CRUISE REPORT
MARINE GEOLOGICAL CRUISE TO ULLSFJORDEN, LYNGEN, OFOTEN AND
TYSFJORDEN, NORTH NORWAY
RV Jan Mayen 6. - 12.2 2006
by
Jan Sverre Laberg
DEPARTMENT OF GEOLOGY
UNIVERSITY OF TROMSØ
N-9037 TROMSØ, NORWAY
1. Introduction and scientific objectives
Here we report from a cruise that was organized from the 6th to the 12th of February to the
North Norwegian fjords Ullsfjorden, Lyngen, Ofoten and Tysfjorden (Figs. 1, 6, 7). The aim
was to do multi-beam swath bathymetry surveying and gravity coring. From Ullsfjorden we
acquired multi-beam data and in Lyngen gravity coring was done. Multi-beam mapping was
also done in parts of Ofoten and Tysfjorden. This work is a continuation of previous work that
started in 2004 and continued in 2005 (Laberg and Guidard 2004, 2006). The data will be
analysed as part of the Norwegian Research Council-funded SPONCOM project
(http://www.ig.uit.no/sponcom/index.htm). SPONCOM (Sedimentary Processes and Palaeoenvironment on Northern Continental Margins) is a strategic University project at the
University of Tromsø.
2. Cruise participants
In addition to the regular crew of the University of Tromsø research vessel Jan Mayen
(http://www.nfh.uit.no/hmenyvis.aspx?id=194) the cruise participants were:
Jan Sverre Laberg, Research Scientist, Department of Geology, University of Tromsø (cruise
leader)
Trine Dahl, Laboratory technician, Department of Geology, University of Tromsø
Kai Flöistad, Reseach assistant, Department of Geology, University of Tromsø
Steinar Iversen, Science Engineer, Department of Geology, University of Tromsø
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3. Cruise narrative
Monday 6th of February
Weather: partly cloudy, southerly breeze reaching Gail in the afternoon, then decreasing.
Departure from Tromsø at 11:00 local time sailing for Ullsfjorden. At 12:25 we had to return
to Tromsø due to multi-beam software problems. We got the new software and left Tromsø at
about 15:00 sailing for Ullsfjorden. Arriving Ullsfjorden we finished a CTD-station
(06JM0044) (Fig. 2) for sound velocity data and calibrated the Kongsberg Simrad EM300
multi-beam system.
The calibration was done and at about 19:00 we started surveying the fjord running lines
parallel to the fjord axis. The data was of good quality (Fig. 1).
Tuesday 7th of February
Weather: cloudy, southerly breeze.
We continued surveying Ullsfjorden throughout the night and morning. No software problems
any more, the multi-beam system was working fine. We got nice data from the inner and
eastern part of Ullsfjorden including the Skarpnes moraine crossing the inner part of the fjord
(Fig. 5). Then we surveyed the innermost part, Kjosen, and identified irregular, transverse
ridges (Fig. 5).
In the afternoon and evening we continued data acquisition, now in the western part of the
fjord. At about 19:00 we did a CTD-station (0045) in the outer, central part of the fjord (Fig.
3). Above 180 m the water masses were very homogenous; the underlying water is about 1o
warmer and more saline. During the evening we finished surveying the inner part of
Ullsfjorden and took a CTD cast (0046) (Fig. 4).
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Wednesday 8th of February
Weather: partly cloudy, breeze, nice weather.
The outer, western part of the fjord was surveyed during the night. This area has a relatively
shallow water depth (< 150m). From the morning we left Ullsfjorden for a gravity core
transect from Spåkenes, Lyngen (Younger Dryas ice front position) and out-fjord (Fig. 6). We
did 11 gravity core stations and they were completed successfully at about 19:00. The core
length varied from 115 to 535 cm (Tab. 1), a very good result.
After finishing the core transect we returned to Ullsfjorden and continued surveying in the
outermost part to complete the survey that started in 2005 (Laberg and Giudard, 2006).
Thursday 9th of February
Weather: snow, breeze.
The Ullsfjorden survey was completed at about 03:30 and we returned to Tromsø. Here we
picked up J. Mienert and the Marine Geophysics students for a one day student course
demonstrating the geophysical equipment of RV Jan Mayen and the basic principles of data
interpretation. The course was ended in Tromsø at about 16:00; we unloaded some equipment
and sailed for Ofoten at 18:00.
Friday 10th of February
Weather: cloudy, partly snow, breeze
We arrived the outer part of Ofoten at about 04:00 and started multi-beam surveying. The first
line was running into the fjord along the south side, filling the data gap left from our first
survey to this area in 2005 (Laberg and Guidard 2006). Then we continued doing the
innermost part of Ofoten (Herjangsfjorden) (Figs. 7, 8). At about 12:30 a CTD station was
done in this area (0049) (Fig. 9).
