Suppose a high concentration of oxygen 16 was found in the ice caves of Antarctica and Greenland. Which of the following conditions likely occurred at the time the ice was formed?

Question

Quizplus · Accepted Answer

Oxygen 16 is a stable isotope of oxygen that is present in water molecules. Its high concentration in the ice caves of Antarctica and Greenland suggests that the water from which the ice was formed had a higher concentration of oxygen 16. This, in turn, suggests that the air temperatures were cold at the time of ice formation, as colder temperatures promote the concentration of heavier isotopes like oxygen 16 in water molecules. Mild winters would not lead to a high concentration of oxygen 16 in the ice. Intense ultraviolet radiation or the caves being under the ocean would not directly affect the concentration of oxygen isotopes in the water.

Suppose a High Concentration of Oxygen 16 Was Found in the Ice