Site ground motion (peak ground velocity) for a simulated Portland Hills Fault M 6.8 earthquake, Clackamas, Multnomah, and Washington Counties, Oregon

Oregon Department of Geology and Mineral Industries 2018 Site ground motion (peak ground velocity) for a simulated Portland Hills Fault M 6.8 earthquake, Clackamas, Multnomah, and Washington Counties, Oregon raster digital data Oregon Department of Geology and Mineral Industries Open-File Report Open-File Report O-18-02 Portland, Oregon, USA Oregon Department of Geology and Mineral Industries http://www.oregongeology.org Oregon Department of Geology and Mineral Industries 2018 Earthquake regional impact analysis for Clackamas, Multnomah, and Washington Counties, Oregon file geodatabase Oregon Department of Geology and Mineral Industries Open-File Report Open-File Report O-18-02 Portland, Oregon, USA Oregon Department of Geology and Mineral Industries http://www.oregongeology.org/ Peak ground velocity (pgv) is the maximum ground velocity that is estimated to occur at a location on the soil surface for a simulated earthquake. Data in cm/sec. To provide pgv (peak ground velocity) site ground motion information throughout the study area from a simulated Portland Hills Fault M 6.8 earthquake. Used in building and infrastructure damage models. Peak ground velocity (pgv) is equal to the maximum ground velocity that estimated to occur during earthquake shaking at a particular location. This is a simulated earthquake, or a 'scenario', which represents one realization of a potential future earthquake by assuming a particular magnitude, location, and fault-rupture geometry and estimating shaking using a variety of strategies. 2018 Complete None planned -123.504229 -121.646769 45.809239 44.853985 ISO 19115 Topic Category geoscientificinformation Oregon Geospatial Enterprise Office Metadata Keyword Thesaurus ground motion ground shaking earthquake active fault strong motion earthquake hazard earthquake occurrence Oregon Geospatial Enterprise Office Metadata Keyword Thesaurus Clackamas Multnomah Washington Oregon Geospatial Enterprise Office Metadata Keyword Thesaurus Land surface Oregon Geospatial Enterprise Office Metadata Keyword Thesaurus None REPORT DATA: This product is for informational purposes and may not have been prepared for or be suitable for legal, engineering, or surveying purposes. Users of this information should review or consult the primary data and information sources to ascertain the usability of the information. This publication cannot substitute for site-specific investigations by qualified practitioners. Site-specific data may give results that differ from the results shown in the publication. See the accompanying text report for more details on the limitations of the methods and data used to prepare this publication. Oregon Department of Geology and Mineral Industries mailing and physical address

800 NE Oregon Street Suite 965

Portland Oregon 97232 USA 1 971 673 1555 1 971 673 1562 dogami-info@oregon.gov When contacting DOGAMI about this data set, please reference the data set title or other identifying information in your correspondence. DOGAMI publications can be downloaded from http://www.oregongeology.org John Bauer Oregon Department of Geology and Mineral Industries Geohazards Analyst jpeg image (.jpg) This work was funded on behalf of Regional Disaster Preparedness Organization with an Urban Area Security Initiative grant for the Portland Metropolitan Region. Unclassified Site ground motion developed based on bedrock ground motion, which is a model of a Portland Hills fault. An actual subduction zone earthquake will likely vary significantly in magnitude and in attenuation from the simulated earthquake. Site response is driven by the NEHRP site classification, which was driven by surficial geologic unit designations. Site response can vary significantly, depending on particulars and depth of the soil column relative to the underlying bedrock. The NEHRP site amplification functions are an approximation and generalization of the site effect. Sites classified as "F" were given an "E" rating for loss modeling purposes, and have the largest uncertainty. Maximum, minimum, average of continuous data is consistent with expectations, and are comparable to the published USGS ShakeMap data for a M 7.1 Portland Hills Fault. Spatial pattern of data consistent with the NEHRP site designations and the expected amplification, given the bedrock ground motion. All three three counties are fully represented with data. Areas outside of the three counties are represented as NoData. Site ground motion developed based on bedrock ground motion, which is a model of a Portland Hills fault. An actual earthquake along the fault will likely vary significantly in magnitude and in attenuation, compared to the simulated earthquake. Site response is driven by the NEHRP site classification, itself based on geologic polygons drawn at a range of scales, from 1:4000 to 1:24000 in the study area. not applicable USGS Earthquake Hazards Program 2016 Unpublished data, Bedrock ground motion for a M 6.8 Portland Hills Fault vector digital data Seattle, Washington USGS Earthquake Hazards Program 2016 Oregon Department of Geology and Mineral Industries 2018 NEHRP Site Classification for Clackamas, Multnomah, and Washington Counties, Oregon vector digital data Oregon Department of Geology and Mineral Industries Open-File Report In preparation Portland, Oregon Oregon Department of Geology and Mineral Industries 1:4000 - 1:100000 The pgv bedrock ground motion point data delivered with this project (PHF_M6p8_bedrock_groundmotion) was converted using Esri Spatial Analyst Natural Neighbor function, to a 30-ft continuous grid. The NEHRP Site Classification was converted to a 30-ft classified grid, designating the location as either B, C, D, or E. All sites designated as NEHRP "F" were converted to NEHRP "E". Site ground motion calculations were performed using the equations listed in the accompanying report, Table 11-1. Oregon Department of Geology and Mineral Industries mailing and physical address

800 NE Oregon Street Suite 965