1 December 2020.

Introduction:

Thousands  of people have been evacuated as activity in Indonesian volcanoes increases.

Mount Seemeru is an active volcano located in East Java, Indonesia. The volcano is located in the subduction zone where the Indo-Australia plate subducts under the Eurasia plate. The Mount Semeru is a stratovolcano. Since 1818, around 55 eruptions have been recorded in Mt Semeru.

What is called stratovolcano?

• The stratovolcano is also called a conical volcano. It is built by many layers of hardened lava.
• The lava of stratovolcano is highly viscous.
• It cools and hardens before spreading far.
• Also, the stratovolcano has periodic effusive eruptions.
• The lava from stratovolcano are is not of significant threat to humans as they are highly viscous.
• On the other hand, the Nyiragongo is the only dangerous stratovolcano in the world as its magma are unusually low in silica which makes the lava quite fluid.
• This increases the flow rate of the lava.

Ring of Fire

• The Ring of Fire, which is also known as the Circum-Pacific Belt, is a 40,000 km long path along the Pacific Ocean where majority of Earth’s volcanoes and earthquakes takes place.
• Recently, Mount Ili Leotolok in eastern Indonesia within the Ring of Fire erupted, forcing thousands of people to evacuate.
• This mountain is among the three currently erupting volcanoes in the country.
• The other two includes Merapi on Java Island and Sinabung on Sumatra island.
• Indonesia has more than 400 volcanos as it is the meeting point of three major continental plates.
• They are the Indo-Australian plate, Pacific plate and the Eurasian plate.
• It is also joined by the much smaller Philippine plate.
• Out of these 400, 127 are active and account to one-third of the world active volcano.
• The plates in the region are constantly moving and sliding past.
• They move above and below each other.
• This movement of the plates result in volcanic eruptions, deep trenches and earthquake epicentres along the boundaries where the plates meet.