5 ms·

From Wikipedia: The energy release of an earthquake, which closely correlates to its destructive power, scales with the 3⁄2 power of the shaking amplitude. Thu

From Wikipedia: The energy release of an earthquake, which closely correlates to its destructive power, scales with the 3⁄2 power of the shaking amplitude. Thus, a difference in magnitude of 1.0 is equivalent to a factor of 31.6 ( = (101.0)(3 / 2)) in the energy released; a difference in magnitude of 2.0 is equivalent to a factor of 1000 ( = (102.0)(3 / 2) ) in the energy released.[2]

borism 16y ago
so the correct answer is that this one was 1000 times more powerful than Kobe, and also very shallow (depth of 24 km), but fortunately offshore (but unfortunately that means powerful tsunami).
jules 16y ago
How does energy scale with distance from epicenter?
- ars 16y ago
  Probably goes down by r^2 However earthquakes may be "flat", in which case it's by r (i.e. r^1). It's probably somewhere in between those.
  - jules 16y ago
    Wouldn't it go down by r^2 if the earthquake is flat, and by r^3 if it's not?
    - wisty 16y ago
      No. A circle with 2X the radius has 2X the diameter, thus the energy will be cut in half. Unless you also expect a linear attenuation, due to energy loss through the bedrock.
- wisty 16y ago
  Small earthquakes have a lot of energy in the higher end of the frequency scale, which is rapidly dissipated. Larger earthquakes have more low-frequency energy, so they go further. There's no simple equation, they just use regression to fit the attenuation as a factor of 1/r, 1/r^2 (...), and for magnitude, and for frequency. You can start here: http://earthquake.usgs.gov/hazards/about/attenuation.php http://earthquake.usgs.gov/hazards/about/attenuation.php