Metadata:
  Identification_Information:
    Citation:
      Citation_Information:
        Originator: Alexandra J. Pickering
        Originator: Carol S. Prentice
        Originator: Stephen B. DeLong
        Publication_Date: 2019
        Title: Landscape change associated with the upper Scenic Drive landslide, La Honda, California January 10-June 28, 2017
        Geospatial_Data_Presentation_Form: Digital Data
        Series_Information:
          Series_Name: Open-File Report
          Issue_Identification: OFR 2019-1024
        Publication_Information:
          Publication_Place: Reston, VA
          Publisher: U.S. Geological Survey
        Online_Linkage: https://doi.org/10.3133/ofr20191024
    Description:
      Abstract:
        This database includes mapping and Real-time Kinematic (RTK) GPS measurements documenting movement of the 2017 upper Scenic Drive landslide (USDL) in La Honda, California. The Scenic Drive area in La Honda has experienced several past episodes of landslide motion, which were documented in 1998 (Jayko and others, 1998), 2005 (Wells and others, 2005), and 2006 (Wells and others, 2006). The 2017 USDL occurred adjacent and upslope of previous Scenic Drive landslide episodes, representing formation of a new, separate landslide. Movement of the 2017 USDL began on or just before January 10, 2017. In mid to late January, coincident with a series large storms, the landslide moved several meters to the west-southwest. On January 27, 2017 we collected lidar data with a Riegl VZ400 Terrestrial Laser Scanner. These point cloud data were georeferenced using a Leica Viva GS15 survey grade RTK GPS to provide a snapshot of the 2017 upper Scenic Drive landslide. Using a combination of interpretation of a bare-earth hillshade map produced from terrestrial lidar data and direct field observation we interpret morphological features from the 2017 USDL. To monitor ongoing landslide movement, we conducted eight GPS surveys, repeatedly surveying 58 points (nails and other markers) inside and outside of the landslide from January 27 to June 28, 2017.  Between January 28 and February 23, total horizontal movement was at least 5 cm (station BLUE15) and no more than 28 cm (BLUE13). No measureable landslide motion occurred after February 23, and none of the monuments outside of the current 2017 USDL boundaries moved within the limits of our measurement error (horizontal, about 2 cm; vertical, about 3 cm). 

        Jayko, A.S., Rymer, M.J., Prentice, C.S., Wilson, R.C., and Wells, R.E., 1998, Scenic Drive landslide of January-March 1998, La Honda, San Mateo County, California: U.S. Geological Survey Open-File Report 98-229, https://pubs.usgs.gov/of/1998/of98-229/. 

        Wells, R.E., Rymer, M.J., Prentice, C.S., and Wheeler, K.L., 2005, Map showing features and displacements of the Scenic Drive landslide, La Honda, California, during the period March 31-May 7, 2005: U.S. Geological Survey Open-File Report 2005-1191, scale 1:400, https://pubs.usgs.gov/of/2005/1191/. 

        Wells, R.E., Rymer, M.J., Prentice, C.S., and Wheeler, K.L., 2006, Map showing features and displacements of the Scenic Drive landslide, La Honda, California, during the period March 31, 2005-November 5, 2006: U.S. Geological Survey Open-File Report 2006-1397, 2 sheets, scale 1:400, https://pubs.usgs.gov/of/2006/1397/.
      Purpose: Data were collected to characterize landslide behavior in La Honda, California. This database depicts a snapshot of landslide features at a 1:400 scale. This database includes GPS survey data used to monitor landslide motion from January 27 - June 28, 2017.
