stronger than the previous one. The power of the Japan earthquake was as strong as 1000 nuclear bombs thrown on Hiroshima. Was it a unique unpredictable event or it could be and should be predicted?
The final goal of seismologists is to predict earthquake some days before the event. To be a useful forecast it should report when, where and how strong an earthquake would be and probability of this event. Now we don't have such a technology. We can predict an earthquake in a wide area many years before the event with probability 50%. Something like that: it would be or would not. So modern forecasts of earthquakes are quite useless.
But if you live in an area where small earthquakes happen every day it would be good idea to be prepared for the strong one, because it will happen sooner or later. You ought to think of moving to another area. It might worth it.
Good luck and steady ground! |