Use of Pele’s Tears and Spheres as an Indicator of Lava Fountain Height in Hawaiian Volcanoes

Abstract

Though lava flows have presented the greatest hazard to human property during the most recent eruptions of Hawaiian volcanoes, lava fountains represent the source of the lava flows and an additional hazard which should be considered. Previous workers have identified the exsolved gas content of the magma in Hawaiian volcanoes to be the main determinant of lava fountain height. Here, methods are described to empirically derive a relationship between the modal diameter of vesicles within Pele’s tears and spheres and lava fountain height, using samples of Pele’s tears which were produced during the last eruptions of Kīlauea Iki (1959) and Mauna Ulu (1969). The empirical relation follows the trendline H_max = -2575d + 820, where Hmax is maximum lava fountain height and d is modal vesicle diameter. This empirical relationship may be applied to eruptions which were not directly measured or observed to assess long-term shifts in lava fountain heights and thus the exsolved gas contents of a volcanic system.