    Time_Period_of_Content:
      Time_Period_Information:
        Range_of_Dates/Times:
          Beginning_Date: 20170127
          Ending_Date: 20170628
      Currentness_Reference: ground condition
    Status:
      Progress: Complete
      Maintenance_and_Update_Frequency: None planned
    Spatial_Domain:
      Bounding_Coordinates:
        West_Bounding_Coordinate: -122.40974230512
        East_Bounding_Coordinate: -122.10761828169
        North_Bounding_Coordinate: 37.436864466114
        South_Bounding_Coordinate: 37.244703648375
    Keywords:
      Theme:
        Theme_Keyword_Thesaurus: USGS Thesaurus
        Theme_Keyword: gps
        Theme_Keyword: landslide
      Place:
        Place_Keyword_Thesaurus: GNIS
        Place_Keyword: La Honda
        Place_Keyword: San Mateo County
    Access_Constraints: none
    Use_Constraints: none
    Point_of_Contact:
      Contact_Information:
        Contact_Person_Primary:
          Contact_Person: Alexandra J Pickering
          Contact_Organization: PACIFIC REGION
        Contact_Position: Geologist
        Contact_Address:
          Address_Type: mailing and physical
          Address: Mail Stop 977, 345 Middlefield Road
          City: Menlo Park
          State_or_Province: CA
          Postal_Code: 94025
          Country: US
        Contact_Voice_Telephone: 650-329-4797
        Contact_Electronic_Mail_Address: apickering@usgs.gov
  Data_Quality_Information:
    Attribute_Accuracy:
      Attribute_Accuracy_Report: No formal attribute accuracy tests were conducted
    Logical_Consistency_Report: No formal logical accuracy tests were conducted
    Completeness_Report: 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.
    Positional_Accuracy:
      Horizontal_Positional_Accuracy:
        Horizontal_Positional_Accuracy_Report: No formal positional accuracy tests were conducted
      Vertical_Positional_Accuracy:
        Vertical_Positional_Accuracy_Report: No formal positional accuracy tests were conducted
    Lineage:
      Process_Step:
        Process_Description:
          On January 27-28, 2017 we collected high-resolution lidar data using a Riegl VZ400 laser scanner in the vicinity of Scenic Drive in La Honda, California, to characterize a newly initiated landslide. The 2017 survey, consisting of 32 scans, was performed using real-time positioning information fed from the Leica Viva GS15 GNSS system to the Riegl VZ400 scanner and several GNSS-measured targets. This technique allows for initial centimeter-scale alignment of individual scan positions using real-time differential GNSS positions and the VZ400 internal electronic compass and level sensors. Each data set was aligned into a single merged and aligned point cloud using a modified iterative closest point (ICP) algorithm (Besl and McKay, 1992) as implemented in the Riegl RiScan Pro Multi-Station Adjustment software tool. The point clouds were georeferenced and exported as NAD83 UTM zone 10N coordinates using Leica Geo Office software. The aligned and georeferenced point clouds were then filtered to remove error points. Data were then decimated using an octree filter to lower data density to  about1 point per 0.02 cubic meters and exported as an aligned, georeferenced point cloud. All points were then classified as either (1) unclassified, (2) ground, (3) low vegetation (0-0.05 m above ground), (4) medium vegetation (0.05-2 m above ground), (5) high vegetation (2-100 m above ground), (6) building or (7) low point (noise), using Terrasolid Terrascan software. Digital elevation models (DEMs) were generated using Golden Software Surfer 14. Bare earth DEMs were generated at 0.05 m resolution from point class 2 (ground) and used to create bare earth hillshades at varying sun angles (45 degrees, 130 degrees, 225 degrees, 275 degrees, and 305 degrees) in ARCGIS. We used the resulting bare-earth hillshades in addition to field surveying to map morphological landslide features at a 1:400 scale.  Although lidar data are located within a few centimeters at the time of measurement, the uncertainties in identifying and mapping landscape features may approach 0.5 meter.  
          This ESRI Geodatabase contains RTK GPS measurements for eight repeated surveys of ground points collected between January 27 and June 28, 2017, to monitor slip direction and magnitude. The surveys were conducted using a Leica Viva GS15 real-time kinematic GPS. We set up a local base station outside the boundary of the 2017 USDL and kinematically surveyed 16 survey nails (labeled ROADPK in database) installed along Scenic Drive and along Fir View and Woodland Vista roads; we set up five of these nails previously and surveyed them as part of a previous 2016 TLS survey (labeled PK01-05 in database). In addition, we surveyed 16 lane reflectors (labeled road reflector in database) along Scenic Drive, as well as 26 temporary UAV targets (labeled BLUE01-26 in database) throughout the vicinity of the USDL to monitor stability of past Scenic Drive landslides and movement of the 2017 USDL. GPS measurements were post-processed using the NGS OPUS online service (www.ngs.noaa.gov/OPUS/) and exported as NAD83 UTM zone 10N coordinates using Leica Geo Office software. GPS survey campaigns were conducted on 01/27/2017, 02/04/2017, 02/12/2017, 02/23/2017, 03/04/2017, 03/11/2017, 03/27/2017, and 06/28/2017. Measurement error for these datasets is approximately 2 cm horizontally and 3 cm vertically. 

