HR: 15:10h
AN: G33D-07    [Abstracts]
TI: Four-dimensional surface deformation analysis, snow volume calculation, and fault mapping with Ground Based Tripod LiDAR
AU: * Bawden, G W
EM: gbawden@usgs.gov
AF: US Geological Survey, 3020 State University Drive East Modoc Hall Suite 4004, Sacramento, CA 95819 United States
AU: Schmitz, S
EM: sschmitz@usgs.gov
AF: US Geological Survey, 3020 State University Drive East Modoc Hall Suite 4004, Sacramento, CA 95819 United States
AU: Howle, J F
EM: jfhowle@usgs.gov
AF: US Geological Survey, 229 North Lake Blvd, Carnelian Bay, CA 96140 United States
AU: Laczniak, R J
EM: rlaczni@usgs.gov
AF: US Geological Survey, 160 N. Stephanie Street, Henderson, NV 89074 United States
AU: Bowers, J
EM: jcbowers@usgs.gov
AF: US Geological Survey, 13581 John Glenn Rd, Apple Valley, CA 92308 United States
AU: Osterhuber, R
EM: randall@sierra.net
AF: UC Berkeley, Box 810, Soda Springs, CA 95728 United States
AU: Irvine, P
EM: pirvine@consrv.ca.gov
AF: California Geological Survey, 655 South Hope Street Suite 700, Los Angeles, CA 90017 United States
AB: Ground-based tripod or terrestrial LiDAR (T-LiDAR) has the potential to significantly advance science and hazard assessments in a broad number of research disciplines using remotely collected ultra-high resolution (centimeter to subcentimeter) and accurate (ñ4 mm) digital imagery of the scanned target. This can be accomplished at distances from 3 to >800 meters, depending on the instrument and target's infrared reflective properties. Scientific analysis of the ultra-high resolution T-LiDAR imagery is through the direct analysis of three-dimensional datasets to calculate target dimensions, volume, and area; alternatively, repeated surveys of the target, differential four-dimensional time-series analysis can be used to evaluate volume change, target stability, surface displacements, or change-detection. Three examples are given that show a range of scientific T-LiDAR application to earth science research: (1) fault mapping at Yucca Flat, Nev.; (2) snow volume calculations in the central Sierra Nevada, Calif.; and (3) hazard mitigation and change-detection and hazard mitigation for the June 1, 2005, Laguna Beach Landslide, southern Calif. The fault-mapping example is a static analysis of many detailed (1- to 5-cm spot spacing) T-LiDAR scans collected on the Nevada Test Site at Yucca Flat at a crater created by an underground nuclear test. The analysis identifies and maps centimeter-level fractures and faults in and near the crater. The level of detail of the T-LiDAR-generated fault and fracture database enhances existing fracture maps. The snow-volume calculation example is a differential analysis of three T-LiDAR surveys at the U.C. Berkeley Central Sierra Snow Lab between March and June 2004. The surveys were aligned and differenced to calculate spatially varying snow volumes. These volumes were combined with water-density measurements to estimate the total water volume. The change detection and hazard-assessment example analyzes repeated T-LiDAR imagery following the June 1, 2005, Laguna Beach Landslide to assess hillslope and structure stability of the slide and the immediate surroundings, and to evaluate T-LiDAR as a hazards response tool. There were no land-surface changes within the landslide after the initial T-LiDAR survey (10 to 21 days after the event) other than minor small-scale readjustments, property recovery efforts, and monitoring within the landslide. T-LiDAR provided direct measurements for the full surrounding region and confirmed that many of the nearby homes were not moving during this time period and could be reinhabited.
DE: 1209 Tectonic deformation (6924)
DE: 1294 Instruments and techniques
DE: 1863 Snow and ice (0736, 0738, 0776, 1827)
DE: 8010 Fractures and faults
DE: 8094 Instruments and techniques
SC: Geodesy [G]
MN: Fall Meeting 2005