CRUISE REPORT MARINE-GEOLOGICAL CRUISE TO WEST SPITSBERGEN FJORDS R/V ”Jan Mayen” in front of Chomjakovbreen, Hornsund, Spitsbergen, August 7th 2007; Foto: M. Forwick on R/V Jan Mayen, July 2nd – July 8th 2007 by Matthias Forwick DEPARTMENT OF GEOLOGY, UNIVERSITY OF TROMSØ, N-9037 TROMSØ, NORWAY MARINE-GEOLOGICAL CRUISE TO WEST SPITSBERGEN FJORDS Content Page 1. Summary 3 2. Background 4 3. Objectives 4 4. Participants 5 5. Equipment 6 6. Methods 6 7. Journal 8 8. Preliminary results 17 9. References 21 10. Tables of collected data 22 Remarks: Jan P. Holm and Trine Dahl from the Department of Geology, University of Tromsø, contributed with data processing and the creation of figures to this cruise report. They are hereby acknowledged! 2 Cruise report – West Spitsbergen fjords, July 2007 1. Summary From the evening of August 2nd to the afternoon of August 8th 2007, the Department of Geology of the University of Tromsø (UiTø), Norway, arranged a scientific cruise to West Spitsbergen fjords on R/V “Jan Mayen”. The port of departure and arrival was Longyearbyen. Investigated areas were Isfjorden, Sassenfjorden, Tempelfjorden, Nordfjorden, Dicksonfjorden, van Keulenfjorden, Hornsundbanken, as well as Brepollen and Samarinvågen in Hornsund (Fig. 1). In Sassenfjorden and Tempelfjorden, 8 conductivity-temperature-depth and turbidity measurements (CTDT) were performed. Furthermore, nine box cores (BC), one piston core (PC) and one gravity core (GC) were retrieved. Whereas one GC was retrieved in Nordfjorden, two PC and one GC were retrieved in Dicksonfjorden. In van Keulenfjorden, 4 CTDT casts were performed and three BC, two PC and two GC were retrieved, respectively. One PC and one GC were sampled on Hornsundbanken. In Brepollen, one CTDT cast was performed and 2 GC were retrieved. Swath-bathymetry surveys were carried out in Sassenfjorden/Tempelfjorden, van Keulenfjorden, as well as in Brepollen and Samarinvågen. A total of 100 high-resolution seismic profiles have been acquired in Tempelfjorden, van Keulenfjorden, Horsundbanken, Hornsund, Brepollen and Samarinvågen, respectively. Figure 1: Map of Svalbard (A) and map showing locations mentioned in the report (B). 3 Cruise report – West Spitsbergen fjords, July 2007 2. Background The cruise was arranged as part of the strategic university programme “Sedimentary Processes and Paleoenvironment on Northern Continental Margins” (SPONCOM). The overall goal of the project was to assess the changes in the physical environment of the sea-floor and the overlying water and ice of West Spitsbergen and North Norwegian fjords, as well as on adjacent continental margins during the last glacial – interglacial cycle. 3. Objectives The objectives of the cruise were: - To collect swath-bathymetry data in Sassenfjorden, Tempelfjorden, van Keulenfjorden and the inner parts of Hornsund with the purpose of identifying morphological features on the seafloor that might provide information about subglacial conditions in the past. - The retrieval of eight box cores for surface sampling (0-1 cm), as well as CTD measurements in Sassenfjorden and Tempelfjorden in order to continue monitoring of the influence of environmental changes on foraminifera-fauna assemblages in these fjords (see Korsun & Hald, 2000). - To continue measurements of the physical properties of and sediment concentrations in the waters in Sassenfjorden and Tempelfjorden, with the purpose of obtaining repeated information about the influence of the river Sassenelva, as well as the glaciers Tunabreen and Von Postbreen on the water masses in these fjords. - To retrieve surface samples from Sassenfjorden and Tempelfjorden for biogeochemical, geochemical and mineralogical analyses, in order to investigate the influence of the river Sassenelva, as well as the glaciers Tunabreen and Von Postbreen on the sedimentation pattern in these fjords. - To retrieve sediment cores off a sediment lobe in Tempelfjorden, described by Plassen et al. (2004), in order to investigate the influence of the rivers Sassenelva and the glaciers Tunabreen and von Postbreen on the sedimentation at the core site in the past. - To retrieve sediment cores from Nordfjorden, Dicksonfjorden, van Keulenfjorden, Hornsundbanken and Brepollen in order to investigate sedimentary processes and to infer palaeoenvironmental conditions. - To retrieve surface samples from van Keulenfjorden for biogeochemical, geochemical, sedimentological and forminifera-fauna analyses. 