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Measurements of the cooling at the base of Pahoehoe Flows
Author(s) -
Keszthelyi Laszlo
Publication year - 1995
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/95gl01812
Subject(s) - lava , crystallization , geology , volcano , heat flow , lava dome , mineralogy , thermodynamics , thermal , geochemistry , physics
Temperature measurements were made in August and October of 1994 at the base of small active pahoehoe flow lobes on Kilauea Volcano, Hawai'i. Surprisingly, after about 2 minutes of initial rapid cooling, the basal temperatures increased significantly before resuming a slower cooling trend. The recorded temperatures are also warmer than those predicted by simple conductive cooling models. Preliminary calculations suggest that these observations can be explained by the insulating effect of microfractures in the underlying flow and the kinetics of crystallization. The initial cooling may be rapid enough to super‐cool the lava such that the onset of crystallization is delayed. When crystallization does begin, it is initially rapid, releasing sufficient latent heat to re‐heat the lava. As the system equilibrates, the flow resumes a slow cooling.