FRAM-2012 Expedition: Weekly Report, 17 to 23 September 2012
The first five days of the week was the end of a 10 day long period of winds up to gale force from the sector south to east and ice drift to the northwest in opposite of the general Transpolar Drift direction. During this weather situation, temperatures were just below freezing and one instance of a heavy rain shower. Water collected (3 cm) on top of the 10 cm thick ice on the melt ponds and snow on the ground melted and became to some degree water logged. The temperature dropped to minus 12 C mid-week on the 20 Sept. and remained cold since. In terms of visibility, we had three days of complete white-out, two days with 5-7 hours of visibility and one Arctic dream day with a blue sky and sunshine all day.
During the last four days of the week we have met a very large field of ice rubble with blocks twisted in all directions and not penetrable by hovercraft. We have searched for paths through with no success so far and the progress during this period has essentially been the limited to the general ice drift.
Downloaded a satellite image from 22 September where the ice edge is well defined. The closest ice edge is 90 nautical mile to the southeast at 20 degrees East, but the challenge so far has been finding ways through the ice rubble in this direction. If we compensate for ice drift since early August, and consider our position relative to the sea ice cover, we are now roughly in a latitude sense where we had our first ice problems on the way north. However,we went north about 100 km to the east of where we are now. By now, we have spent 1/3 of the fuel obtained from ODEN - remaining fuel is 1800 liters.
Position: 84 13' N, 00 23' W. Temp. minus 1 Centigrade (corrected), wind 7 knots from southeast, low cloud cover, white-out all day, heavy rain for 10 minutes at 0620 hours. Ice drift is still to the northwest at 200 m/hour. The 10 cm thick ice on the melt water ponds now have nearly 3 cm of water on top. Snow thickness is on average 8 cm and on large flat areas the melt has given the snow surface a brownish tint.
Position: 84 09' N, 00 13' W. Temp. minus 4 Centigrades (corrected), wind 5 knots from the southeast, overcast, but clear sky near the horizon in the morning, the sun cleared the horizon at 0630 hours. Ground fog came and went before noon, and white-out after 2000 hours. Ice drift is to the northwest. This is the first time in six days the sun has been visible and also light conditions for driving. Had five hours of useable visibility. Saw a sea gull (brownish in colour)
Position: 84 10' N, 00 33' W. Temp. minus 4 Centigrades (corrected), winds from the southeast 6-10 knots, low clouds and white-out all day. Another day with low clouds and white-out. Not much to do about that.
Position: 84 02' N, 00 09' W. Temp. minus 12 Centigrades (corrected), winds 5 knots from the southeast, broken clouds, the sun visible all day, good driving condtions. An Arctic Ocean dream day in terms of visibility, but cold. Saw an ismåke" today.
Position: 84 00' N, 00 42' W. Temp. minus 7 Centigrades (corrected), winds 7 knots from the east-northeast and in the afternoon from north-northeast, a complete lid of low clouds and white-out all day. The good news is that after 11 days of continuous northward ice drift, the wind direction has changed and today, the ice drift turned west-southwest. The speed is about 200 m/hour. No sign of animal life.
Position: 83 54' N, 01 36' W. Temp. minus 10 Centigrades (corrected), winds 0-6 knots from the north, fog and white-out until noon, usable visibility from 1300 -2000 hours with sunshine from a clear sky. The area has ice rubble in all directions except north, made only five minutes of latitude south after having to detour and go north again three times. Ice drift is due south at 200 m/hour. Saw a seal in a lead.
Position: 83 52' N, 01 41' W. Temp. minus 12 degrees, wind 2 knots from the north, partly clouded, good visibility until noon when ground fog arrived. Light snow fall from 2000 to 0200 hours. The sun was over the horizon at 0730 hours. No sign of animal life in the white landscape.
All is well, we are delayed, that is all.
FRAM-2012 Expedition: Weekly Report, 10 to 16 September 2012
The week began reasonably well with a total of 4 hours of usable visibility for driving and the hovercraft moved 17 nautical miles due south to 84 N with underway ice thickness measurements. Continuous low clouds and white-out conditions persisted from noon Wednsday September 12 and throught the rest of the week with winds from the south and later southeast (8-23 knots). During this period, the ice moved 28 nautical miles to the northwest and we have just crossed the Gakkel Rift Valley beneath and will be crossing the geographic Greenwich Meridian shortly.
Temperatures have been between zero and minus 3 Centigrades. We have had 4 days with 1-4 hour periods of light rain this week. The thickness of the snow cover is in the range 5-13 cmm. It is melting and melt ponds all have 1-2 cm of water on top of the 10 cm thick new ice.
