BUILDING RISK KNOWLEDGE
WHY THE FOUNDATION WAS BORN? >
Networks of GPS receivers track ground movement at volcanoes
The Global Positioning System (GPS) consists of a group of satellites orbiting the Earth that continuously transmit information to receivers on the ground. Using this data, it is possible to calculate the exact position of the receiver on the Earth at any given time.
To use GPS data for volcano monitoring, multiple receivers are placed around a volcano as a GPS network. In some locations, instruments are permanently installed and record data continuously. However, sometimes scientists setup a “campaign” GPS network above “benchmarks” (sites with a standard point of reference) where they are left for several days to record data. Campaign-style data are often recorded from the same benchmark sites annually or as needed to detect changes in volcano behavior.
By looking at data from a single receiver over a period of time, scientists can determine whether the ground surface has deformed. By combining the data collected from a GPS network, it is possible to get a larger view of which areas of the volcano’s surface are moving as well as the speed and direction of movement. This large-scale picture of volcano deformation can be used to construct a model of what is happening beneath the surface—for example, the location of any magma reservoirs or active faults.
The GPS data is very accurate
GPS sensor networks can track three-dimensional movements of the ground surface. The systems are inexpensive and allow a very accurate study.
GPS is the name of the United States’ satellite navigation system. Other countries have launched their own satellite navigation systems, including GLONASS (by Russia) and Galileo (by Europe), but all follow the same basic principles as GPS. We refer to these systems as GNSS (Global Navigation Satellite System). Modern receivers can record data from several types of GNSS satellites, which increases the overall accuracy of calculated positions.
Global Positioning System receiver (called a GPS monument) at North Rim Station, a monitoring location at Newberry volcano, Oregon.
Since 2021 VOLCANO ACTIVE FOUNDATION has been committed to the UN Global Compact corporate responsibility initiative and its principles in the areas of human rights, labour, the environment and anti-corruption.
