Which of the following correctly lists the climate indicated by a higher 18O/16O ratio in ocean sediment cores and a higher 18O/16O ratio in ice cores?
A)Cooler; warmer.
B)Warmer; cooler.
C)Cooler; cooler.
D)Warmer; warmer.

Question

Quizplus · Accepted Answer

A higher 18O/16O ratio in ocean sediment cores is indicative of cooler climates because during colder periods, more of the lighter isotope 16O is taken up by ice sheets, leaving a higher proportion of 18O in ocean water. Similarly, a higher 18O/16O ratio in ice cores indicates a warmer climate. This is because during warmer periods, more of the lighter isotope 16O evaporates from the ocean and falls as snow, leaving a higher proportion of 18O in the remaining water, which eventually becomes ice.

Which of the Following Correctly Lists the Climate Indicated by a Higher