BookRiff

If you don’t like to read, you haven’t found the right book

How do you date an ice core?

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.

What is ice core sampling?

An ice core is a core sample that is typically removed from an ice sheet or a high mountain glacier. The physical properties of the ice and of material trapped in it can be used to reconstruct the climate over the age range of the core.

What do ice cores reveal?

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 far back can ice cores dated?

800,000 years
Ice core records allow us to generate continuous reconstructions of past climate, going back at least 800,000 years[2].

How old are the oldest ice cores from Antarctica?

The oldest continuous ice core records extend to 130,000 years in Greenland, and 800,000 years in Antarctica.

How do ice core samples work?

Ice cores are cylinders of ice drilled out of an ice sheet or glacier. Crucially, the ice encloses small bubbles of air that contain a sample of the atmosphere – from these it is possible to measure directly the past concentration of gases (including carbon dioxide and methane) in the atmosphere.

Are ice core samples accurate?

Ice cores are remarkably faithful recorders of past climate, providing multiply duplicated reconstructions with small and quantifiable uncertainties.

Why is the Vostok ice core important?

Ice cores provide uninterrupted information on important properties of paleoclimate, including local temperature and precipitation rate, humidity, and wind speed as well as changes in atmospheric composition.

What is Epica Dome C?

The European Project for Ice Coring in Antarctica (EPICA) is a multinational European project for deep ice core drilling in Antarctica. Deep drilling took place at two sites in Antarctica: Concordia Station at Dome C and Kohnen Station. In 2008 the project received the Descartes Prize for Research.

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.

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 is δ 18 O used in ice cores?

δ 18 O can be used with ice cores to determine the temperature from when the ice was formed. Lisiecki and Raymo (2005) used measurements of δ 18 O in benthic foraminifera from 57 globally distributed deep sea sediment cores, taken as a proxy for the total global mass of glacial ice sheets,…

What can δ 18 O be used for?

δ 18 O can be used with ice cores to determine the temperature from when the ice was formed.

How are isotopes used to date ice cores?

Both the δ 18 O values and the temperature data are from the summit of the Greenland ice sheet some 3200 meters above sea level. Source. The clarity of the annual signal in the isotope data makes counting of annual layers in δ 18 O data one of the most accurate ways of dating ice cores.

How is a δ18 O increase equivalent to a cooling?

Based on the simplifying assumption that the signal can be attributed to temperature change alone, with the effects of salinity and ice volume change ignored, Epstein et al. (1953) estimated that a δ18 O increase of 0.22‰ is equivalent to a cooling of 1 °C (or 1.8 °F).