New Burst Of Ash From Awoken Indonesian Volcano

Mount Sinabung of Indonesia sent a fresh powerful burst of hot ash and debris two miles (thousands of meters) into the air early Friday. AFP reported that villagers started to move back to emergency shelters.

Many scientists were caught off guard when the Indonesian volcano erupted for the first time in 400 years on Sunday and Monday. The eruption forced at least 30,000 people living along its fertile slopes in North Sumatra province to be evacuated.

Despite warnings by vulcanologists that the alert level was still high many had already returned to areas within the "safety zone" — well away from the crater's mouth —

Mount Sinabung is a Pleistocene-to-Holocene stratovolcano of andesite and dacite in the Karo plateau of Karo Regency, North Sumatra, Indonesia. Many old lava flows are on its flanks and the last known eruption, before recent times, occurred in the year 1600. Solfataric activities (cracks where steam, gas, and lava are emitted) were last observed at the summit in 1912, but no other documented events had taken place until an eruption in the early hours of 29 August 2010. With the 2010 eruption, Sinabung joins other, long inactive volcanoes such as Fourpeaked Mountain in Alaska which have erupted in recent years.

Indonesia belonged to the so-called "Ring of Fire," which is home to 129 active volcanoes.

The Ring of Fire has 452 volcanoes and is home to over 75% of the world's active and dormant volcanoes. It is sometimes called the circum-Pacific belt or the circum-Pacific seismic belt.

About 90% of the world's earthquakes and 80% of the world's largest earthquakes occur along the Ring of Fire. The next most seismic region (5–6% of earthquakes and 17% of the world's largest earthquakes) is the Alpide belt, which extends from Java to Sumatra through the Himalayas, the Mediterranean, and out into the Atlantic. The Mid-Atlantic Ridge is the third most prominent earthquake belt.