Sample details and near-real-time ED-XRF, grain size, and grain shape data collected during the November – December 2022 eruption of Mauna Loa volcano, Island of Hawaiʻi

At 11:21 p.m. (Hawaii Standard Time [HST]) on November 27, 2022, Mauna Loa volcano on the Island of Hawaiʻi started erupting from fissures at its summit caldera, Mokuʻāweoweo. This was followed shortly afterwards by the opening of a segment of fissures in the direction of the Southwest Rift Zone. These were mostly within the structural boundary of the caldera, so their location is denoted as ‘South Caldera,’ with the exception of a short fissure that extended into the uppermost Southwest Rift Zone. By November 28, activity had shifted to four fissures that opened in the upper Northeast Rift Zone (Lynn and others, 2023). By December 2, eruptive activity was focused from Northeast Rift Zone fissure 3A supplying lava flows that extended approximately 19 kilometers (12 miles) down slope to the north by the end of the eruption (Dietterich and others, 2023). Eruptive activity abruptly waned on December 8, with all activity ceasing by December 10. The U.S. Geological Survey’s Hawaiian Volcano Observatory (HVO) collected a total of 87 samples, of which 73 samples were collected during the eruption as water-quenched (for molten material) or air-quenched samples from fissures, channels, lava flow margins, and lava flow fronts. Fifty-four of the 73 samples collected during the eruption were analyzed by energy dispersive X-ray fluorescence (ED-XRF) spectrometry for major-oxide and trace-element abundances at the University of Hawaiʻi at Hilo, as a part of near-real-time petrologic and geochemical monitoring (Gansecki and others, 2019). Additionally, 15 tephra samples collected during the eruption were run on a Microtrac CAMSIZER® P4 instrument for grain size and shape data in the HVO tephra lab. Most samples were analyzed by these methods within 24–48 hours of collection. Sample collection and near-real-time analyses are a part of HVO’s monitoring and response efforts.

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  "010:12"
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  "geospatial"
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