Inflation - John Seach
|Inflation begins as magma rises into
the summit reservoir. Tiltmeters measure changes in slope of the ground.
The Global Positioning System (GPS) is used to measure the position of
benchmarks. In order to determine the deformation caused by an episode
of inflation, scientists must install and survey the benchmarks and install
tiltmeters and GPS receivers (if continuous measurements are desired) before
As the magma reservoir becomes inflated,
the ground around it cracks to accommodate its increasing volume. Many
small earthquakes occur in the area surrounding the magma as the rocks
break. As the surface of the volcano changes shape, tiltmeters record tiny
changes in slope, distances increase between benchmarks on opposite sides
of the caldera, and elevations of the stations increase.