We had a polar bear aound the hovercraft on Wednsday evening. He moved away as the engine was started, but seemed to keep the hovercraft under surveillance.The following night he paid an unnoticed visit. Instead of taking interest in the three boxes with food on deck, the animal chewed up the serial connectors joining two sections of the data cable from the EM ice thickness instrument. The damage was later successfully repaired. We observed two seals and one snow bunting during the week.
Position 84 12' N, 03 28' E. Temp. 0 Centigrades (corrected), no wind, white-out through the morning until 1030 hours. After 1400 hours white-out and dense fog moving in. Ice drift is to the south at 200 m/hour. Had 2 hours of useable visibility and moved 6 nm in southerly direction with ice thickness measurements and two calibration stops.
Position: 84 01' N, 03 54' E. Temp. - 3 Centigrades (corrected), wind 6 knots from the west-southewest, partly clouded with sun visible from 0730 hours, ground fog on and off during the day and complete white-out after 1800 hours.
Position: 84 00' N, 03 38' E. Temp. minus 3 Centigrades (corrected), no wind, clear sky from 0800 hours, but ground fog and no visibility. Fog lifted for one hour at about 1100 hours. In the evening overcast and white-out. Light rain between 2000 and 2400 hours.
Position: 84 04' N, 03 20' E. Temp. minus 1 Centigrade (corrected), up to 17 knots wind from the south-southeast, overcast and dense fog all day.
Position: 84 08' N, 02 45' E. Temp. minus 1 Centigrade (corrected), wind from the south reaching gale force (22 knots) at 0800 hours, but generally more than 12 knots all day. Wind direction changed to southeast from the afternoon on. Low clouds and white-out all day, light rain between 1700 and 1830 hours.
Position: 84 12' N, 01 22' E. Temp. minus 2 (corrected), winds 16-22 knots from the southeast, low clouds, white-out, light rain 0800-1000 hours. Pressure ridges are being formed.
Position: 84 13' N, 00 22' E. Temp. minus 1.5 Centigrades (corrected), winds 8-12 knots from the southeast, overcast, fog coming and going, white-out, light rain 1100-1200 hours.
FRAM-2012 Expedition: Weekly Report, 03 to 09 September 2012
The first four days of the week were spent drifting over the Gakkel Rift Axis with three instruments placed in a triangle 5 km on the side, each with a hydrophone in the water to record the sound, and at one site a broadband seismometer. On Tuesday, we felt and heard the rumble of a local earthquake and recorded our nicest event to date. Several small ones followed. One of the instruments was over the rift valley floor and the two others 5 km away, up over the southern flank. This is where the rift valley is the deepest (5400 m) area in the Arctic Ocean. On Sept. 7 the instruments were picked up and the hovercraft moved to 84 23' N, 03 54' E and parked to wait for icebreaker ODEN to arrive. At this point the hovercraft had only 100 liters of diesel left after an unplanned period of over five weeks with no access to fuel.
A total of 19 days of operational monitoring of the microearthquake activity on Gakkel Ridge with three deployments on two contrasting sections of the rift valley, was very successful. Several hundred events were recorded. In terms of operation, it has involved only two people, and the opportunity to continuously monitor progress and respond with action needed to optimize the science. It has demonstrated the usefulness of hovercraft as an alternative logistic science platform for projects which involve relatively light weight equipment (few hundred kilos) in a joint operation with an icebreaker.
ODEN arrived on Saturday 8 Sept. at 0830 hours, and made a deep CTD cast and biological station while the hovercraft received 2654 liter diesel, some minor food items, we had a shower, discussed ice conditions and the transit south. The Danish UNCLOS work had been very successful. Among the achievements were about 300 kilos of rocks recovered by dredging from the slopes of Lomonosov Ridge. These are to the best of our knowledge the first samples of Lomonosov Ridge basement ever obtained.
Due to notorious white-out conditions, the option of taking the hovercraft on the deck of ODEN for the return transit south, was seriously considered and generously offered in spite of marginal crane capacity for loading and unloading. However, the ice thickness measurements that can be obtained with the hovercraft is a unique scientific contribution at a time when health of the Arctic Ocean ice cover is in a state of flux. We obtained a continous ice thickness profile from the ice edge to 85 N on the way north, and would also like to do so on the way south. However, there are some less attractive consequences. We will be severly delayed in reaching the ice edge due to poor light conditions for driving dominated by white-out.
Therefore the crew member Gaute Hope, boarded ODEN for the return to Longyearbyen in accordance with the stipulation laid out in the FRAM-2012 cruise plan. Yngve Kristoffersen drive the hovercraft back to the ice edge and carry out the underway ice thickness measurements. This opportunity will also be used to shoot a seismic profile drifting between 83 N and 82 N across a major sediment drift banked up against the northern flank of Yermak Plateau. This sediment drift is a target for future scientific drilling in the Arctic Ocean as it contains a record of the strength of inflow of Atlantic Water into the Arctic Ocean. The extent of this work will be adjusted according to how well progress is made.
