The last volcanic eruption (which is debatable) occurred in 1963, in a small submarine eruption off the northwest coast (north of Cachorro in Santa Luzia). Prior to this, major volcanic activity was evident in lava fields generated in only the areas of Prainha (1562–64), Santa Luzia (1718), São João (1718) and Silveira (1720). The paths of the lava flows are still visible; those in the 16th century and 1718 were particularly substantial, extending for over 10 km. Today, the only visible evidence of active volcanism appears on the summit of Pico, in the base and interior of the Piqueninho (the mini-peak on the summit); there are irregular emissions from cracks in this zone. Additionally, there are emissions on the eastern flanks between 1500 and 2000 meters altitude. There have also been found areas of de-gasification along the fault associated with the Lagoa do Capitão and another in the Topo Volcano, as well as a spring rich in CO2 in the area of Silveira.