Re: what was the worst earthquake?how many killed, injured, damage too property

There are, of course, different ways to define "worst". It could be the most property damage, most loss of life, most powerful at its focus (the actual origin of the quake), or most powerful at its epicenter (the place on the Earth directly above the focus).

Prior to recent times, no one had accurate instruments to measure energy released in an earthquake, and no one kept accurate records of damage. The longer ago an earthquake occurred, and the less developed the area where it occurred, the less we know about it. Information regarding after shocks and duration is usually not available.

Good sources for information are:

http://wwwneic.cr.usgs.gov/neis/eqlists/eqsmosde/html or
http://www.usgs.gov and click on “Earthquake.”

According to them (the U.S. Geological Survey National Earthquake Information Center)

Most Destructive Known Earthquakes on Record in the World
                         (50,000 deaths or more)
             (Listed in order of greatest number of deaths)


Date               Location            Deaths    Mag    Comments

January 23, 1556   China, Shansi       830,000 

October 11, 1737   India, Calcutta**   300,000

July 27, 1976      China, Tangshan     255,000*  8.0

August 9, 1138     Syria, Aleppo       230,000

May 22, 1927       China, near Xining  200,000   8.3  Large fractures.

December 22, 856+  Iran, Damghan       200,000

December 16, 1920  China, Gansu        200,000   8.6  Major fractures,
                                                      landslides.

March 23, 893+     Iran, Ardabil       150,000

September 1, 1923  Japan, Kwanto       143,000   8.3  Great Tokyo fire.

October 5, 1948    USSR                110,000   7.3
		   (Turkmenistan, Ashgabat)

December 28, 1908  Italy, Messina       70,000   7.5  Deaths from 
                                    to 100,000        earthquake and 
                                    (estimated)       tsunami.
    
September, 1290    China, Chihli       100,000 

November, 1667     Caucasia, Shemakha   80,000

November 18, 1727  Iran, Tabriz         77,000

November 1, 1755   Portugal, Lisbon     70,000   8.7  Great tsunami.

December 25, 1932  China, Gansu         70,000   7.6

May 31, 1970       Peru                 66,000   7.8  $530,000 damage,
                                                      great rock slide,
                                                      floods.

    1268           Asia Minor, Silicia  60,000

January 11, 1693   Italy, Sicily        60,000

May 30, 1935       Pakistan, Quetta     30,000   7.5  Quetta almost
                                     to 60,000        completely destroyed.

February 4, 1783   Italy, Calabria      50,000

June 20, 1990      Iran                 50,000   7.7  Landslides.

* Official casualty figure--estimated death toll as high as 655,000.
+ Note that these dates are prior to 1000 AD.  No digit is missing.
** Later research has shown that this was a typhoon, not an earthquake.
   (Source: The 1737 Calcutta Earthquake and Cyclone Evaluated by 
			Roger Bilham, BSSA, Vol. 84, No. 5, October 1994)
Data compiled from several sources.
United States Geological Survey 
National Earthquake Information Center