SPACING OF VOLCANOES 505 



Quite the opposite view concerning the relative age of these two active 

 volcanoes is taken by Jaggar, who, in a recent paper^^ on the problem, 

 has called attention to the rhythmic arrangement of Kilanea, Manna Loa, 

 and Hualalai around Mauna Kea as a center. Along the Hawaiian rift 

 the lava is supposed to liave migrated from Kohala to Mauna Kea, later 

 to Hualalai as Mauna Kea became extinct, then to Kilauea, and finally 

 to Mauna Loa as Kilauea became decadent. 



Better maps of the Hawaiian Islands and a closer examination of the 

 original centers of activity may aid in elucidating the problem of the 

 arrangement of the vents and of their relative age. It must be noted 

 that the original central vents were not all located in the portions of 

 the islands now remaining. Kauai was originally a volcanic doublet, the 

 western half of which has disappeared. ]^iihau is but a remnant of the 

 original volcano, the center of which was east of the present island. The 

 Waianae volcano of western Oahu was centered not far northwest of the 

 Kolekole Pass, if we are to judge from the great number of dikes in that 

 vicinity and from the dip of the flows ; and the Koolau volcano of eastern 

 Oahu may have risen from a point between the Pali and Kaneohe, judging 

 from the same reasons. The Wailau volcano of eastern' Molokai rose 

 from a. point north of the present island. 



Measurements of distances between centers of activity are as follows : 



Miles 



Kauai : Waialeale to northwestern center 21 



Waialeale to Niihau center 33 



Northwestern center to Niihau center 35 



Oahu : Waianae — Koolau center 22^^ 



Molokai : Mauna Loa — Wailau center 22% 



Mauna Loa — Lanai center 28 



Wailau — West Maui center 28% 



Wailau — Lanai center 28 



Maui : West Maui — Haleakala 25 



West Maui — Lanai 19% 



West Maui — ^Kahoolawe 23 



Kahoolawe — Lanai 26 



Kahoolawe — Haleakala 25 



Hawaii : Kohala — Mauna Kea 23 



Kohala— Hualalai 281/2 



Mauna Kea — Hualalai 27% 



Mauna Kea — 'Kilauea 31 



Mauna Kea — Mauna Loa 25 



Mauna Loa — Hualalai 24 



Mauna Loa — Kilauea 21 



'^ T. A. Jaggar, Jr. : The cross of Hawaii, Honolulu, 1912, 12 pp. 



