The Osmussaar earthquake occurred on 25 October 1976 near the north tip of Osmussaar, an island close to the coast of Estonia. Its hypocenter was 10–13 kilometres (6–8 mi) below ground level, and it was measured at 4.5–4.7 mb. The earthquake was the most powerful recorded in Estonia; it caused rockfall along the north and northeastern coasts, and some houses took structural damage. The earthquake was largely felt in surrounding areas like north Estonia, south Finland and Sweden. Aftershocks also took place in November.