The volcano Mount Merapi in Indonesia has been erupting for a week so far, and the country reported increased rumblings at 21 other active volcanoes in the area.

These recent volcanic eruptions have turned the public’s eye to volcanoes that have been long dormant but could explode at any time. Yet there are volcanoes that are erupting almost constantly, and have been for years.

Sangay, Ecuador – 94 years

Sangay is an active stratovolcano in central Ecuador. It exhibits mostly strombolian activity. Geologically, Sangay marks the southern boundary of the Northern Volcanic Zone, and its position straddling two major pieces of crust accounts for its high level of activity.

Sangay has had frequent eruptions in historic times, mostly of Strombolian type. The present-day volcano was built within horseshoe-shaped calderas of two previous edifices, which were destroyed by collapse to the east, producing large debris avalanches that reached the Amazonian lowlands. The modern edifice dates back to at least 14,000 years ago.

Santa María, Guatemala – 101 years

The Santa Maria Volcano towers over Guatemala’s Pacific coastal plain. Santa Maria is a 12,375-foot (3,772-meter) tall stratovolcano consisting of alternating layers of hardened ash, lava and rock.

A catastrophic eruption in 1902, one of the largest eruptions of the 20th century. Caused severe damage throughout southwestern Guatemala and carved a crater on the volcano’s flank. Since 1922, a lava-dome complex, Santiaguito, has been forming in the 1902 crater.

Stromboli, Italy – 108 years

Stromboli Volcano, off the west coast of southern Italy and the north coast of Sicily, has been erupting nearly continuously for over 2,000 years. Which has earned it the nickname “Lighthouse of the Mediterranean.”

Eruptions from the summit craters typically result in a mild energetic bursts that last for only a few seconds and emit ash. Incandescent lava fragments and lithic blocks up to a few hundred meters in height.

The explosive style of volcanic eruption that this and other volcanoes exhibit has even been named Strombolian. Stromboli’s activity is almost exclusively explosive, but lava flows do occur at times.