HR: 1330h
AN: ED32B-1193 INVITED [PDF]
TI: Application Of Geowall Technology To The Analysis Of A Three Dimensional Geologic Map Of The Santa
Clara (Silicon) Valley, California
AU: * Phelps, G A
EM: gphelps@usgs.gov
AF: U.S. Geological Survey, 345 Middlefield Rd, MS 989, Menlo Park, CA 94025 United States
AU: Jachens, R C
EM: jachens@usgs.gov
AF: U.S. Geological Survey, 345 Middlefield Rd, MS 989, Menlo Park, CA 94025 United States
AU: Wentworth, C M
EM: cwent@usgs.gov
AF: U.S. Geological Survey, 345 Middlefield Rd, MS 989, Menlo Park, CA 94025 United States
AU: Langenheim, V E
EM: zulanger@usgs.gov
AF: U.S. Geological Survey, 345 Middlefield Rd, MS 989, Menlo Park, CA 94025 United States
AU: Hanson, R T
EM: rthanson@usgs.gov
AF: U.S. Geological Survey, 5735 Kearny Villa Rd, San Diego, CA 92123 United States
AU: Faunt, C C
EM: ccfaunt@usgs.gov
AF: U.S. Geological Survey, 5735 Kearny Villa Rd, San Diego, CA 92123 United States
AB:
Geowall, a stereo projection system suitable for meetings and conferences, is being used to visualize, understand, interpret,
and test a three-dimensional geologic map of the Santa Clara (Silicon) Valley, southern San Francisco Bay area, California.
Geowall*, developed at the Electronic Visualization Laboratory associated with the University of Illinois, uses dual
polarized images projected onto a polarization-preserving screen to create the illusion of three dimensions when viewed
through polarized glasses.
The map of Santa Clara Valley encompasses a 45 by 45 km area, extends to a depth of 14 km, and includes the northern Santa
Clara Valley and surrounding hillsides between the active Calaveras and San Andreas faults. It is currently divided by
several major faults into tectonic blocks, within which 9 units represent the Cenozoic and Mesozoic sections. Many of these
units will be subdivided as the map evolves. The map is being constructed in EarthVision*(TM, Dynamic Graphics, Inc.), a
geologic modeling software that includes three dimensional rendering and model manipulation capabilities. Earthvision
generates data and model images of which the entire, or only portions of the model, can be viewed in three dimensions. The
geowall presentation will explore the datasets and three-dimensional geologic map of Santa Clara Valley and structures
defined by geologic mapping, stratigraphy, hydrology, potential field geophysics, seismic reflection, and earthquake
seismicity.
The map is the result of a collaborative effort among several earth science disciplines, and as such requires the integration
of diverse datasets and the communication of diverse ideas. The geowall is particularly effective at promoting group
discussion and analysis of the three-dimensional map, because the map can be displayed in a group setting as a 6x6 ft.,
stereo image. The spatial relationships of the datasets are easily seen, and the map can be deconstructed and particular
relationships isolated. For example, trends in scattered clouds of point data are often difficult to perceive in two
dimensions. The rendering of earthquake hypocenter data coupled with the ability to view only the fault planes in the map,
from any perspective, permits rapid examination of coherent point patterns relative to modeled fault planes. Visualizing
hydrologic data simultaneously with geologic data permits scientists to see relationships that were not apparent in
two-dimensions or individually. Such concurrent analysis among project scientists is vital to the iterative process of
exploring relationships between data sets, hypothesis testing, and model improvement.
Another important use of the geowall is the communication of project ideas and results to others. The geowall has proven to
be an effective tool for conveying information about Santa Clara Valley to managers, scientific audiences, and local
citizens. Managers and scientists are able to grasp the geologic problems quickly and ask targeted questions, whereas
citizens with non-earth science backgrounds are able to understand such concepts as pull-apart basins and gain knowledge of
the scale of geologic structures.
* Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply
endorsement by the U.S. Government.
DE: 6605 Education
SC: Education and Human Resources [ED]
MN: 2003 Fall Meeting