Topics of Section 2.1
1. Hazard and risk dynamics
The understanding and quantification of extreme events and the associated risk is the key to risk assessment and disaster reduction. We focus together with other sections of the GFZ on two science questions:
- What are the critical process interactions that lead to extreme events?
- How can changes in hazard and risk be quantified and integrated in risk assessments?
We investigate interactions between different geophysical processes and/or different compartments of the system Earth. Examples are earthquake-earthquake interactions, volcano-earthquake interactions, or earthquake-induced landslides or tsunamis. To this end, we combine field and laboratory experiments, long-term monitoring, and numerical and analytical modeling.
Traditionally, hazard and risk analyses were based on the concept of stationarity. Today, risk and in certain instances also hazard has to be seen as a time-varying quantity, for example, due to changes in societal vulnerability. We need to understand how risks change in time and which drivers contribute to changes in hazard, vulnerability and risk.
2. Early warning and limits of predictability
One of the cornerstones of disaster reduction is early warning and predicting, as far as possible, the places affected, the timing and scale of an adverse phenomenon. At the same time, disasters are possibilities for learning. Hence, our research and development activities focus on two scientific questions:
- How can we use technology to improve early warning and to provide rapid information immediately before, during and after disasters?
- What are the limits of predictability and how can models be rigorously tested?
GFZ has a proven record of technology and method developments in the fields of rapid disaster information and early warning. We build on these experiences by developing new methods for earthquake and volcanic early warning, including rapid event monitoring and real-time seismology. We integrate space- and ground-based earth observation systems and simulation tools in (near) real-time.
Although technological advances rapidly improve the capabilities for forecasting and early warning, there are distinct limits of predictability. Past events may be an unreliable guide to future risks, or interacting, non-linear processes may lead to developments not taken into account in models and predictions. Frequently applied physical models in hazard assessment, e.g. characteristic or maximal events, may be unjustified if tested against large databases. Rigorous and prospective testing of scientific hypotheses and models, using community-accepted testing procedures and protocols, will be employed to quantify the limits of predictability in earthquake and ground motion forecast and for hazard and risk assessment procedures.
3. Field and testing areas
Our methods are applied in different interdisciplinary field missions and at our plate boundary observatories in Chile, Turkey and Central Asia, where long-term monitoring is performed. Plate boundaries form coupled systems in which multiple parameters interact over wide ranges of spatial and temporal scales. Understanding these coupled systems remains a key challenge for the ability to assess tectonic hazards resulting from earthquakes, faulting, volcanic eruptions, or landslides.