Volcanic ash geochemistry and leachate analyses from the 2008 opening of Halemaʻumaʻu crater, Kīlauea Volcano, Hawaiʻi

On March 19, 2008, an explosive eruption occurred at the summit of Kīlauea Volcano for the first time since 1924. This event marked the beginning of a continuous summit eruption that lasted until the 2018 Kīlauea lower East Rift Zone eruption (Neal and others, 2019). The March 19 explosive eruption excavated a crater approximately 35 meters wide and scattered volcanic tephra over a 30-hectare area. Only non-juvenile tephra was erupted on March 19 (Houghton and others, 2011). Two subsequent, minor explosions occurred on April 9 and April 16, 2008. These two explosions were dominated by lithic material though did also include some juvenile tephra. Tephra was produced continuously after the initial March 19 eruption but, excluding these two April explosions, decreased substantially in the weeks that followed.

Following the onset of tephra production, the U.S. Geological Survey Hawaiian Volcano Observatory (HVO) collected tephra samples daily, each representing 24 hours. Tephra samples were collected at various locations within 300 meters southwest of the vent during normal trade winds, initially in aluminum pans and soon after in plastic buckets. Additional samples were donated to HVO by residents who live in Wood Valley (20 km from vent) and the South Point area (63 km from vent).

To prepare tephra for analysis, the bulk samples were homogenized and split using the cone-and-quartering technique. One quarter of the sample was archived and the remainder dry sieved at 2 mm (-1 φ). The