<P> 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 . 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 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 , making it one of the deadliest earthquakes in history . </P>
<P> 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 . 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 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 , making it one of the deadliest earthquakes in history . </P>
what was the magnitude of the lisbon earthquake
what was the magnitude of the lisbon earthquake
in the range 8.5 -- 9.0
in the range 8.5 -- 9.0