By Abigail Mullen
On Friday, September 22nd, Mount Agung, a volcano on the Indonesian island of Bali, started showing signs that it would erupt soon. As of Wednesday, more than 75,000 people have been evacuated and were housed in over 300 temporary shelters. According to CNN, the evacuation zone extends 12 kilometers (7.46 mi) from Mount Agung, which was determined by the last time the volcano erupted in 1963. The volcano is classified as a level 4 on the Indonesian Alert System, meaning there is a possibility it may erupt in the following 24 hours from when the alert is given.
Mount Agung is a composite volcano built up by volcanic ash and lava. Some famous composite volcanoes are Krakatoa and Vesuvius. One of the characteristics of this type of volcano is that its eruption can sometimes leave a crater. The volcanic ash and gases that are thrown up into the atmosphere can have temporary cooling effects on climate. One such composite volcano in Indonesia, Mount Tambora, erupted in 1815. According to the US Geological Survey, its volcanic cloud of sulfur dioxide (SO2) lowered global temperatures by up to 3.5 C (38.3 F). This is because SO2 reflects the Sun’s radiation, preventing the Earth from increasing to its normal temperature. Many parts of the Northern Hemisphere experienced a cooler summer the following year as a result of the Mount Tambora eruption.
Volcanologists cannot predict exactly when the eruption will happen, but an increase in seismic activity indicates that it will be soon. ABC News reported that hundreds of tremors can be felt every hour. These tremors are detected by a monitoring station near the top of Mount Agung. From the seismic activity, it appears that the volcano will erupt in the upcoming days.