Page:Popular Science Monthly Volume 77.djvu/448

442 was elevated only recently, and certainly not longer ago than in late Tertiary times.

Altogether the most interesting problem raised by Alexander Agassiz's researches in the Pacific is the question of the relation between these elevated tertiary reefs and the growing coral reefs of to-day, and it still remains unsolved, despite the careful studies made by Mr. E. C. Andrews, whom Alexander Agassiz sent to the Fiji Islands especially to study this problem, for Andrews's investigation has merely served to show that the subject is very complex and can not be solved until prolonged study of certain favorable localities has been completed.

From August, 1899, until March, 1900, Alexander Agassiz had for the second time the scientific direction of the Albatross. Commander Jefferson F. Moser, U.S.N., was in command and the cruise began at San Francisco and extended across the tropical regions of the Pacific to the Ladrone Islands and thence northward to Japan. On this great cruise the Albatross visited the Marquesas, Paumotos, Society, Cook, Nieue, Tonga, Fiji, Ellice, Gilbert, Marshall, Caroline and Ladrone Islands, steaming many thousands of miles in and out among the atolls. From San Francisco the vessel steamed 4,000 miles straight to the Marquesas, making many soundings and trawl hauls which led to the discovery that there is here a great basin between 2,500 and 3,000 fathoms deep, the bottom of which is covered with manganese nodules and the teeth of extinct sharks. It was an impressive sight to see the great trawl bring up tons of the manganese nodules looking like gritty brown potatoes, and all nearly as cold as ice, for the temperature of the deep floor of the ocean here was less than 3° F. above freezing. Despite the heat of the tropic sun beating upon our deck our hands stung with the cold as we felt among the mass of nodules and cracked them open to discover the enclosed nucleus of pumice, the encrusted ear-bone of an extinct whale or a shark's tooth imbedded in the soft brown rock. Some of these shark's teeth were so large that the shark itself was probably more than a hundred feet long. A deep submarine area far greater than that of the United States is covered thickly by these manganese nodules and sharks' teeth, and Alexander Agassiz named it the "Moser Deep," in honor of the commander of the Albatross.

Very little animal life was found, either floating in the sea or on the bottom, over this vast desert of manganese nodules.

The chief result of this expedition was the discovery that a widespread elevation of the Pacific islands occurred in late Tertiary times. The Hawaiian, Paumotos, Society, Cook, Nieue, Tonga, Fiji, Ladrone and Caroline Islands all show elevated coral or limestone reefs, but there are no visible indications of elevation in the Marshall or Gilbert Islands where the underlying rock is not lifted above the sea. Makatea in the Paumotos may have been an atoll which was elevated about 230