Rigor MS thesis figures

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Figure 1.1. The Palos Verdes fault crosses the study area on the outer San Pedro Shelf, offshore Los Angeles, California. Location of recent earthquake epicenters greater than M 3 in the Los Angeles area, from Richards-Dinger and Shearer (2000). GPS measured geodetic strain at several station locations is measured in mm/yr (Hudnut and Jackson, 1998). The polygon represents the area of the Beta 3-D seismic survey, used as the basis for most of this study. Long Beach Los Angeles Anaheim San Pedro Bay study area Los Angeles Area Faults, Earthquakes and Measured Strain 2 Whittier Fault Newport - Inglewood Fault Zone Santa Monica Fault Palos Verdes fault East Santa Cruz Basin fault San Pedro Basin fault Santa Catalina Island Lasuen Knoll Palos Verdes Hills San Joaquin Hills kilometers Santa Monica Bay

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Figure 2.1. Major Cenozoic geologic and tectonic deformation events in the Los Angeles Basin area from Wright (1991) and Crowell (1987). S-1 through S-3 refer to Kelsch (1998)’s deformation phases based on his observations of the Beta oilfield 3D survey. 7 Los Angeles Basin Cenozoic Tectonic History and Vertical Deformation Intensity

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Anaheim Long Beach Irvine Huntington Beach East Los Angeles Los Angeles Basin Santa Catalina Island Palos Verdes Hills Lasuen Knoll San Joaquin Hills Whittier Fault Newport-Inglewood Fault Palos Verdes fault San Pedro Shelf Figure 2.2. Bathymetry (Gardner et al., 1999; USGS-Walrus, 2002) and elevation (USGS-EDC, 2002) along the Palos Verdes fault and in Los Angeles Basin. Inset map gives location of study with respect to the southwestern United States. The Palos Verdes Hills and San Pedro Bay anticlinoria form slight ridges in the study area (Nardin and Henyey, 1978), there is additionally a much smaller ridge within the fault zone between the mapped strand and the San Pedro Bay anticlinorium (Vedder, 1990). 11 Elevation and Bathymetry of the Los Angeles Area Elevation Bathymetry meters meters NV OR CA kilometers 0 10 20 San Pedro Bay anticlinorium San Gabriel submarine canyon Palos Verdes Hills anticlinorium

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Figure 3.1. Polygon outlines the coverage area of the Beta 3-D seismic survey, offshore Long Beach, California. The three dotted lines show the location of the 2-D seismic data, and the location of wells used for time horizon to sediment correlation are shown as circles with crosshairs. Note that the 2-D surveys were not perfectly straight, including line 81, which deviated from its path to avoid the well platform for OCS 296-2. 17 Palos Verdes fault zone kilometers 0 5 10 shoreline active faults 3-D survey outline 2-D profiles well location

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22 Figure 3.2. Synthetic seismogram (positive and negative phase) of extracted wavelet from line 82 based on well 296-1 as compared to the nearest traces on line 82. Formation tops picked at well 296-1 are dashed lines, time to depth is seconds to feet. Wh = top of Wheelerian, Dl = top of Delmontian, and Mn = top of Mohnian.

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Figure 4.1. Column of stratigraphic units of the San Pedro Shelf, compiled from Fischer et al. (1977; 1979) and Nardin and Henyey (1978). Dark shaded areas on the right represent missing section. 26 Stratigraphic Units of the San Pedro Shelf

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uplifted broad anticline (a) Horizon B-top N broad anticline uplifted (b) Horizon C-top N 34 segment A segment B segment C segment D segment E segment A segment B segment C segment D segment E 4000 m

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uplifted (c) Horizon D-top N uplifted (d) Horizon E-top N 35 segment A segment B segment C segment D segment E segment A segment B segment C segment D segment E 4000 m

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Figure 5.1. (a) Line 80a cdp 1100-2100 used to constrain geometry on segment D. (b) The central fault zone (PVFZ) is Palos Verdes segment D, and the western fault zone is the southern-most segment of the Cabrillo fault. CDPs are marked at intervals of 32, or roughly 100 m. W E 39 C-top B-top E-top D-top C-top 200 m PVFZ

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Figure 5.2. Location of the segments and features of the Palos Verdes fault through the Beta 3-d survey area. Green lines indicate the locations of the three 16-channel seismic lines, background is a time slice of the 3-d survey at 1600 ms. In-line cross-sections 80, 120, 186, 320, and 360 are interpreted in Figures 5.3 a to e, to correspond to cross-sections A-A’ through E-E’ respectively. Intervals between in-lines and cross-lines are 50.3 m anf 24.6 m respectively. 41 Study Area Index Map 2500 m

