KILAUEA 269 



identity in location can have been bnt very small. It may be added that 

 a slight shifting of the surface orifice may reasonably be expected al)o\'e 

 ;i fixed conduit that discharges through a more or less thick accumulation 

 (vf loose scoria^ lapilli^ and ash, as would be especially true of the Sciarra 

 vent. 



Farther back on the terrace points of reference are lacking, or at least 

 'ess definitely marked; yet even here we can trace back for some twenty- 

 live years three small areas of activity which are quite persistent in their 

 general locations. These are, of course, the Central, Scarp, and Fuma- 

 role vents. These would seem to be (at least at the surface) rather 

 groups of vents, the individuals of which shift in number and somewhat 

 in position from time to time, while each group occupies a ratlier definite 

 and restricted area of activity. 



In the case of this portion of the crater terrace it is importaiit to 

 remember that it has been the scene of profound changes, as in the erup- 

 tion of 1907, becoming at times a large and ver}^ deep funnel, which has 

 been subsequently filled up with loose or but slightly coherent material. 

 The diffuse character of the surface points of discharge from single vents 

 or conduits below through the accumulation of loose material is hence 

 readily understandable. 



We may conclude, then, that at Stromboli, for about a century and a 

 half, at least three vents, of relatively small size (varying from 10 to 50 

 meters in diameter), have persisted continuously in their positions, with 

 possibly a very slight amount of shifting, and that at other parts of the 

 crater terrace three groups of vents have been in more or less intermittent 

 activity, each group occupying a rather restricted area, for at least twenty- 

 five years and probably much longer. 



KiLAUEA 



Another volcano which offers opportunity to study the persistence of 

 volcanic vents in location is Kilauea, by reason of the length of time that 

 it has been observed, the series of plans and sketches made of the crater 

 floor at different dates, and the fact that the crater topography furnishes 

 means for the identification of location of the main focus of activity. 

 Only a very brief statement of the main features of persistence at this 

 volcano can be given here. 



It will be recalled that the crater of Kilauea measures about 5 by 3 

 kilometers, with a somewhat domed floor and precipitous walls about 200 

 meters high. In the southwestern (the highest) part of the floor of this 

 is a small lava pit, called Halemaumau, about 500 meters in diameter. 



