[CHAPTER III]
THE VOLCANIC ISLAND OF HAWAII
The volcanic island of Hawaii, the largest of the Sandwich Island chain, is situated in the mid Pacific, south of the Tropic of Cancer. As shown in [Fig. 5], this island chain consists of Hawaii, Maui, Molokai, Oahu, Kauai, Nihau, and about eight large islands, together with numerous small islands, extending in a general northwest direction from Hawaii to Nihau, a distance of about 400 miles. Like most volcanic islands they lie in more or less straight lines, probably along fissures, in this case in two nearly parallel lines. The island of Nihau, however, is an exception, the direction of the greatest length being almost straight across the two parallel lines.
The Sandwich Islands lie 2,000 miles from San Francisco in deep water, between 2,000 and 3,000 fathoms, or between 12,000 and 18,000 feet in depth. This island chain consists of great volcanic mountains, that had, at one time, fifteen active volcanoes of the first class. These are now all extinct but three, and all of these are on the island of Hawaii.
In his report to the United States Geological Survey for 1882-83, Dutton states that the summit of Mt. Haleakala on East Maui is 10,350 feet above the sea level. Oahu has peaks on its eastern side 2,900 feet high, and peaks on the western side 3,850 feet high. The summit of Kauai is probably 6,200 feet above the sea.
Fig. 5. The Hawaiian Islands
From U. S. Geological Survey
It can be shown by deep-sea soundings that all these volcanic piles are the summits of a gigantic mountain mass that rises abruptly from the bed of the Pacific. There are reasons for believing that this submarine chain continues for many hundreds of miles in the same direction beyond Kauai.