Contributions of Geodesy to Monitoring Natural Hazards and Global Change

Contributions of Geodesy to Monitoring Natural Hazards and Global Change

The definition and realization of precise and stable geodetic reference frames play an important role in modern geodesy as well as in other geosciences, as they are required when we want to monitor changes on the Earth such as plate tectonics or global sea level rise. An overview of the various natural hazards and global change phenomena that can be observed by geodetic techniques will be given. Depending on the spatial scale, various types of measurements can be used, from space geodetic techniques such as GNSS (Global Navigation Satellite Systems), SLR (Satellite Laser Ranging), VLBI (Very Long Baseline Interferometry), and DORIS (Doppler Orbitography and Radiopositioning Integrated by Satellite), via dedicated gravity satellite missions and regional observations such as airborne gravimetry, to local measurements by geodetic surveying instruments. All these techniques and the underlying models are combined in GGOS, the Global Geodetic Observing System of the IAG (International Association of Geodesy), and the concept of this integrative enterprise will be described. Case studies will be presented that document the essential role of precise geodetic data, accurate analysis methods, and realistic mathematical and physical models.