Val works as a paleoclimatologist in Alaska. While studying ice core samples, she identifies an increase in the isotopic ratio of oxygen 10,000 years ago. From this discovery, she knows that Earth's temperature at that time was
7. Aside from
temperature, Val can also learn about
from the ice cores. Val's data suggests that she's uncovered a glacial
climate for this time period. During a glacial climate, Val knows, there would have been
sea level, compared to what
she witnesses today.