GEOLOGY AND TOPOGKAIMIY UF HAWAII. lo5 



ers. But before such a joiiriicy is undertaken it is well to be iiiforiued of some 

 of the more important facts connected wilh Kilaiica's lonnr. varied and inter- 

 esting history, a history that in a way prepares tlic visildi' ti) j'ppreciate what 

 is to be seen at the great caldera as one stands on the vci-y Iti'ink of the burning 

 lake where the island-building activity is actually going on. 



KiLAUEA AN Independent Crater. 



Geologists supposed for a great many years that Mauna Loa and Kihiuea 

 were very closely related or sympathetic volcanoes. Further study, however, 

 has demonstrated that they are distinct in all essential features and may act in 

 the main entirely independent of each otlier, though there may be some remote 

 connection, as the eruptions in 1832, '49. '55, '68, '77, '87 and 1907 occurred in 

 both craters during the same years. The belief in reference to their intimate 

 relation seems to have grown from hasty conclusions based on llie superficial 

 fact of their proximity, their relative size and the further fact tluit they both 

 were more or less continually active. To the casual observer Kilauea, situated 

 as it is on the southeastern slope of Mauna Loa, appears to be but a secondary 

 crater,^ — a mere wart — on the side of the great dome that rises almost ten tliou- 

 sand feet above it. 



Whether Kilauea was formed before or after, or at the same time with 

 Mauna Loa, its action in recorded time has generally l)een of a character to ])rove 

 it more or less independent of the summit crater. AVbile eruptions have taken 

 place on top, Kilauea, much lower down and only sixteen miles distant, has 

 often exhibited no signs of active sympathy. So throu<i'h a long period of 

 activity it has proved itself to be a distinct crater, doing the work it has to do 

 in its own way and for that reason it is (juite properly admitted to l)e the worhl's 

 greatest active crater. 



» 



Dimensions of Kilauea. 



To give some idea of the magnitude of Kilauea it is necessary to give a few 

 of its main dimensions. The Volcano House, which is a comfortal)le hotel 

 located on the very edge of the crater, is 4,040 feet abov(» tlie •-lea. The crater 

 from north to south measures 2.93 miles ^ and from east to west 1.95 miles.- 

 Its circumference is 7.85 miles ^ and the floor of the crater has an area of 

 4.14 square miles.^ From the \^)lcano House at the present time it is 484 feet 

 down to the floor of the crater, which is made up of an uneven mass of cold, 

 ink-black, shining lava. To reach the ])resent scene of action the visitor nuist 

 descend into the crater and cross over this floor for two mih*s to the brink of 

 the pit Halemaumau. in the bottom of which perhaps one hundred and flft\- feet 

 below the observer, the red hot hiva will he seen boiling in a wild, mad fury. 



If what has been said is sufflcient to flx in mind a great, rouglily oval-sliaped 

 crater with apx^roximately vertical walls, and to make it clear ^hat the bottom 

 of this caldera is now formed of black lava of recent origin, and that it is five 



115,500 feet. = io,300 feet. ^ 41 500 feet. ■> 2650 acres. 