NORBJØRN's sailing schedule suggest possible pick-up at the ice edge at about 27 September or 10 October. The hovercraft's food provisions may last until mid-October.
Position: 84 4' N, 03 30' E. Temp. +4 centigrades, winds 4 knots from the west, overcast, useful visibility from 1000-1800 hours, otherwise white-out. Light snow fall 1300-1400 hours. Ice drift was 200 m/hour to the south moving over the center of the rift valley wall.
Position: 84 36' N, 03 24' E. Temp. +2 centigrades, winds 8 knots from the northwest, overcast, useful visibility from 1600-1830 and after 2100 hours, otherwise white-out.
Position: 84 30' N, 03 15' E. Temp. +2 centigrades, winds 12 knots from the north-northwest, overcast. From 0900-1500 hours, the visibility was fair, but the diffuse light rendered no clear definition of surface features, otherwise white-out all day. The ice drift was 11 km due south over the last 24 hours.
Position 84 26' N, 03 13' E. Temp. + 1 Centigrades, wind 6 knots from northwest, white-out all day and snow fall after 2200 hours. Ice drift is due south at 200 m/hour and away from the rift axis.
Position 84 23' N, 03 54' E. Temp. + 2 Centigrades, wind 7 knots from the north. Good visibility from the early morning 0700 hours until 1400 hours.Picked up the remaining two seismic buoys and moved about one degree of longitude to the east (10.5 km) and parked to wait for ODEN.
Position 84 20' N, 03 57' E. Temp. 0 Centigrades, wind 5 knots from the east, overcast and fog. NOTE! Comparison between the more accurate temperature monitoring system on ODEN and the hovercraft shows the temperature sensor on the hovercraft is giving readings which are + 4 Centigrade too warm!!! Hereafter, our stated temperature is corrected accordingly.
Position 84 18' N, 03 16' E. Temp. -2 Centigrades (corrected), calm and white-out all day. Ice drift is to the west at 200 m/hour. Run up on a ridge late last night in deteriorating visibility and came off in the early morning after 7 hours work.
No sign of animal life during the whole week
All is well.
FRAM-2012 Expedition: Weekly Report, 27 August to 04 September 2012
Yngve Kristoffersen and Gaute Hope
As the week began, we were in the third day of drifting and listening for earthquakes at a particular section of Gakkel Ridge characterized by no volcanism and no earthquakes recorded by the global network of seismigraph stations. This is peculiar as the widening of the Arctic Ocean here is the same as at the nearby volcanic section of the ridge.
At first the ice drift took us from the north across the rift valley, then a U-turn and back towards it just 2 km off, and then paralell to it for over 15 km and then away. At the end of the week we picked up the instruments at the three sites and move them upstream to the north of the rift valley again. Here, they were placed in the pattern of a triangle with 5 km long sides. This is our final deployment during FRAM-2012.
We have recorded about hundred microearthquakes during the week and 25% of them were very well defined events (signal to noise ratios 30-40). The Jan Mayen earthquake was also recorded.
As mentioned in earlier reports, the light condition, mainly white-out is our daily consern. We keep a 24 hour watch observing the visibility. For the last week, the total number of hours with sufficient visibility for driving has been 33 hours, i.e. less than 20% of the total time.
Our imposed decision to abandon pursuit of ODEN and our Lomonosov Ridge objectives, implied that we unexpectedly faced a period of more than 5 weeks without access to fuel. Fortunately, the direction of ice drift throughout the whole period has been much to our advantage and we have avoided major sacrifices in terms of science opportunities. Usable fuel left now with one more week to go, is about 300 liters i.e. 15% of fuel capacity.
No signs of animal life during the whole week.
Monday 27 August
Position: 84 37' N, 03 56' E. Temp. +9 Centigrades, wind 5 knots from the southwest, overcast and white-out all day. The drift was straight south at 200 m/hour and we were about 6 km south of the rift axis.
Tuesday 28 August
Position: 84 37' N, 03 25' E. Temp. +4 Centigrades, wind 10 knots from the westnorthwest, overcast and white-out all day, light snow between 1600 and 2000 hours. The ice drift made a surprising U-turn in the early morning and took us back towards the rift valley, now 3.5 km away.
Wednsday 29 August
Position: 84 40' N, 04 08' E. Temp. +3 Centigrades, wind 15 knots from the southwest, overcast and white-out until 1900 hours. We moved parallel to the rift valley with the center of the instrument array about 2 km away from the rift valley floor.
