11 June 2010

Now it is beginning to get exiting

Gregory inspects the polished ice before it goes into the optical scanner.

If drilling continues at the present rate, then in the next few weeks it
will be revealed what the ice sheet here at NEEM might be hiding at depth.
We are still in known territory. Everything we see can be related to the
other ice cores from Greenland. The NGRIP ice core is so far the longest
in time, reaching some 125,000 years back, until the middle of the
previous interglacial, the EEMian. There it stopped, because melting at
the base due to geothermal heat had melted away all older layers from

The NEEM site was selected from radar survey to be where the ice at
the base should be much older, so that an ice core from here should reach
back through the EEMian and into the second last ice age.

However, radar images can be misinterpreted, and we believe that there is
some basal melting here at NEEM too. The question is: How much melting?
If basal melting is more intense than we think, then we should soon begin to find
our ice layers deeper than expected, because melting removes layers from
below, causing all layers above to sink. If basal melting is weaker, or it
doesn’t occur, then our ice layers should soon show up higher in the ice
than expected. Right now, it looks fine. Our layers are 5 m above
predictions, but it is still too early to say anything conclusive…

What we have done today:
1. Drilling and logging.
2  Processed ice cores: 38 bags, from 3546 to 3583.
3. Measuring CFA. Measured 17.6 m. CFA depth: 1605.45 m.
4. Welding stabilizers onto runners of one tank sled.
5. Removing snow drifts between the two workshop tents.

Ad.1: Drillers report:
Drilling is in a stable mode. Today we made several good runs with full
chip recovery. In one run the core broke some 50 cm from the top; but we
were able to go down and collect the rest in good order.

Driller’s depth 2030.83 meters.  Logging depth: 2039.95 m.

Ad.2: The onset of IS 19 and the termination of IS 20 have been found at
2009.5 m and 2015 m respectively using the DEP profile.

Weather: Some sun and several strong snow showers. Temp. - 15 °C  to - 5 °C ,
10-15 knots from SE and S. Visibility: Unrestricted, during showers down
to ¼ mile.

FL, J.P. Steffensen


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