This data set provides a polygon shapefile delineating relatively large, slow-moving (4-17 cm/year in the radar line-of-sight direction) landslides in the continental U.S. western coastal states (California, Oregon, and Washington). The polygons also are provided in a Google Earth .kmz file. Delineated landslides were identified from displacement signals captured by InSAR (Interferometric Synthetic Aperture Radar) interferograms of ALOS PALSAR (Advanced Land Observing Satellite; Phased Array type L-band Synthetic Aperture Radar) images between 2007 and 2011, and ALOS-2 PALSAR-2 images between 2015 and 2019. The ALOS PALSAR images utilized cover the three states entirely; the ALOS-2 PALSAR images utilized cover primarily the western half of the study area where 97.6% of the identified landslides are located. The Scene IDs of the used ALOS and ALOS-2 images are provided in text files. The 1/3 arc-second National Elevation Datasets from the U.S. Geological Survey (https://apps.nationalmap.gov/downloader/, last accessed November 12, 2020), and optical images available from Google Earth were utilized to assist in landslide identification. Each polygon in the shapefile outlines the active area of a landslide. The active areas identified for a given landslide using the ALOS PALSAR and ALOS-2 PALSAR-2 interferograms differ slightly in some cases. For these, we used the larger polygon as the landslide boundary. The shapefile attribute table indicates which data were used to identify the landslide (“Comments”), and this is also indicated by the “Flag” field of the table, where values of 1, 2, and 3 indicate ALOS, ALOS2, and both datasets, respectively; a flag value of 4 was assigned for rock glaciers, which were only identified using ALOS data. The attribute table also provides areas of each polygon in square meters. These data support a study described in: Xu, Y., Schulz, W.H., Lu, Z., Kim, J., and Baxstrom, K., 2021, Geologic controls of slow-moving landslides near the U.S. west coast: Landslides, doi:10.1007/s10346-021-01732-3

The winter rainy season of 2016-2017 brought abundant rainfall to the state of California, including the San Francisco Bay region. Thousands of shallow landslides were triggered as a result of saturated soils and intense rainfall from strong winter storms in January and February 2017. The highest concentration of landslides from these storms occurred in the eastern part of the bay region, where landslides in the hills east of the Cities of Richmond, Berkeley, Oakland, Hayward, and Fremont, and elsewhere in the region, damaged homes, displaced a major electrical transmission-line tower, and blocked several heavily traveled state highway routes. The data presented here support our published map titled, "Landslides Triggered by the 2016-2017 Storm Season, Eastern San Francisco Bay Region, California" where we mapped a total of 8,928 landslides throughout the study area. The mapping encompasses a total area of approximately 1,050 square kilometers (km²) bounded by the Carquinez Strait and San Francisco Bay to the north and west, respectively, to the Interstate Highway 680 corridor to the south and east. Using high-resolution imagery, we mapped individual landslides as polygons. The greatest calculated landslide concentration (measured as the total number of landslides per unit area) exceeded 80 landslides per 0.25 km2 in the hills east of the City of Berkeley.

The winter rainy season of 2016-2017 brought abundant rainfall to the state of California, including the San Francisco Bay region. Thousands of shallow landslides were triggered as a result of saturated soils and intense rainfall from strong winter storms in January and February 2017. The highest concentration of landslides from these storms occurred in the eastern part of the bay region, where landslides in the hills east of the Cities of Richmond, Berkeley, Oakland, Hayward, and Fremont, and elsewhere in the region, damaged homes, displaced a major electrical transmission-line tower, and blocked several heavily traveled state highway routes. The data presented here support our published map titled, "Landslides Triggered by the 2016-2017 Storm Season, Eastern San Francisco Bay Region, California" where we mapped a total of 8,928 landslides throughout the study area. The mapping encompasses a total area of approximately 1,050 square kilometers (km²) bounded by the Carquinez Strait and San Francisco Bay to the north and west, respectively, to the Interstate Highway 680 corridor to the south and east. Using high-resolution imagery, we mapped individual landslides as polygons. The greatest calculated landslide concentration (measured as the total number of landslides per unit area) exceeded 80 landslides per 0.25 km2 in the hills east of the City of Berkeley.

