Plattform Platform	Reise-Nr. Cruise-No.	Zeitraum Period	Projekt Project	Arbeitsgebiet Working area
Polarstern	PS87 ARK-XXVIII/4	05.08.2014 - 08.10.2014	ODP	Arctic Ocean

Fahrtleiter Chief Scientist	Institut Institute	Auslaufhafen Port of departure	Einlaufhafen Port of return	Stationskarte Station map	Schiffsroute Trackchart
Stein Rudiger	Alfred-Wegener-Institut fur Polar- und Meeresforschung	Troms?	Bremerhaven

Ziel der Reise / Objectives of Cruise:

The Expedition PS87 (ARK-XXVIII/4) was mainly related to geoscientific investigations in the central Arctic Ocean, focusing the Lomonosov Ridge. The overall goals of the marine-geological research program were (1) detailed studies of changes in paleoclimate, paleoceanic circulation, paleoproductivity, and sea-ice distribution in the central Arctic Ocean and the adjacent continental margin during Late Quaternary (especially postglacial-Holocene) times, and (2) the long-term history of the Mesozoic and Cenozoic Arctic Ocean and its environmental evolution from a warm (Greenhouse) to an ice-covered polar (Icehouse) ocean. The core locations (as well as potential locations for later IODP-type drilling on Lomonosov Ridge) were determined by seismic and Parasound profiling. For this it was of great importance to run long seismic profiles across the basin and ridge structures. Furthermore, the seismic data will provide new insights into the tectonic and sedimentary evolution of the Arctic Ocean and the adjacent continental shelves. The geoscientific program were supplemented by additional activities related to sea ice physics (i.e., measurements of sea ice thickness, distribution and drift), oceanography (i.e., measurements of temperature and salinity by XCTDs), and polar ecology (i.e., counting of sea birds and marine mammals). Measured data: 1. Multichannel seismic reflection profiling 2. Ship's magnetic and gravity measurements 3. Hydrosweep and Parasound Profiling 4. Geological sampling of sediments (box corer, multicolor, gravity corer, kastenlot corer) 5. Measurement of ice thickness and ice drift using EM-Bird helicopter flights and drift buoys, respectively 6. XCTD measurements (Temperature and conductivity in upper 1100 m of water column) 7. Counting of seabirds and marine mammals on the bridge 8. Measurements of isotopes in water vapor on the peildeck

Messungen / Measurements