Entries in the log mark the scientific work that continues day and night on an oceanographic cruise. During a recent cruise aboard the R/V Oceanus that WHOI scientist Phoebe Lam participated in, the objective was to determine the amount of iron in the ocean west of the Cape Verde Islands, off Africa's west coast. Every day the ship would stop so the researchers could take repeated samples of water at several depths. To collect the samples researchers used a Vane sampler, which has no metal parts that could contaminate the water.
(Photo by Alexander Dorsk, Woods Hole Oceanographic Institution)