386 Wood — Effects in Mokuaweoweo of the Eruption of 191^. 



summit walls approached closel}' and then opened out to 

 engirdle the " south pit," which was known to Wilkes as 

 " pohaku o hanalei." At the north the "north lunate" ter- 

 minated against a low cliff rising to a platform at a still higher 

 level situated at the northeast end of the crater as a whole. In 

 this paper this will be referred to as the " northeast platform." 

 In it was sunk a small, deep, " north pit " near its eastern 

 border. According to the figures given by Dana* on the cut 

 of this map published by him, in 1885 the floor of the large 

 central depression was S00 feet (about 241 meters) below the 

 highest, western, summit point, 250 feet (about 76 meters) 

 below the south lunate platform near its west end and 50 feet 

 (about 15*2 meters) below the north lunate bench near its cen- 

 ter. This bench, moreover, stood some 125 feet (about 15*7 

 meters) lower than the edge of the northeast platform near its 

 center. 



Subsequent to 1885 there has been action in Mokuaweoweo 

 on several occasions, as follows : Possibly in 1887 for a day or 

 two beginning January 16, preceding the flow at the south, — 

 though there was no direct observation or definite report of 

 this; in 1892 for three days, more or less, beginning December 

 1 ; in 1896 for about fifteen days beginning April 21 ; in 1899 

 for four or five days beginning July 1, preceding the flow at 

 the northeast; in 1903 for about two months beginning Octo- 

 ber 6 ; and possibly in 1907 for a short time beginning Janu- 

 ary 10, preceding the flow at the south. 



Then followed the action beginning on November 25, 1911, 

 and ending on or about January 10, 1915, the effects of which 

 are here under discussion. 



As a result of all this action at the summit prior to 1913 the 

 writer found that the crater in October of that year exhibited 

 marked changes with reference to the map of 1885. 



The floor of the large central depression had been built up 

 very considerably by outflow of lava upon it. Thus the height 

 of the cliff under the south lunate platform had been much 

 reduced, though no numerical estimate of the amount can be 

 ventured. Also, in all probability, a small portion of this plat- 

 form, near its contact with the west wall, had collapsed into 

 the central depression, making a recess at this place deeper than 

 that mapped in 1885. 



At the north side of the central depression the floor had 

 been up-built so much that new lava had over-run by far the 

 greater part of the north lunate platform — its lower central 

 portion, — leaving uncovered only its higher, sloping portions, 

 which rise at the west and east to their contacts with the main 



* J. D. Dana, Characteristics of Yolcanoes, plate X, p. 181. New York, 

 1891. 



