Dating tree cores
For each dating or chronological method there is a link in the box at right to take you to that section of this page.There, you will find a brief description of the method, plus links to take you to other webpages with more extensive information.It is not uncommon to read that ice cores from the polar regions contain records of climatic change from the distant past.Research teams from the United States, the Soviet Union, Denmark, and France have bored holes over a mile deep into the ice near the poles and removed samples for analysis in their laboratories.Ice-core records show that climate changes in the past have been large, rapid, and synchronous over broad areas extending into low latitudes, with less variability over historical times.These ice-core records come from high mountain glaciers and the polar regions, including small ice caps and the large ice sheets of Greenland and Antarctica.
The team were travelling across the West Antarctic Ice Sheet to study snow accumulation.
By looking at past concentrations of greenhouse gasses in layers in ice cores, scientists can calculate how modern amounts of carbon dioxide and methane compare to those of the past, and, essentially, compare past concentrations of greenhouse gasses to temperature. Ice cores have been drilled in ice sheets worldwide, but notably in Greenland and Antarctica[4, 5].
* Solar variation at 65°N due to en: Milankovitch cycles (connected to 18O). Ice core records allow us to generate continuous reconstructions of past climate, going back at least 800,000 years.
The Greenland ice sheet averages almost 4000 feet thick.
If we were to assume the ice sheet has been accumulating at this rate since its beginning, it would take less than 1000 years for it to form and the recent-creation model might seem to be vindicated. In making our calculations, we did not take into account the compaction of the snow into ice as it is weighted down by the snow above.