"CEATERS OF THE MOON" STEARNS 313 



there is a gradual wasting away of the ice, but melting proceeds 

 slowly, as even during the summer the temperature of the interior of 

 the caves does not rise above 40° F. Ice and water are found also in 

 the deep inverted funnel-shaped craters of the spatter cones. The 

 snow accumulates in the crater during the winter and is exposed to 

 the direct rays of the sun for only a short time each day. Thus 

 there results a continuall}^ increasing heap of ice which, in the Ice 

 Cave near the end of the motor road, is about 20 feet thick. 



Ice Caves do not occur anj^where in the world except where there 

 are freezing temperatures during some part of the year. On the 

 active volcano of Kilauea, Hawaii, where thousands of similar caves 

 occur and where much rain falls, no ice occurs in the caves. The 

 explanation of this is apparent, for no snow falls nor do freezing 

 temperatures occur during the year. Mauna Loa Volcano, which 

 i rises nearly 14,000 feet above the sea into the snow zone, contains 

 numerous ice caves in and near the crater, and many are found only 

 a stone's throw from a steam vent. The lava in the Craters of the 

 I Moon is so fissured that no water is found in it throughout the year 

 except where it lies upon an impermeable body of ice. 



Despite the freshness and bareness of the black lava, the longer 

 I one studies them the more one realizes the time that must have 

 elapsed since the last eruption. The absence of the soil on many of 

 f the flows is easily accounted for. All the fine dust is blown away or 

 into near-by cracks. This hidden soil accounts for the numerous 

 shrubs and pines that grow in the crevices where no soil is visible. 

 The vegetation has about a four months' growing season and is 

 poorly adapted to its environment. The writer found a pine growing 

 in a crack in the Big Crater lava flow, a flow that appears as black 

 and recent as any in the monument. This tree has fresh black lava 

 of the Big Crater flow actually touching the trunk two feet above 

 the base of the tree, and the tongue of pahoehoe in which the tree 

 grows is split open and wedged apart by the roots of the tree. This 

 tree is 33 inches in diameter and has been dead only two or three 

 years, having been killed by lightning. It is perfectly sound and 

 shows no burning scars nor any indications of fire. Counting the 

 annular rings of this tree shows that it was 461 years old. Other 

 larger trees can be found rotting on the lava surface that have been 

 dead at least 100 years. The lava was certainly extruded before these 

 trees came into existence. 



