xSpreading ridge : An oceanic spreading ridge is the fracture zone along the ocean bottom where molten mantle material comes to the surface, thus creating new crust.
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