The FNCA meeting included presentations by ANSTO researchers on the use of stalagmites in climate studies, radiocarbon in environmental and climate research, cosmogenic isotopes
in climate and landscape, and a tour of ANSTO facilities.
Cosmic rays bombard the Earth's surface and build up cosmogenic isotopes
in surface rocks.
In his research, Muscheler worked to reconstruct previous changes in solar activity by studying how cosmogenic isotopes, for example of beryllium-10 and carbon-14, have been stored in both ice cores and annual rings in trees.
Cosmogenic isotopes are formed in the atmosphere as a result of cosmic radiation from space.
Galactic cosmic rays, that is, those originating beyond the solar system, generally have higher energies than solar cosmic rays and are, therefore, more likely to produce cosmogenic isotopes during collisions.
Methods involving cosmogenic isotopes typically entail measurement of the present activity of a radioactive isotope in a sample by counting disintegrations or determination of the isotopic concentration by mass spectrometry.
2006, Using cosmogenic isotopes
to interpret the landscape record of glaciation: Nunataks in Newfoundland: in, Knight, P.
Bierman PR (1994) Using in situ produced cosmogenic isotopes to estimate rates of landscape evolution: a review from the geomorphic perspective.
Bierman P, Steig EJ (1996) Estimating rates of denudation using cosmogenic isotope abundances in sediment.
The premise of cosmogenic isotope surface exposure dating is that buildup and accumulation of cosmogenic isotopes begins once a rock is exposed at or near the surface.
Beryllium-10 cosmogenic isotope analysis of two tors and three outcrops from the upper surface indicate the island has been under the influence of a subaerial periglacial environment at least for the last 36 000 years (MIS 3) and probably for 254 000 (MIS 7/8).
Objective: The rate of production of cosmogenic isotopes
plays an important role in our understanding of past climate variability since they provide information about the solar irradiance related to the Sun s magnetic field.