Volcanic Activity in Indonesia

Mount Merapi is the most recently active volcano in Java.

Indonesia, located just North of Oceania and just Southwest of Cambodia, is home to 147 volcanoes, 76 of which are active.  The one with the most activity is Mount Merapi, or Gunung Merapi, which erupted again in both January and March of this year.  The name translates to “Fire Mountain”.  Located between the cities of Java and Yogyakarta, residents had been alerted that they may have to evacuate at any point. The January eruption forced more people to leave the island for safety than the March eruption did.  Indonesians have also been told to stay at least 3 miles from the center of the volcano to avoid injury from lava.  Mining industries in Java were instructed to stop for the time being for safety, and tourism companies were to stay away from the volcanoes out of caution.  Both of these industries having to stop work for the time being due to eruptions, negatively affected the economy. 

When Mount Merapi last had a large eruption, over 300 people died in 2010.  Last month, no casualties were reported from the eruption thankfully, but it brought pyroclastic flows.  That means rocks, debris, lava, and gasses spewed out of the volcano down to the city.  The great number of active volcanoes in Indonesia is due in part to the region being an archipelago or a group of many islands.  These islands are located along the Ring of Fire, which is the region around the coast of the Pacific Ocean where volcanoes are active, and earthquakes are quite common.  

Another volcano that recently erupted in August 2020, was Mount Sinabung in North Sumatra, which caused air pollution and increased health concerns for residents.  These volcanic eruptions can have lasting negative implications on the climate and environment.  An intense eruption of Anak Krakatau in the Sunda Strait in 2018 happened to spark a tsunami.  A tsunami can be catastrophic, as it is an intense coastal wave that is created by earthquake activity, which we know is common around the Ring of Fire.  

Volcanoes in Indonesia

On the map, you can see that the terrain of Indonesia is mostly coastal high mountains and volcanoes with narrow coastal plains.  The tropical region experiences dry and wet seasons, with a long monsoon season.  Monsoon is the seasonal reversal of wind flows where latitude is low and is powered by atmospheric pressure gradients governing precipitation patterns.  While the ash from eruptions is not pleasant, it contributed to Indonesia’s rich soil, which helps support the high population density.  The red dots represent thermal activity along the islands which can indicate wildfires for a variety of reasons, including heat emitted from volcanic activity.  Finally, the colored circles represent volcanic eruptions, and some provide general details about the volcano itself and its past eruptions.  It is important to study volcanic activity to know when to escape to safety, as lava can be fatal if it comes in contact with humans, animals, and plants.  We want to be able to predict eruptions, so we know when to evacuate.