What are the Parental Magma Compositions for Historical Kilauea Lavas?

University Of Hawaii, Honolulu

Investigators

Abstract

Kilauea Volcano, on the Island of Hawaii, is one of the most active and best monitored volcanoes in the world. Previous field, petrologic, geochemical and geophysical studies have established the basic structure of Kilauea's magmatic plumbing system, leading it to be called "the best understood basaltic volcano in the world". This makes Kilauea an ideal venue for addressing fundamental questions about how magma is formed in basaltic volcanoes. The physical mechanisms behind the long-term and short-term geochemical fluctuations in lavas chemistry at Kilauea are poorly understood. Why does the volcano exhibit distinctive geochemical variations over different time scales? What process caused the change in the trajectory of the temporal geochemical trends? What is the origin of the "common" trend? Our hypothesis is that the short-term and long-term variations in lava chemistry at Kilauea reflect the dynamics of melt generation, extraction and transport within the heterogeneous Hawaiian mantle plume. The outcomes for this four year study will include new analyses of the petrography, mineral chemistry, whole-rock major element and trace element abundances, and Pb, Sr, Nd and U-series isotope ratios for lavas from the current eruption, prehistoric summit lavas exposed in Uwekahuna Bluff, selected rift zone lavas, and olivine-hosted melt inclusions from these and other olivine-rich basalts. These data will be used to determine the mantle causes for compositional variation in the Kilauea lavas, for example, source variations vs. changes in the amount of melting. These processes control the eruption rate of volcanoes, so our work will have implications for predicting the duration of future eruptions. The broader impacts of this research include mentoring graduate and undergraduate students, teaching volcanology, petrology and geochemistry courses at universities with a large population of underrepresented students using examples from our research, involving underrepresented students in our research, giving public lectures to school groups and the local community, gaining a better understanding of volcanoes that can negatively influence the quality of life, and increasing international and national scientific cooperation through collaboration and utilization of multi-user facilities.