Society cannot afford to miss opportunities to make space-based observations in areas where land-based observations are unavailable or are impractical because of physical or political restrictions on access.
In this chapter, the Panel on Solid-Earth Hazards, Natural Resources, and Dynamics identifies the three highest-priority satellite missions essential for advancing the knowledge base that society needs to manage, understand, forecast, and mitigate natural hazards; to improve discovery and management of energy, mineral, and soil resources; and to address fundamental questions in solid-Earth dynamics. The first mission addresses when, where, why, and how much the surface of Earth is deforming. Surface deformation can be a measure of the accumulation and release of stress and strain through the earthquake cycle, and it can be the harbinger of catastrophes such as volcanic eruptions or landslides. The second mission addresses how and why Earth’s surface composition and thermal properties vary with location and time and has implications for resources, susceptibility to natural hazards, and ecosystem health. The third proposed mission seeks to determine much more accurately the topography of all seven continents; this would allow improved prediction of flood inundation and landslide likelihood and would provide an understanding of how topography evolves over time.
To put these missions into perspective, it is important to realize that we now have the capability to monitor the events and processes responsible for natural hazards in real time, allowing the possibility for short-term forecasting of their occurrence. Tremendous advances in computational power provide the platform to model complex systems over a variety of timescales. What is lacking is sufficient quantitative observation of the relevant physical processes. If such observations are combined with realistic parameterizations of Earth material properties over the spatial scales needed to understand events that trigger catastrophic hazards, as well as the processes that unfold after initiation, it will be possible to improve forecasting for protection of property and human lives. The three missions required to implement this vision are summarized below and discussed in more detail in the remainder of the chapter.
Mission to monitor deformation of Earth’s surface. The first priority for solid-Earth science is a mission to observe and characterize subcentimeter-level vector displacements of Earth’s surface. Surface deformation is a visible response to processes at depth that drive seismic activity, volcanism and landslides (Figure 8.1). Local subsidence and uplift from groundwater extraction and recharge and hydrocarbon production are also visible in maps of deformation.