IS AN ice age on its way? A new way of working out the age of ocean currents
could tell us.
You usually find out how long water has been in a current by measuring levels
of the radioactive isotope carbon-14, which has a half-life of 5000 years. It is
created by cosmic rays at the ocean’s surface, but levels gradually fall off
once currents take it down to the ocean floor. But Phillipe Collon’s team at
Columbia University in New York City have found a way to measure levels of
argon-39 instead.
“With a half-life of just 269 years it gives more detail on the…
