Japan is still cleaning up and investigating the scope of the disaster from the tsunami that hit the area hard. The massive tidal wave hit Japan and devastated coastal areas and caused major damage to the nuclear power plant that was in its path causing radiation leakage. Some new details about the destructive wave prove that part of the reason the devastation was so massive was that the wave that hit Japan was the result of the two merged tsunamis.
This sort of tsunami merging had been theorized in the past but never directly observed until the devastating disaster in Japan. Data from NASA and radar packing satellites operated by European agencies were in place to view the tsunami. Apparently, when the two waves merged they went from a single height wave to a double height wave.
As the wave crossed undersea mountain ranges it gained destructive power. NASA says it was a one in ten million chance of having satellites in orbit to view the tsunami. The satellites that viewed the wave were the NASA-European Jason-2, NASA-French space Agency satellite altimeter, and the ESA EnviSAT. All three satellites had altimeters and could tell the height of the wave to centimeters as it moved. The data collected will help scientist's model new prediction algorithms for tsunamis that will hopefully make predictions more accurate.