
Our friend Enigma recently raised the question about strange happenings as potential predictors of major seismic events. Her blog mused about:
China 2 Hours Before The Quake… Really Strange Skies. I’m no scientist, just curious, but it did remind me of my own thoughts on major seismic predictors.
It began when I was living on top of the Juan de Fuca subduction zone in BC. If Californians are concerned about their slip faults then they would be really frantic about the subduction zone through the coast of Washington and BC, a big one there would create destructive powers way beyond anything further south.
But the series of Asian quakes, like the 2004 Indian Ocean quake had me thinking that enormous pressure must be relieved on the eastern side of the Pacific plate as the western side becomes increasingly active.
That is prediction one, sure the western Americas coastline will continue to be shaken, probably more so in the South American region. Well, observation suggests that SA is still fairly active where NA has quieted significantly.
But for how long? Well given the massive upheavals occurring around the giant Indo-Australian plate there could be a real reduction of stresses in the north eastern Pacific for centuries. The fact is, the Indo-Australian plate is in the process of breaking apart, and the adjoining African and Arabian plates are changing too.
Now prediction two is more about a potential predictor based on precursor events, or the potential to identify those signs. I’m still slowly gathering evidence, but essentially I suspect that preceding events somewhere along a plate line might give a few days warning of a big one.
Not being very scientific I had focused on the area around Antarctica. The 2004 Indian Ocean earthquake was an undersea, subduction earthquake, triggering a massive tsunami. Two days earlier there was a significant (8.1) quake just off Macquarie Island, near the Antarctic.
Of course, thinking this through, the danger is not the size of the quake but its proximity to large populations. The China quake, probably driven by stresses from the north moving Indo-Australian plate, preceded another Antarctic even a few days later. Perhaps my predictor fails on the basis that if first one occurs in a heavy population area we might only hope to save a few penguins.
I’m also curious to figure in South American events, perhaps they are related to the Indian/Southern Ocean events, making it a North South, rather than an East/West prediction model. I’m sure a computer modeling program could correlate the data we are constantly receiving. Unfortunately, lacking the skill or patience, I’m stuck with patchy observation.