486 



C. H. HITCHCOCK MOHOKEA CALDERA 



Mokuaweoweo and Kilauea on Hawaii, Haleakala on Maui, and Crater 

 lake in Oregon are cited as examples. 



Location and Peculiarities of Mohokea 



The Mohokea depression is situated in Kan, in the southwestern part 

 of the island of Hawaii, to the north of the harbor of Honuapo, which at 

 present is the end of the sea voyage for those who skirt the leeward side 

 of the great island on the way from Honolulu to Kilauea. There is a 

 line of stages from Honuapo to the volcano, rising gradually for a dis- 

 tance of 30 miles to the altitude of 4,040 feet. Hilea, about 4 miles from 

 the seaport, is the best point from which to traverse the depression. It is 

 the residence of the head overseer of the sugar plantation, who very kindly 

 accompanied me to the principal points of interest in the caldera. From 

 the house, situated upon lava, the road ascends a steep hill covered by 

 volcanic ashes to about 1,200 feet altitude, and thence another thousand 

 feet to Makawao, where the soil seems to have originated from rock de- 

 composition. This hill is on the southeast side of Kaiholena, the highest 

 elevation in the district. 



Mauna Loa is an elongated dome 13,650 feet in height, sloping grad- 

 ually to the sea or to an intersection with an adjacent volcano. On the 

 northwest side, next to Hualalei, the base is 4,500 feet; on the northeast 

 side, next to the extinct Mauna Kea, at the sheep ranch Humuula, the 

 col is 6,600 feet ; on the southeast side, next to Kilauea, the base is about 

 3,800 feet. The slopes to the sea at Hilo and South cape are gradual 

 for distances of 30 miles. The mass of Kilauea is often regarded as 

 being on the flank of Mauna Loa, because the discharges from the latter 

 cover up much of the former. Kilauea is as well defined a caldera, with 

 its own periods of eruption, as Mokuaweoweo. The locations of the 

 eruptions from Kilauea range from Nanawili, in Puna, on the east, to 

 Punuluu on the west, which is on the seashore only 3 miles from Hilea. 

 A. very conspicuous fault extends 20 miles long from Kohaualea westerly 

 to near the flow of 1823. The land makai (shoreward) of this fault has 

 dropped down 1,100 feet. A somewhat similar but more irregular es- 

 carpment may be traced from near Kapapala to Waiohinu, 17 or 18 miles 

 in length, but is on the south slope of the mass of Mauna Loa. The 

 caldera of Mohokea has this escarpment for its southern boundary. It is 

 an elliptical depression, 6 miles long northwest and southeast, and 5 

 miles wide northeast and southwest, but truncated by the escarpment 

 named. It has been hollowed out from the basaltic sheets of Mauna Loa. 

 The total area is about 30 square miles. 



