(Text sent by IGV researcher Christian Stranne, from the R/V Marion Dufresne)

On the 16 of May, I embarked the French research vessel Marion Dufresne in Bridgetown, Barbados, for a one-month research expeditions to the region outside the Amazon river delta. The Amaryllis-Amagas expedition consist of two legs, one month each, with the overarching goal to investigate the role of the Amazon region in the Earth's climate system, and to reconstruct the climate history of the Amazon basin and northeastern Brazil.

The Amazon River brings more sediment to the ocean than any other river, and during this first leg of the expedition we are investigating the relationship between gas hydrates and large submarine landslides in the upper Amazon deep-sea fan (both related to the large sediment load). One of the main goals is to assess the extent of seafloor methane gas emissions on the deep-sea fan.

I am currently active within two separate fields of research: gas hydrates dynamics (how “frozen methane” in the sediments interact with our climate) and midwater acoustics (observing things, like for instance gas bubbles, in the ocean by means of echosounders). As the focus of this first leg of the expedition to a large extent revolves around these two topics, I happily said yes when I was offered to participate on the campaign.

One special thing with Marion Dufresne is that the ship was built specifically for doing long piston coring. With the so-called Calypso corer on board this vessel, more than 60 meter (!) long sediment cores can be recovered from the seafloor. This provides many possibilities of which one is the ability to recover gas hydrates. Under these tropical conditions, however, with air and ocean temperatures at around 30 °C, significant over-pressure can build up within the core barrel as the gas hydrate melts – this has sometimes led to minor explosions when the core head is removed and pressure is released.

Christian Stranne holding a piece of gas hydrate on bord the R/V Marion Dufresne. Photo: Private

Although I have been studying gas hydrates for almost ten years, it wasn’t until yesterday that I had the opportunity to actually see gas hydrates with my own eyes and to touch it with my own hands – of course we had to put a piece of gas hydrate on fire (it feels and tastes like ice but burns with a yellow flame)! If you want to learn more about gas hydrates you can read our popular science article on the subject that was published earlier this year (Flammable ice of profit and doom, https://www.nature.com/articles/s41557-022-01132-7).

Read more about Christian Stranne's research

More information about The Amaryllis-Amagas Expedition (in French)