R06: Dangerous Ocean
We will primarily focus on large events (e.g., plate boundary earthquakes and associated tsunamis, sudden relative sea level rise, floods and storms) in order to evaluate their impacts on the coastal zone and to develop adaptation strategies for coastal geohazards, based on the analyses of ongoing, recent, and past events. Recent experience teaches mankind that oceanic geohazards, such as plate boundary earthquakes, volcanic eruptions, coastal and submarine landslides, and resulting tsunamis can reach dimensions that exceed the probable and the expected, as would be defined by conventional hazard and risk analysis. This new class of threats (e.g. the 2011 Sendai event in Japan) results from a chain of superimposed disasters, and can produce an immediate impact on the intricately linked global community and economy. They affect large populations and sensitive industrial installations on coasts and offshore, already confronted with problems of rising sea level, rapid coastline retreat, delta subsidence, sediment trapping in upstream river systems, and severe storms. We envision an integrated and multidisciplinary research approach covering the continental slope, the shelf, and coastal areas in order to investigate the entire chain from the physical state of the seafloor to consequences on the coast.
Rather than assessing the chain of global impacts of these events, our results are intended to provide support for informed policy decisions and management strategies for the adaptation of coastal communities. We aim at answering the following integrative research questions:
- How dangerous are critical geological systems, at the seafloor, like seismic faults and unstable slopes?
- How resilient are coastal systems such as subsiding deltas, when affected by ocean hazards?
- How can improved understanding of ocean and coastal hazards be provided to assist in reducing risks and impacts to coastal communities?
The general approach for addressing these questions is an integrated analysis from offshore to onshore, and from natural to social sciences, focusing on the following topics:
- Investigations at the seafloor will attempt to assess the state of pre-seismic loading on selected fault systems in earthquake-prone regions, and the state of criticality in potentially unstable continental slope segments.
- Extreme landscape-modifying events drastically alter the bathymetry and on-land elevation of coastal environments.