1. Scattered Over the Pacific Ocean.—This district includes the following active volcanoes; i. e., the Hawaiian Islands, nearly in mid-ocean, almost directly below the Tropic of Cancer; in the west central parts of the South Pacific; in the New Hebrides; in the Friendly Islands, the Tongan or New Zealand Islands, in the Santa Cruz Islands, and in the Ladrones.
Fig. 24. Map of the World, Showing Location of Active and Recently Extinct Volcanoes
2. On the Borders of the Pacific.—This district includes the volcanoes that extend from the southern part of South America at intervals along the Andes Mountain range. Of these there are thirty-two in Chile, seven or eight in Bolivia and Southern Peru; about twenty in the neighborhood of Quito. Further north there are thirty-nine in Central America, and seven in Mexico. Proceeding northwards through the United States, there are a number of volcanic mountains, generally extinct, in portions of the Sierra Nevadas and Cascade Ranges. Probably a number of volcanic mountains exist in portions of Canada lying between the northern boundaries of the United States and Alaska, and a number in Alaska; some twenty-one volcanic mountains in the Aleutian Islands; some fifteen or twenty in Kamtschatka; thirteen in the Kuriles; some twenty-five or thirty in Japan and the neighboring islands; some fifteen or twenty in the Philippines; several along the northern coasts of New Guinea; a number in New Zealand and south of Cape Horn; the volcanoes of the Deception Island with its hot springs, and also in the South Shetlands 62° 30' S.
3. In the Indian Ocean.—On the western border of the Indian Ocean there are a few volcanoes in Madagascar; in the Island of Bourbon; Mauritius; the Comoro Islands; and in Kerguelen Land on the south. There are also volcanoes on the western border of the Indian Ocean where the lofty peak of Kilima Ndjro, 18,000 feet, is volcanic.
4. Over the Seas that Separate the Northern and the Southern Continents and in their Vicinity.—This is an especially active region of volcanoes. For the sake of convenience the continents of the world are sometimes divided into three pairs or double continents; namely, North and South America, connected by the Isthmus of Panama; Europe and Africa, connected by the Isthmus of Suez; and Australia and Asia, completely separated by a sunken isthmus, the summits of which form the Sunda Island chain. In the first of these regions we have the very active group of the West Indies, where there are ten volcanic islands. In the second pair of double continents we have the volcanoes of the Mediterranean and Red Seas, and their borders, such as Sicily, Vesuvius, and other parts of Italy, Spain, Germany, the Grecian Archipelago, Asia Minor, and extending eastward through the Caspian, Mt. Ararat, Demavend, on the south shores of the Caspian, Mt. Ararat, and some few others along the borders of the Red Sea.
In the East Indies we find the most intense centre of volcanic activity in the world. Here there are some 200 volcanoes of which there are nearly fifty in Java alone, more than half of which are still active. There are nearly as many volcanoes in Sumatra, and many in the small islands near Borneo, the Philippines, etc.