VOLCANOES. 27

 

45. The number of volcanoes is not accurately
known. The best authorities estimate it at about
672, of which 270 are active. Of the latter, 175
are on islands, and 95 are on the coasts of the con-
tinents.

46. Regions of Voleanoes.—The principal vol-
canic regions of the earth are—*

(1.) Along the Shores of the Pacific, where an
immense chain of volcanoes, with but few breaks,
encircles it in a huge “Sea of Fire.”

On the Eastern Borders, in the Andean range,
are the volcanic series of Chili, Bolivia, and Ecua-
dor; those of Central America and Mexico; in
the United States are the series of the Sierra
Nevada and Cascade ranges and of Alaska; and
finally, connecting the system with Asia, the vol-
canic group of the Aleutian Islands.

On the Western Borders volcanoes occur in the
following districts: the Kamtchatkan Peninsula,
with its submerged ranges of the Kurile Islands;
the Japan, the Loo Choo, and the Philippine
Islands; the Moluccas; the Australasian Island
Chain, terminating in New Zealand ; and finally,

nearly in a line with these, the volcanoes of Ere-’

bus and Terror on the Antarctic continent.

(2.) In the Islands of the Pacifie—Volcanic
activity is not wanting over the bed of the Pa-
cific. The Sandwich Islands, the Society Group,
the Marquesas, Friendly Islands, New Hebrides,
Ladrones, and many others, are volcanic.

(3.) Scattered over the Seas that divide the
Northern and Southern Continents, or in their
Vicinity, viz.: in the neighborhood of the Carib-
bean Sea, in the Mediterranean and Red Seas,
and in the Pacific and Indian Oceans between
Asia and Australia.

In the neighborhood of the Caribbean Sea.—This
region includes the two groups of the Antilles in
the Caribbean Sea, and the Gallapagos Islands in
the Pacific Ocean.

In the neighborhood of the Mediterranean and
Red Seas.—This region includes the voleanoes of
the Mediterranean and its borders, those of Italy,
Sicily, the Grecian Archipelago, of Spain, Central
France, and Germany, together with those near
the Caspian and Red Seas.

Between Asia and Australia.—This region in-
cludes the Sunda Islands, Sumatra, J ava, Sum-
bawa, Flores, and Timor, which contain numerous
craters. In Java there are nearly 50 volcanoes,
28 of which are active, and there are nearly as

 

* We follow mainly the classification of Dana.

4

 

 

many in Sumatra. There ate 169 volcanoes in
the small islands near Borneo.

(4.) In the Northern and Central Parts of the
Atlantic Ocean.

All the islands in the deep ocean which do not
form. a part of the continent are volcanic; as,
for example, the island of St. Helena, Ascension
Island, the Cape Verdes, the Canaries, the Azores,
and Iceland. The Cameroons Mountains, on the
African coast near the Gulf of Guinea, together
with some of the islands in the gulf, are volcanic.

(5.) In the Western and Central Parts of the
Indian Ocean.

Volcanoes are found in Madagascar and in the
adjacent islands. They also occur farther south,
in the island of St. Paul and in Kerguelen Land,
and in Kilimandjaro, near the eastern coast of
Africa.
~ 47, Submarine Volcanoes.—From the difficulty in ob-
serving them, submarine volcanoes are not so well known
as the others. The following regions are well marked:

In the Mediterranean Sea, near Sicily and Greece.

Near the island of Santorin the submarine volcanic en-
ergy is intense. It has been aptly described as a’ region
“Where isles seem to spring up like fungi in a wood.”

In the Atlantic Ocean; off the coast of Iceland; near
St. Michael, in the Azores; and over a region in the nar-
rowest part of the ocean between Guinea and Brazil.

In the Pacific Ocean; near the Aleutian Islands,
where two large mountain-masses have risen from the
water within recent time. Near the Japan Islands, where,
about twenty-one centuries ago, according to native his-
torians, Fusi Yama, the highest mountain in J. apan, rose
from the sea in a single night.

In the Indian Ocean, the island of St. Paul, in the
deep ocean between Africa and Australia, exhibits signs
of submarine activity.

48. Peculiarities of Distribution—Nearly all
volcanoes are found near the shores of continents
or on islands.

The only exceptions are found in the region
south of the Caspian Sea, and in that of the
Thian Shan Mountains. As volcanoes are but
openings in the earth’s crust which permit an es-
cape of materials from the pasty interior, they
will occur only where the crust is weakest. This
will be on the borders of sinking oceans, in the
lines of fracture formed by the gradual separa-
tion of the ocean’s bed from the coasts of the
continent. The floor of the ocean in all latitudes
is covered with a layer of quite cold water, so
that the difference in the amount of the contrac-
tion will in general be most marked on the bor-
ders of the oceans or on the edges of the conti-
nents.

In most regions the volcanoes lie along lines