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In the evening we did three gravity core stations in the inner part of Ofoten, gravity core
06JM009 (370 cm length) and 06JM010 (400 cm length) (Fig. 12, Tab. 1). No cores were
acquired from the third station were we also did a CTD run (CTD 0050) (Figs. 8, 10).
Saturday 11th of February
Weather: cloudy, little or no wind and very nice working conditions
Continued multi-beam surveying, during the night we did the Balangen – Bogen transect, then
Rombaken during the morning and Skjomen during the afternoon. In Skjomen we nicely
mapped the terminal (Preboreal) moraine across the outer part of the fjord as well as the
basins further into the fjord. One CTD cast (0051) was done in Skjomen (Fig. 11). The next
area of survey was Tysfjorden (Hellemofjorden) which we started at about 23:00. Nice
weather and working conditions in Tysfjorden.
Sunday 12th of February
Weather: cloudy, rain, breeze.
We did one multi-beam line into Hellemobotn and returned, this survey was completed at
08:00 including CTD station 0052 in the outer, deepest part of the fjord (Figs. 13, 14). The
outer part of the fjord has steep sidewalls and a flat, undisturbed sea-floor. Further into the
fjord it narrows and we passed a threshold at Musken. In the innermost part an irregular sea
floor was identified.
After completing the survey we sailed for Tromsø. Time of arrival: 18:00.
4. Equipment (from Laberg & Guidard, 2004)
4.1. The EM 300 multibeam system
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A Kongsberg Simrad EM 300 multibeam echo sounder runs with a nominal sonar frequency
of 30 kHz, in order to obtain an optimal balance between small dimensions, narrow beams
and good range capability. This results in an angular coverage of up to 150 degrees and 135
beams (which are always within the active swath) per ping as narrow as 1 degree. The beam
spacing is normally equidistant, with equiangular available. The transmit fan is split in several
individual sectors, with independent active steering according to vessel roll, pitch and yaw to
place all soundings on a best-fit to a line perpendicular to the survey line, thus ensuring a
uniform sampling of the bottom and 100% coverage. Pulse length and range sampling are
variable with water depths, to obtain best resolution. The swath width, dependent on seabed
sediments, in shallow waters (< 500 m) is typically 5 times the water depth. Down to 2000 m,
a swath width is 4-5 km is common.
The system runs on a high performance PC (dual 2.8 GHz, 2 GB RAM), displaying the data
collected and logging them to hard disk. As a standard, the following parameters are logged:
depth, seabed imaging, vessel position, vessel attitude, and sound speed. The operator station
converts range and angle data to xyz triplets, applying all corrections required by varying
vessel attitude and sound speed. Sound speeds were loaded from external data source, being
CTD sound velocity through the water column, after appropriate filtering and editing. A
graphical user interface provides control on the data quality and parameters used. Note that,
because of the protection housing installed around the hardware to avoid damage of ice
contact, the amplitudes recorded are slightly attenuated (~6 dB). See Laberg and Guidard
(2004) for further details.
4.2 The gravity corer
Our gravity corer has a 6 m long steel pipe and an inner PVC liner of 110 mm diameter.
Onboard, the samples are cut in 1m sections, numbered, sealed and stored in a cooling room
(temperature 4-6 o C).
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5. Preliminary results
5.1 Ullsfjorden
Ullsfjorden is an asymmetric N-S oriented basin with an E-W oriented tributary in its inner
part (Kjosen) (Fig. 1). The fjord basin is deepest towards the East, the western outer part
forms a shallow platform of 100 – 150 m water depth. The deepest part has a flat sea floor, the
sides are steep and irregular but relatively few indications of mass wasting is seen. The
shallow platform shows longitudinal and transverse ridges inferred to be of subglacial origin
and thus formed during the last glacial maximum.
In the inner part a prominent ridge, the Skarpnes moraine is crossing the fjord basin (Plassen
and Vorren, 2003). In Kjosen a series of transverse ridges has been identified, they are
inferred to be formed during the Younger Dryas readvance (Fig. 5).
5.2 Lyngen
The coring in Lyngen (Fig. 6) had two main objectives: 1) to elucidate on the age, origin and
present level of activity of a channel system that can be followed from Spåkenes and
northward into the deepest part of the fjord (cores 06JM001-006), see also Jenssen (2006),
and 2) improve on the deglaciation chronology for the outermost part of Lyngen and to get a
minimum age estimate for the deglaciation of the outer part of the fjord (06JM007-008).
