Jason W. Kean Joel B. Smith Jeffrey A. Coe 20200207 tabular digital data Reston, VA U.S. Geological Survey https://doi.org/10.5066/P9MUWDFN https://doi.org/10.5066/P9MUWDFN This data release includes 2014 time-series data from three debris-flow monitoring stations at Chalk Cliffs in Chaffee County, Colorado, USA. The data were collected to help identify the triggering conditions, magnitude, and mobility of debris flows at the site. The three stations are located sequentially along a channel draining the 0.3 km^2 study area. The Upper, Middle, and Lower stations have respective drainage areas of 0.06, 0.16, and 0.24 km^2. The location (UTM zone 13) of each station is: 396826E/4287851N (Upper), 396893E/ 4287815N (Middle), and 396929E/4287712N (Lower). See also “ChalkStationLocations.jpg” in the README.zip file. The 2014 data includes three types of time series: (1) 1-minute time series of rainfall recorded by tipping bucket rain gages at each station, (2) 10-Hz time series of flow stage recorded by laser distance meters at each station, and (3) 333-Hz time series of ground vibrations and basal normal force at the Upper station only. Ground vibrations were recorded by two 4.5 Hz triaxial geophones separated by 18 m along the channel. Basal normal force was recorded by a 232 cm^2 force plate installed in the bedrock channel bed directly beneath the laser distance meter. The 10-Hz stage data is collected only when it is raining due to data storage limitations. Similarly, the 333-Hz ground motion and force data are provided only during significant flow events. These events occurred on 4 July 2014, 31 July 2014, 1 August 2014, 4 August 2014, and 6 August 2014. The first three events are primarily debris flows and the last two events are debris floods. Note that the rain gage at the Lower station, which is partially shielded by a near-vertical cliff, is used primarily as a trigger for sampling 10-Hz stage data rather than providing an accurate representation of rainfall at the station. Details of the sensors and photos of each station are contained in the “README.zip” file. The file also contains formulas for (1) converting the distance between the laser and the flow surface (or stationary bed surface) to stage above the datum for each station, and (2) converting the raw voltage readings from the geophones and force plate transducer into engineering units of ground velocity and normal force, respectively. Additional details of the study are provided in the journal articles: McCoy, S. W., J. W. Kean, J. A. Coe, G. E. Tucker, D. M. Staley, and T. A. Wasklewicz (2012), Sediment entrainment by debris flows: In situ measurements from the headwaters of a steep catchment, J. Geophys. Res., 117, F03016, doi:10.1029/2011JF002278. Kean, J. W., J. A. Coe, V. Coviello, J. B. Smith, S. W. McCoy, and M. Arattano (2015), Estimating rates of debris flow entrainment from ground vibrations, Geophys. Res. Lett., 42, doi:10.1002/2015GL064811. The data were collected to help identify the triggering conditions, magnitude, and mobility of debris flows at the site. 2014 publication date Complete None planned -106.191530 -106.181788 38.737247 38.729782 None USGS Landslide Hazards Program Geologic Hazards Science Center GHSC debris flow flood monitoring earth science USGS Metadata Identifier USGS:5e30a148e4b0a79317d62738 Geographic Names Information System (GNIS) Colorado none none Jason W Kean U.S. Geological Survey, ROCKY MOUNTAIN REGION Research Hydrologist mailing address

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Denver CO 80225 US 303-273-8608 303-273-8600 jwkean@usgs.gov J. W. Kean J. A. Coe V. Coviello J. B. Smith S. W. McCoy M. Arattano 20150807 publication Geophysical Research Letters vol. 42, issue 15 n/a American Geophysical Union (AGU) ppg. 6365-6372 https://doi.org/10.1002/2015GL064811 S. W. McCoy J. W. Kean J. A. Coe G. E. Tucker D. M. Staley T. A. Wasklewicz 20120810 publication Journal of Geophysical Research: Earth Surface vol. 117, issue F3 n/a American Geophysical Union (AGU) ppg. n/a-n/a https://doi.org/10.1029/2011JF002278 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 refer to publication 2020 This information is contained in the associated journal articles: https://doi:10.1002/2015GL064811 and https://doi:10.1029/2011JF002278 doi:10.1002/2015GL064811 and doi:10.1029/2011JF002278 Staff 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. none 20200821 GHSC Data Steward U.S. Geological Survey, Geologic Hazards Science Center Open Data Policy coordinator Mailing and Physical

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