Methods of Volcano Monitoring To Predict Likelihood of Eruption in Long Valley Caldera

Volcano monitoring uses knowledge of volcanic processes and extensive data gathering to analyze areas of volcanic activity. The main goal is to learn the nature of the volcano, the magmatic processes occurring, and the likelihood of a future eruption. Volcano monitoring centers around three aspects of volcanic processes: ground deformation, seismic activity, and gas emissions. These techniques are used to assess the present volcanic situation in the Long Valley Caldera. Even though many advances have been made in this field, it is still difficult to pinpoint eruptions on a human time scale when volcanic activities are so complex and occur over a large geological time scale. One method of monitoring volcanoes is measuring ground deformation. Ground deformation is defined as the “change of shape of the ground surface due to an applied force” (“Yellowstone InDepth”). This force is the movement of magma beneath the earth’s surface. Magma rises from the mantle because it is molten rock and therefore less dense than the solid rock of the mantle and crust. Typically, it accumulates into a large magma chamber relatively close to the earth’s surface. (Marshak, 2004). As the magma builds up in the chamber, it places massive amounts of pressure on the surrounding rocks, and as a result these rocks are pushed upwards and outwards as shown in Figure 1 (“Volcano Monitoring Techniques”). Measuring these changes in topography is one way that scientists can become familiar with the dimensions of a magma chamber. The oldest and simplest methods of measuring ground deformation are electronic distance meters (EDM) and tiltmeters. As explained earlier, the pressure from a magma chamber pushes overlying rock up and outwards. Electronic distance meters measure the distance between