UoB Cruise No. HB-11-170 19. - 23. September 2011

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Marine Geological/Geophysical Cruise Report

from

Byfjorden, Herdlefjorden and Salhusfjorden

R/V "HANS BRATTSTRØM"

UoB Cruise No. HB-11-170 19. - 23. September 2011

Department of Earth Science University of Bergen, Norway

September 2011

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Marine Geological/Geophysical Cruise Report

from

Byfjorden, Herdlefjorden and Salhusfjorden

R/V “Hans Brattstrøm”

UoB Cruise No. HB-11-170

19. - 23. September 2011

B.O. Hjelstuen H.F. Kleiven

S. Monsen

&

Student Team

University of Bergen, Department of Earth Science, Allegt. 41, N-5007 Bergen, Norway

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Hjelstuen, B.O., Kleiven, H.F., Monsen, S. & Student Team, 2011. Marine Geological/Geophysical Cruise Report from Byfjorden, Herdlefjorden and Salhusfjorden. Report No. 100-03/11, Department of Earth Science, University of Bergen, Bergen, Norway, 17 pp.

University of Bergen

Department of Earth Science

Allegt. 41,

N-5007 Bergen, Norway

First Published 2011

ISSN

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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 Byfjorden 7

Figure 3: Sub-bottom profile from Herdlefjorden 7

Figure 4: Sub-bottom profile from Salhusfjorden 8

Figure 7: CTD profile from Byfjorden 10

Figure 8: CTD profile from Herdlefjorden 11

Figure 9: CTD profile from Salhusfjorden 12

Table I: General Survey Log 15

Table II: Station Log 16

Table III: Seismic Profiles 17

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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. 67 students participated during the cruise week.

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 Lecturer

Stig Monsen UoB Technician

Student team – UoB

Christine Andersen, Eileen Bø Arnesen, Karoline Aylin Atakan, Svein-Harald Bakke, June Sviland Berge, Anders Bjerga , Mona Karin Boge, Marianne Vandeskog Borge, Margrethe Sæterdal Bøyum, Elisa Christensen, Amalie Skarsbø Dale, Irene Egeland, Anna Ellingsæther, Marie Djupevåg Eri, Ingunn Farsund, Anders Friestad, Anders Fylkesnes, Inger Førland, Maiken Ørke Haugvaldstad, Lars Haug Holen, Øystein S Hordvik, Andreas Børve Hovland, Kristian Agasøster Haaga, Anders Haaland, Margreth Bjørkum Jensen, Martin Hefre Johnsen, Silje Smith Johnsen, Marita Jørstad, Katrine Ljones Karlsen, Jostein Koldingsnes, Vegard Kragseth, Silje Rolstad Larssen, Lina Hedvig Line, Petter Andreas Lundekvam, Eva Maria Lunnan, Magnus Holten Løland, Kurt Inge Miljeteig, Olav Aleksander Naurstad, Harald Nedrebø, Kristoffer Nilsen, Tonje Elvik Nilsen, Randi Nådland, Linn Terese Orre, Line Merete Owe, Jonas Fiskum Pedersen, Simen Raudstein, Sølvi Moberg Salbu, Lena Sande, Erlend Schiøtz Smørdal, Natalie Vikse Soltvedt, Øystein Spinnangr, Alexander Steinsbu, Siri Anne Haugland Strand, Joachim Myre Strømme, Eirik Styve, Arve Rene Alfarnes Svean, Tove Syltøy, Steinar Polden Sæverud, Cecilie Tellefsen, Ragnhild Johanne Tunheim, Renate Eimind Tveit, Sune Aase Tønnessen, Kristi Vangdal, Alice Hestad Vie, Silje Henriksen Vindenes, Anders Norstrand Østigård, Tea Karoline Aamodt

UoB: University of Bergen, Dept. of Earth Science, Allegt. 41, 5007 Bergen, Norway

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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. 2-6). The profiler operates in the frequency range of 2-16 kHz. The profiler has a theoretical penetration of up to 60 m. 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)

Throughout the entire cruise a box core was used to collect samples from the upper part of the sediment column (Fig.1; Table II).

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Box core used during the cruise. (Photo: Eva Bjørseth; February 2009)

CTD profiles were collected in Byfjorden, Salhusfjorden and Herdlefjorden (Figs. 1, 7-11;

Table II). The CTD was connected to a winch, and lowered to the seabed before withdrawal.

CTD used on cruise.

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Gravity cores were collected at five 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)

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The students were divided into five groups and each group had one day onboard the R/V Hans Brattstrøm. Totally, 67 students participated. In addition participated Angela Roberts, from St. Andrews in UK, collecting surface samples for her PhD-study. 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 five 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

 5 box cores, 5 gravity cores and 5 CTD profiles were collected (Table II).

 A total of ca 20 km with seismic profiles were collected (Table III)

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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.

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Figure 2. Sub-bottom profile, across Station 01 in Byfjorden. Station location in Fig. 1.

Figure 3. Sub-bottom profile (H-TP2) from Herdlefjorden. Location in Fig. 1.

