New Zealand researchers are trying to find out whether deep ocean currents around the country slowed in
the last ice age in an attempt to better understand global warming. Knowing how much of the carbon dioxide
from the atmosphere was concentrated at the bottom of the ocean as glaciers advanced and later as the earth
warmed, is considered crucial to that understanding. A US research vessel, Roger Revelle, will collect seabed
cores. New Zealand could provide a unqiue record because the ash from North Island volcanic eruptions was
laid down over wide areas of the seabed and could now be seen as stripes in the cores of sediment that acted
as time markers. There are a total of 24 scientists on board for the four-week voyage which will take cores at
six sites in both sub-Antarctic and subtropical waters.