4 Cruise report – West Spitsbergen fjords, July 2007 4. Participants Crew R/V “Jan Mayen”: Captain: Hans R. Hansen Vice captain: Per-Kristian Langaune Chief engineer: Atle Honningsvåg Second engineer: Sindre Myking Boatswain: Jan R. Dalsbø Boatswain: Jan A. Johansen Able seaman: Eivind Halsnes Able seaman: Rolf P. Halsnes Able seaman: Ronny Johansen Stewart: Børge Pedersen Galley assistant: Bente Mortensen Scientific crews: Participant Affiliation Dahl, Trine (engineer) UiT Forwick, Matthias (Post. Doc., chief scientist) UiT Hedquist, André (teacher) TJC Holm, Jan P. (engineer) UiT Kim, Dongjin (student) CNU Kim, Yumi (student) CNU Lydersen, Kyrre (engineer) UiT Marienborg, Tove (director) SCNN Oh, Jongmin (student) CNU Park, Byungno (student) CNU Robertsen, Roy (engineer) UiT Roh, Yul (professor) CNU Sandaker, Knut (engineer) UiT Stenvoll, Trude (teacher) KSJC Szczuciński, Witold (research scientist) UoP Ørmen, Bianca (teacher) KBJC UiT = University of Tromsø, Norway TJC = Tromsdalen junior college, Tromsø, Norway CNU = Chonnam National University, South-Korea SCNN = Science Centre of Northern Norway (Nordnorsk Vitensenter Tromsø) KSJC = Kvaløysletta junior college, Tromsø, Norway UoP = University of Poznań, Poland KBJC = Kongsbakken junior college, Tromsø, Norway 5 Cruise report – West Spitsbergen fjords, July 2007 5. Equipment Acoustic equipment - Kongsberg Maritime EM 300 multibeam echo sounder - EdgeTech 3300-HM hull-mounted sub-bottom profiler ("Chrip"); 4*4 arreys - Echo Sounder, Simrad EK 500, 38 kHz Coring equipment - Piston corer (total weight c. 2200 kg; 2*6 m steel barrels; inner diameter of steel barrel: 11 cm) - Gravity corer (total weight 1900 kg; 6 m steel barrel; inner diameter of steel barrel: 11 cm) - Giant box corer (50*50*50 cm3) Water properties: - CTD (Seabird 911 Plus) with compact rosette - Seapoint Turbidity Meter 6. Methods Acoustic investigations Seafloor mapping: Swath-bathymetry surveys in Sassenfjorden, Tempelfjorden, van Keulenfjorden, as well as in Brepollen and Samarinvågen, have been carried out using a Kongsberg Maritime EM 300 multibeam echo sounder. A sound-velocity profile of the water column for calibrating the equipment was recorded from CTD casts within the mapped areas. The equipment worked well during the acquisition and most of the data is of good quality. However, the estimated sound velocities from the CTD cast and the actual sound velocity of the water masses in Sassenfjorden and Tempelfjorden appear not the same so that the data are of somewhat lower quality. This problem is still to be solved. Because of too large data amounts, one hard drive of the multibeam echo sounder PC stopped working properly. This problem was solved by starting a new survey. The collected data are stored on DVD. Some preliminary data cleaning was performed using the software programme Neptune version 4.1.2. Gridding and visualising of the results has been carried out in GMT (The Generic Mapping Tools; Wessel & Smith, 1998). Seismic profiling: High-resolution seismic profiles, using an EdgeTech 3300-HM hull-mounted sub-bottom profiler, were collected along several ship tracks during the swath-bathymetry data acquisition in van Keulenfjorden, as well as in Brepollen and Samarinvågen. Single lines were acquired in Tempelfjorden and on Hornsundbanken, respectively, in order to determine coring sites. The equipment worked well and the data are of good quality. The available data are stored on DVD. 6 Cruise report – West Spitsbergen fjords, July 2007 Sediment sampling The seafloors in Sassenfjorden, Tempelfjorden, Nordfjorden, Dicksonfjorden, van Keulenfjorden, Hornsundbanken and Brepollen have been sampled with a piston corer (PC), a gravity corer (GC) and a giant box corer (BC), respectively. Long cores were retrieved with a 12-m long piston corer and a 6-m long gravity corer. Plastic liners with an outer diameter of 11 cm (inner diameter: 10 cm) were put into the steel barrels. After retrieval, the plastic liners were cut into sections of up to 100 cm length. They were covered with plastic caps, taped, labelled and stored at +4ºC. The giant box corer has been used with the purpose of retrieving undisturbed samples of the seafloor in Sasssenfjorden, Tempelfjorden and van Keulenfjorden. After taking colour pictures, the uppermost c. one centimetre was sampled for biogeochemical and foraminifera-fauna analyses. The material was stored in prepared glass bottles and plastic tubes (biogeochemistry), as well as in plastic bottles (foraminifera). The foraminifera samples were preserved in alcohol (95%) with Rose Bengal stain immediately after sampling; they were subsequently stored at +4°C. The biogeochemistry samples were stored at room temperature. Water properties Water properties – temperature, salinity – were measured using a Seabird 911 Plus CTD. Additionally, the suspension contents in the water masses were measured with a Seapoint Turbidity Meter attached to the CTD. Data collection was performed during downcasts at a speed of 0.5 m/s. Water samples were taken in Sassenfjorden, Tempelfjorden and