RISE OF MOLTEN ROCK TO THE EARTH'S SURFACE 109 



Although in many cases the lava which has thus flooded the 

 crater has suddenly drained away without again becoming visible, 

 it is probable that in such cases an outlet has been found to some 

 submarine exit, since under-ocean discharge effects have been 

 observed in connection with eruptions of each of the volcanoes. 



Inasmuch as no earthquakes are felt in connection with such 

 outflows as have been described, it is probable that the hot lava 

 fuses a passageway for itself into some open channel underneath 

 the flanks of the mountain. Such a course is well illustrated by 

 the outflow of Kilauea 

 in 1840, when, it will 

 be remembered, oc- 

 curred the great down- 

 plunge of the crater 

 that yielded the pit 

 below the black ledge. 

 At this time the lava 

 first made its appear- 

 ance upon the flanks 

 of the mountain at the 

 bottom of a small pit 

 or inbreak crater 

 which opened five 

 miles southeast of the 

 main crater of Kilauea 



FIG. 104. Map showing the manner of outflow of 

 lava from Kilauea during the eruption of 1840. 

 The outflowing lava made its appearance succes- 

 sively at the points A, B, C, m, n, and finally at a 

 point below n, from whence it issued in volume and 

 flowed down to the sea at Nanawale (after J. D. 

 Dana). 



(Fig. 104). Within 

 this new crater the 

 lava rose, and small ejections soon followed from fissures formed in 

 its neighborhood. Some time after, the lava sank in the first new 

 crater, only to reappear successively at other small openings (Fig. 

 104, B, C, m, n) and finally to issue in volume at a point eleven 

 miles from the shore and flow thereafter upon the surface of the 

 mountain until it had reached the sea. Only the slightest earth 

 tremors were felt, and as no rumblings were heard, it is evident 

 that the lava fused its way along a buried channel largely open at 

 the time (see below, p. 112). 



In a majority of the eruptions of Mokuaweoweo, when the 

 outflowing lavas have become visible, the molten rock has ap- 

 parently fused its way out to the surface of the mountain at 



