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NOVEMBER MEETING NOTICE
***Tuesday, November 11th***
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||"Geohazard Challenges of the Woodside OceanWay LNG Development, Offshore Southern California"
||Dr. Phil Hogan, P.G., C.E.G.
Principal Marine Engineering Geologist, Fugro West, Inc.
10901 Victory Blvd. North Hollywood, CA 91606
NOTE CHANGE FROM REGULAR VENUE
||6:00 p.m.-Social Hour; 7:00 p.m.-Dinner, 7:45 p.m.-Presentation
||$30 per person with reservations, $35 without reservations, $15 with a valid Student ID. House beverages are included in the $30 fee. No charge for parking.
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Coauthors: Andy Lane, Jim Hooper, Aaron Broughton, and Brian Romans
Geotechnical data and high resolution seismic data collected for Woodside’s OceanWay LNG project allow an improved understanding of the tectonic and sedimentary processes in Santa Monica Bay. Primary geohazards of concern include high seismicity, active faults, and turbidity currents.
A broad zone of deformation exists from the shelfbreak down to the base of slope at the northeast margin of Santa Monica Basin. The Palos Verdes fault zone on Santa Monica Shelf exhibits transtensional structures, including numerous left-stepping en echelon horsts and grabens. Farther north, the main trace of the Palos Verdes fault bends towards the west, more closely paralleling the structural grain of the Transverse Ranges to the north. The San Pedro Basin fault exhibits transpressional features, including surface fault rupture and growth folding affecting late Quaternary strata. Active faults crossing the proposed pipeline route present a ground rupture hazard on the continental slope.
Active sedimentary processes and high sediment accumulation rates are documented on Hueneme Submarine Fan in Santa Monica Basin. High-resolution seismic lines across DSDP borehole 1015 provide a well-dated chronostratigraphic record. Turbidity currents in Santa Monica Basin are sand-dominated, and have increased in frequency in the Late Holocene. Five thin (<8 cm thick) turbidites have been documented in the basin in the last 500 years. Numerous thicker turbidites are present, with a recurrence interval of about 330 years over the past 7 ka. The amount of sediment per event increases markedly starting around 2 ka, and may be related to an increase in seismicity in the LA Basin vicinity, increased El Nino Southern Oscillation (ENSO) frequency, or other factors. Approximately 3 kyBP the sediment accumulation rate in the basin increased from 1.1 m/ka to 2.5 m/ka, concurrently with the increase in the average sand thickness/bed.
The potential exists for seismicity, surface fault rupture, and turbidity currents to affect the proposed pipeline within the lifetime of the project. These geohazards will be mitigated through appropriate geohazards analyses, risk studies, and engineering design of the OceanWay facilities, allowing safe and secure importation of natural gas to the West Coast of the USA.
Dr. Hogan has 20+-years of experience specializing in marine geohazard surveys for coastal and offshore infrastructure and energy projects. Dr. Hogan played a key role in interpretation and integration of marine geophysical, geotechnical, and geologic data for the Woodside OceanWay Secure Energy LNG project. Since 2004 he has been a Principal Marine Engineering Geologist with Fugro West, following his more-than-15 year career with Dames & Moore/URS. He has performed geologic reconnaissance and geohazard evaluations in a variety of tectonic and sedimentary environments worldwide.
Dr. Hogan has a strong background in seismic hazards evaluation, structural geology, sedimentology, engineering geology, Quaternary geology, geochronology, geomorphology, and stratigraphy. Dr. Hogan has a broad-based knowledge of all aspects of geology, while specializing in offshore geohazard studies, seismic hazard analysis, and marine geology. He has participated in high-resolution geophysical mapping surveys of modern marine continental shelf and slope areas in central and southern California, Australia, Turkmenistan, Beaufort Sea (Alaska), Hawaii, Spain, Trinidad, Papua New Guinea, Sakhalin Island, Japan, Philippines, Indonesia, Bulgaria, Canada, and Abu Dhabi. Dr. Hogan has carried out investigations of landslide hazards, debris flows, turbidity currents, liquefaction potential, basin analysis, water resource evaluation, surface fault rupture displacement, seismic source characterization, coastal erosion potential, and shallow and deepwater marine foundation engineering conditions.
Dr. Hogan grew up on the Palos Verdes Peninsula, and has an in-depth understanding of both the onshore and offshore geology of this area. He received his undergraduate degree in geology from Princeton University, and both his M.S. and Ph.D. degrees from the University of Southern California. Dr. Hogan’s undergraduate thesis focused on geologic structure and uplift rates of the Palos Verdes Peninsula, while his M.S. work addressed mass movement processes in the California Continental Borderland and Santa Maria Basin. Dr. Hogan worked in the SW Pyrenees for his doctoral studies, deciphering the timing and rates of tectonic and sedimentary processes through application of magnetostratigraphic age dating techniques to foreland basin deposits.