Post by Robert Wright, and Mary C. Bourke,
Hawaii Institute of Geophysics and Planetology, University of Hawaii at Manoa, US.
Department of Geography, Trinity College, Dublin, Ireland.
The temperature at which active lava is erupted correlates well with the composition of the lava. Mafic lavas may be up to 200-330 degrees celsius hotter than felsic lavas. The range of temperatures observed on active lava surfaces can also be used to determine the style with which the lava is erupted (i.e. as aa or pahoehoe lava flows, as lava lakes, or as lava domes). This is possible because the ease with which the crust is fractured depends on the volumetric flux of lava and its rheology (Image 2). As a result, lava bodies that fracture their cool crusts more easily (like aa flows) have hotter temperature distributions than those that fracture their upper surfaces less readily (such as viscous lava domes). (more…)