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Figure 4. Sub-bottom profile (S-TP1) from Salhusfjorden. Location in Fig. 1.

Figure 5. Sub-bottom profile, (B-TP2), from Byfjorden. Location in Fig. 1.

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Figure 6. Sub-bottom profile, B-TP4, from Byfjorden. Location in Fig. 1.

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Figure 7. CTD profile HB-11-170-01CTD collected in Byfjorden 19. September 2011. Position in Fig. 1. Red curve is salinity and green curve is temperature.

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Figure 8. CTD profile HB-11-170-02CTD collected in Herdlefjorden 20. September 2011. Position in Fig. 1.

Red curve is salinity and green curve is temperature.

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Figure 9. CTD profile HB-11-170-03CTD collected in Salhusfjorden 21. September 2011. Position in Fig. 1.

Red curve is salinity and green curve is temperature.

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Table I

General Survey log

GEOV108 student cruise HB-11-170, R/V Hans Brattstrøm

Date Time Subject

19.09.2011 13:30 – 14:00 Mobilization at Nykirkekaien. Late start as the trawl winch had to be fixed.

14:00-16:30 Collection of seismic profiles, CTD, box core and gravity core from Byfjorden 16:30 End of day, arriving Nykirkekaien

09:00 Leaving Marineholmen

09:30-14:15 Collection of seismic profiles, CTD, box core and gravity core from Herdlefjorden

20.09.2011

14:45 End of day, arriving Marineholmen

09:30:00-13:45 Collection of seismic profiles, CTD, box core and gravity core from Salhusfjorden

21.09.2011

14:15 End of day, arriving Marineholmen.

10:15-13:30 Collection of seismic profiles, CTD, box core and gravity core from Byfjorden 22.09.2011

13:50 End of day, arriving Marineholmen.

09:10

Leaving Marineholmen

09:45-13:00 Collection of seismic profiles, CTD, box core and gravity core from Byfjorden 23.09.2011

13:15 End of day, arriving Nykirkekaien. Demobilisation. End of cruise

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Table II Station Log

Date Station no Latitude (N) Longitude (E) Location, water depth 19.09.2011

HB-11-170 -01BC

1 sample taken and stored in box.

Added ca. 100 ml Bengal Rosa

60^o 24.636’ 5^o 16.667’ Byfjorden, 346 m

19.09. 2011

HB-11-170- 01CTD (File name:

Byfjorden_19september2011)

60^o 24.636’ 5^o 16.667’ Byfjorden, 346 m

19.09. 2011

HB-11-170 -01GC

c. 2.0 m long core sampled. Cut into two segments. Samples sieved onboard. Stored > 0.150 mm fraction in plastic bags.

60^o 24.636’ 5^o 16.667’ Byfjorden, 346 m

20.09.2011

HB-11-170 -02BC

Added ca. 100 ml Bengal Rosa Several samples sieved onboard.

Stored fractions in plastic bags.

60^o 30.369’ 5^o 11.905’ Herdlefjorden, 403 m

20.09.2011

HB-11-170-02CTD (File name:

Herdlefjorden_20september2011)

20.09.2011

HB-11-170 -02GC

Ca 2.5 m long core sampled. Cut into two segments.

21.09.2011

HB-11-170 -03BC

Added ca. 100 ml Bengal Rosa Several samples sieved onboard.

Stored fraction in plastic bags.

60^o 31.172’ 5^o 15.510’ Salhusfjorden, 537 m

21.09.2011

Herdlefjorden_21september2011)

21.09.2011

HB-11-170 -03GC

Ca 2.5 m long core sampled. Cut into two segments, each 1.25 m long.

22.09.2011

HB-11-170 -04BC

60^o 29.348’ 5^o 14.040’ Byfjorden, 308 m

22.09.2011

60^o 29.348’ 5^o 14.040’ Byfjorden, 308 m

22.09.2011

HB-11-170 -04GC

2 m long core sampled. Cut into two segments, each 1 m long.

60^o 29.348’ 5^o 14.040’ Byfjorden, 308 m

23.09.2011

HB-11-170 -05BC

60^o 24.649’ 5^o 16.580’ Byfjorden, 346 m

23.09.2011

HB-11-170-05CTD (File name::

60^o 24.649’ 5^o 16.580’ Byfjorden, 346 m

23.09.2011

HB-11-170 -05GC

Ca 2.3 m long core sampled. Cut into two segments, each ca. 1.15 m long.

60^o 24.649’ 5^o 16.580’ Byfjorden, 346 m

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File name Date Location B-P1 (line survey non-

stop) 19.09.11 Byfjorden

H-LP1 20.09.11 Herdlefjorden H-TP1 20.09.11 Herdlefjorden H-TP2 20.09.11 Herdlefjorden S-LP1 21.09.11 Salhusfjorden S-TP1 21.09.11 Salhusfjorden

B-LP2 22.09.11 Byfjorden

B-TP1 22.09.11 Byfjorden

B-LP3 23.09.11 Byfjorden