Submarine geohazards are widespread across the globe. Submarine geohazards range from volcano eruption to earthquakes, tsunamis, seabed liquefaction, seabed creep, submarine slides, turbidity currents, shallow gas eruptions, mud volcanoes, and sediment instability such as migrating bedforms and scour and erosion around marine and offshore structures. Submarine landslide tsunamis are now seen from all geological environments; passive, convergent and transform margins, as well as volcanoes. The Task Group on Submarine Geohazards (TGSG) targets the full spectrum of such geohazards that impact people’s lives and critical infrastructures. Offshore renewable energy systems are rapidly advancing to meet global requirements for sustainable development. Underwater fiber optic cables, underwater power cables, and underwater pipelines have been laid over many parts of the seafloor, and their importance, either strategic and economic, increased dramatically in recent years. However, these marine and offshore infrastructures are at risk from multiple cascading multi-geohazards that include landslides, tsunamis, earthquakes, and volcanic eruptions. Due to their widespread occurrence across the globe, submarine geohazards are a globally relevant and critical issue to be better addressed in the face of global climate change.
Therefore, the global development of offshore renewable energy systems is facing new challenges. For the development of offshore renewable energy in a wide variety of geological settings including narrow continental shelves, plate subduction zones and steep seafloor topography, risk management and geohazard mitigation strategies need to be defined. These require advancement and integration of research across marine geology, oceanography, and physical processes. To this end, TGSG will work with the offshore renewable energy and submarine cable industry to identify and address key knowledge gaps. Further, the TGSG aims to provide global mapping of submarine geohazard risks and create guidelines for assessing various submarine geohazard risks pertaining to emerging energy transitions. The targeted submarine geohazards are indeed broad, as described above. Suggested objectives and actions include providing the sector with (1) Case studies of submarine geohazards, (2) Data archive of offshore geological and geophysical data, (3) Guidelines of seafloor geological and geophysical surveys, (4) Submarine geohazards risk assessment, and (5) International capacity building and knowledge exchange.
We aim to resolve these issues together with our cooperative works in this proposed international framework across Asia-Oceania, Europe-Africa, and North America-South America regions.