Japanese Earthquake Pushes the Ground Up at 4 Gs

The fact that earthquakes throw the ground around in all possible directions is old news, especially given the fact that we know some of the largest mountains in the world were formed due to severe seismic activities. However, never in the history of recorded data, has an earthquake, other than Japan's 6.9 Iwate-Miyagi, displaced such a large mass of soil at such a huge speed.
 

Geologists were puzzled when they looked at the readings for this June 14th tremor. It appears that the ground was pushed upwards at such an incredible pressure, that the mind-boggling amount of rock and soil reached about 4 g in acceleration, meaning they "jumped" up at about 4 times the speed with which Earth attracts everything to its core – the gravitational pull. Scientists likened this to a man jumping off a trampoline, where the trampoline throws a jumper 4 times faster than gravity can pull him back.

 
A further reason for concern was the fact that, after reaching its peak, the earth came down slower than it was thrown up. This event cannot be explained by any of the existing predicament models for tectonic plate movements, so geologists turned their eyes to the records and analyzed some 6,800 other tremors that occurred in Japan over the years.
 

They found out that only two of the others showed signs of unusual thrust forces being directed upwards, instead of sideways. Horizontal movement accounts for most of the devastation that takes place during an earthquake, as resistance structures disintegrate and buildings come crashing down. Vertical motions affect smaller areas, but with more ferocity. Such a "kick" from below would send even the most well-constructed building upwards.
 

The only way to protect against these natural disasters is through warning, Japanese scientists say. They argue that highly-sensitive motion sensors, buried under and around sensible buildings, such as schools, hospital and public offices, could offer at least a few minutes of warning before the actual tremor hits. This could be enough to save countless lives, they concluded.