Reservoir effect radiocarbon dating
The relationship is consistent and linear over Antarctica. Snow falls over Antarctica and is slowly converted to ice. Past precipitation rates are an important palaeoenvironmental indicator, often correlated to climate change, and it’s an essential parameter for many past climate studies or numerical glacier simulations. Ice cores provide us with lots of information beyond bubbles of gas in the ice. 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. U from dust in the ice matrix can be used to provide an additional core chronology.
The drill fluid used is normally a petroleum-derived liquid like kerosene.
Seasonal differences in the snow properties create layers – just like rings in trees.
Unfortunately, annual layers become harder to see deeper in the ice core.
The bottom plot shows global ice volume derived from δ18O measurements on marine microfossils (benthic foraminifera) from a composite of globally distributed marine sediment cores. An example of using stable isotopes to reconstruct past air temperatures is a shallow ice core drilled in East Antarctica.
The presence of a “Little Ice Age”, a cooler period ending ~100 to 150 years ago, is contested in Antarctica.