Pahoehoe sentence example
The pahoehoe has a smooth but billowy or hummooky surface, and is marked by lines which show that it cooled as it flowed.
As the same stream sometimes changes abruptly from one kind to the other, the two kinds must be due to different conditions affecting the flow, and among the conditions which may cause a stream to break up into the aa have been mentioned the greater depth of the stream, a sluggish current, impediments in its course just as it is granulating, and, what is more probable, subterranean moisture which causes it to cool from below upward instead of from above downward as in the pahoehoe.
Dana introduced the term "as" for this rough kind of lava-stream, whilst he applied the term "pahoehoe" to those flows which have a smooth surface, or are simply wrinkled and ropy; these terms being used in this sense in Hawaii, in relation to the local lavas.
The surface of the upper slopes of Mauna Loa is almost wholly of two widely different kinds of barren lava-flows, called by the Hawaiians the pahoehoe and the aa.Advertisement