Published: 13.10.09
Expedition report IODP

Bering Sea: coming back to reality

ETH researcher Gretta Bartoli spent two months working on board the research ship in the northern Pacific. Now back in Zurich, she takes a look back at an eventful period far removed from her daily routine.

Gretta Bartoli
Transit of IODP expedition 2009 in the northern Pacific.
Transit of IODP expedition 2009 in the northern Pacific. (large view)

After two months of intense work and two weeks of well-deserved holidays in Japan, I am back at ETH, ready to start working on the samples collected during the cruise. As a matter of fact, a big cardboard box was waiting for me on my desk when I arrived.

The first days spent in my home in Zürich were strange. Especially when I went for groceries shopping, I had to decide what to buy and later at home try to remember how to cook. When I arrived late in the evening to my house, my bed was not made and, worse, my laundry was not washed nor perfectly folded and ironed. Then I remembered that only three months ago, I used to do all of this for myself and that it was time to start again.

After only few days spent in Zürich, I was already off for Bremen, where the INVEST meeting took place. This meeting was organized to discuss the future science plan of IODP (Integrated Ocean Drilling Program), an organization that is supervising the drilling operations on the research vessels “Joides Resolution”, the “Chikyu” and some European drilling platforms. The current science plan was developed for until the end of 2012 and a new science plan should be written for after 2013. We discussed the major society-relevant scientific topics that have to be addressed by IODP in the future phase, such as the rate of sea-level changes, the risk of sub-marine landslides and earthquakes, the search in the marine records for past tsunamis events, the sub-sea floor resources, the geological storage of atmospheric CO2, the ocean acidification, the relation between humankind and climate, etc.

Former Swiss members of IODP expeditions were there as well, in particular, Michi Strasser who wrote several articles for ETH Life and Natalia Efimenko who wrote a report for the Swiss IODP website.

It was also the occasion for the members of the expedition to the Bering Sea to present our initial results. In brief, we collected more than 5 km of sediment at seven sites and we have some continuous sedimentary records of the Pleistocene and Pliocene Epochs down to 4 million years ago with sedimentation rates of about 12 cm per 1000 years. These high sedimentation rates will enable climatic reconstructions with a resolution of about 200 years. We noted a first apparition of sea ice in the south of the Bering Sea at about 3 million years ago that coincides with the first glaciation of the northern hemisphere. The Bering Sea is a very highly productive region and the sediments contain a lot of organic carbon. The microbiological activity is very high in the sediments and bacteria are found alive and active even at 700 m below the seafloor.

My study together with Prof. Gerald Haug and his group will focus on reconstructing the sea surface water conditions (temperature, salinity, nutrient concentration) during the onset of northern hemisphere glaciation and compare these data with data from the North Pacific, the Arctic Ocean and the North Atlantic.

Hopefully I will be able to present you my results in a year.