1840s earthquakes

An earthquake occurred on 2 July 1840 at 16:00 local time with 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).

The 1847 Zenkoji earthquake (善光寺地震, Zenkōji jishin) occurred at about 21:30 local time on 8 May at Nagano, Japan. It had a magnitude of 7.4 on the surface-wave magnitude scale. It caused the destruction of many houses in Nagano and at least 8,600 people were killed. The earthquake triggered many landslides, the largest of which dammed the Sai River (a tributary of the Shinano River). 19 days later, the failure of this earthquake dam caused a flood that destroyed many more houses and killed 35 people.

The 1841 Caída da Praia earthquake (1841 Fall of Praia), also known as the Second Caída da Praia, was a series of seismic events occurring between 12 June and 15 June 1841, on the island of Terceira in the Portuguese archipelago of the Azores. Similar in scope to the first 1614 Cáida da Praia earthquake that destroyed most of the community, this second event is noted for the systematic process to assistance, document and catalogue the events of the tragedy.

The 1841 Kamchatka earthquake occurred in the Pacific Ocean on May 17 at 08:00 local time. The earthquake had an epicenter off the Russian Far East's Kamchatka Peninsula. With an estimated moment magnitude of 9.0 or higher, it is one of the largest to strike the region. A large tsunami with a run-up height of up to 15 metres (49 ft) struck the coast.