Problems with radiometric and carbon 14 dating

15 Jan

Cores are drilled with hand augers (for shallow holes) or powered drills; they can reach depths of over two miles (3.2 km), and contain ice up to 800,000 years old.

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.

Hand augers can be rotated by a T handle or a brace handle, and some can be attached to handheld electric drills to power the rotation.

With the aid of a tripod for lowering and raising the auger, cores up to 50 m deep can be retrieved, but the practical limit is about 30 m for engine-powered augers, and less for hand augers.

It can be up to about 20 m thick, and though it has scientific value (for example, it may contain subglacial microbial populations), Cores are often drilled in areas such as Antarctica and central Greenland where the temperature is almost never warm enough to cause melting, but the summer sun can still alter the snow.

In polar areas, the sun is visible day and night during the local summer and invisible all winter.

These include soot, ash, and other types of particle from forest fires and volcanoes; isotopes such as beryllium-10 created by cosmic rays; micrometeorites; and pollen.

The lowest layer of a glacier, called basal ice, is frequently formed of subglacial meltwater that has refrozen.

The cutting apparatus of a drill is on the bottom end of a drill barrel, the tube that surrounds the core as the drill cuts downward.It can make some snow sublimate, leaving the top inch or so less dense.When the sun approaches its lowest point in the sky, the temperature drops and hoar frost forms on the top layer.A design for ice core augers was patented in 1932 and they have changed little since.An auger is essentially a cylinder with helical metal ribs (known as flights) wrapped around the outside, at the lower end of which are cutting blades.