THE ONE A NATIONAL PARK IN NORTHERN CALIFORNIA, THE OTHER A NATIONAL MONUMENT IN ALASKA
BECAUSE most of the conspicuous volcanic eruptions of our day have occurred in warmer climes nearer the equator, we usually think of volcanoes as tropical, or semi-tropical, phenomena. Vesuvius is in the Mediterranean, Pelee in the Caribbean, Mauna Loa and Kilauea on the Hawaiian Islands. TOf course there is Lassen Peak in Californiathe exception, as we say, which proves the rule.
As a fact, many of the world’s greatest volcanoes are very far indeed from the tropics. Volcanoes result from the movement of earth masses seeking equilibrium underneath earth’s crust, but near enough to the surface to enable molten rock under terrific pressure to work upward from isolated pockets and break through. Volcanoes occur in all latitudes. Even Iceland has its great volcano. It is true that the volcano map shows them congregating thickly in a broad band, of which the equator is the centre, but it also shows them bordering the Pacific Coast from Patagonia to Alaska, crossing the ocean through the Aleutian Islands, and extending far down the Asian coast. It also shows many inland volcanoes, isolated and in series. The distribution is exceedingly wide.
Volcanoes usually occur in belts which may or may not coincide with lines of weakening in the earth’s crust below. Hence the series of flaming torches of prehistoric days which, their fires now extinguished and their sides swathed in ice, have become in our day the row of spectacular peaks extending from northern California to Puget Sound. Hence also the long range of threatening summits which skirts Alaska’s southern shore, to-day the world’s most active volcanic belt. Here it was that Katmai’s summit was lost in the mighty explosion of June, 1912, one of enormous violence, which followed tremendous eruptions else-where along the same coast, and is expected to be followed by others, perhaps of even greater immensity and power.
These two volcanic belts contain each an active volcano which Congress has made the centre of a national reservation. Lassen Peak, some wise men believe, is the last exhibit of activity in the dying volcanism of the Cascade Mountains. Mount Katmai is the latest and greatest exhibit in a volcanic belt which is believed to be young and growing.