Why is the core repository such an important place?
The Lamont-Doherty Core Repository (LDCR) contains one of the world’s most unique and important collection of scientific samples from the deep sea. Sediment cores from every major ocean and sea are archived at the Core Repository.
How far back do sediment cores go?
While data from ice cores stretches back over 500,000 years into the past, sediment cores have been used to look even farther back in time, up to 200 million years ago.
Where would you find the oldest sediment in a core?
The oldest continental rocks are found in cratons.
What do marine sediment cores tell us?
Rocks and soil embedded in the icebergs sink to the ocean floor and later show up in ocean sediment cores. Their final location tells scientists where currents once flowed, and, indirectly, where water warm enough to melt the ice existed. Ocean cores proved invaluable as scientists built a picture of the Ice Age Earth.
How far back in time can a record of past Antarctic climate be obtained from a sediment core?
17-million-year
What is the highest concentration of CO2 in the past 650000 years?
387 parts per million
At what time period is CO2 highest?
Concentrations reach a peak in May as the Northern Hemisphere spring greenup begins, and decline to a minimum in October, near the end of the growing season. 2 concentrations and their impact on the present-day biosphere.
How accurate is ice core data?
In the 200-year-long U.S. ITASE ice cores from West Antarctica, they showed that while the absolute accuracy of the dating was ±2 years, the relative accuracy among several cores was <±0.5 year, due to identification of several volcanic marker horizons in each of the cores.
How old is the oldest ice core?
The oldest continuous ice core records extend to 130,000 years in Greenland, and 800,000 years in Antarctica. Ice cores are typically drilled by means of either a mechanical or thermal drill.
How do you date an ice core?
Determining the age of the ice in an ice core can be done in a number of ways. Counting layers, chemical analysis and mathematical models are all used. Annual layers of snowfall recorded in an ice core can be counted — in much the same way that tree-rings can be counted — to determine the age of the ice.