Pico, Terceira, Don Joao de Castro Bank, Sete Cidades, Agua de Pau and Furnas have erupted in the last 2,000 years. Flores and Graciosa have erupted in the last 10,000 years. Flores is a stratovolcano with no known historic eruptions. Eruptions associated with Calderia Funda de Lajes and Calderia Comprida occurred in 1200 and 950 BC, respectively. These eruptions were from central vents, explosive, and produced lava flows.
Most eruptions are moderate effusions of lava with some small Strombolian explosions.
Two eruptions at San Jorge have been fatal. Ten people were killed by the 1580 eruption and eight in 1808. In both eruptions small glowing clouds were reported. A possible submarine eruption as reported southwest of the island in 1964 but was not confirmed. A single historic submarine eruption occurred at this volcano in 1720.