Volcanos have wiped out whole civilations and towns. Luckly now we have more knowladge about them. It is important to understand how they work in modern society.
There are a few indicators of volcanic activity. One of the indicators is what type of volcano it is. The volcanoes are classified into three categories. The categories are as following, extinct volcanoes, dormant volcanoes, and Active volcanoes. Extinct volcanoes have not erupted in recorded history, and probably never will. Dormant volcanoes are not currently erupting, but have a past record of eruption. Active volcanoes are currently erupting, or show signs or eruption in the near future. Scientists study dormant and active volcanoes in order to predict eruptions.
Most active volcanoes produce small earthquakes before an eruption, so if the number and intensity of the earthquake goes up, the volcano may erupt soon. This is one of the best ways to predict an eruption.
Another way to predict an eruption is to study the volume and composition of volcanic gases. The ratio of certain gases may be important in predicting volcanoes, especially that of sulfur dioxide to carbon dioxide. The changes in this ratio may indicate changes in the magma chamber below.
Determining the slope and temperature of a volcano helps predict an eruption. Prior to an eruption, the magma moves upward, this may cause the earth to swell or the side of the volcano to bulge. Scientists use certain instruments to observe the temperature and slope of a volcano.
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