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GSA Today Article: High Resolution Lidar Topography of the Puget Lowland, Washington VOLUME 13, NUMBER 6 JUNE 2003 GSA TODAY publishes news and information for more than ON THE COVER: Shaded relief image 17,000 GSA members and subscribing libraries. GSA Today calculated from lidar topography of part of lead science articles should present the results of exciting new research or summarize and synthesize important problems or the Seattle fault zone, 15 km west of Seattle, issues, and they must be understandable to all in the earth site of the 2003 GSA Annual Meeting. Scene science community. Submit manuscripts to science editors is 4.5 km across. For location, see Figure 3 of Keith A. Howard, [email protected], or Gerald M. Ross, [email protected]. “High-resolution lidar topography of the Puget Lowland—A bonanza for earth GSA TODAY (ISSN 1052-5173 USPS 0456-530) is published 11 times per year, monthly, with a combined April/May issue, by science,” by R.A. Haugerud, D.J. Harding, The Geological Society of America, Inc., with offices at 3300 S.Y. Johnson, J.L. Harless, C.S. Weaver, and Penrose Place, Boulder, Colorado. Mailing address: P.O. Box B.L. Sherrod, p. 4–10. 9140, Boulder, CO 80301-9140, U.S.A. Periodicals postage paid at Boulder, Colorado, and at additional mailing offices. Postmaster: Send address changes to GSA Today, GSA Sales and Service, P.O. Box 9140, Boulder, CO 80301-9140. Copyright © 2003, The Geological Society of America, Inc. (GSA). All rights reserved. Copyright not claimed on content SCIENCE ARTICLE prepared wholly by U.S. government employees within scope of their employment. Individual scientists are hereby granted 4 High-resolution lidar topography of the Puget Lowland, permission, without fees or further requests to GSA, to use a single figure, a single table, and/or a brief paragraph of text in Washington—A bonanza for earth science, Ralph Haugerud, other subsequent works and to make unlimited photocopies of David J. Harding, Samuel Y. Johnson, Jerry L. Harless, Craig S. Weaver, items in this journal for noncommercial use in classrooms to further education and science. For any other use, contact and Brian L. Sherrod Copyright Permissions, GSA, P.O. Box 9140, Boulder, CO 80301-9140, USA, Fax 303-357-1073, [email protected]; 10 Correction: Reactivation, trishear modeling, and folded basement in reference GSA Today, ISSN 1052-5173. Permission is granted to authors to post the abstracts only of their articles on their own Laramide uplifts: Implications for the origins of intra-continental faults or their organization’s Web site providing the posting includes this reference: “The full paper was published in the Geological Society of America’s journal GSA Today, [include year, month, and page numbers if known, where the article will appear].” GSA provides this and other forums for the presentation of diverse 13 Geoscience Horizons: Seattle 2003 opinions and positions by scientists worldwide, regardless of GSA Annual Meeting & Exposition their race, citizenship, gender, religion, or political viewpoint. Opinions presented in this publication do not reflect official Greetings from the General Chair . .13 positions of the Society. Special Events . .14 SUBSCRIPTIONS for 2003 calendar year: Society Members: 2003 Exhibitors . .15 GSA Today is provided as part of membership dues. 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Good ADVERTISING: 56 Announcements Classifieds & display: Ann Crawford, 1-800-472-1988, ext. 1053, (303) 357-1053, Fax 303-357-1070; [email protected] 58 Homeland and Climatic Security at the Crossroads of Science and GSA ONLINE: www.geosociety.org Policy: GSA–USGS Congressional Science Fellow Midyear Report Printed in U.S.A. using pure soy inks. 60 Classified Advertising 50% Total Recovered Fiber 10% Postconsumer High-Resolution Lidar Topography In 1999, geographic information system (GIS) specialists, planners, and earth sci- of the Puget Lowland, Washington entists working for local government agencies, the U.S. Geological Survey —A Bonanza for Earth Science (USGS), and the National Aeronautics and Space Administration (NASA) formed the Ralph A. Haugerud, [email protected], U.S. Geological Survey, c/o Department of Puget Sound Lidar Consortium (PSLC) and Earth and Space Sciences, Box 351310, University of Washington, Seattle, Washington began an experiment to purchase cooper- 98195, USA atively high-resolution, public-domain lidar David J. Harding, [email protected], National Aeronautics and Space topographic survey data. The initial impe- Administration, Code 921, Goddard Space Flight Center, Greenbelt, Maryland 20771, USA tus behind this effort was to find fault scarps for seismic hazards studies. To date, Samuel Y.Johnson, [email protected], U.S. Geological Survey, P.O. Box 25046, the PSLC has acquired over 10,000 km2 of Lakewood, Colorado 80225, USA high-resolution digital elevation models Jerry L. Harless, [email protected], Puget Sound Regional Council, 1011 Western Ave, (DEMs) of the heavily forested Puget Suite 500, Seattle, Washington 98104, USA Lowland of western Washington, and we Craig S. Weaver, [email protected], and Brian L. Sherrod, [email protected], U.S. have discovered more than half a dozen Geological Survey, c/o Department of Earth and Space Sciences, Box 351310, University scarps of possible tectonic origin. The of Washington, Seattle, Washington 98195, USA experiment has been a success. In this report, we describe some of the hazards facing the Puget Lowland, lidar ABSTRACT forest cover stymies traditional photogram- mapping technology, the PSLC data collec- 2 More than 10,000 km of high-resolu- metry. The survey was commissioned by tion effort, and our use of these data for tion, public-domain topography acquired Kitsap Public Utility District to map identifying seismic hazards and for geo- by the Puget Sound Lidar Consortium is groundwater infiltration and runoff on morphic mapping. revolutionizing investigations of active Bainbridge Island, just west of Seattle faulting, continental glaciation, landslides, (Harding and Berghoff, 2000). Among the THE PUGET LOWLAND and surficial processes in the seismically landforms portrayed was a 1–5-m-high, Seattle and the surrounding Puget active Puget Lowland. The Lowland—the east-trending scarp that offsets north-south Lowland lie in the forearc of the Cascadia population and economic center of the glacial grooves at the south end of the is- subduction zone (Fig. 2). Two hundred Pacific Northwest—presents special prob- land, within the Seattle fault zone (Fig. 1). kilometers to the west, off the Pacific lems for hazards investigations, with its Previous routine topographic mapping, coast, the Juan de Fuca plate subducts young glacial topography, dense forest geologic mapping, and examination of northeast beneath the North American cover, and urbanization. Lidar mapping aerial photographs had failed to identify plate at ~4 cm/yr. To the east of Seattle rise during leaf-off conditions has led to a de- this scarp concealed beneath dense second- active volcanoes—Mount Rainier, Glacier tailed digital model of the landscape be- and third-growth forest. Subsequent Peak, and Mount Baker—of the Cascade neath the forest canopy. The surface thus trenching of the scarp confirmed that it volcanic arc. The Olympic Mountains to revealed contains a rich and diverse record formed during one or more large, the west of Seattle are a rapidly uplifting of previously unknown surface-rupturing Holocene, surface-rupturing earthquakes forearc high. Between the Cascades and faults, deep-seated landslides, uplifted (Nelson et al., 2002). This discovery the Olympics lies the Puget Lowland (Fig. Holocene and Pleistocene beaches, and quickly led to the realization that other 3), part of a broad forearc depression that subglacial and periglacial features. More
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