Lawrence Livermore National Laboratory

Cosmogenic isotopes are rare isotopes created when a high-energy cosmic ray interacts with the nucleus of an atom, causing cosmic ray spallation.

These isotopes are produced within earth materials such as rocks or soil, in Earth's atmosphere, and in extraterrestrial items such as meteorites. By measuring cosmogenic isotopes, scientists are able to gain insight into a range of geological and astronomical processes.

Cosmogenic nuclides can provide a measure of how long minerals have been within the upper meter or so of the Earth's surface and provide fundamental information about landform age and landform modification rates. The ability to measure the concentrations of cosmogenic nuclides in rock and sediment has revolutionized geomorphology. Erosional surfaces and depositional features formed by rivers or glaciers can be dated directly. Before the advent of quantitative cosmogenic nuclide methods landform ages were estimated or dated indirectly via correlation or by constraining ages from underlying and overlying sediments.

CAMS specializes in the AMS measurements of several cosmogenic isotopes, including Be-10, Al-26, and Cl-36 for a wide range of earth science applications Current projects include research in applications of cosmogenic nuclides to assess terrestrial paleoclimate records, earthquake fault slip rates, erosion rates and landscape evolution, seismic hazard and extreme ground motion assessments, geomorphological processes in semi-arid environments, atmospheric circulation, hydrology, burial dating, and calibration of cosmogenic nuclide production rates.