{"accessLevel": "public", "bureauCode": ["010:12"], "contactPoint": {"@type": "vcard:Contact", "fn": "Peter Kelly", "hasEmail": "mailto:pkelly@usgs.gov"}, "description": "This release contains data collected during two uncrewed aircraft systems (UAS) flights to sample gas plume compositions within Halema\u2019uma\u2019u crater, K\u012blauea Volcano, Hawai'i.  Gas compositions were measured on October 26, 2019 with a multi-GAS (multiple Gas Analyzer System) instrumented DJI M600 Pro multi-rotor UAS.  The first flight targeted emissions from deep within the crater and the UAS flew as much as 510 m below its crater-rim launch point (1161 m elevation).  The second flight focused on sampling emissions from gas vents in the northern crater wall.\nThe multi-GAS payload included sensors to measure water vapor, carbon dioxide (CO2), and sample pressure (PP Systems SBA-5), sulfur dioxide (SO2; City Technology, Ltd. T3ST/F), hydrogen sulfide (H2S; City Technology, Ltd. T3H), a GPS unit (Garmin GPS 18x), and a datalogger (Campbell Scientific CR300-WIFI). The responses of the CO2, SO2, and H2S sensors were checked at the crater rim after the flights using portable gas standards (CO2 = 1000 ppm \u00b1 2%, SO2 = 10 ppm \u00b1 10%, H2S = 10 ppm \u00b1 10%). The CO2 response was within -1% of the standard gas value and the baseline-corrected SO2 and H2S responses were accurate within 2% and 4%, respectively, when an ideal gas pressure correction was applied to the sulfur sensors' output.  Based on the sensor verification results, the accuracy of the CO2, SO2, and H2S measurements were limited by the accuracy of the gas standards.\nPlease see the associated publication for interpretative results:\n[insert Nadeau et al. citation]", "distribution": [{"@type": "dcat:Distribution", "accessURL": "https://doi.org/10.5066/P99H412X", "description": "Landing page for access to the data", "format": "XML", "mediaType": "application/http", "title": "Digital Data"}, {"@type": "dcat:Distribution", "description": "The metadata original format", "downloadURL": "https://data.usgs.gov/datacatalog/metadata/USGS.62b35844d34ea7748d9b08ea.xml", "format": "XML", "mediaType": "text/xml", "title": "Original Metadata"}], "identifier": "http://datainventory.doi.gov/id/dataset/USGS_62b35844d34ea7748d9b08ea", "keyword": ["USGS:62b35844d34ea7748d9b08ea", "volcanic gas emission"], "modified": "2023-03-30T00:00:00Z", "publisher": {"@type": "org:Organization", "name": "U.S. Geological Survey"}, "spatial": "-155.296, 19.402, -155.280, 19.41", "theme": ["geospatial"], "title": "Chemical and isotopic composition of gas, water, and solids from the 2019-2020 water lake in Halema\u2019uma\u2019u Crater, K\u012blauea Volcano, Hawaii: Gas Chemistry"}