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?

Question

Quizplus · Accepted Answer

By looking at the sediments off west Africa, we can observe if there were biogenic sediments (marines organisms contributions) interbedded with sediments with terrigenous input corresponding to the dry, interglacial intervals. If we find biogenic sediments, it would indicate a more productive ocean during a wetter climate, which would indicate the existence of a wetter Sahara. The sediments with terrigenous input would provide evidence of increased dust input for dry interglacials when the Sahara was dry. Therefore, we could test whether the Sahara was a desert during glacial periods in the northern hemisphere. Option A and C are not relevant to the hypothesis, and D is not true.

African Dust from the Sahara Desert Is Observed Across the Atlantic