          Besl P.J. McKay Neil D., 1992, A method for registration of 3-D shapes: IEEE Transactions on Pattern Analysis and Machine Intelligence, v. 14, p. 239Ð256, doi:10.1109/34.121791.
        Process_Date: 20170628
  Spatial_Data_Organization_Information:
    Indirect_Spatial_Reference: La Honda, CA; San Mateo County, CA
    Direct_Spatial_Reference_Method: Point
  Spatial_Reference_Information:
    Horizontal_Coordinate_System_Definition:
      Planar:
        Grid_Coordinate_System:
          Grid_Coordinate_System_Name: Universal Transverse Mercator
          Universal_Transverse_Mercator:
            UTM_Zone_Number: 10
            Transverse_Mercator:
              Scale_Factor_at_Central_Meridian: 0.9996
              Longitude_of_Central_Meridian: -123.0
              Latitude_of_Projection_Origin: 0.0
              False_Easting: 500000.0
              False_Northing: 0.0
        Planar_Coordinate_Information:
          Planar_Coordinate_Encoding_Method: coordinate pair
          Coordinate_Representation:
            Abscissa_Resolution: 0.001
            Ordinate_Resolution: 0.001
          Planar_Distance_Units: METERS
      Geodetic_Model:
        Horizontal_Datum_Name: D_North_American_1983
        Ellipsoid_Name: WGS84
        Semi-major_Axis: 6378137.0
        Denominator_of_Flattening_Ratio: 298.25
    Vertical_Coordinate_System_Definition:
      Altitude_System_Definition:
        Altitude_Datum_Name: WGS_84 ellipsoid
        Altitude_Resolution: 0.001
        Altitude_Distance_Units: meters
        Altitude_Encoding_Method: Explicit elevation coordinate included with horizontal coordinates
  Entity_and_Attribute_Information:
    Overview_Description:
      Entity_and_Attribute_Overview: These data can be described by the the NED Data Dictionary
      Entity_and_Attribute_Detail_Citation: http://nationalmap.gov/3DEP/3dep_prodmetadata.html
  Distribution_Information:
    Distributor:
      Contact_Information:
        Contact_Person_Primary:
          Contact_Person: N/A
          Contact_Organization: U.S. Geological Survey - ScienceBase
        Contact_Address:
          Address_Type: mailing and physical
          Address: Denver Federal Center, Building 810, Mail Stop 302
          City: Denver
          State_or_Province: CO
          Postal_Code: 80225
          Country: USA
        Contact_Voice_Telephone: 1-888-275-8747
        Contact_Electronic_Mail_Address: sciencebase@usgs.gov
    Distribution_Liability: 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. Although these data have been processed successfully on a computer system at 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. The USGS or the U.S. Government shall not be held liable for improper or incorrect use of the data described and/or contained herein. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
    Technical_Prerequisites: These data are available as .laz binary point clouds. See www.laszip.org for more information. DEMs are shared as GeoTiff files, which are readable by GIS software.
  Metadata_Reference_Information:
    Metadata_Date: 20190318
    Metadata_Contact:
      Contact_Information:
        Contact_Person_Primary:
          Contact_Person: Alexandra J Pickering
          Contact_Organization: PACIFIC REGION
        Contact_Position: Geologist
        Contact_Address:
          Address_Type: mailing and physical
          Address: Mail Stop 977, 345 Middlefield Road
          City: Menlo Park
          State_or_Province: CA
          Postal_Code: 94025
          Country: US
        Contact_Voice_Telephone: 650-329-4797
        Contact_Electronic_Mail_Address: apickering@usgs.gov
    Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata
    Metadata_Standard_Version: FGDC-STD-001-1998