Japan earthquake and tsunami

kresspin wrote: CNN said the 8.9 is 8,000 times more powerful than the earthquake that hit New Zealand. Perhaps someone with knowledge can explain that. I know the jump of one point on the logarithmic scale is exponentially higher (10 times as powerful as a point below). I'm not sure how CNN came up wih an 8,000 times increase.

This might help: http://en.wikipedia.org/wiki/Peak_ground_acceleration
Most telling is the chart on Notable Earthquakes comparing Peak Ground Acceleration, Magnitude (Richter scale), and depth. The type of soil will affect the PGA such that there will be varying PGAs in the same earthquake (why you want to be standing on solid bedrock instead of landfill - I have friends who own houses south of San Fran that were built on "reclaimed" bay, the houses "float" on a concrete pad underneath the landfill which is designed to keep it from sinking in the event of liquefaction. Not comfy enough for me. During Loma Prieta, there were reports of people on Alcatraz who felt nothing, but never verified that story), and no two similar magnitude earthquakes will have the same destructive capacity because of the depth of each earthquake differing, geographical locations having different physical characteristics, and whether structures built on those ground types were built to withstand seismic shifts.

Is there anything I missed Rockdoc or lionshead?