Global Warming - Icecore Data from Greenland

Icecore Data from Greenland - Dye3

The GISP (Greenland Ice Sheet Program) initiative collected 20 cores from the Greenland ice sheet. Of these, the Dye 3 ice core (located at lat. 65.19N, Long. 43.82W) is the deepest at 2037 meters. Though many analyses appear to have been done, only two files are available

dye3.txt	delta 18-O verses depth
dye3-1yr.txt	delta 18-O verses time

I was hoping for CO2 data, but, alas, only delta ¹⁸O (a temperature proxy) is available.

Here are some plots of this data.

No data is collected for the firn - the top 82.11 meters.
When depth is used for the x-axis, the newest data is on the left; when age is used, it is on the right.
At a depth of about 1,540 meters, the delta ¹⁸O data changes significantly. I have not found this discussed in the literature. However, it appears that fewer measurements per meter were taken below this point. Therefore, I am assuming that the filtering algorithm changed. In other words, the data above this transition is more representative of reality, and data below this level is more filtered.
The full core covers about 20,000 years, but the dataset with associated dates covers only about 4,000 years.

Refs: Constitutive properties of ice at Dye 3, Greenland

This zoom of the most recent few centuries shows without a doubt that the Little Ice Age (LIA) (around 1650 AD) is not recorded. It is ice cores like these that support the theory that the LIA was regional and not global.

However, you should also note that, because the data record ends in 1872 AD, this data can not be used to determine if the current temperatures are higher than at any time in the recent past.

δ¹⁸O is a well known temperature proxy. However, it is also possible to actually measure the temperature of the inside of the borehole. Combining the δ¹⁸O data from above with borehole temperatures from the Niels Bohr Institute Centre for Ice and Climate produces the following. Notice - there is no correlation at all between the two data sets. Oh, and the Medieval Warm period (around 900 AD) and the LIA are very obvious.

Greenland dye3 - delta 18O and borehole temperature

What this data does indicate is that at the end of the last ice age, there was very little ice on Greenland. Specifically, when it was much colder than today, there was much less ice. It wasn't until after the global temperature started to rise that significant ice accumulation began. Let's be clear

Warmer weather causes more ice Thus, the Al Gore doom and gloom of warmer weather causing the Greenland ice cap to melt is totally disproved by simply looking at the data.

Well, it is not quite that simple

It is possible that there was a lot more ice on Greenland during the last ice age
Most of the ice melted when the Earth warmed
Then, around 4,000 years ago, the Earth had cooled enough that the ice started to come back

There are other possible scenarios, but the point is that there is a lot more ice now than there was 4,000 years ago .. and no one has presented any evidence of falling sea levels.

Do you see the point? If 4,000 years of ice accumulation does not cause sea levels to fall, then the Global Warming claim that the Greenland ice cap is melting can not be used to predict a 26 foot sea level rise.

Well, this is only one core .. let's see what the others say.

Ref: Wikipedia provides some good background.

Author: Robert Clemenzi

Icecore Data from Greenland - Dye3

URL: http:// questionable-science.com / Global_Warming / Icecore_Data / Greenland-Dye3.html