Photo: Håkan Dahlström (Flickr)
The Tohaku earthquake that shook Japan in two thousand eleven and tsunami that followed destroyed entire towns, killed thousands and destroyed nuclear power plants. Rated a magnitude of nine point zero, it was one of the biggest quakes recorded since nineteen hundred, but not the largest.
Earthquakes are measured using the Richter Scale, which gives scientists an idea of the size of the seismic wave or ground shaking that happens. It also indicates how powerful the quake is.
The scale is logarithmic, so each whole number represents ten times more shaking than the previous number. In terms of energy, a magnitude one point zero quake equals six ounces of TNT and a magnitude eight point zero quake has the power of six million tons.
The quake holding the world record for “largest magnitude” occurred in southern Chile near the city of Concepción in nineteen sixty. It measured nine point five on the Richter scale, killed over sixteen hundred people, and left over two million homeless. The tsunami wave it produced killed hundreds in Hawaii and Japan.
The Most Dearly Large Quake
The second largest earthquake occurred off Alaska’s coast in nineteen sixty four. The magnitude nine point two quake lifted the ground forty five feet in some places and destroyed thirty blocks in Anchorage. The resulting tsunami in the Gulf of Alaska killed over one hundred.
The most deadly large quake since nineteen hundred occurred in two thousand four off the coast of Northern Sumatra. In that location, the India crustal plate dives beneath the Burma plate in a jerky motion known as subduction.
The magnitude nine point one earthquake was generated by a jump of almost sixty feet along the main thrust fault between the plates. The resulting tsunami killed over two hundred thousand people and displaced nearly two million from their homes.
- Largest Earthquakes in the World Since 1900 (USGS)