UNIVERSITY OF BERGEN REPORT: 100-04/10 Department of Earth Science Marine Geological Cruise Report from Byfjorden, Herdlefjorden and Salhusfjorden R/V "HANS BRATTSTRØM" UoB Cruise No. HB-10-165 20. - 24. September 2010 Department of Earth Science University of Bergen, Norway September 2010 Marine Geological Cruise Report from Byfjorden, Herdlefjorden and Salhusfjorden R/V “Hans Brattstrøm” UoB Cruise No. HB-10-165 20. - 24. September 2010 B.O. Hjelstuen1 H.F. Kleiven1,2 S. Monsen1 & 1 Student Team 1 University of Bergen, Department of Earth Science, Allegt. 41, N-5007 Bergen, Norway 2 Bjerknes Centre for Climate Research, Allegt. 55, 5007 Bergen, Norway i Report 100-04/10 Department of Earth Science University of Bergen (UoB) Bibliographic reference: Hjelstuen, B.O., Kleiven, H.F., Monsen, S. & Student Team, 2010. Marine Geological Cruise Report from Byfjorden, Herdlefjorden and Salhusfjorden. Report No. 100-04/10, Department of Earth Science, University of Bergen, Bergen, Norway, 15 pp. Copyright 2010 by: University of Bergen Department of Earth Science Allegt. 41, N-5007 Bergen, Norway First Published 2010 ISSN ii Report 100-04/10 Department of Earth Science University of Bergen (UoB) CONTENT 1. INTRODUCTION 1 1.1. Objectives 1 1.2. Scientific party 1 2. RESEARCH VESSEL and EQUIPMENT 2 2.1. Research vessel 2 2.2. Equipment 2 3. FIELD OPERATIONS 5 3.1. Weather and sea state conditions 5 3.2. Equipment Performance 5 3.3. General cruise performance 5 Figure 1: Overview map 6 Figure 2: Sub-bottom profile from Herdlefjorden 7 Figure 3: Sub-bottom profile from Salhusfjorden 7 Figure 4: Sub-bottom profile from Byfjorden 8 Figure 5: Sub-bottom profile from Byfjorden 8 Figure 6: CTD profile from Herdlefjorden 9 Figure 7: CTD profile from Salhusfjorden 10 Figure 8: CTD profile from Byfjorden 11 Figure 9: CTD profile from Byfjorden 12 Table I: General Survey Log 13 Table II: Station Log 14 Table III: Seismic Profiles 15 iii Report 100-04/10 Department of Earth Science University of Bergen (UoB) 1. INTRODUCTION 1.1. Objectives The marine geological/geophysical cruise to Byfjorden, Herdlefjorden and Salhusfjorden (Fig. 1) was part of the UoB course GEOV108 “Introduction to marine geology and geophysics”. The main objective of the cruise was to introduce students to marine geological/geophysical field work. This report will give a short description of the cruise performance. Figure 1 shows the survey area, whereas a general survey log is provided in Table I. 1.2. Scientific Party Berit O. Hjelstuen UoB Lecturer, cruise leader Helga (Kikki) F. Kleiven UoB/BCCR Lecturer Stig Monsen UoB Technician Student team – UoB Aadneram, J.M., Aasheim, D.S., Al-Samarray, A.A., Angell, H.L., Beck, K.M., Berge, K.O., Birkeland, T.I., Boxaspen, M.A., Brevik, G., Broch, T.M., Edvardsen, D.H., Eide, C.T., Enerstvedt, G.E., Flølo, I., Glaw, L., Greiner, N.S., Hansen, S.W., Hovda, L., Johnsen, O.P., Knutsen, E.R., Kolstø, S., Kristensen, T.B., Laukemann, M., Lien, Ø.F., Lindstrøm, S., Lunde, M., Lægreid, T., Mathiesen, T., Monkenbusch, J., Namdar, S., Natterøy, T., Nordang, K.L., Rasmussen, J.B., Rønnevik, C., Sirevaag, H., Smaadal, K., Songve, M., Stensland, A., Stokke, H.H., Storaker, S.,Svindland, J.A., Sætre, L., Sætre, M., Tengesdal, H.C., Våga, V., Waage, M., Wahla, S.R., Wiberg, D.H., Østergaard, C.D. 1UoB: University of Bergen, Dept. of Earth Science, Allegt. 41, 5007 Bergen, Norway 2 BCCR: Bjerknes Centre for Climate Research, Allegt. 55, 5007 Bergen, Norway 1 Report 100-04/10 Department of Earth Science University of Bergen (UoB) 2. RESEARCH VESSEL and EQUIPMENT 2.1. Research vessel R/V Hans Brattstrøm has a length of 24.3 m, beam of 6.5 m, a displacement of 97 tonnes, and a top speed of 13 knots. The research vessel is owned by the University of Bergen and is operated by the Institute of Marin Research, Bergen. The main duties are research operations within the areas of fishery, environment research, sea-bed sampling and educational surveys for students. The research vessel has a crew of 2, and operates in the coastal areas out to 20 nautical miles from the coast. 2.2. Equipment A sub-bottom profiler (SBP), SB-216S from EdgeTech, was used throughout the entire cruise to map the characteristics of the sub-seabed sediments (Figs. 2-5). The profiler operates in the frequency range of 2-16 kHz. The profiler has a theoretical penetration of up to 60 m, depending on sediment type. The profiler was towed behind the vessel, at a level of 1-2 m below the sea surface. Sub-bottom profiler used during the cruise. (Photo: Eva Bjørseth; February 2009) 2 Report 100-04/10 Department of Earth Science University of Bergen (UoB) Throughout the entire cruise a box core was used to collect samples from the upper part of the sediment column (Fig.1; Table II). Box core used during the cruise. (Photo: Eva Bjørseth; February 2009) CTD profiles were collected in Byfjorden, Salhusfjorden and Herdlefjorden (Figs. 1, 6-9; Table II). The CTD was connected to a winch, and lowered to the seabed before withdrawal. CTD used on cruise. 