With more and more of the world's population coming to live under the shadows of active volcanoes, an accurate prediction of when and where a volcano will erupt is critical. This report will focus on the main ways to predict when a volcano will erupt, how a town can be saved from an advancing lava flow, and the ways a volcano can be helpful in the long run.
All volcanoes that are believed to be a threat can be monitored... for a price. The equipment and personnel needed to monitor a dangerous volcano comes at a very steep cost. Ironically most of the world's very active volcanoes are in third world countries that cannot afford to monitor the volcanoes inside their country.
There are three main ways of monitoring a volcanic activity: tilt meters, surveillance by satellite, and seismographic monitoring. More frequent gas emissions and various squeaks, groans, belches, and wheezing noises can also warn of a coming eruption. Hazard maps can also help the people in the most danger evacuate in time if their property is threatened by an eruption by showing where the lava will flow and so on.
Tilt meters are levels that are extremely accurate. Tilt meters are just pots that contain water or mercury. They are arranged in a triangle shaped way so that they can detect very minute ground deformations. The most noticeable ground deformation occurs when magma (molten lava) that is rising to the surface forces the ground to bulge to "accommodate" it. This can happen slowly or quickly over time, depending on how fast the magma is rising. Massive bulges occurred before the Mount Saint Helens eruption. Some of the bulges "grew" at a rate of five feet per day.
Satellites are becoming more technologically advanced and cheaper in cost every day. "The Global Positioning System (GPS) for example is used to monitor ground displacements, including those around volcanoes, which might pinpoint future activity" (Prediction, 2). Satellites can also be used to show how the clouds of gasses from an eruption are being dispersed around the globe. Seismographic monitoring is one of the best ways to predict when a volcano eruption will occur. When magma is rising to the surface, it often causes noticeable earthquakes. As the magma nears the surface, the earthquakes become increasingly violent. Seismographs are used to measure and record these eruptions for observation. The more earthquakes that occur the better the chances that an eruption is about to occur.
As the magma rises closer to the surface fumaroles, solfataras, and mud pots give off increased gas emissions. The emissions are highly toxic to humans and damage the delicate instruments that are used to gather information. Sometimes this has heralded an upcoming an eruption and at others, an eruption never occurred. (Prediction, 1-3)
The newest predictor of a volcanic eruption may well be the noises a volcano makes before an eruption. These various noises can tell a lot to a scientist wondering when a volcano will erupt. One of the best examples happened in Alaska. "For half a day in April 1999, Shishaldin volcano in the Aleutians hummed. When the humming stopped, the ground shook, and the volcano blew its stack" (Listening,1). More research is being done in this area to improve the ability to pick up these noises that come from inside the heart of the volcano.
The most success in predicting when a volcano would erupt came at Mount Etna in Italy.
""Three minutes," gushes Gene Ulmer, a Temple University geologist. "That's all they missed by." Not only did Ulmer witness the eruption (which killed no one), he was in Nicolosi the previous night when European volcanologists predicted that Mount Etna would erupt at 1:30 p.m.--one of the most accurate predictions in history. Scientists have historically had little success in predicting eruptions. There are instruments to monitor the geophysical changes that may suggest a volcano is...