|
|
|
|
|
Daily reports from the NGRIP-camp - week 30, 2004
Monday, July 19
|
|---|
| Daily life |
| A very sunny day with cold morning temperatures (-13.5
deg C), warm tempertures during the afternoon (-5 deg C) and no wind. A slight
breeze late afternoon from northeast a very unusual wind direction. The
excitement in camp is getting bigger, as bedrock is approached. Bedrock
will hopefully be reached one of the coming days. |
| Science |
| 6 drill runs today with core lengths 1.44m, 0.92m, 1.11m,
0.98m, 1.23m and 1.02m with a total daily production 6.70 m. We are approxing
bedrock (again) and we are preparing for the break through. We have calculated
that a liquid level of 78m from the top will allow the basal water to enter
the lowest 5 m of the borehole. We are monitoring the liquid level carefully
with the drill and from Tuesday also with a thermister. When the water
has entered the hole and we have monitored the change of the liquid level
we will add drill liquid from the surface and press the basal water down
to 2-3m. We will rest the drill 30 min just below the bottom during each
run from Tuesday morning so we are sure the drill has the same temperature
as the surrounding ice and water. The excitement of reaching bedrock has infected the camp. Daily production 6.70m, drillers depth 3078.98m Today we managed to carry out the last two planned radar flights for this season from NGRIP. All together we made all 11 proposed survey flights during the last week for a pre-site survey for a deep ice core drill site north-west of NGRIP as well as for ice thickness measurements of the drainage basin east of the camp. Thanks to all in camp and behind the scene for supporting us and the great hospitality we experienced in Greenland. |
| Logistics |
| The skiway was groomed and the BAS Twin Otter left camp.
The crew brought out new pictures
to Kangerlussuaq. The fresh fruit that arrived on the C-130 last week has
been re-arranged, and another pallet with empty drums has been made. |
Tuesday, July 20
|
|---|
| Daily life |
| On top of the excitement of almost reaching bedrock
the generator had problems today and had to be shut down for several hours.
Just at 13.00 the generator had to be stopped because the frequency showed
oscillations. The drill just managed to return to surface before the failure.
After fearing for a while that it was the electronic speed control unit that
had failed a loose plate was found in the generator. After repair of the
plate the generator runs well again. The generator was running again at
15.00. A partly sunny day with warm temperatures. During the morning sunny and no wind later in the day overcast and wind from 160M, 10 kn. Pressure 1003.8 mb. Temperatures during night -13 deg C, during day -5 deg C. |
| Science |
| We had 3 runs today with the core lengths 0.91m, 0.31m
and 0.00m with a total daily production of 1.22m. The liquid level has been
raised to 84m and attempts to add more liquid in order to raise it to 78m
have not been succesfull. We speculate if it is basal water in the hole or
a leakage in the casing at 84m. We are monitoring the borehole level very carefully with the thermister probe for shallow holes. The second run had a very hard crystal break of 1600 kg (including cable and drill weight). In the last run the load cell showed unnormal values and it was not possible to penetrate at the bottom. On return to the surface we could observe ice on the cutters. We believe we are very close to the bedrock. Daily production 1.22m, drillers depth 3080.20m |
| Logistics |
| The German Polar2 plane left for Kangerlussuaq today.
We plan to take down the red dome
tomorrow if weather permits As this is the last season at NGRIP most things
have to be packed down and sent out this year. |
Wednesday, July 21
|
|---|
| Daily life |
| Ground fog and rim in the early morning clearing before
noon. A day with banks of low clouds rolling in from time to time with light
snow. Wind from 270M, between 8 and 15kn, temperatures between -14 deg C
and -6 deg C. |
| Science |
| We had 5 runs today with the core lengths 0.52m,
1.23m, 0.58m, 1.02m and 0.56m with a total daily production 3.91m. The liquid
level has been between 84m and 86m and 100 l D60 has been added. There might
be a leak in the casing, since the liquid level won't rise much further.