Thursday 30 August
Position: 84 39' N, 04 26' E. Temp. +4 centigrades, wind 4 knots from southeast, ground fog in the morning, shunshine at noon and overcast and white-out in the evening. The ice drift was very slow all day; mostly 200 m/ hour or less and in a direction along the ridge. This day was special; we saw the sun for the first time in a week! Have had to work on the assumption it should be there.
Friday 31 August
Position: 84 40' N, 03 38' E. Temp. +2 centigrades, wind 10 knots from south, overcast and diffuse light with poor ground contrast until noon, complete white-out in the evening. Rain between 1700 and 2200 hours. Winds from the south drove the ice over 2 nautical miles to the northwest during the day.The rainfall in the evening turned the white snow surface into a more bluish water saturated appearance.
Saturday 1 September
Position: 84 42' N, 03 14' E. Temp. +4 centigrades, winds 5-15 knots from southwest, overcast and diffuse light with poor ground contrast until 1000 hours, then the sun broke through the clouds and good visibility until white-out conditions again in the early evening.Light rain in the early morning hours. Winds were from the southwest and ice drift is to the northeast and much to our favour, parallel to the rift axis.
Sunday 2 September
Position: 84 42' N, 03 24' E. Temp. +4 centigrades, winds 8 knots from the west, overcast and white-out. Light snow fall around noon. A very quiet day with the ice drifting at c. 200 m/hour towards the rift valley. Our current position is on the north slope and about 4 km off the rift axis with the nearest instrument.
All is well.
FRAM-2012 Expedition: Weekly Report, 20 to 26 August 2012
Yngve Kristoffersen and Gaute Hope
We are drifting with the sea ice over the Gakkel Ridge - the place where the Arctic Ocean constantly widens at a rate of less than 1 centimeter per year. The ridge has a deep, less than 2 km wide rift valley (up to 5400 m depth) flanked by steep mountain sides which rise 1 km shallower over a distance of just 2 km. Our mission is to contribute to the knowledge of how this widening is accomodated by rocks which constitute the Earth's crust.
We have just completed 9 days of drift, listening with instruments placed in a triangle 2.8 km on the side and the hovercraft in the middle of the triangle with another instrument and a broadband seismometer. The result of this was a record of several hundred potentially useful microearthquakes.
As this week began, we were in the process of picking up the last instrument and move to another segment on the ridge. However, gale force winds and white-out conditions during the first solid four days, prevented us from anything else, but wait it out.
On Friday, when the weather conditions had finally improved, we deployed the instruments within 2 hours over a section of the rift valley where no earthquakes have ever been recorded by distant stations. The direction of ice drift for the next days were along the rift valley, exactly where we wanted it to be. Only one earthquake was recorded the first 24 hours, but later several dozens small earthquakes followed.
At the end of the week, winds from southwest were associated with exrtaordinary warm air (+8 C) for this time of the year near 85 N.
Only animal life sighted is an occasional single sea gull.
Monday 20 August
Position: 84 56' N, 10 24' E. Temp. +2 Centigrades, wind 18 knots from the N with blowing snow, about an hour of usable visibility in the morning, but white-out the rest of the day. Gale force winds (>22 knots) for a brief period in the afternoon. Waiting on visibility to improve to pick up the last seismic buoy and move to another location.
Tuesday 21 August
Position: 84 50' N, 09 13' E. Temp. +2 Centigrades, wind 16 knots from NNE, low clouds, white-out, occasional snow. Waiting for improvement in visibility.
Wedn sday 22 August
Position: 84 46' N, 07 51' E. Temp. +2 Centigrades, winds 16-24 knots from NE, low clouds, white-out. Gale force winds most of the day and white-out conditions. Waiting for improvement in visibility for safe driving.
Thursday 23 August
Position: 84 44' N, 06 11' E. Temp. +2 Centigrades, winds from NE at 21 knots in the early morning coming down to 15 knots in the evening, white-out until noon, and finally good visibility in the afternoon. Found the last seismic buoy and started driving towards the rift valley for a new instrument deployment.
Friday 24 August
Position: 84 47' N, 4 51' E, Gakkel Rift Valley - non-magmatic zone Temp. +4 Centigrades, wind 8 knots from the northeast, white-out during the night and marginal visibility during the day. Deployed buoys and broad-band seismometer in a section of the Gakkel Rift Vally which is characterized by no magmatism and from here no earthquakes are recorded at teleseismic distances. Array geometry is a triangle with sides 2.8 km.
Saturday 25 August
Position: 84 44' N, 4 15' E, Gakkel Rift Valley - non-magmatic zone Temp. +6 Centigrades, wind 6 knots from the west, overcast and white-out on and off all day. The ice drift in on an ideal course right down the rift axis - could not do better even if we had the ability direct the ice drift.