The maps in this data release show active landslide structures in three areas along the north flank of the Slumgullion landslide. After the entire active part of the landslide was mapped in 1992 and 1993 (Fleming and others, 1999), we remapped these three smaller areas at roughly decadal intervals. Our goal was to learn what structures might persist and how they might change as heterogeneous landslide material of variable thickness passed through the areas. Together with the original 1999 map, these maps provide snapshots of the deformational features at converging and diverging margins of the landslide at four periods in about a 30-year time span (1992-2023). During summer months in 2002, 2013, and 2023, we conducted 1:1000-scale mapping using a traditional technique of manually drawing lines on topographic base maps to represent the structures we observed in the field. There was generally a lapse of two or more years between acquisition of the topographic base data and the field mapping. Meters of landslide displacement during the lapse resulted in a mismatch between the topographic map and topography on the active landslide at the time of our fieldwork. When drawing features on the topographic base, we referenced fixed topographic features directly north of the active landslide’s strike-slip boundary to compensate for the mismatch. The data are recorded in Geographic Information System (GIS) files that contain the line styles used to portray and distinguish the different landslide structures. The files record the shapes and positions of the mapped landslide structures. An index of line styles used to portray mapped structures is shown in Figure 1. Topographic base maps used for the 2002, 2013, and 2023 structural maps were from 2000, 2011, and 2018, respectively. One-meter Digital Elevation Models (DEMs), contours, and shaded-relief maps from these three years are included in this data release. The 2000 DEM was created from 2 m contours of the landslide on July 31, 2000, as originally published in Messerich and Coe (2003). The 2011 DEM was created by the authors using a structure-from-motion photogrammetric method and 1:6000 scale aerial photos acquired on September 23, 2011. The 2018 DEM is lidar data collected between October 5, 2018 and September 24, 2019, with the original data available from the U.S. Geological Survey 3DEP Lidar Explorer (U.S. Geological Survey, 2024). The contour interval used for the 2000 DEM is 2 m. The contour interval used for the 2011 and 2018 DEM is 1 m. All GIS data are projected in the Universal Transverse Mercator (UTM) zone 13N cartesian coordinate system. Portable Document Format (PDF) files of the landslide structure maps of each area in 2002, 2013, and 2023, are also provided. Figure 1. Line and polygon types used for landslide structures and features mapped at the Slumgullion landslide. References Fleming, R.W., Baum, R.L., and Giardino, Marco, 1999, Map and description of the active part of the Slumgullion Landslide, Hinsdale County, Colorado: U.S. Geological Survey Geologic Investigations Series Map I-2672 , scale 1:1,000, https://doi.org/10.3133/i2672 Messerich, J.A. and Coe, J.A., 2003, Topographic map of the active part of the Slumgullion landslide on July 31, 2000, Hinsdale County, Colorado: U.S. Geological Survey Open-File Report 03-144, 7 p., 1:1,000 scale map. http://pubs.usgs.gov/of/2003/ofr-03-144/ U.S. Geological Survey, 2024, 3DEP Lidar Explorer, data available at: http://prd-tnm.s3.amazonaws.com/index.html?prefix=StagedProducts/Elevation/1m/Projects/CO_Southwest_NRCS_2018_D18

