The Multicorer

Big smiles on deck: All the tubes of the multicorer are filled with sediment. Now the work begins in the lab.

The twelve sediment cores that the multicorer punched out of the seabed, are distributed among the different working groups in the "Polarstern" laboratory.

Here, biogeochemist Anna Lichtschlag of the National Oceanography Centre, Southampton, is carefully opening one of the tubes. What will she find in the sediments?

Some research groups are specifically investigating the boundary layer between sediment and seawater.

Marta Torres, professor at Oregon State University's College of Earth, Ocean, and Atmospheric Sciences does not need seawater for her research, and uses a syringe to aspirate it, so that the sediments …

… can be removed layer by layer.

The precious mud from the depth …

… is being gently packed in sample bags.

Centimeter by centimeter, the geochemistry team works hard to develop a complete profile, to determine the changes in concentrations of dissolved chemical substances. Geochemists use such concentration profiles to quantify the exchange processes between seawater and the seabed.

All sediments are safely packed to lie in the refrigerated container for the remainder of the cruise. The sediments will be analyzed later at the institutes onshore.

The next working station. Again, the winch wire hangs in the water and takes the multicorer to the bottom of the sea.

Biogeochemist Anna Lichtschlag is happy about a new, undisturbed sediment core.

This sediment is composed of millions of tiny marine animals.

Many of them form shells or skeletons made of carbonate or silicate, sinking to the bottom of the sea at the end of their short life and depositing there in the seabed.