Sunday 26 August
Position: 84 40' N, 03 58' E, Gakkel Rift Valley - non-magmatic zone Temp. +8 Centigrades, wind 6 knots from the southwest, overcast all day and white-out on and off, light rain first 1/3 of the day. Plus eight degrees and rain at the end of August at 85 N! The ice drift has slowly turned south and we are heading out of the rift axis after moving 15 km in a straight line within it.
All is well.
FRAM-2012 Expedition: Weekly Report, 13 to 19 August 2012
Yngve Kristoffersen and Gaute Hope
This week was spent at 85 N drifting passively with the ice over the Gakkel Ridge, a mountain range which in the center has a deep (>4600 m), 10 km wide valley, the Gakkel Rift Valley, and is flanked by mountains which rise over 1 km higher over a distance of 5 km away. This mountain range extends from northeast of Greenland to the Siberian continental margin and is where the Arctic Ocean slowly widens.
Three seismic instruments each recording the signal from a hydrophone in the water are placed in a triangle with sides 2.8 km. The hovercraft is parked in the middle of the triangle with another listening hydrophone.
On Sunday 19 August, we were about 15 km south of the rift valley and decided to recover the seismic buoys and the broadband seismometer and move upstream. We picked up 3 out of 4 before the light conditions turned to white-out and no terrain contrast by midnight.
This deployment lasted for 9 days and the drift path mainly followed the rift valley as hoped for. About 30 well defined microearthquake events and maybe hundred smaller ones have been recorded. We are both very pleased with how Gaute's self designed and self built instruments have worked.
Monday 13 August
Position: 85 14' N, 10 25' Ø. Temp. +10 Centigrades, wind 5 knots from N, low clouds and poor visibility until early afternoon, in the evening sunshine from a cloud free sky.
Tuesday 14 August
Position: 85 12.9' N, 10 27' E. Temp. +7 Centigrades, calm, broken clouds, good visibility. In the afternoon, ground fog, above is a clear sky, wind 10 knots from SW.
Wednsday 15 August
Position: 85 10.4' N, 10 15' E, Gakkel Rift Valley. Temp. +5 Centigrades, calm , ground fog with poor visibility, but clear sky above. After noon, 10-14 knots wind, partly clouded, good visibility.
Thursday 16 August
Position: 85 05.6'N, 10 13' E. Gakkel Rift Valley. Temp. +5 Centigrades, wind 10 knots from NW, low clouds, fair visibility, but diffuse light which gives low contrast.
Friday 17 August
Position: 85 02' N, 09 57' E. Temp. +8 Centigrades, wind 5 knots from NE, low clouds, white-out.
Saturday 18 August
Position: 85 03' N, 10 23' E. Temp. +4 Centigrades, wind 10 knots from SW, white-out for most of the last 24 hours and light rain in the evening.
Sunday 19 August
Position: 84 59' N, 10 58' E. over southern flank of Gakkel Rift Valley Temp. 5 Centigrades, wind 6 knots from the west, white-out until afternoon, but by 2000 hours sunshine from a partly clouded sky until midnight and then back to white-out.
No seals have been sighted this week. Have daily seen a single sea gull. Woke up at 0500 hours on Sunday by the alarm from the motion detector where the food was buried in a small ridge - we had a bear visitor. To our surprise, he did not touch the food. Started the engine and he showed us his behind, but stayed at 100 m distance the rest of the day until we left the site to pick up instruments.
All is well.
FRAM-2012 Expedition: Weekly Report, 06 to 12 August 2012
Yngve Kristoffersen and Gaute Hope
Monday 06 August
Position: 85° 02' n, 11° 06' E. Temp. +3° Centigrades, wind 10 knots from SE, overcast and fog.
No visibility all day for driving. By late afternoon ODEN would be 100 nm ahead of us, a distance equivalent to two days of driving under optimum conditions. Obstructions represented by ice fields can be worked at and around, but downtime from poor visibility and light conditions are totally out of our control. Under present circumstances, we anticipated ODEN would probably have to transit a minimum of two days roundtrip in order to provide us with fuel at the start of their first seismic line. We need the fuel to make the last third of the transit to Lomonosov Ridge. This being the case at the beginning of our field season and in all likelihood no improvement in general light conditions, further pursuit of the original cruise plan would require ODEN time for our support far beyond what was stipulated in the contract between LOMROG 2010 and FRAM-2012 expeditions. Also, excessive need of ODEN's time would be at the expense of Danish UNCLOS work. We therefore reluctantly decided that the most responsible scenario would be to remain on the Gakkel Ridge and carry out the planned earthquake monitoring project awaiting ODEN's return journey. ODEN and NPD were informed by e-mail about our decision.
