Project 585 - E-Marshal: Earth's Continental MARgins: aSsessing the geoHazard from submarine Landslides
Submarine slope instability represents a geohazard for its destructive potential on nearshore structures and life and offshore seabed structures. Submarine slides may bear a tsunamigenic potential and are capable of methane gas release into the seawater and atmosphere.
Recent examples of catastrophic submarine landslide events that have afflicted human populations (including tsunamogenesis) are numerous (Stromboli in 2002, Papua-New Guinea in 1998, Finneidfjord in 1996, Nice airport in 1979, …). Recent awareness has also been raised because it has been shown that not only the terrestrial environment, but also the deep-sea environment is sensitive to natural climatic changes. Therefore, according to the geological record, the risk from submarine landslides it is expected to grow given the actual trend in global warming and global sea level rise.
Major advances in understanding submarine slope failure have been possible thanks to the use of state-of-the-art technologies in geophysical exploration and in-situ measurements, which have allowed mapping submarine landslides on continental margins. However, the interplay among the numerous geological factors controlling submarine landslides is still at the frontier of knowledge. It is therefore now time to start a new approach that includes not only measurements, and high resolution geophysical data acquisition, but also deep subsurface sampling and long-term monitoring. Major advances in our understanding of submarine landslides require capturing episodic events related to: seismology, geodesy, sea level, gas vents, physical oceanography and pore pressure transients that lead to slope failure. Key scientific questions with regard to submarine landslides and submarine slope instability that still remain unanswered include:
- What is the link between trigger mechanisms and preconditioning factors?
- Which mechanisms control the development of mobility in submarine slope failures?
- What is the role of fluids in submarine geohazard dynamics?
- How does continental margin development affect fluid flow focusing and generation of high pore pressures?
- What is the role of global climate change in submarine landslide generation and recurrence intervals?
- Can we identify physical parameters that might be used as indicators or precursory signs of slope instability?
To answer these questions, it is necessary that the research community strengthen cooperation with deep subsurface sampling and monitoring programmes. In order to answer the scientific questions above E-MARSHAL aims to provide a platform for members to lobby within national and international funding agencies to fund scientific projects in this research topic, promote the publication of scientific articles and books on this submarine geohazard, promote events that enhance the exchange of results and scientific ideas on the problems above, provide knowledge transfer to developing countries and improve the links between academia, industry and public administrations.
Given the technological and scientific complexity, worldwide distribution and potential for increasing risk, an international and interdisciplinary approach is essential to improve understanding and prediction of geohazard from submarine landslides. IGCP is one of the few initiatives that may give such an international umbrella. It is also one of the few initiatives that might allow international collaboration and cooperation beyond the frontiers of national research programs.