Ogburn, Sarah E. 20250226 Structured Query Language (SQL) self-contained file Vancouver, WA U.S. Geological Survey https://doi.org/10.5066/P13CMDC2 Volcanic mass flows, especially lahars and pyroclastic density currents (PDCs) are among the most destructive volcanic hazards due to their speed, mobility, and the often-unexpected behavior these flows exhibit as they interact with topography. Mitigation of risk associated with PDCs and other volcanic mass flows depends upon accurate forecasting of magnitude and frequency, potential inundation areas, and possible runout lengths. Measurements of PDCs and other volcanic mass flows, their deposits, and their properties are used in model development and refinement, provide natural examples for benchmarking and comparing model performance, inform laboratory experiments, serve as useful analogs when local data are sparse, and define input parameter distributions for probabilistic flow modeling. These properties are numerous and varied and include information such as triggering mechanism, flow type, frequency, volume, velocity, runout length, and mobility measurements. Statistical forecasting methods, including event trees, rely upon databases to establish base-rates for flow frequency. To aid these goals, FlowDat: Volcanic Mass Flow Database has been developed. FlowDat is a comprehensive global database of mass flows, including dome-collapse and column-collapse PDCs, ash-cloud surges, ignimbrites, directed blasts, volcanic ice-slurry flows or mixed avalanches, lahars, and volcanic, non-volcanic and extra-terrestrial debris avalanches. This initial version of the database, ver. 1.0, focuses on PDCs. Forthcoming versions will include lahars and volcanic debris avalanches. Measurements of PDCs and other volcanic flows can help model development and refinement (Esposti Ongaro et al. 2020), provide natural examples for benchmarking and comparing model performance (Charbonnier et al. 2012; Ogburn et al. 2017; Esposti Ongaro et al. 2020), inform laboratory experiments (Lube et al. 2015, Esposti Ongaro et al. 2020), serve as useful analogs when local data are sparse (Siebert et al. 2010; Whelley et al. 2015), and define input parameter distributions for probabilistic flow modeling (Ogburn et al. 2016, 2017; Charbonnier et al. 2012). FlowDat aims to make this information accessible and useful to the greater scientific community. 20150501 20250123 publication date Complete Annually USGS Thesaurus volcanic activity USGS Metadata Identifier USGS:6792f3f3d34e88f5864c4c54 Common geographic areas Antarctica North America Central America South America Europe Africa Australia and New Zealand Asia Asia Minor and Middle East Southeast Asia Atlantic Indian Arctic Pacific Southern none none Sarah E Ogburn ALASKA REGION: VOLCANO SCIENCE CENTER Research Geophysicist mailing and physical

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Vancouver WA 98683 US 360-993-8983 sogburn@usgs.gov No formal attribute accuracy tests were conducted No formal logical accuracy tests were conducted Data set is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details. No formal positional accuracy tests were conducted No formal positional accuracy tests were conducted Volcanic mass flow data were collected from a variety of sources, including scientific literature, volcanic observatory reports, the Smithsonian Institute Global Volcanism Program Volcanoes of the World Database (Global Volcanism Program, 2024), and the LaMEVE database (Crosweller et al. 2012). Where possible, original primary literature was located and data cited in secondary literature compilations were verified. All units were converted to metric units. Calculations for unreported values were made using other related properties. Occasionally, printed maps and plots without accompanying text or tabular measurements were digitized using WebPlotDigitizer (Rohatgi version 5.2). Volcanic flows were categorized according to the "ref_flow_types" table. Uncertain dates and times were categorized according to the "ref_time" and "ref_date" tables. Commonly, multiple properties of the same property type exist for the same event; preferred properties are indicated with a "1" in the "preferred_value" column. 20250123 Point 1.0E-4 1.0E-4 Decimal degrees World Geodetic System 1984 (WGS 84) WGS_1984 6378137.0 298.257223563 North American Vertical Datum 1983 5.0 meters Explicit elevation coordinate included with horizontal coordinates Volcano names, volcano numbers, volcano coordinates, and other volcano-level data are taken from the Smithsonian Institute Global Volcanism Program Volcanoes of the World Database (Global Volcanism Program, 2024). Global Volcanism Program, 2024. [Database] Volcanoes of the World (v. 5.2.2; 22 Aug 2024). Distributed by Smithsonian Institution, compiled by Venzke, E. https://doi.org/10.5479/si.GVP.VOTW5-2024.5.2 U.S. Geological Survey - ScienceBase mailing and physical

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Denver CO 80225 USA 1-888-275-8747 sciencebase@usgs.gov Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. This sql file contains data available in a Structured Query Language (SQL) self-contained file. The user must have software capable of ingesting a sql file and querying the contained database. A free graphical user interface SQL program such as MySQL Workbench is available from MySQL at www.mysql.com. 20250226 Sarah E Ogburn ALASKA REGION: VOLCANO SCIENCE CENTER Research Geologist mailing and physical

1300 SE Cardinal Court, Bldg 10, Ste 100

Vancouver WA 98683 US 360-993-8983 sogburn@usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998