Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Abstract Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Engelkemeir, R. M. Articles by Khan, S. D. GeoRef GeoRef Citation

Lidar mapping of faults in Houston, Texas, USA

¹ Department of Geosciences, University of Houston, Houston, Texas 77204-5007, USA

View larger version (90K): [in this window] [in a new window]   Figure 1. Regional map, showing the northwestern Gulf of Mexico. Red dashed lines show the eastward migration of depocenters. The salt basin extends from the Luling-Mexia-Talco fault zone to the Sigsbee escarpment. The blue rectangle shows the study area that is detailed in Figure 2. Beaumont and Victoria are shown.

View larger version (90K): [in this window] [in a new window]   Figure 2. Houston area map showing active surface faults interpreted on lidar imagery and the locations of salt domes. Only known faults interpreted on the lidar are shown here. Houston is in Harris County, and most of Harris County is visible. Note that the faults in northwest Houston have a NE-SW trend, whereas some faults in southeast Houston radiate from salt domes. Salt domes are taken from O'Neill and Van Siclen (1984). Major fault systems of northwest Houston are shown: Hockley-Conroe Fault System; Addicks Fault System; Long Point-Eureka Heights Fault System. Locations discussed in the text are labeled: IAH—Bush Intercontinental Airport; B—Brownwood subdivision; AR—Addicks Reservoir; BR—Barker Reservoir. The locations of Figures 3, 4, and 12 are also shown.

View larger version (69K): [in this window] [in a new window]   Figure 3. Lidar DEM hillshade showing interpreted scarps for northwest Houston. Known faults are shown in red: Addicks (down to the coast); Brittmore (down to the coast); Breen (down to the coast); White Oak (antithetic); Woodgate (down to the coast); Lee (antithetic); Long Point (down to the coast); Piney Point East and West (antithetic); Eureka Heights (down to the coast); Memorial Park (antithetic); Pecore East and West (antithetic). Unconfirmed scarps are shown in yellow: Long Point Splinter (down to the coast); Little York (down to the coast); Memorial Forest (down to the coast); PX (antithetic—extension of Piney Point); Homestead (down to the coast); Addicks New (down to the coast—new picks). Blue circles show DEM processing artifacts.

View larger version (83K): [in this window] [in a new window]   Figure 4. Comparison of images for a portion of the Long Point Fault. (A) Map of lidar DEM. Elevations decrease from the northwest to the southeast. The elevation break along the Long Point Fault is clear. The Piney Point Fault can also be seen. The channel of Buffalo Bayou is noticeable. Also shown are the locations for Figures 5, 6, 7, 9, 10, and 11.

View larger version (126K): [in this window] [in a new window]   Figure 4 (continued). (B) Hillshade of lidar DEM showing scarps of the Long Point Fault and the Piney Point Fault, antithetic to the Long Point Fault. Note that the Long Point Fault scarp is darker than the surrounding image, whereas the Piney Point Fault is lighter. Also shown are the locations for Figures 5, 6, 7, 9, 10, and 11.

View larger version (133K): [in this window] [in a new window]   Figure 4 (continued). (C) Slope aspect map derived from lidar DEM. The Long Point Fault is hard to identify. Slope aspect shows the dip direction for each DEM pixel.

View larger version (87K): [in this window] [in a new window]   Figure 4 (continued). (D) Slope map derived from lidar DEM. Both the Long Point and Piney Point Faults can be seen, but not as distinctly as on either 4A or 4B images. Slope shows the magnitude of dip, with red indicating high slope and green indicating low slope.

View larger version (104K): [in this window] [in a new window]   Figure 5. Long Point Fault at Bunker Hill: Location of map is shown in Figure 4. The image in the upper left is the lidar DEM. The hillshaded image on the lower right shows the location of the scarp. A yellow line segment shows the location of the topographic profile on both images. The photo is looking updip along the west side of Bunker Hill. Note tilted sidewalk slabs along scarp face. Red lines from the topographic profile lead to corresponding locations on the photo.

View larger version (82K): [in this window] [in a new window]   Figure 6. Comparison of portion of Long Point Fault mapped with lidar and previously published versions. Note that the fault trace from Fisher is inappropriate for a map at this scale (1:4500).

View larger version (111K): [in this window] [in a new window]   Figure 7. Comparison of orthophoto with lidar for fault detection. Location of map is shown in Figure 4. (A) Hillshade of lidar DEM. The fault is clearly visible trending west to east through the pit.

View larger version (79K): [in this window] [in a new window]   Figure 7. (continued). (B) The Long Point Fault is not visible in the orthophoto, except for a slight change in tone within a water detention pond (pit), built on a site previously occupied by an apartment complex.

View larger version (17K): [in this window] [in a new window]   Figure 8. Model for scarp formation (after Verbeek and Clanton, 1979). In this cut-and-fill process, erosion removes material from the footwall and deposits it on the hanging wall.

View larger version (98K): [in this window] [in a new window]   Figure 9. Photograph of a 10-m–long crack in the pavement of a parking lot in Houston. The photo is looking east along the scarp of the Long Point Fault. A slight inclination to the south (to the right) can be observed on the hanging wall.

View larger version (50K): [in this window] [in a new window]   Figure 10. (A) Lidar hillshaded image showing Long Point Fault where it crosses St. Francis Street. East-west segment of trace on east side of street runs along the property line between two houses. The kink is due to grading the lot on the south side. With ongoing fault movement, the house (not shown) on the south side of the scarp is at risk. Location of map is shown in Figure 4.

View larger version (105K): [in this window] [in a new window]   Figure 10. (continued). (B) Photograph looking east across St. Francis Street.

View larger version (88K): [in this window] [in a new window]   Figure 11. Lidar hillshaded image of several branches of the Long Point Fault. Location is shown in Figure 4.

View larger version (82K): [in this window] [in a new window]   Figure 12. Contours showing subsidence between 1978 and 1995 (1 and 1.5 m), and Addicks depression boundary (Stork and Sneed, 2002), superimposed on a lidar image. The boundary of the subsidence depression is indicated by tics. The locations of the Long Point and Addicks Faults systems are shown, as is Cypress Creek. The lidar image was generated by removing a linear trend from the lidar DEM. The resultant residual image was then hillshaded. The Addicks subsidence depression is not clearly seen in the residual, and the hillshade shows only drainages, streets, and NE-trending fault scarps.