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44 2500 m

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45 (c) cross-section C-C’

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46 2500 m

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(b) late Pliocene Venturian isopach between horizon C and D thick thin thin N (a) early Pleistocene Wheelarian isopach between horizon D and E thick thin thin N 53 2 km segment A segment B segment C segment D segment E segment A segment B segment C segment D segment E

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Delmontian isopach between horizon A and B thick thin N (c) mid Pliocene Repettian isopach between horizon B and C thick thin thin N (d) early Pliocene 2 km 54 segment A segment B segment C segment D segment E segment A segment B segment C segment D segment E

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1. 2. (a) Releasing Bend 2. 1. (b) Restraining Bend 57 thin thick

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Figure 6.3. Isopach C, west of the Palos Verdes fault, between horizon B-top and C-top, includes the Repetto Formation. This isochron shows deposition thickness of the Repetto as nearly continuous, with thinning above the Palos Verdes Hills anticlinorium in the north where it has been previously exposed and partially cut away. Color scale is measured in ms two-way travel-time, red is thin, blue is thick. 62

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61 Figure 6.2. Graph of locations of measured thick and thin isopach spots within the Beta monocline. The age of the isopach is plotted versus the distance of the location of thickened or thinned sediment along the PDZ from the intersection of the PDZ with the north edge of the 3-D survey area. The purple line is a 3 mm/yr estimate, based on McNeilan et al. (1996), extending from the location of present maximum uplift within segment C of the Beta monocline, approximately 8.6 km southeast of the edge of the survey. Error bars represent the uncertainty of the location of the center of the thick or thin spot and the age of the isopach.

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Figure 6.1. Depocenter migration model based on areas of thick and thin sediment. Location of thick and thin spots in isopachs show right-slip over time. Late Pleistocene A B C D E N Hallian thinning Wheelarian thinning Venturian thinning Repettian thinning Delmontian thinning Wheelarian thickening Venturian thickening Repettian thickening Delmontian thickening 60

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Figure 6.3. Isopach C, west of the Palos Verdes fault, between horizon B-top and C-top, includes the Repetto Formation. This isochron shows deposition thickness of the Repetto as nearly continuous, with thinning above the Palos Verdes Hills anticlinorium in the north where it has been previously exposed and partially cut away. Color scale is measured in ms two-way travel-time, red is thin, blue is thick. 62

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61 Figure 6.2. Graph of locations of measured thick and thin isopach spots within the Beta monocline. The age of the isopach is plotted versus the distance of the location of thickened or thinned sediment along the PDZ from the intersection of the PDZ with the north edge of the 3-D survey area. The purple line is a 3 mm/yr estimate, based on McNeilan et al. (1996), extending from the location of present maximum uplift within segment C of the Beta monocline, approximately 8.6 km southeast of the edge of the survey. Error bars represent the uncertainty of the location of the center of the thick or thin spot and the age of the isopach.

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Figure 6.1. Depocenter migration model based on areas of thick and thin sediment. Location of thick and thin spots in isopachs show right-slip over time. Late Pleistocene A B C D E N Hallian thinning Wheelarian thinning Venturian thinning Repettian thinning Delmontian thinning Wheelarian thickening Venturian thickening Repettian thickening Delmontian thickening 60

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Figure A.1. (a) This stacking diagram cartoon shows that the shot geometry of this survey is such that there exist two CRPs for each shot interval. (b) NMO correction is applied to the CRPs to create the equivalent of a zero-offset section. (a) 76 shot #2 (b) shot #1 CRP source receiver ray path source receiver normal incidence reflection ray path

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Figure A.2. A portion of line 81 after NMO correction and stack. CDP numbers are on left and time in ms is at top. 100 200 300 400 500 600 700 800 900 0 ms 80

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Figure A.3. Constant velocity stacks from 1400-1900 m/s of line 80A, CMP 205. Stacked reflectors at two-way travel times whose true stacking velocity matches the stacking velocity used will add to narrower, higher amplitude wavelet than those that do not. 82

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Figure A.4. Example semblance plots from line 80a. Color scale has been converted to grayscale, cdp number is printed near center of each plot. 84

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(a) (b)       Figure A.5. Generalized velocity profiles used for normal move-out (NMO) correction. Numbers across top correspond to CMP number along lines 80a (a) and 81 (b), two-way travel time is on the right. Tick marks above and below each curve indicate a baseline velocity of 1500 m/s at each location, where faster velocities are to the right. The distance between each baseline corresponds to 500 m/s of variation along each curve. 85

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(a) (b) (d) (c) Figure A.6. Examples from F-K migration bracketing of line 80a, at (a) 500 m/s, (b) 1000 m/s, (c) 1500 m/s, and (d) 600 m/s 87