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Samples of the crater lake water were filtered in the field with a 0.45 micron filter. Subsequently, additional precipitates formed in the solute-rich samples (secondary precipitates) which were subsequently filtered in the lab with a 0.45 micron filter. Resulting residues were analyzed both in situ on the filter and after scraping. Samples were sputter coated with 10 nm Au, then imaged in a Tescan VEGA3 scanning electron microscope (SEM) equipped with an Oxford 150 mm2 X-MaxN large area energy dispersive spectrometer at the U.S. Geological Survey, Menlo Park, CA. Elemental backscatter (BSE) images were collected with an accelerating voltage (HV) of 30 kV and a working distance (WD) of ~15 mm. Magnification is indicated...
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Samples of the crater lake water were filtered in the field with a 0.45 micron filter. Subsequently, additional precipitates formed in the solute-rich samples (secondary precipitates) which were subsequently filtered in the lab with a 0.45 micron filter. The mineralogy of secondary precipitates for samples HM19-01 and HM20-01A,B,C that were collected on 10/26/2019 and on 1/17/2020, respectively was determined by X-ray diffraction (XRD). Analysis was carried out at the British Natural History Museum with a Enraf-Nonius PDS120 diffractometer equipped with a primary Germanium (111) monochromator and an INEL 120° curved position sensitive detector (PSD). Data were collected from 7-120° 2θ using Co Kalpha1 radiation...
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Methods Total element abundances in the bulk tephra samples were determined by inductively coupled plasma mass spectrometry (ICP-MS) following a 4-acid digest at the USGS analytical laboratories in Denver, CO. Briefly, the tephra samples were digested using a mixture of hydrochloric, nitric, perchloric and hydrofluoric acids at low temperature following the methods of Crock and otheres (1983). The resultant fluid was aspirated into a 42-element ICP-MS for analysis following the analytical procedure of Briggs and Meier (2002). USGS geochemical reference materials BIR-1, BCR-1, and BHVO-1 were analyzed before and after Kilauea tephra samples for data quality control. Kīlauea sample A7-0641 was analyzed as an analytical...
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Puhimau thermal area, located in the upper East Rift Zone of Kīlauea Volcano, Hawai`i formed around 1936 when heat and gases migrated to the surface following a magma intrusion. As of April 2020, the area is about 0.2 km2 in size with regions of steaming ground. The site may be valuable for monitoring changes in gas and heat emissions related to movement of magma down the rift zone. On November 4-5, 2019 we used the accumulation chamber method and thermocouple probes to make 164 measurements of soil CO2 flux and temperature (20 cm depth) at 30-m spacing on a 0.2 km2 grid. Three gas samples were collected from areas of steaming ground on November 5-6, 2019 and analyzed for bulk chemical and carbon isotope (d13C-CO2)...
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Sulphur Banks, near the summit of Kīlauea Volcano on the Island of Hawai`i, is a thermal area where volcanic gases and steam are discharged. A research well drilled in the 1920s at Sulphur Banks (Allen, 1922) has developed into a “fumarole” that has been used for gas sampling over the years (e.g., Friedman and Reimer, 1987; Hilton and McMurtry, 1997; Shinohara and others, 1999), but has not been subject to periodic monitoring. Following the 2018 Kilauea eruption, draining of the lava lake, and cessation of activity at the summit (Neal and others, 2019), Sulphur Banks represents a continuing window into the outgassing dynamics at Kīlauea’s summit. Gas samples were collected at Sulphur Banks periodically since March...
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