kipuka
This kipuka formed during the Pu'u O'o-Kupaianaha eruption on the east rift zone of Kilauea Volcano, Hawaii. Credit: J. D. Griggs / US Geological Survey.
'Kipuka' is a Hawaiian term for an 'island' of land completely surrounded by one or
more younger lava flows. A kipuka forms when
lava encircles a hill or a slight rise in the ground as it moves downslope
or across relatively flat ground. Because they are surrounded by more recent
flows, kipukas are often covered with mature vegetation.
The word kipuka is a variation of the Hawaiian word puka which means hole.
Puka-shell necklaces, popular with tourists, are made with small shells
which have holes worn in the center by wave action on sandy beaches.