State of Utah - Utah Geological Survey (UGS) 2008 None vector digital data UGS Special Study SS 127 Salt Lake City, UT Utah Geological Survey Digital data at 1:24,000 William R. Lund, Tyler R. Knudsen, Garrett S. Vice, and Lucas Shaw; Utah Geological Survey 2008 UGS Special Study SS 127 Salt Lake City, UT Utah Geological Survey Liquefaction withheld This dataset represents liquefaction geologic hazard St George - Hurricane metropolitan area, Washington County, Utah at a scale of 1:24,000. The data can be used for analysis and display at 1:24,000. The purpose of this study is to provide planners and other city and county officials with information on the kind and location of geologic hazards and adverse-construction conditions that may impact existing and future development in the St. George - Hurricane metropolitan area. en 2008 publication date Complete None planned -113.721069 -113.241079 37.303247 36.990755 258793.050400 300580.017700 4097077.691600 4130683.217900 Utah geology hazards liquefaction earthquake Utah St George Hurricane Washington County None Although this product represents the work of professional scientists, the Utah Department of Natural Resources, Utah Geological Survey, makes no warranty, expressed or implied, regarding its suitability for a particular use, and does not guarantee accuracy or completeness of the data. The Utah Department of Natural Resources, Utah Geological Survey, shall not be liable under any circumstances for any direct, indirect, special, incidental, or consequential damages with respect to claims by users of this product. For use at 1:24,000 scale only. Data released to the Receiving Agency (RA) remains the property of the originating data source (see Source_Information) and cannot be reproduced for sale by the RA without the written consent of that data source. Redistribution of datasets unchanged as obtained from UGS and without fee is allowed. Any hardcopies utilizing these data sets shall clearly indicate their source. If the RA has modified the data in any way they are obligated to describe the types of modifications they have performed on the hardcopy map. RA specifically agrees not to misrepresent these data sets, nor to imply that changes they made were approved by UGS. Tyler Knudsen Utah Geological Survey (UGS) - Cedar City Office Geologist mailing and physical address

88 E Fiddler Canyon Rd., Ste. C

Cedar City UT 84720 USA

1594 W North Temple, Suite 3110

Salt Lake City UT 84116 USA 435-865-9041 tylerknudsen@utah.gov GIS Data: Garrett Vice, Tyler Knudsen, Lucas Shaw (UGS) Project Manager: Gary Christenson, (UGS (Ret.)) Review: Utah Geological Survey None Unclassified None ESRI ArcCatalog 9.2.2.1350 Shapefile Feature attributes were taken from the source material. Code assignments are believed to be representative of source materials. UGS estimates the accuracy to be close to, but not completely conforming to, the 1:24,000 scale UGS standards. Dataset copied. withheld 20090730 15520900 Vector G-polygon 0 Simple Polygon FALSE 0 FALSE FALSE coordinate pair 0.000000 0.000000 meters Universal Transverse Mercator 12 0.999600 -111.000000 0.000000 500000.000000 0.000000 North American Datum of 1927 Clarke 1866 6378206.400000 294.978698 GCS_North_American_1927 NAD_1927_UTM_Zone_12N 0.000010 Explicit elevation coordinate included with horizontal coordinates Liquefaction Feature Class 0 Shape Feature geometry. ESRI Coordinates defining the features. Shape_Area Area of feature in internal units squared. ESRI Positive real numbers that are automatically generated. FID FID String 50 Internal feature number. ESRI Sequential unique whole numbers that are automatically generated. UNIT UGS 1:24,000-scale geologic map units String 50 Class Liquefaction-susceptibility category Float 19 11 class class Float 19 11 Shape_Leng Shape_Leng Double 19 0 0 Liquefaction and liquefaction-induced ground failures are major causes of earthquake damage (Keller and Blodgett, 2006). Upon liquefaction, a soil loses its strength and ability to support the weight of overlying structures or sediments. Liquefaction chiefly occurs in areas where ground water is < 50 feet deep, when a water-saturated, cohesionless soil is subjected to strong ground shaking (Seed, 1979; Martin and Lew, 1999). Liquefaction and liquefaction-induced ground failure can have four major adverse effects: (1) foundations may crack, (2) buildings may tip, (3) buoyant buried structures, such as septic tanks and storage tanks, may rise, and (4) liquefied soils and overlying materials may move down even gentle slopes. We used information about the age, textural characteristics (grain size and sorting), cementation of unconsolidated geologic deposits, the presence of shallow (< 50 ft) ground water in those units, and the liquefaction response of similar units in historical earthquakes to prepare a Liquefaction-Hazard Map (plate 2) for the study area. Descriptions of the liquefaction-hazard categories are presented below, and table 1 shows the liquefaction hazard of unconsolidated Quaternary geologic units in the study area. VH Geologic units that liquefied during the 1992 St. George, Utah, M L 5.8 earthquake, and consist of well-sorted sands, silty sands, and gravels along modern stream drainages and young alluvial terraces where depth to ground water is < 10 feet. H High - Geologic units that consist of well-sorted sands, silty sands, and gravels where depth to ground water is < 50 feet. None of these units are known to have liquefied during the 1992 St. George earthquake. H2 High2 - Geologic units with textural characteristics of the High category, but ground-water information is lacking. M Moderate - Geologic units that consist of moderately sorted sands, silty sands, and gravels where depth to ground water is < 50 feet. M2 Moderate2 - Geologic units with textural characteristics of the Moderate category, but ground-water information is lacking. L Low - Geologic units that consist of moderately to poorly sorted sands and gravels where depth to ground water is < 50 feet. Liquefaction hazard is considered low in these units because of their textural characteristics and/or degree of cementation. L2 Geologic units with textural characteristics of the Low category, but ground-water information is lacking. Unclassified areas on the Liquefaction-Hazard Map (plate 2) include unconsolidated Quaternary and Tertiary geologic units with textural or cementation characteristics that generally preclude liquefaction, areas where depth to ground water is > 50 feet, and areas where bedrock crops out. These geologic units are considered to have no liquefaction hazard; however, small areas of liquefaction hazard too small to show at the scale of this study may exist locally within unclassified areas of the map. DVD-ROM 0.000 0.000 20080616 Utah Geological Survey Geologic Hazards Program GIS Analyst 1594 West North Temple Suite 3110 Salt Lake City UT 84116 USA 801-537-3386 801-538-4810 FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998 local time en http://www.esri.com/metadata/esriprof80.html ESRI Metadata Profile 20141217 16585100 FALSE 20080616 12033500 20080616 13151100 1.0 ESRI ArcCatalog 9.2.2.1350 Liquefaction 258793.0504 300580.0177 4130683.2179 4097077.6916 1 -113.721069 -113.241079 37.303247 36.990755 1 ISO 19115 Geographic Information - Metadata DIS_ESRI1.0 dataset 002 withheld 0.000 Shapefile NAD_1927_UTM_Zone_12N 0 20080616