The entire AMARYLLIS-AMAGAS cruise resulted from merging two complementary, international and multidisciplinary scientific research projects, namely AMARYLLIS ("From Amazon deep-sea sediments to natural climate variability and slope instability processes") and AMAGAS ("Degassing of the Amazon deep-sea fan: depth distribution and activity of seafloor fluid vents"). It aims to better establish the major but uncertain role played by the Amazon region in the Earth's global climate system.

The AMARYLLIS-AMAGAS cruise has been organized in two legs addressing specific scientific topics. AMARYLLIS-AMAGAS I (leg 1) deals with the presence of gas within the sediments of the Amazon deep-sea fan and its role in the triggering of large-scale submarine landslides. AMARYLLIS-AMAGAS II (leg 2) investigates past changes in western tropical Atlantic circulation and terrestrial tropical South American climate over various time scales.

AMARYLLIS-AMAGAS II retrieved long and high-quality sedimentary sequences from the two geographical areas located along the French Guiana, northern and northeastern Brazilian margins - the Amazon area and the NE Brazil area - in order to:

1. document, with unprecedented resolution, the regional variability and drivers of precipitation and vegetation in tropical South America on complementary time scales (anthropogenic, millennial-scale, orbital) of the last few million years;
2.  investigate the modern and past long-range North African dust transport by documenting the modern and Quaternary variability of Saharan dust supplied to the Amazon region and its impact on past Amazon climate and ecosystem.

AMARYLLIS-AMAGAS II relies on the strong scientific collaboration that exists in paleoclimatology between several French research institutes and several Brazilian universities.