what was the magnitude of the lisbon earthquake
1755 Lisbon earthquake The 1755 Lisbon earthquake, also known as the Great Lisbon earthquake, occurred in the Kingdom of Portugal on the morning of Saturday, 1 November, the holy day of All Saints' Day, at around 09:40 local time.[2] In combination with subsequent fires and a tsunami, the earthquake almost totally destroyed Lisbon and adjoining areas. Seismologists today estimate the Lisbon earthquake had a magnitude in the range 8.5–9.0[3][4] on the moment magnitude scale, with its epicentre in the Atlantic Ocean about 200 km (120 mi) west-southwest of Cape St. Vincent. Estimates place the death toll in Lisbon alone between 10,000 and 100,000 people,[5] making it one of the deadliest earthquakes in history.
Richter magnitude scale The Richter magnitude of an earthquake is determined from the logarithm of the amplitude of waves recorded by seismographs (adjustments are included to compensate for the variation in the distance between the various seismographs and the epicenter of the earthquake). The original formula is:[27]
2011 Christchurch earthquake The earthquake was a "strike-slip event with oblique motion" which caused mostly horizontal movement with some vertical movement,[85] with reverse thrust causing upwards vertical movement.[3] The vertical acceleration was far greater than the horizontal acceleration.[85]
Earthquake prediction 1993 came, and passed, without fulfillment. Eventually there was an M 6.0 earthquake on the Parkfield segment of the fault, on 28 September 2004, but without forewarning or obvious precursors.[156] While the experiment in catching an earthquake is considered by many scientists to have been successful,[157] the prediction was unsuccessful in that the eventual event was a decade late.[158]