What happened
Late in the afternoon of 12 January 2010, local time, a fault near Léogâne slipped only about 25 kilometres from Port-au-Prince. The focus was shallow, and the city was dominated by weak, unreinforced buildings that collapsed en masse – including the presidential palace, the cathedral and the UN mission headquarters. Estimates of the death toll range from about 100,000 to more than 300,000. More than a million people lost their homes, and recovery was hampered by a cholera epidemic and political instability.
How to read these data
Magnitude measures the energy released at the focus: each step is about 32 times more energy, so an M 9 earthquake releases about a thousand times more energy than an M 7. Its effects, however, also depend on focal depth, distance to cities, ground conditions and building quality – a shallow M 7 beneath a city can be deadlier than a deep M 8 under the ocean.
Data: USGS ComCat (usp000h60h) · Wikipedia (pl) · Wikipedia (en)