The forerunners of Greenland

The first focus of the expedition, however, was a submarine mountain range – the Knipovich Ridge. Here, the continents of Eurasia and North America drift apart so slowly that magma hardly manages to fill the gap between the diverging plates. As a result, giant volcanoes form at some places whereas the Earth’s mantle is brought to the surface at other places. To better understand how new ocean floor is created at these so-called ultraslow spreading ridges, we record the small earthquakes that accompany this process.

In rough seas four ocean bottom seismometers were deployed at the ridge axis. The depths of the earthquake foci will allow us to estimate the thickness of the young ocean lithosphere and to determine its temperature. The earthquake distribution will tell us where active deformation takes place and will delineate areas that deform without any earthquakes. Together with 23 ocean bottom seismometers deployed last year the 4 devices will be recovered in October this aboard R/V Merian, hopefully returning exciting data from the bottom of the ocean.

Having accomplished the seismological work we steamed toward Fram  Strait – marking the transition between the Nordic Seas and the Arctic Ocean.  Going along the prime meridian we reached the marginal ice zone before arriving at 80°50’N – the northernmost location of this expedition. Along the transect, observation of the hydrography and the circulation were acquired and water samples were taken.

In eastern Fram Strait the West Spitsbergen Current  - representing the extension of the Gulf Stream – North Atlantic Current System - carries warm, saline waters to the north. While a part of this water subsequently continues its voyage to the Arctic Ocean, a sizable fraction of it leaves the boundary current and moves to the west within Fram Strait - only to flow back southward along its western side. This recirculation so far has received very little scientific attention, yet it supposedly plays a central role for the research questions of our expedition. Ultimately, the strength of the recirculation determines the amount of oceanic heat that can be transported onto the shelf of Northeast Greenland, where it contributes to the melting of the marine outlet glaciers.

Meanwhile we have crossed the East Greenland Current and find ourselves on the shelf of Northeast Greenland Current. Here the first sightings of icebergs remind us of the proximity of the Greenlandic coast. The Sea Ice Biology Team samples polar cod larvae with a bongo net on the Northeast Greenland shelf. Two net trawls have already been accomplished. The team aims at investigating the genetic connectivity of Greenland populations with other Arctic populations. Good knowledge on polar cod’s spatial and temporal dynamics, population diversity and adaptive divergence is critical for making predictions about its future distribution in a changing Arctic Ocean and for protecting this key species in the Arctic.

Many greeting from board

Torsten Kanzow, Michaela Meier, Julia Ehrlich and Sarah Maes