VOLCANO MONITORING USING HOURLY GPS SOLUTIONS

GPS has long been used in volcanic studies, to assess what has occurred underground after a deformation signal is detected. More and more GPS is being used as a hazard monitoring tool at volcanoes. The main draw back is that classic GPS processing only gives one position estimate per day. In situations where real time hazard monitoring is the goal, daily GPS positions are not sufficient. Traditionally GPS position estimates use 24 hours worth of data. Processing the GPS data requires additional information about satellite position, which is available from processing centers generally within 10 days to 18 hours of the time the data is collected, depending on the quality of orbit information desired. These characteristics do not make GPS a desirable tool for real time hazard monitoring.

To improve the usefulness of GPS data to volcano monitoring, hourly solutions have been implemented at the Alaska Volcano Observatory. This hourly solution technique uses predicted orbit parameters and one hour worth of GPS data that is collected and processed in less than one hour latency. This processing technique allows for information about surface deformation to be available rapidly for use in decisions regarding volcanic hazards.

Recent activity at Mount St. Augustine has allowed us to verify the usefulness of this technique. Hourly solutions allowed us to recognize deformation signals hours after they began rather than the days or weeks it might take to notice the same signal in the classic daily GPS solutions.