Oxygen isotopic ratios in the dating of ice cores dating agencies in melbourne
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.
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.
U from dust in the ice matrix can be used to provide an additional core chronology.
Slow ice flow at the centre of these ice sheets (near the ice divide) means that the stratigraphy of the snow and ice is preserved. The relationship is consistent and linear over Antarctica. Snow falls over Antarctica and is slowly converted to ice. Melt layers are formed when the surface snow melts, releasing water to percolate down through the snow pack. They form bubble-free ice layers, visible in the ice core.