Question R17 Q24 - NSB 2013

How is the ratio of oxygen-18 to oxygen-16 useful in serving as a proxy for paleoclimatic [pay-lee-oh-kly-MAH-tik] temperatures in ice-core samples?

W) Oxygen-16 is preferentially stored in ice and only released during warmer periods

X) Oxygen-16 changes into oxygen-18 at higher temperatures

Y) Oxygen-18 is released from water molecules at higher temperatures

Z) Water with oxygen-18 freezes at lower temperatures than water with oxygen-16

Science Bowl Question