Quakes of this magnitude are rare, happening perhaps once every
couple of hundred years, the only one in the last hundred years to even
come close to it was the 8.4 1964 Prince William Sound quake which
occurred in Alaska, which also triggered a large tsunami.
6 months later, the damage caused to the earth is still being assessed.
New information on changes to the earth as a result of the quake is
astonishing and continues to flow in.
When the initial quake
occurred it was so unusual in magnitude and nature that the computers
used to make calculations of quake magnitudes and pinpoint their
epicenter, choked initially on the math involved. Initial estimates put
it in the 8.5+ category; however, after the calculation problems were
ironed out, astonishingly, the quake turned out to be three times
larger than initially estimated.
One thing that came to light not long after the data was analyzed, was
that the earth began swaying like a bell, and still is. The release of
such a massive burst of energy caused the earth to attain a slight
wobble, like a spinning top when lightly tapped.
The North Pole
shifted by 2.5 cm in an easterly direction from its original position,
in fact almost everywhere on the globe showed movement from the massive
jolt of the quake
The earth also changed shape, despite popular
conceptions of the earth being a perfectly spherical marble floating in
space, it is infact slightly egg shaped, flattish at the top and
bulging at the equator by about 20+ kilometers. After the quake it was
found the equatorial bulge had decreased by about 1 part in 10 billion,
this may not seem like much but it is significant enough to alter our
length of day by 2.8 microseconds.
Like an ice skater pulling
in their arms to speed their rate of rotation, the earths decrease in
bulge did the same, causing rotation to speed up, resulting in the
length of day decreasing.
All these changes may seem very
insignificant, but it must be remembered, the earth is a delicately
balanced planet, weather patterns, climate, currents and its ability to
support the variety of life that exists here are dependant on that
balance being maintained, once that balance is even slightly shifted it
effects every part of the whole system.
More immediate changes are evident in the habitats destroyed or altered by the devastating tsunami caused by the quake.
Many areas are now ecological disasters. It will be many years before this damage repairs itself.
When the effects of this quake on the earth are considered it is easy
to look back 65 million years ago to the Cretaceous and imagine the
devastating effects another massive release of energy had as asteroids
impacted with this planet bringing about the extinction of the
dinosaurs and associated fauna.
The 2004 quake and tsunami are
small compared to that event, but provide insight into the global
effects of such a catastrophe.
I would like to express my condolences to the families of victims of the Dec 26 tsunami.
Those who were lost will not be forgotten.
Tags:
style earth global weather style disasters planet tsunami 