Tuesday 07 August
Position: 84° 58' N, 11° 58' E. Temp. +4° Centigrades, wind 8 knots from SE, low clouds, ground fog, visibility 300-400 m, improving after lunch. Got 1.5 hours of driving during a window of improved light conditions in the early afternoon and found a way out of the field of ice rubble towards NE. While moving over severe melt pond terrain, the front-mounted boom broke off and EM instrument for ice thickness measurements fell into a melt pond. Recovered everything.
Wednsday 08 August
Position: 85° 04' N, 12° 35' E. Temp. +6° Centigrades, wind 4 knots from SW, low clouds, light snow and white-out conditions. Proceeded during two 1-1.5 hour visibility windows in the earliest morning. Got stuck on a ridge and came off after 6 hours work.
Thursday 09 August
Position: 85° 21' N, 11° 32' E. Temp. +6° Centigrades, wind 4 knots from SW, ground fog, light conditions on and off until 1800 hours when the fog partly lifted. Arrived at position on Gakkel Rift Valley north flank for deployment of seismic buoy #1 just before midnight.
Friday 10 August
Position: 85° 23' N, 11° 30' E. Temp. +6° Centigrades, wind 4 knots from SW, bright sunshine from a cloud-free sky. Deployed the three seimic buoys in a triangle with 2.8 km legs in 5 hours. The hovercraft is positioned in the middle of the triangle with a fourth station. The array records several small earthquake events pr hour.
Saturday 11 August
Position: 85° 18' N, 10° 57' E. Temp. +10° Centigrades, wind 6 knots from the E, ground fog, but cloud free sky above. Drifting parallel to the rift valley at 0.2 knots and monitoring. Several nice near events recorded.
Sunday 12 August
Position: 85° 17.8' N, 10° 50' E. Temp. +8° Centigrades, calm, partly clouded,light snow. Still drifting parallel along the flank of the rift valley at 0.1 knots, turning southwards after lunch. All equipment works well.
Four consecutive days with poor light conditions for driving subsequent to our decision to remain on Gakkel Ridge underscore the problem of keeping up a planned progression at this time of the year in the Arctic pack ice. We reluctantly acknowledge that the decision was most likely correct, and express our disappointment for not reaching our primary geological objectives on Lomonosov Ridge within the imposed time constraints, i.e., time constraints determined by the availability of fuel.
Why monitor earthquates from the Gakkel Rift Valley?
The Earth's surface is divided into plates that move relative to one another - a physical expression of how the Earth looses its internal heat. As the plates are moving, parts of their boundaries are associated with zones of compression (island arcs f.ex. Japan) or expansion (mid-ocean ridges f.ex. Mid-Atlantic Ridge). The Gakkel Ridge is the northward extension of the Mid-Atlantic Ridge, the site where a constant widening of the Atlantic Ocean and the Arctic Ocean takes place. At the mid-ocean ridge, the widening is associated with: i) volcanic activity where new material from the Earth's interior fill the void or ii) by faulting and stretching of the crust that is already there. These processes at the Mid-Atlantic Ridge can be observed in Iceland. The Gakkel Ridge is special, because it represents a case where rate of opening is slowest in the global ridge system; the opening rate decreases from 1.3 cm/year northwest of Svalbard to 0.6 cm/year at the Laptev Sea continental margin. As the opening rate becomes slower, we expect less heat is involved and less volcanism. A large international effort in 2001 (AMORE) with two icebreakers surveying and recovering rock samples from the Gakkel Rift Valley from its western end to about 85 E (ca. 900 km), suddenly made this ridge segment one of the best surveyed in the world's ocean. One major finding was no simple decrease in volcanism and and hydrothermal vent fields as you move towards east along the Gakkel Ridge and the opening rate decreases.
Earthquakes are expressions of rocks failing under increasing stresses associated with the plate motion. In the rift valley, this is mainly related to faulting assosiated with magmatism or amagmatic faulting associated with stretching of the crust. With the new AMORE precise multi-beam bathymetry and reconnaissance mapping of rift valley petrology, it is now possible to directly relate the shallowest seismic activity to tectonic movements assosiated with specific features of the rift valley topography and the dominant seabed rock type. Deeper seismic events within the crust or upper mantle tell us about the depth extent of relatively cold and strong lithosphere. Four microearthquake field campains have so far been carried out at other locations along the Gakkel Ridge by German colleagues in order to study how the crust extends at ultra-slow spreading rates.
In the context of FRAM-2012, the microearthquake survey was originally planned as an add-on activity to the primary work on Lomonosov Ridge.