The maps in this data release show active landslide structures in three areas along the north flank of the Slumgullion landslide. After the entire active part of the landslide was mapped in 1992 and 1993 (Fleming and others, 1999), we remapped these three smaller areas at roughly decadal intervals. Our goal was to learn what structures might persist and how they might change as heterogeneous landslide material of variable thickness passed through the areas. Together with the original 1999 map, these maps provide snapshots of the deformational features at converging and diverging margins of the landslide at four periods in about a 30-year time span (1992-2023). During summer months in 2002, 2013, and 2023, we conducted 1:1000-scale mapping using a traditional technique of manually drawing lines on topographic base maps to represent the structures we observed in the field. There was generally a lapse of two or more years between acquisition of the topographic base data and the field mapping. Meters of landslide displacement during the lapse resulted in a mismatch between the topographic map and topography on the active landslide at the time of our fieldwork. When drawing features on the topographic base, we referenced fixed topographic features directly north of the active landslide’s strike-slip boundary to compensate for the mismatch. The data are recorded in Geographic Information System (GIS) files that contain the line styles used to portray and distinguish the different landslide structures. The files record the shapes and positions of the mapped landslide structures. An index of line styles used to portray mapped structures is shown in Figure 1. Topographic base maps used for the 2002, 2013, and 2023 structural maps were from 2000, 2011, and 2018, respectively. One-meter Digital Elevation Models (DEMs), contours, and shaded-relief maps from these three years are included in this data release. The 2000 DEM was created from 2 m contours of the landslide on July 31, 2000, as originally published in Messerich and Coe (2003). The 2011 DEM was created by the authors using a structure-from-motion photogrammetric method and 1:6000 scale aerial photos acquired on September 23, 2011. The 2018 DEM is lidar data collected between October 5, 2018 and September 24, 2019, with the original data available from the U.S. Geological Survey 3DEP Lidar Explorer (U.S. Geological Survey, 2024). The contour interval used for the 2000 DEM is 2 m. The contour interval used for the 2011 and 2018 DEM is 1 m. All GIS data are projected in the Universal Transverse Mercator (UTM) zone 13N cartesian coordinate system. Portable Document Format (PDF) files of the landslide structure maps of each area in 2002, 2013, and 2023, are also provided. Figure 1. Line and polygon types used for landslide structures and features mapped at the Slumgullion landslide. References Fleming, R.W., Baum, R.L., and Giardino, Marco, 1999, Map and description of the active part of the Slumgullion Landslide, Hinsdale County, Colorado: U.S. Geological Survey Geologic Investigations Series Map I-2672 , scale 1:1,000, https://doi.org/10.3133/i2672 Messerich, J.A. and Coe, J.A., 2003, Topographic map of the active part of the Slumgullion landslide on July 31, 2000, Hinsdale County, Colorado: U.S. Geological Survey Open-File Report 03-144, 7 p., 1:1,000 scale map. http://pubs.usgs.gov/of/2003/ofr-03-144/ U.S. Geological Survey, 2024, 3DEP Lidar Explorer, data available at: http://prd-tnm.s3.amazonaws.com/index.html?prefix=StagedProducts/Elevation/1m/Projects/CO_Southwest_NRCS_2018_D18

This inventory was originally created by Harp and others (1984) describing the landslides triggered by a sequence of earthquakes, with the largest being the M 6.5 Mammoth Lakes, California earthquake that occurred on 25 May 1980 at 19:44:50 UTC. Care should be taken when comparing with other inventories because different authors use different mapping techniques. This inventory includes landslides triggered by a sequence of earthquakes rather than a single mainshock. Please check the author methods summary and the original data source for more information on these details and to confirm the viability of this inventory for your specific use. With the exception of the data from USGS sources, the inventory data and associated metadata were not acquired by the U.S. Geological Survey (USGS) and thus have not been reviewed for accuracy and completeness by the USGS. They are presented as part of this data series for convenience of the user only, as part of an effort to make published ground-failure inventories more accessible from a single aggregated site. 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 inventory was originally created by Harp and others (1984) describing the landslides triggered by a sequence of earthquakes, with the largest being the M 6.5 Mammoth Lakes, California earthquake that occurred on 25 May 1980 at 19:44:50 UTC. Care should be taken when comparing with other inventories because different authors use different mapping techniques. This inventory includes landslides triggered by a sequence of earthquakes rather than a single mainshock. Please check the author methods summary and the original data source for more information on these details and to confirm the viability of this inventory for your specific use. With the exception of the data from USGS sources, the inventory data and associated metadata were not acquired by the U.S. Geological Survey (USGS) and thus have not been reviewed for accuracy and completeness by the USGS. They are presented as part of this data series for convenience of the user only, as part of an effort to make published ground-failure inventories more accessible from a single aggregated site. 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.

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On February 14, 2019, just before 2:56 am local time (Pacific Standard Time), a landslide initiated from the natural hillslopes above the City of Sausalito, California. The landslide, properly identified as a debris flow, overran a road (Sausalito Boulevard) located immediately below the landslide source area, and impacted and destroyed several residential structures. One person was located in one of the residences and survived the disaster after being transported in their home down the slope. The U.S. Geological Survey responded to this event within hours of the landslide and provided situational awareness of possible secondary landslide hazards associated with the event. The USGS also rapidly mobilized its topographic surveying capabilities (specifically, GPS and terrestrial lidar devices) and collected a three-dimensional point cloud model of the landslide source area and surrounding terrain to capture the as-failed condition of the slope for potential future studies. This data collected during this response is presented in this data release.