Taiwan is a tropical island exposed to extreme events, with both climatic (typhoons, heavy rains) and tectonic origin (earthquakes, tsunami). These phenomena of great magnitude induce a strong erosion of the island, catastrophic floods, numerous landslides. In the marine domain, these phenomena frequently generate turbidity currents, which are recorded in deep marine sediments by turbidite deposits. The study and dating of deep marine sediments on selected sites around Taiwan should provide the chronology of turbidite deposits and thus to estimate the recurrence times of these large-scale events. It is therefore possible to reconstruct the calendar of major earthquakes that have occurred in recent tens of thousands of years (paleoseismological approach) and thus to study the frequency and regularity of these events.

The objective of the EAGER cruise is to obtain about 30 Calypso cores, coupled with interface cores (Multitube or Boxcore) in the area located east of Taiwan along the Ryukyus subduction zone and the eastern margin, and southwest Taiwan on the Manila accretion prism. At most sites, we target the sedimentary recording of large earthquakes in small basins isolated from terrestrial sediment inputs. For some sites, coring targets are in the continuity of large canyons fed by rivers, to also obtain a recording related to climatic events (typhoons). 

With accurate dating and stratigraphy, we hope to be able to distinguish some exceptional events occurring every millennia or more, but also to provide a chronology of the most important earthquakes and typhoons over 10000 years or more. Such an integrated study between extreme telluric and meteorological events is a challenge but applies remarkably to the situation in Taiwan. This study should allow progress not only on an assessment of natural hazards but also on the interactions between tectonic and climatic forcing.

This project was built and is being conducted jointly with Taiwanese researchers. Co-founding of the cruise is provided by the Taiwan Ministry of Energy to obtain some cores on the southwest margin of Taiwan as part of a research project on gas hydrates.