3 Report 100-04/10 Department of Earth Science University of Bergen (UoB) Gravity cores were collected at four locations (Fig. 1, Table II). A core barrel length of 2-2.5 m was used. Gravity corer used during the cruise. (Photo: Eva Bjørseth; February 2009) 4 Report 100-04/10 Department of Earth Science University of Bergen (UoB) 3. FIELD OPERATIONS The students were divided into four groups and each group had one day onboard the R/V Hans Brattstrøm. Totally, 49 students participated. A summary of the ship-board operations is provided in Table I. 3.1. Weather and sea state conditions The weather conditions during the cruise were generally good for surveying. The sea state was calm, with waves less than 1 m. 3.2. Equipment performance The chirp was run with success during the entire survey, and the data collected had an overall good quality. The sub-seafloor penetration depended very much on the sediment characteristics. The box corer functioned well throughout the cruise. Several samples was taken and stored in plastic boxes for further analyses at the Department of Earth Science, UoB. Bengal Rose was added to these samples. Samples were also sieved onboard, and the fractions were stored in plastic bags. The gravity coring system was used without any problems. The four gravity cores raised were labeled and transported to the Department of Earth Science, UoB, for further analyses and storage. The CTD functioned well throughout the cruise. 3.3. General cruise performance 4 box cores, 4 gravity cores and 4 CTD profiles were collected (Table II). A total of ca 25 km with seismic profiles were collected (Table III) 5 Report 100-04/10 Department of Earth Science University of Bergen (UoB) Figure 1. Overview map, showing locations of box cores, gravity cores and CTD stations (red dots). Black lines indicate approximate position of sub bottom profiles. 6 Report 100-04/10 Department of Earth Science University of Bergen (UoB) Figure 2. Sub-bottom profile, HF-tp-no2, from Herdlefjorden. Location in Fig. 1. Figure 3. Sub-bottom profile, SF-tp-no2, from Salhusfjorden. Location in Fig. 1. 7 Report 100-04/10 Department of Earth Science University of Bergen (UoB) Figure 4. Sub-bottom profile, BF-tp-no1, from Byfjorden. Location in Fig. 1. Figure 5. Sub-bottom profile, BF-tp-no2, from Byfjorden. Location in Fig. 1. 8 Report 100-04/10 Department of Earth Science University of Bergen (UoB) Figure 6. CTD profile HB-10-165-01CTD collected in Herdlefjorden 21. September 2010. Position in Fig. 1. Red curve is salinity and green curve is temperature. 9 Report 100-04/10 Department of Earth Science University of Bergen (UoB) Figure 7. CTD profile HB-09-160-02CTD collected in Salhusfjorden 22. September 2010. Position in Fig. 1. Red curve is salinity and green curve is temperature. 10 Report 100-04/10 Department of Earth Science University of Bergen (UoB) Figure 8. CTD profile HB-09-160-03CTD collected in Byfjorden 23. September 2010. Position in Fig. 1. Red curve is salinity and green curve is temperature. 11 Report 100-04/10 Department of Earth Science University of Bergen (UoB) Figure 9. CTD profile HB-09-160-03CTD collected in Byfjorden 23. September 2010. Position in Fig. 1. Red curve is salinity and green curve is temperature. 12 Report 100-04/10 Department of Earth Science University of Bergen (UoB) General Survey log Table I GEOV108 student cruise HB-10-165, R/V Hans Brattstrøm Date Time Subject 20.09.2010 10:00 – 13:00 Mobilization at Nykirkekaien and testing of sub-bottom profiler. 09:00 Leaving Marineholmen Collection of seismic profiles, CTD, box core and gravity core from 21.09.2010 09:30-14:00 Herdlefjorden 15:00 End of day, arriving Marineholmen 09:00 Leaving Marineholmen Collection of seismic profiles, CTD, box core and gravity core from 22.09.2010 09:30:00-13:45 Herdlefjorden 14:30 End of day, arriving Marineholmen. 09:00 Leaving Marineholmen 23.09.2010 09:30-13:00 Collection of seismic profiles, CTD, box core and gravity core from Byfjorden 13:40 End of day, arriving Marineholmen. 09:00 Leaving Marineholmen 24.09.2010 10:00-14:00 Collection of seismic profiles, CTD, box core and gravity core from Byfjorden 14:30 End of day, Nykirkekaien. Demobilisation. End of cruise 13 Report 100-04/10 Department of Earth Science University of Bergen (UoB) Table II Station Log Date Station no Latitude (N) Longitude (E) Location, water depth HB-10-165 -01BC 21.09.2010 1 sample taken and stored in box.