92 J. D. Dana — History of the Changes in Kilauea. 



violent shock, a decline began in the fires of Kilauea. By 

 night of that same Thursday, the liquid lavas had disappeared 

 from all cones and were confined to the lakes; by Saturday 

 night, all the lakes were emptied except the Great Lake ; 

 finally, by Sunday night, the 5th, the Great Lake had lost its 

 lavas, and all was darkness and quiet. A down-plunge of the 

 central plateau of the crater took place at the same time, so that 

 again a lower pit existed, as in 1840. Mr. Coan, in describing 

 it, says that the plateau " sagged down " 300 feet ; and. another 

 writer, after a visit to the pit, gives the same depth and re- 

 marks "just as ice falls when the water is drawn from be- 

 neath." The great sunken area had. not vertical walls, like 

 that of 1840, but sloping sides as the term "sagged" implies; 

 the slope, generally 30 to 60 feet, but at a much less angle on 

 the side toward Halema'uma'u. There was again a black 

 ledge, and it was nearly of its old width, but at a somewhat 

 higher level owing to the overflows. The emptied Great Lake, 

 3000 feet in diameter at the top, 1500 feet below, and 500 feet 

 deep, was literally empty ; it snowed no light at bottom by day 

 and not much at night. The discharge of lava may have been 

 as great as in 1840, although the lower pit made by the under- 

 mining had less extent. 



Another remarkable fact is stated that just before the earth- 

 quake of the 2nd of April, " the lavas of Kilauea burst up ver- 

 tically in Little Kilauea (Kilauea Iki). and spread over the old 

 deposit of 1832." 



On Tuesday, April 7th, five days after the beginning of the 

 Kilauea discharge, the lavas were ejected in great volume at 

 Kahuku in southwestern Hawaii, and flowed to the sea. It 

 was at first a question whether a part of the Kahuku flow 

 might not have come from Kilauea. But the extinction of the 

 summit fires occurred at the same time, and the Kahuku dis- 

 charge was in a line with fissures leading toward it from the sum- 

 mit, so that Mokuaweoweo is believed to have been their only 

 source. The conduit of the Kilauea lavas, was probably rup- 

 tured at the time of the great shock, and hence the discharge. 



The curving of the Kilauea fissures from Kapapala toward the 

 coast seems to point to a submarine discharge off that part of 

 the island. 



3. Kilauea from 1868 to 1886. 



This period of eighteen years passed without another down- 

 plunge of the floor of the pit. The gradual filling of the new- 

 made lower pit, and the ultimate merging of all slopes at the 

 crater's bottom into those leading off in all directions from 

 Halema'uma'u, are the chief events of the period. Mr. Lyd- 

 gate's map on page 94, shows an intermediate stage in the 

 progress. 



