How long does it take for ice cores to form?
Setting up base camp and drilling into the ice may take six to eight weeks for two cores that are each 700 feet long, Osterberg says. Some researchers, particularly in Antarctica, may drill two miles and take much longer.
What can be learned from ice cores?
Ice cores can tell scientists about temperature, precipitation, atmospheric composition, volcanic activity, and even wind patterns. The thickness of each layer allows scientists to determine how much snow fell in the area during a particular year.
How do ice cores show evidence of climate change?
Scientists often use ice cores to detect changes in temperatures. When snow falls it traps air into the ice. When scientists take a core of ice it reveals the atmospheric gas concentrations at the time the snow fell. This is used to calculate temperature at that time.
What are ice cores for kids?
An ice core is a long piece of ice taken from a glacier. The ice is drilled very deep, so that the ice core goes back to old ice at the bottom of the glacier. Usually, ice cores are taken from Antarctica, Greenland or very high mountains. Snow falls on ground and accumulates (gets deeper).
How long have ice cores been studied?
Ice cores have been studied since the early 20th century, and several cores were drilled as a result of the International Geophysical Year (1957–1958). Depths of over 400 m were reached, a record which was extended in the 1960s to 2164 m at Byrd Station in Antarctica.
How can the age of a layer of ice be determined?
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.
How do ice cores work?
The most important property of ice cores is that they are a direct archive of past atmospheric gasses. Air is trapped at the base of the firn layer, and when the compacted snow turns to ice, the air is trapped in bubbles. Older records of carbon dioxide are therefore best taken from Antarctic ice cores.
How are ice cores formed?
An ice core is a vertical column through a glacier, sampling the layers that formed through an annual cycle of snowfall and melt. As snow accumulates, each layer presses on lower layers, making them denser until they turn into firn. The weight above makes deeper layers of ice thin and flow outwards.
How do we date ice cores?
Ice cores can be dated using counting of annual layers in their uppermost layers. Dating the ice becomes harder with depth. Other ways of dating ice cores include geochemisty, wiggle matching of ice core records to insolation time series (Lemieux-Dudon et al.
How old are the oldest ice cores from Antarctica?
800,000 years
The oldest continuous ice core records extend to 130,000 years in Greenland, and 800,000 years in Antarctica.
Who studies ice cores?
Scientists who study Earth’s past climates, called paleoclimatologists, take a similar approach. However, instead of digging into the soil, they look for clues about our planet’s climate history by studying coral reefs, digging into ocean and lake floor sediment and drilling deeply into glaciers and ice sheets.
What do ice cores tell us about the past?
Each layer gives scientists a treasure trove of information about the climate each year. Like marine sediment cores, an ice core provides a vertical timeline of past climates stored in ice sheets and mountain glaciers. Ice sheets contain a record of hundreds of thousands of years of past climate, trapped in the ancient snow.
How old is the oldest record of an ice core?
By the time Alley and the GISP2 project finished in the early 1990s, they had pulled a nearly 2-mile-long core (3,053.44 meters) from the Greenland ice sheet, providing a record of at least the past 110,000 years. Even older records going back about 750,000 years have come out of Antarctica.
When did scientists start to drill ice cores?
To pry climate clues out of the ice, scientists began to drill long cores out of the ice sheets in Greenland and Antarctica in the late 1960s.
How long does it take to collect the deepest ice cores?
Collecting the deepest ice cores (up to 3000 m) requires a (semi)permanent scientific camp and a long, multi-year campaign [6]. If we want to reconstruct past air temperatures, one of the most critical parameters is the age of the ice being analysed.