Related Experiment Video
Updated: Jul 27, 2026

Sediment Core Extrusion Method at Millimeter Resolution Using a Calibrated, Threaded-rod
Published on: August 17, 2016
New half-life measurement of 182Hf: improved chronometer for the early solar system
C Vockenhuber1, F Oberli, M Bichler
1Vienna Environmental Research Accelerator (VERA), Institut für Isotopenforschung und Kernphysik, Universität Wien, Währinger Strasse 17, A-1090 Wien, Austria.
Abstract:
The decay of 182Hf, now extinct, into stable 182W has developed into an important chronometer for studying early solar system processes such as the accretion and differentiation of planetesimals and the formation of the Earth and the Moon. The only 182Hf half-life measurements available were performed 40 years ago and resulted in an imprecise half-life of (9+/-2)x10(6) yr. We redetermined the half-life by measuring the specific activity of 182Hf based on two independent methods, resulting in a value of t(1/2)(182Hf)=(8.90+/-0.09)x10(6) yr, in good agreement with the previous value, but with a 20 times smaller uncertainty. The greatly improved precision of this half-life now permits very precise intercalibration of the 182Hf-182W isotopic system with other chronometers.
Related Concept Videos
Radioactive Decay and Radiometric Dating
High-Resolution Mass Spectrometry (HRMS)
Chemical Shift: Internal References and Solvent Effects
The internal reference compound generally used in NMR spectroscopy is tetramethylsilane (TMS). TMS is preferred because it is chemically inert, soluble in NMR solvents, and easily removable. Also, the highly shielded methyl protons in TMS yield an intense...