This was accomodated by 2 weeks earlier departure from Longyearbyen ahead of ODEN. The objective was to test new seismic buoy technology integrated into a local area network for seismic work from drifting sea ice, and apply it:
- to a microearthquake survey case to expand earlier studies on Gakkel Ridge. Then use the data base of recorded earthquakes to invert for crustal structure and earthquake source mechanisms, and
- later during work on Lomonosov Ridge, to acquire 3-D seismic reflection data which is a new level in Arctic Ocean exploration.
All this including instrument design and construction are the subject of a M.Sc. thesis of the crew member Gaute Hope. All experiments will now be carried out at the Gakkel Ridge spreading center.
FRAM-2012 Expedition: Weekly Report, 23 to 29 July 2012
Yngve Kristoffersen and Gaute Hope
Monday, 23 July
Position 83° 18' N, 14° 16' E Temp. + 6° Centigrades, wind 9 knots.The sun broke through at midday and we got a total of four hours of driving before visibility deteriorated and we parked. Average speed in a north direction was 5.5 knots.
Tuesday, 24 July
Position 83° 38' N, 13° 38' E Temp. + 6° Centigrades, wind 10 knots from NE. Got almost two hours of driving in the early morning, before terrain contrast deteriorated and it started to rain lightly. This condition persisted until next morning. Average speed in a north direction 2.8 knots.
Wednsday, 25 July
Position 83° 43' N, 12° 38' E. Temp + 4° Centigrades, wind 10 knots from the east, visibility improved at 1000 hours. Got about six hours of driving. Average speed in north direction was 4.2 knots before lunch and 3 knots after lunch. Stopped at 1700 hours due deteriorating visibility and ice getting more broken up and difficult.
Thursday, 26 July
Position 83° 58' N, 11° 39' E. Temp. +6° Centigrades, wind 8 knots from NE. Started off at 0500 hours, had relatively good driving conditions, but got stuck three times and in one case the rear end of the craft swiped an ice block and the skirt was torn from the bottom to the deck. Repair work took four hours. When driving, northward progression was 6 knots before we came into a very complicated area and had to loop three nautical miles south again to get out of it. Have about 1000 liter diesel remaining.
Friday, 27 July
Position 84° 17' N, 11° 28, E. Temp. + 8° Centigrades, calm, light rain, acceptable visibility after 1200 hours. Visibility cleared by noon and got 7.5 hours of driving. Average progression northward was at 3 knots.
Saturday, 28 July
Position 84° 39' N, 12° 01' E. Temp. + 6° Centigrades, no wind, clear sky - a beautiful day. After driving over long stretches of 3-4 meter thick level ice, we hit an area which was broken up in all directions. Climbed to the roof of the hovercraft to scan the horizon for less rugged terrain. We had to turn south again to search for openings. As we moved over a small but very deep melt pond we got stuck on a ridge in the middle since we moved too cautiously and had insufficient momentum. The craft got a 30 degree list to port with the starbord skirt hanging up to 1 meter above the ground. Built a wall of iceblocks, cut by chain saw to trap the air cushion and also had to remove some ice under the keel before we regained lift and moved off. The job took 15 hours. After a short rest, we got only one hour of driving before fog moved in. As we parked for the night we experienced skirt control failure.
Sunday, 29 July
Position: 84° 40' N, 12° 34' E. Temp. + 6° Centigrades, wind 3 knots, fog. Worked on locating the fault and established that the charge splitter which distributes the charge from the alternator between our two sets of batteries was burnt and the alternator dead. Completed the remaining assembly of our new powerful roof mounted windmill and got it online for charging. Spare parts may reach ODEN before departure from Longyearbyen. To what degree the charge from the wind mill is sufficient for extended periods of driving will be tested as soon as driving conditions improve.
The general ice thickness increases noticably north of 83° N, and occurrences of thicker 2-3 m ice become more frequent. With this, the frequency of melt ponds increases dramatically, in places to more than 50% of the surface and the difference in level between water and ice up to 0.5 meter. The hovercraft is very suceptible to surface slope and the meltwater pond topography makes an otherwise level area difficult to drive in as you have to go relatively slow.
North of 84° 20' N, the ice was consistently 3-4 meters thick (up to more than 6 meter), with no leads. For stretches of up to a mile, the surface of thick ice was free of pressure ridges. These relatively extensive flats were separated by smaller pressure ridges until, at about 84° 37' N, we came into a very messy area with broken up thick ice in all directions. We are still in this situation, but see conditions in the northeast as the most promising direction to continue as visibility again improves. Getting an overview is a problem, your only option is to climb the roof of the hovercraft and scan the horizon using binoculars.
We have had difficulties with sufficent power for the EM instrument measuring ice thickness, and decided to cannibalize the power pack of an ARGOS buoy to keep it going until we meet ODEN and get a permanent solution.
Ice stained with algae is frequently observed. We encounter an occasional sea gull almost every day and have seen two seals this week but no polar bears. Now, with the windmill going, we assume polar bears will keep at a distance.
