1. During the last glacial maximum, 20,000 years ago, the amount of ice is estimated to have been 52,000,000 km3 more than it is today. When water freezes, the ice produced is about 110% of the water volume. Calculate the volume of water that would be tied up if glaciers returned to the same volume as 20,000 years ago. Would sea level rise or fall?
a. 52,000,000 km3 of water, sea level would fall
b. 57,200,000 km3 of water, sea level would rise
c. 57,200,000 km3 of water, sea level would fall
d. 46,800,000 km3 of water, sea level would fall
e. none of the above
2. Why would the ratio of 18O to 16O increase in shells of forams during ice ages?
a. when Earth’s climate becomes colder, 18O does not evaporate as easily as 16O from the oceans, therefore relatively more 18O is incorporated into the shells of forams.
b. when Earth’s climate becomes colder, 16O does not evaporate as easily as 18O from the oceans, therefore relatively more 18O is incorporated into the shells of forams.
c. when Earth’s climate becomes colder, 18O does not evaporate as easily as 16O from the oceans, therefore relatively more 16O is incorporated into the shells of forams.
d. when Earth’s climate becomes colder, 18O evaporates similarly to 16O, therefore relatively more 16O is incorporated into the shells of forams.
e. none of the above
3. What would happen to the ratio of 18O to 16O of ice during ice ages? The water evaporated from the ocean is precipitated as snowfall that becomes part of the ice sheet.
a. Increases
b. Decreases
c. Stays the same.