The 1840 Ahora earthquake occurred on 2 July at 16:00 local time, affecting Ağrı Province in the Eastern Anatolia Region of present-day Turkey. The earthquake had an epicenter near Mount Ararat, where it triggered an eruption and caused a landslide that destroyed villages. An estimated 10,000 people were killed by the earthquake and its damaging aftershocks. Earthquake catalogs place the surface-wave magnitude at Ms  7.4 and maximum Modified Mercalli intensity scale assigned IX (Violent).