RV Polarstern expedition ARK XXIV/2

10 July - 3 August 2009, Longyearbyen - Reykjavic

arkxxiv_logoThis cruise aims to detect and track the impact of large-scale environmental changes in the transition zone between the northern North Atlantic and the central Arctic Ocean, and to determine experimentally the factors controlling deep-sea biodiversity. This is part of a larger, long-term experiment set up by the Alfred Wegener Institute for Polar and Marine Research (AWI), who established a deep-sea long-term observatory in the Arctic called HAUSGARTEN. This represents the first, and until now the only open-ocean long-term station in a polar region. It is located west of Svalbard at 79ºN and consists of 16 sampling stations covering a water depth range of 1000 to 5500 meters.
The planned research programme during the first half of the RV Polarstern expedition ARK XXIV/2 contributes to the time-series studies at this deep-sea long-term observatory, where AWI has been investigating the impacts of climate change on an Arctic marine deep-sea ecosystem through field studies, observations and models since 1999. This research programme also contributes to the EU funded projects ESONET (European Seas Observatory NETwork), EMSO (European Multidisciplinary Seafloor Observatories), HERMIONE (Hotspot Ecosystem Research and Man’s Impact on European Seas) and HYPOX. Additionally, it is part of the StatoilHydro co-funded project KONGHAU (“Impact of climate change on Arctic marine community structures and food webs”).

The main aim of the second part of expedition ARK XXIV/2 is the implementation of a long-term observatory on the Norwegian margin to study mud volcanism. Liquefied mud, gas, and fluids rising from at least 3 km below the seafloor have formed a highly active mud volcano with a diameter of 1.5 kilometer, characterized by permanent gas emission. Fluid flow velocities decrease radially towards the outer rim of HMMV, which is stabilized by gas hydrates. Earlier investigations at HMMV showed that fluid flow rates control the distribution of chemosynthetic communities, the stability of the hydrate system and gas emission. By installing a long term observatory, we can carry out detailed investigations of the changes over time at HMMV, in order to follow the sequence of events before, during, and after an eruption, and to analyze the effects on gas hydrate stability, seafloor morphology and the distribution and colonization patterns of benthic communities.

For both areas of investigation the availability of a Remotely Operated Vehicle (ROV) is essential. Therefore, for the second time since 2007, the ROV 'QUEST' (owned by the Centre for Environmental Sciences (MARUM) at the University of Bremen) will be on board RV Polarstern to carry out detailed investigations and sampling.

The team on board Polarstern is lead by Chief Scientist Dr Michael Klages from the Alfred Wegener Institute in Germany. The team will be sending weekly blogs about activities on board the ship and their scientific progress - use the links below to read the latest installments from the Arctic:
> Blog 1: 10-17 July 2009
> Blog 2: 18-25 July 2009
> Blog 3: 26 July - 2 August 2009