African dust from the Sahara desert is observed across the Atlantic as far west as the Caribbean region where it produces a hazy sky condition during the annual dry season. You are a climate scientist and make a prediction that the Sahara was not a desert during glacial periods in the northern hemisphere. How could you test this hypothesis by looking at deep sea sediments from the Atlantic off west Africa?
◦ The hypothesis is untestable with deep sea sediment.
◦ You would look at fossils to see if there were organisms that preferred dusty conditions vs. clear water conditions.
◦ You could measure the isotopes in the sediment to estimate the sea surface temperatures.
◦ You could look at the sediments to see if there were biogenic sediments interbedded with sediments with terrigeneous input corresponding to the dry, interglacial intervals.