Greenland ice core dating
Since then, they have revealed previously unknown details of atmospheric composition, temperature, and abrupt changes in climate.Such changes include “flickers” that appear to occur in periods lasting only 3 to 10 years—much more quickly than the traditional view of the pace of climate shifts.Vostok has not been drilled to bedrock, as it is underlain by a subglacial lake some 500 metres (1,600 feet) deep that is being protected from surface contamination. In addition, it has long been recognized that high-altitude glaciers near the Equator or in temperate latitudes can supply a different view of global climate.Mountain glaciers have been cored in the Andes, the Himalayas, and on Mt. A typical ice-coring effort employs large geodesic domes for protection of an electric hollow-auger drill.Crystal structure helps determine age, as well as changes in temperature, snowfall, seasonality, and potential ice movement.Dust content is measured directly by lasers and by melting fractions of the ice and collecting residuals.The cores are handled and wrapped in clean-room facilities to prevent contamination.
Many historic eruptions over the past 2,000 years are confidently tied to core data, and others can be approximately tied to other historically or geologically dated eruptions.Our editors will review what you’ve submitted and determine whether to revise the article.Join Britannica's Publishing Partner Program and our community of experts to gain a global audience for your work!The following year GISP-2 was completed at a site 30 km (19 miles) to the west of the GRIP site.
This effort reached a depth of 3,053 (10,014 feet).Paleoclimate is studied in a more direct way by measuring the dust content in the ice, either directly or through electrical conductivity.