Passed an old rusty fuel drum on the ice, no discernble markings.
Remaining fuel is for 6-7 hours of driving and will be spent to get in position for rendevous with ODEN.
FRAM-2012 Expedition: Weekly Report, 17 to 22 July 2012
Yngve Kristoffersen and Gaute Hope
The air cushion boat SABVABAA left Longyearbyen Monday, July 16 at. 2230 on the deck of the boat NORBJØRN goods. The air cushion vessel was set on the water and bunkered Wednesday, July 18 at 0830 in position 80° 52 ' N, 15° E.
It was scattered ice, fog and weak winds in the area. SABVABAA encountered close ice (8-9/10) at 81 ° 03 'and started the measurements of ice thickness with an electromagnetic (EM) sensor mounted in front of the vessel. After 3.5 hours drive 22 nautical mil north of the ice we met with LANCE Stig Falk-Petersen and a group of biologists. Here we were invited to dinner. There were problems with the power supply to the EM sensor and LANCE helped with spare batteries until we get a permanent solution when ODEN arrive.
Wednesday, July 18
Overcast, but good visibility, + 6° C, still, an ice thickness ±0.1 m, much smooth ice sheets, efficient run-time 5.5 hours, effective average speed of 6.7 knots northerly direction, parked and stayed in position 81° 28 'N, 15° E.
Thursday, July 19
Clear, good visibility, + 6° C, still, ice thickness from 1 to 1.5 m, but is keyed more frequent, efficient run-time 6 hours, effective average speed in the northerly direction 4.3 knots, parked and stayed in position 82° 20 'N, 14° 47' E.
Friday, July 20
Fog until lunch, later partly cloudy, + 7° C, wind 6 knots from the NW, ice thickness from 1 to 1.5 m, more frequent element of 2 to 2.5 m thick ice, the ice is much keyed up and messy, efficient run-time 5 hours, effective average speed of 3.5 knots northerly direction, parked and stayed in position 82° 58 'N, 14 ° 49' E.
Saturday, July 21
Sol first part of the day, fog and poor visibility afternoon, no wind, elements of 2 - 4 m thick ice and meltwater ponds frequently large and covers more than 50% of the surface, came into the area really keyed up and had to turn and detour run twice, effectively driving 6.5 hours, effective average speed of 2.75 knots northerly direction, parked and spent the night in position 83° 18 'N, 14° 32' E.
Sunday, July 22
Fog, quiet, light rain, + 10° C, for poor visibility to drive. The day was used for processing of ice thickness measurements and maintenance.
The air cushion boat pushes hard ice in an impressive manner. The is reasonably easy to find usable gaps in long pressure ridges. The important limiting efficient driving is visibility. The importance of visibility lies primarily in avoiding run into areas that are completely keyed in all directions because the radar image of pack ice is too complex that it is practical use. It is most profitable to exercise patience and wait for adequate visibility, because the alternative is that you often run out onto ice ridges and uses time gains to come loose.
A diesel-powered icebreaker on the way from the ice to the North Pole holding a effective average speed in the northerly direction at about 3 knots.
Spring effective average speed in the northerly direction is 3-4 knots and includes all maneuvering through pressure ridges and reduced speed over landscape of the melt-water ponds. South of 82° N there was little meltwater ponds on the ice and on flat stretches, it was possible to holding 10 to 15 knots. Farther north increased frequency of meltwater ponds and north of 83° constitute at least 50% of the surface, and represents up to 0.5 meters deep depressions in the ice surface. This means that the average speed drops because we can not keep more than approx. 7 knots because of the size and the distance between meltwater ponds in relation to the length of the boat results in a pitch movement that would otherwise be too noisy. Glacial dams do it is also difficult to steer the boat effectively. It is less than 10 cm granular snow on the ice, and air cushion boat slips easily - too easily. A thicker layer of snow had better friction and made it easier to maneuver.
At 83° N, we had covered half the distance to the first target range of 85° N and had a little over half (approx. 1400 liters) of diesel inventory back. ODEN arrive at 85° N to ca. two weeks. We have been over 1 ton lighter because of the fuel consumed and the marked on the driving performance of the boat. The measurements of ice thickness is very good. We have now completed the first 250 km of the profile from the ice to the North Pole. Gaute Hope made a preliminary processing of the results and made two plots: a showing the distribution of ice thickness from the ice edge and LANCE's position (81.0° N-81.4° N) and one from our far northern section (82.95° N-83.1° N).
Otherwise all is well. Circadian rhythm is determined by the fog. In the first target of 85° N, we set out 5 buoys on the ice within an area with a radius of approx. 4 km to listen for earthquakes up to when ODEN arrives.