ECM has been measured in situ on the cores and the drop to low ECM values
observed in the last meter of the ice core drilled last year was observed
in the 4. core at a depth of 3083.20m. The last core drilled had clear indications
of being in contact with the bottom with refrozen water and small pink spots
on the bottom break. Drillers depth run 107, 3084.25m. Working with ground radar and the GPS-station. |
| Logistics |
| The red dome has been taken down. |
Thursday, July 22 |
|---|
| Daily life |
| Overcast, but clear in the evening. Wind from changing directions up to 16n, temperatures between - 14 deg C and - 6 deg C. Snow fall and drifting snow. |
| Science |
| We had 4 runs today with the core lengths 0.98m, 0.89m,
0.78m and 1.23m with a total daily production 3.88m. The liquid level has
been between 86m and 88m and the last 50l D60 in camp have been added. During
the first two runs the drill shorted , the first time at 2800m during pull
up, the second time at the bottom. It turned out to be a mixture of tar
and ice around the connections in the antitorque section that created shorts
so strong that a big black hole was burned in the small red PVC insolation
disc, which has been replaced. There is no sign of water in the borehole
yet. All the cores drilled today have low ECM values so we have a total of
3.88m of ice with low ECM values compared to the 1.3m from last year. The
ice is soft to drill and we get long core catcher marks as if we are breaking a core of butter. Once again we are producing the longest core in Greenland and we would like to make a comment on the Kansas radar depth not being quiet as accurate as we believed last year. Could it be that we last year due to a big underpressure hit or created a conduit pressing the basal water up into the borehole? Drilling, daily production 3.88 m, drillers depth 3088.09m |
| Logistics |
| There was another short generator stop. It is unclear
whether the problems are due to the decrasing load on the generator (as
the camp is reduced), or whether it is actually are faulty part. The floor of the red dome was removed today. |
Friday, July 23 |
|---|
| Daily life |
| A day with mostly sunny sky. Most of the day the wind
was low (0-10kn) and with temperatures around -8 deg C. At midnight the
temperature was -18 deg C. Next week will be a flight period again. There will be another smaller exchange of staff, and as much cargo as possible will be flown out on two flights. |
| Science |
| We had 4 runs today with the core lengths 0.48m, 0.20m,
0.72m and 0.39m with a total daily production 1.79m. The liquid level has
been between 88m and 90m and 100l DFA has been added. In the second run
the EWS (ethanol-water-solution) bomb did not break and the 20cm long run
consisted of 3 pieces. The drill packed after 5-7 cm of drilling and it
was needed to break. This shows that the EWS bombs are still needed. During
the 3. run the drill shorted just after the break at the bottom. It turned
out to be a short in the plug at the pressure tube. The plug was exchanged.
During the last run the drill current was very unstable and flickered between
5A and 11A. The break was only 800kg (including weight of cable and drill).
When the drill return to surface at midnight a very excited camp was waiting.
There were conglamorates of basal material at the bottom of the core and
all three cutters where totally grinded down. There was small amounts of
basal material in the slush. There is no sign of water in the borehole yet.
It was decided to go down with the drill again next morning. Drilling, daily production 1.79m, drillers depth 3089.88m. |
| Logistics |
| The skiway has been groomed, and two pallets have been built in preparation of next weeks flights. Snow had to be blown away from the inclined trenches. |
Saturday, July 24 |
|---|
| Daily life |
| A day with mostly sunny sky. Wind from 10-16 kn from
240M. Drifting snow and temperatures from -10 to -18 deg C. Today is Saturday, and everybody was ready for a nice Saturday evening after a very exciting week. The evening started with small pizzas as appetizers, a Tour de NorthGRIP including a warm drink in the "Cathedral" followed by an excellent dinner prepared by Peter Iversen. Dancing most of the night. |
| Science |
| The first run resulted in no core and cutters that where
grinded down exactly like the cutters in the last run Friday. It was decided
to change to hardened cutters hoping it would be possible to penetrate the
obstacles. Small teflon shoes where produced for the hardened cutters in the
workshop. While this was going on a run was made with the worn down cutters
in which the drill was brought down cold in order to definitly to test if
there is water in the borehole and to collect slush near at the bottom of
the borehole. No ice covered the drill when it returned to the surface and
the chipchamber was 50% full of slush. We are now ready to 1. Drill with the
hardened cutters. 2. Try to remove the obstacle with the conical reamer
and finally 3. Try the sediment sampler. Drilling, daily production 0.00m, drillers depth 3089.88m. |
| Logistics |
| The last pallet in camp has been freed so it can be
packed for the coming flights. |
Sunday, July 25 |
|---|
| Daily life |
| Last day of deep drilling at NGRIP. The drill tower
is scheduled to go back on next weeks flight, and as you can see below the
drilling was finished just in time with very exciting results! A good day with no wind and blue sky. Temperatures from -10ish to - 18 deg C. |
| Science |
| In the first run #118, the hardened cutters where used.
They became just as grinded down as the last 2 sets of normal cutters. The
slush is becoming redder and we find small pebbles and mud inclusions in
the slush. In the second run #119, the conical scraper was mounted. While
scraping the current flickered up and down as did the load cell just like
under the drilling runs. On surface frozen mud and ice was sticking to the
scraper and the chip champer was 50% full with quite reddish slush. A few pine needles or grass pieces were found in the slush. If they are not things dropped in the borehole these organic items must be several million years old. A third run #120 was made with the sediment sampler and most of the camp personal got their try in ramming the sampler down full speed in the bottom. On surface the sampler was seen to contain lumps of ice and lumps of mud. A last run #121 was made with the scraper because we believe this is how we recover most bottom material. Again a 50% full chip chamber. No sign of water in the borehole. The drilling is hereby declared terminated. Tomorrow we will filter the hole and bail some of the bottom liquid with ethanol up. It is our hope to send the drill tower out on the skier on Tuesday. We have had fantastic and eutusiastic drill teams this season - thank you all. |
| Logistics |
| The skiway has been groomed after i light snowfall yesterday,
and batteries and casing tubes have been packed. |
Continue to Week 31
| Main page | Diary | Pictures | About us | Ice cores | Links |