376 GEOLOGY 



along the east coast of Asia is dotted with active and recently 

 extinct volcanoes. The tortuous zone of mountainous wrinkles 

 that borders the Mediterranean, and stretches thence eastward 

 to the Polynesian Islands, is another notable volcanic tract. These 

 two belts include the greater number of existing and recent vol- 

 canoes on the land. 



4. In latitude. The distribution of volcanoes appears to have 

 no specific relation to latitude. Mounts Erebus and Terror amid 

 the ice-mantle of Antarctica, and Mount Hecla in Iceland, as well 

 as the numerous volcanoes of the Aleutian chain, give no ground for 

 supposing that volcanoes shun the frigid zones, while the numerous 

 volcanoes of the equatorial zone imply that they do not avoid the 

 torrid belt. 



5. In curved lines. In the Antilles, the Aleutian Islands, the 

 Kurile Islands, and in some other tracts, there is a linear arrange- 

 ment of volcanoes, with appreciable curvatures, the convexities 

 of which are turned toward the adjacent ocean. In other cases 

 there is a linear arrangement without appreciable curvature, as 

 in the Hawaiian range. Less often, volcanoes are bunched irreg- 

 ularly, as in some of the groups of volcanic islands of the Pacific 

 (Fig. 295). 



The Relations of Volcanoes 



A significant feature in connection with volcanoes is the ap- 

 parent sympathy between adjacent vents in some cases, and their 

 entire independence in others. The recent outbursts in Martinique 

 and St. Vincent, and the concurrent symptoms of activity in other 

 places, seem to point clearly to sympathy. On the other hand, 

 the independence of neighboring vents is sometimes extraordinary, 

 as those of Mauna Loa and Kilauea in Hawaii. These two volcanoes 

 are only about twenty miles apart, the one on the top and the other 

 on the side of the same great mountain mass. The crater of Loa 

 is about 10,000 feet higher than that of Kilauea, and yet, while 

 the latter has been in constant activity as far back as its history 

 is known, the former is periodic. The case is the more remarkable 

 because of the greatness of the ejections. The outflow of Mauna 

 Loa in 1885 formed a stream 3 to 10 miles in width, and 45 miles 

 in length, with a probable average thickness of 100 feet, and some 



