January 23 in History

In the early hours of 23 January 1556, a massive earthquake struck the Wei River valley in Shaanxi province, in central China, in what is generally regarded as the deadliest earthquake in recorded history. Chinese records put the death toll at about 830,000, a figure that has shaped how the disaster is remembered. It is a stark example of how geology, settlement patterns and housing conditions can combine to produce catastrophe.

In January 1960, the bathyscaphe Trieste carried two men to the floor of the Challenger Deep, the deepest known point in the world's oceans. The dive, made by U.S. Navy Lieutenant Don Walsh and the Swiss oceanographer Jacques Piccard, reached a depth of roughly 10,900 meters (about 35,800 feet) in the western Pacific, near Guam. It remains one of the great feats of exploration, proving that humans could survive at the bottom of the sea's greatest abyss.