5.3 Ofotfjorden
The Ofoten survey was done in order to complete previous surveys to this area (Laberg and
Guidard 2004, 2006) and focused on the innermost part of Ofoten (Herjangsfjorden) as well
as tributary (Rombaken and Skjomen) (Figs 8, 12). In general, there seem to be relatively
little sediments overlying bedrock in the inner part of Ofoten as subcropping bedrock is
clearly seen. Rombakken is a relatively narrow and deep tributary, the fjord basin is deeper
compared to the main fjord basin indicating a larger degree of glacial erosion. Skjomen on the
other hand has a threshold at the fjord mouth and several sub-basins of a relatively flat sea
floor (see also Fløistad, 2005).
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5.4 Tysfjorden
Tysfjorden (Hellemofjorden) has a pronounced outer threshold, a deep basin inside and a
narrow and shallowing inner part (Fig. 13). The sea floor of the outer basin is flat indicating
no recent deposits from sidewall mass wasting. In the inner part a threshold is identified at
Musken and there are indications of sliding in the innermost part of the fjord.
6. References
Fløystad, K.R. 2005. Sedimentary environment and deglaciation history of Ofotfjorden and
tributaries, North Norway. Unpublished Master thesis, University of Tromsø, 168pp.
Jenssen, O.A. 2006. Deglasiasjon og sedimentasjonsmiljø i Lyngen og Storfjorden, Troms.
Unpublished Master thesis, University of Tromsø, 140pp.
Laberg, J.S., Guidard, S. 2004. Marine geological cruise to the Andøya Canyon and
Lyngenfjorden, Northern Norway. Cruise report, University of Tromsø, 19pp.
Laberg, J.S., Guidard, S. 2006. Cruise 1: Marine geological cruise to the Andøya Canyon,
Andfjorden and Ofotfjorden, North Norway, and Cruise 2: Marine geological cruise to
Fugløysundet, North Norway. Cruise report, University of Tromsø, 27pp.
Plassen, L., Vorren, T.O. 2003. Sedimentary processes and the environment during
deglaciation of a fjord basin in Ullsfjorden, North Norway. Norwegian Journal of Geology 83,
23-36.
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Core
Area
Latitude
Longitude Equip
Pene-
Core
Water
-ment
tration
length
depth
station
06JM001
Lyngen
69o46.392
20o23.763
GC
2–2.5 m
115 cm
243 m
06JM002
Lyngen
69o47.416
20o23.352
GC
6m
440 cm
255 m
06JM003
Lyngen
69o48.267
20o25.052
GC
6m
366 cm
257 m
06JM004
Lyngen
69o48.271
20o23.107
GC
6m
535 cm
263 m
06JM005
Lyngen
69o51.512
20o24.747
GC
6m
390 cm
315 m
06JM006
Lyngen
69o53.866
20o25.190
GC
?
210 cm
326 m
06JM007
Lyngen
69o59.081
20o24.049
GC
3m
168 cm
270 m
06JM008
Lyngen
70o00.542
20o18.469
GC
6m
485 cm
231 m
06JM009
Ofoten
68o26.296
17o17.702
GC
6m
370 cm
240 m
06JM010
Ofoten
68o26.095
17o11.828
GC
6m
400 cm
252 m
Table 1: Location of the gravity core stations. GC = gravity corer.
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Figure 1: Bathymetry of Ullsfjorden. The location of the Skarpnes moraine, Kjosen and CTD
stations 0044-0046 (Figs. 2-4) is indicated.
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Figure 2: CTD-station 0044 from the central part of Ullsfjorden. See location on Figure 1.
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Figure 3: CTD-station 0045 from the outer part of Ullsfjorden. For location, see Figure 1.
12
Figure 4: CTD-station 0046 from the inner part of Ullsfjorden. See location on Figure 1.
13
Figure 5: Bathymetry of the inner part of Ullsfjorden.
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Figure 6: Bathymetry of the outer part of Lyngen. The location of gravity core stations
06JM001-008 is indicated.
15
Figure 7: Bathymetric map of Ofotfjorden and tributary fjords, part of Tysfjorden
(Hellemofjorden) and inner Vestfjorden.
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Figure 8: Bathymetry of Ofotfjorden and tributaries. CTD stations 0049-0051 are indicated.
17
Figure 9: CTD-station 0049 from the innermost part of Ofotfjorden (Herjangsfjorden). See
location on Figure 8.
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Figure 10: CTD-station 0050 from the inner part of Ofotfjorden. See location on Figure 8.
19
Figure 11: CTD-station 0051 from Skjomen. See location on Figure 8.
20
Figure 12: Bathymetry of the inner part of Ofotfjorden. Gravity core stations 06JM009 and
010 are given.
21
Figure 13: Bathymetry of Hellemofjorden (Tysfjorden). The location of CTD station 0052 is
indicated.
22
Figure 14: CTD-station 0052 from Hellemofjorden. See location on Figure 12.
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