Cosmogenic burial dating
I was wondering how ice cores are dated accurately.
I know Carbon 14 is one method, but some ice cores go back hundreds of thousands of years.
Would other isotopes with longer half-lives be more accurate? Ice cores can be dated using counting of annual layers in their uppermost layers. Other ways of dating ice cores include geochemisty, wiggle matching of ice core records to insolation time series (Lemieux-Dudon et al.
2010), layers of volcanic ash (tephra) (Vinther et al., 2006), electrical conductivity, and using numerical flow models to understand age-depth relationships (Mulvaney et al., 2012), combined with firn densification modeling to estimate the delta-age (Lemieux-Dudon et al. Usually multiple methods are used to improve accuracy.
Icebergs ‘ground’ on the ocean floor when their keel is deeper than the water depth.They may become stuck until high tide floats them off, or if they are washed into a shallow area, until they melt sufficiently to float away.