There are few petrological constraints on magma storage depths at Mauna Loa, Hawai‘i. Yet understanding the geometry of the magmatic plumbing system is critical for interpreting geophysical signals of unrest at this very high-threat volcano. We address this gap by examining CO₂-rich fluid inclusions (FI) in lava and tephra from seven eruptions (8870 ± 56 14 C yr BP, 1852, 1855, 1868, 1949, 1950, and 1984), supplemented with pu...

Mauna Loa volcano erupts crystal-poor material at its summit and more crystal-rich material on its rift zones. Some of the more olivine-rich lava flows contain xenoliths with diverse mineralogy, including cumulate harzburgites with high-Mg# orthopyroxenes and high-Fo olivines (both > 84). Previous experimental work and thermodynamic modelling has proposed that high-Mg# orthopyroxenes only crystallize from Mauna Loa melts at hi...

A majority of the global net primary production of mangroves is unaccounted for by current carbon budgets. It has been hypothesized that this “missing carbon” is exported as dissolved inorganic carbon (DIC) from subsurface respiration and groundwater (or pore‐water) exchange driven by tidal pumping. We tested this hypothesis by measuring concentrations and δ 13 C values of DIC, dissolved organic carbon (DOC), and particulate o...