06

Landscapes of Japan, 06, Mt. Iwate, a composite or strato-volcano, Backbone Range, elevation 6,734 feet.

Landscapes of Japan, 06, Mt. Iwate, a composite or strato-volcano, Backbone Range, elevation 6,734 feet

Mt. Iwate, a composite or strato-volcano, Backbone Range, elevation 6,734 feet. -- Contributing to the mountainous terrain of Japan are about 200 volcanoes constituting about 6 percent of the Japanese land area. Sixty of these have been active at since the 7th century, sometimes with disastrous results. Volcanoes are formed at boundaries of converging earth plates where one plate descends deep enough beneath the other plate to start melting. The molten rock material, called magma below the earth's surface and lava above it, is relatively light and rises to the surface where it erupts. Depending upon the composition of the lava, eruptions range from relatively quiet extrusion of lava to hazardous explosive ejection of ash and burning gases. -- Some volcanoes, such as Mt. Iwate, erupt lava of different composition at different times. These are called composite or strato-volcanoes and have typical concave shapes with steeper slopes at the top.
 
Editorial assistant: Joseph Augustin. Collection librarian: Amy Bryant. Please send any questions, comments, or content corrections to Michael Thiedeman, Professor of Art, Earlham College, Richmond, IN 47374 USA. email address: thiedmi@earlham.edu -- For specific reference to the images in the Landscapes of Japan set, you are invited to contacted Dr. Charles Martin, Professor Emeritus, Dept. of Geology, Earlham College, email address: martich@earlham.edu