August 12, 1953

1953Thermonuclear bomb testing: The Soviet atomic bomb project continues with the detonation of "RDS-6s" (Joe 4) using a "layered" scheme.^[†]

Nuclear weapons tests are experiments carried out to determine the performance of nuclear weapons and the effects of their explosion. Over 2,000 nuclear weapons tests have been carried out since 1945. Nuclear testing is a sensitive political issue. Governments have often performed tests to signal strength. Because of their destruction and fallout, testing has seen opposition by civilians as well as governments, with international bans having been agreed on. Thousands of tests have been performed, with most in the second half of the 20th century.

1953The 7.2 Ms  Ionian earthquake shakes the southern Ionian Islands with a maximum Mercalli intensity of X (Extreme). Between 445 and 800 people are killed.^[†]

The 1953 Ionian earthquake struck the southern Ionian Islands in Greece on August 12. In mid-August, there were over 113 recorded earthquakes in the region between Kefalonia and Zakynthos, and the most destructive was the August 12 earthquake. The event measured 6.8 on the moment magnitude scale, raised the whole island of Kefalonia by 60 cm (24 in), and caused widespread damage throughout the islands of Kefalonia and Zakynthos. The maximum felt intensity of shaking was X (extreme) on the Mercalli intensity scale. Between 445 and 800 people were killed.