xRayleigh wave : A Rayleigh wave is a seismic surface wave causing the ground to shake in an elliptical motion, with no transverse, or perpendicular, motion.
Geologists have learned that a large earthquake and tsunami that killed 192 people on September 29, 2009 in Samoa, American Samoa and Tonga was in fact a triple-whammy. The magnitude 8.1 "great earthquake"...Read more