On 5 September 1996 at 22:44 local time (CEST, 20:44 UTC), southern Dalmatia, Croatia, was hit by a strong earthquake of moment magnitude 6.0.

The epicentre was near the coastline of the Adriatic Sea, close to the village of Slano, roughly 15 kilometres (9.3 mi) northwest of Dubrovnik.

The worst damage was of intensity VIII on the Medvedev–Sponheuer–Karnik scale, occurring in the epicentral area, but also another 25 km (16 mi) northwest, at the isthmus of the Pelješac peninsula, around the old town of Ston.

The earthquake reduced groundwater levels, and created a submarine spring between Ston and Doli, where the emitted soil and mud temporarily turned the sea red.

[8][6] The significant degree of soil amplification in Ston caused high PGA values of up to 0.313 g in some of the aftershocks as well.