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Prediction of volcanic eruptions

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Introduction

Prediction of volcanic eruptions Why do we need to monitor eruptions? The main reason why volcanoes are monitored is because of the risk of destructive volcanic activity such as pyroclastic flows, lahars, lava flows and ash falls. These hazards cause long term damage to villages and towns which are situated close to the volcanoes. Towns and villages which are unaware of the volcanic activity can suffer a tremendous loss of life if there is no warnings from the government of future eruptions, therefore the volcanoes need to be measured in order to predict and hazardous volcanic eruptions from volcanoes which are threatening to destroy the surrounding areas. It is important that scientists communicate with local government officials and the general public about hazards produced by the volcanoes in their area. This interaction and the development of an emergency plan with established lines of communication will hopefully save lives and encourage better land use planning. Many advances have been made in the study of volcanoes particularly in eruption prediction. ...read more.

Middle

Now we look at volcanic deposits around the volcano to determine their age, type (lava flows, mudflows, ash flows), size, and distance from the volcano. This data will help to determine if the volcano is active. Recording historic eruptions and modern volcano-monitoring in themselves are insufficient to fully determine the characteristic behavior of a volcano, because a time record of such information, though perhaps long in human terms, is much too short in geologic terms to permit reliable predictions of possible future behavior. A comprehensive investigation of any volcano must also include the careful, systematic mapping of the nature, volume, and distribution of the products of prehistoric eruptions, as well as the determination of their ages by modern isotopic and other dating methods. Research on the volcano's geologic past extends the data base for refined estimates of the recurrence intervals of active versus dormant periods in the history of the volcano. With such information in hand, scientists can construct so-called "volcanic hazards" maps that show the zones of greatest risk around the volcano and that designate which zones are particularly susceptible to certain types of volcanic hazards (lava flows, ash fall, toxic gases, mudflows and associated flooding, etc.). ...read more.

Conclusion

Such underground ruptures produced seismic waves that travel through the volcano and are recorded by a network of seismometers placed on the volcanoes surface. Ground motions sensed by the seismometer are converted into electronic signals, which are transmitted by radio and are recorded on seismographs located at the volcano observatory. The seismic data are analysed to determine the time, location, depth, and magnitude of the earthquakes. Mapping the earthquake activity allows scientists to track the subsurface movement of magma. Magma movement and the onset of an eruption produce a distinctive seismic pattern called harmonic tremor. Seismologist must sort through the records of hundreds of earthquakes and determine which are related to the volcano and which were caused by man-induced or natural forces. Cone temperature Remote-sensing imagery from satellites can sometimes show up thermal anomalies near the cones of the volcanoes, caused when rising magma heats the rocks close to the surface on active vents, showing a clear increase in cone temperature prior to an eruption. Images shown by infrared heat sensors detected by the satellite send back images of even the slightest of temperature changes, which makes it a very reliable early warning system. Satellite surveillance offers some of the best future prospects for forecasting eruptions. ...read more.

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