It features numerous vents along E-W and NNW-SSE trending fissures which converge at the coordinates of the volcano center, which is the center of a hypothesized caldera surrounded by rims, visible especially in the south and west. The largest vent is 1 km × 0.5 km in size just SE of the volcano center and along the SE rim of the volcano. The volcano covers a surface area of appr. 25 km2. The silicic volcano center has an eruption history of more than 500,000 years, the last eruption was around 2400 years ago.[1] Eruptions from Aluto may have influenced the dispersal of hominin populations in East Africa.[2]
Strong fumarolic activity continues throughout today. The volcano is permanently inflating and deflating with the strongest movements at the center of the hypothesized caldera, indicating some activity around 5 km below the volcano.[3]
Close to the center of the hypothetical caldera is the site of the high-temperature Aluto–Langano geothermal field with temperatures between 300 and 400 °C at depths below 1,200 meters. This geothermal field covers an area of about 8 km2.[4]