El and Bill
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- Joined
- Nov 8, 2003
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- C Dory Year
- 2000
- C Dory Model
- 22 Cruiser
- Hull Identification Number
- Sold in 2012
- Vessel Name
- Halcyon
Steve on Sea Spray asked a good question, "Can an earthquake in Japan cause one at a distant location?"
Simple answer - Maybe, but ...
There are often small foreshocks before major earthquakes - but, these are usually in proximity to the future quake and do these 'cause' the big one or are they just release of energy before the snap? Many before Japanese quake.
Big ones are often followed by close-by aftershocks (there have been thousands since the recent Japan quake). Are these simply a 'readjustment' after the release of a major pressure on the fault?
What about triggering distant quakes? Did the recent big one in Chile trigger the big quake in New Zealand which then triggered the big one in Japan which might trigger another in... This is postulated but statistically not scientifically 'proven' at this point. The further one gets from the initiating earthquake in both space and time, the more controversial is the association.
The physics involved in actually triggering an earthquake is complex. Most earthquake-generating zones are in a state of being close to failure. If such a zone were to be left completely alone, it would generate significant earthquakes spontaneously. Remote earthquakes, however, are in a position to disturb this critical state, either by shifting the stresses statically, or by dynamic change caused by passing seismic waves.
After the magnitude 7.3 Landers earthquake struck California in 1992, the earthquake map of California lit up like a Christmas tree. But at what distance will the effects be active? This is controversial and the physics is difficult to justify. More research is required.
Back in the '60's I worked for the Desert Research Institute. We had contracts with the (then) Atomic Energy Commission pondering if a nuclear detonation could trigger an earthquake? A 12-kiloton device was detonated underground adjacent to an active fault zone in Nevada (off the test site) - Part of the research was to determine the difference between the seismic response of a nuke shot and a natural earthquake {so we could tell if the Ruskies were nuke testing underground]. Did the shot cause an earthquake? Yes, but a small one on the adjacent fault.
So a one megaton shot was detonated (off the test site) underground (largest ever in the continental US) - it was code named Project Faultless and it, ironically, created huge faults and small natural quakes.
Result of the nuke testing triggering earthquakes? Yes, they could, but the nuke seismic energy was small compared with natural quakes so nothing big was generated in the natural environment. Also, the physics of the waves seemed to be different.
Bottom line, Steve. We don't have definitive evidence that a large quake can cause a far distant quake - maybe? - certainly, if close by.
I have been watching every quake globally very closely since the Japan quake, with great interest.
Simple answer - Maybe, but ...
There are often small foreshocks before major earthquakes - but, these are usually in proximity to the future quake and do these 'cause' the big one or are they just release of energy before the snap? Many before Japanese quake.
Big ones are often followed by close-by aftershocks (there have been thousands since the recent Japan quake). Are these simply a 'readjustment' after the release of a major pressure on the fault?
What about triggering distant quakes? Did the recent big one in Chile trigger the big quake in New Zealand which then triggered the big one in Japan which might trigger another in... This is postulated but statistically not scientifically 'proven' at this point. The further one gets from the initiating earthquake in both space and time, the more controversial is the association.
The physics involved in actually triggering an earthquake is complex. Most earthquake-generating zones are in a state of being close to failure. If such a zone were to be left completely alone, it would generate significant earthquakes spontaneously. Remote earthquakes, however, are in a position to disturb this critical state, either by shifting the stresses statically, or by dynamic change caused by passing seismic waves.
After the magnitude 7.3 Landers earthquake struck California in 1992, the earthquake map of California lit up like a Christmas tree. But at what distance will the effects be active? This is controversial and the physics is difficult to justify. More research is required.
Back in the '60's I worked for the Desert Research Institute. We had contracts with the (then) Atomic Energy Commission pondering if a nuclear detonation could trigger an earthquake? A 12-kiloton device was detonated underground adjacent to an active fault zone in Nevada (off the test site) - Part of the research was to determine the difference between the seismic response of a nuke shot and a natural earthquake {so we could tell if the Ruskies were nuke testing underground]. Did the shot cause an earthquake? Yes, but a small one on the adjacent fault.
So a one megaton shot was detonated (off the test site) underground (largest ever in the continental US) - it was code named Project Faultless and it, ironically, created huge faults and small natural quakes.
Result of the nuke testing triggering earthquakes? Yes, they could, but the nuke seismic energy was small compared with natural quakes so nothing big was generated in the natural environment. Also, the physics of the waves seemed to be different.
Bottom line, Steve. We don't have definitive evidence that a large quake can cause a far distant quake - maybe? - certainly, if close by.
I have been watching every quake globally very closely since the Japan quake, with great interest.