SONGS Seismic Research Projects

Transcription

1 SONGS Seismic Research Projects Energy Division Independent Peer Review Group September 21, 2012

2 Agenda Background Overview Project Support Permits, Approvals, and Reviews Schedule Use of Advanced Technologies Onshore Projects Onshore/ Results 2

3 Background CEC issued the AB 1632 Report which was followed by a letter to SCE from Peevey directing seismic studies Report recommended SCE conduct seismic hazard research, such as 3D seismic reflection mapping, and installation of additional GPS units to further investigate the seismic setting at SONGS for implications of reliability impact CPUC authorized work to start at the end of 2011 with $10M in funding Decision D approved $64M in funding 3

4 Overview The projects will provide new geologic and seismic information relevant to SONGS seismic setting Designed to capture relevant seismic source data (level of activity and history) for: Newport-Inglewood/Rose Canyon (NI/RC) Fault Oceanside Blind Thrust (OBT) Fault Data examples: fault locations, geometries, types, slip rates, recurrence intervals 4

5 Project Support Scripps University of Nevada, Reno GeoPentech Padre Lamont Doherty Earth Observatory USGS GeoTrace Earth Consultants International SDSU UNAVCO NSF 5

6 Permits, Approvals, and Reviews Project 2D Deep Marine Seismic Reflection Survey (federal waters) 2D/3D Shallow and 3D Deep Marine Seismic Reflection Surveys (federal and state waters) Permits/Approvals/Reviews Incidental Harassment Authorization US Army Corps of Engineers 404 Permit California Coastal Commission Consistency Review Incidental Harassment Authorization California Coastal Commission Review Coastal Development Permit California State Lands Commission Permit (EIR) GPS Monitoring Camp Pendleton Permits/Lease Agreements Private Property Lease Agreements Seafloor Survey and Seafloor Sediment Sampling and Age Dating Marine Terrace and Coastal Deformation Investigations California State Lands Commission Geophysical/Geological Sampling Permit Permission from California State Parks Paleoseismic Trenching Caltrans Encroachment Permit City of San Diego Encroachment Permit Seismic Monitoring (federal waters) Camp Pendleton Permits/Lease Agreements US Army Corps of Engineers 404 Permit California Coastal Commission Consistency Review 6

7 Schedule 7

8 Use of Advanced Technologies R/V Langseth 8

9 Historical Marine Geophysical Data Reprocessing and Reanalysis (see Tab 1) Reprocess and reanalyze existing seismic reflection data collected by SCE, USGS, petroleum industry, and academia Identify relevant existing seismic reflection surveys Reprocess appropriate historic seismic data using modern methods Reanalyze historic seismic data using modern 3D visualization software Use results to minimize the offshore survey area and time in the marine environment Provide input for environmental permitting activities, such as extent of survey area and location of ship tracks 9

10 2D Deep Marine Seismic Reflection Survey (see Tab 2) Collect and process 2D deep marine multi-channel seismic and geophysical data across the NI/RC and OBT faults Determination of target area Deploy ocean bottom seismometers (OBS) and onshore geophones Image geometry and architecture of the offshore fault systems Perform QA/QC Interpret the 2D deep data and define the location and size of the 3D deep survey 10

11 2D Deep Marine Seismic Reflection Survey (Continued) Figure shows 2D deep survey ship track lines and location of temporary ocean bottom seismometers and onshore geophones Source 3300 in 3 tuned air gun array Streamer 6 km, 12.5 m hydrophone group, 480 channels 2200 line km 28 OBS 40 land nodes (geophones) 27 days 11

12 2D Deep Marine Seismic Reflection Survey (Continued) 12

13 2D Deep Marine Seismic Reflection Survey (Continued) Sorlien et al. (in prep) 13

14 2D Deep Marine Seismic Reflection Survey (Continued) Rivero et al. (2000) 14

15 3D Deep Marine Seismic Reflection Survey (see Tab 4) Collect and process 3D deep marine multi-channel seismic and geophysical data across the intersection of the NI/RC and OBT faults Results of 2D deep survey will identify if 3D deep survey is warranted Collect 3D deep data using multiple streamers and closely spaced track-lines, and perform QA/QC in real-time Process data to remove artifacts and increase signal-to-noise 15

16 3D Deep Marine Seismic Reflection Survey (continued) Green shaded box below shows a 40 km by 25 km area that will be imaged during 3D deep survey (60 days with 12.5 x 37.5 m bin size) 16

17 2D Shallow Marine Seismic Reflection Survey (see Tab 5) Collect and process 2D shallow marine seismic reflection data to image the geometry of the NI/RC Fault and shallow deformational features associated with the OBT Target area will be based on data obtained from the 2D deep survey and existing 2D shallow data Collect 2D shallow data and perform QA/QC in real-time Scripps and UNR will process the 2D shallow data Determine the location and size of the 3D shallow survey 17

18 2D Shallow Marine Seismic Reflection Survey (continued) The 2D shallow survey will be conducted in the operational area shown for the 2D deep survey but will also extend into California state waters 18

19 2D Shallow Marine Seismic Reflection Survey (continued) Schematic of shallow seismic imaging and generalized profile of offshore geologic structure 19

20 2D Shallow Marine Seismic Reflection Survey (continued) R/V Melville 90 in 3 GI gun 48 channel GeoEel streamer m hydrophone group spacing SAS CHIRP Nine 500 Hz 6 khz transducers Two 2-16 khz transducers Six 16 channel hydrophone arrays incorporating low noise pre-amplifier, 24-bit A/D conversion and data serialization New deep penetration CHIRP system (the Schocker) 20

21 3D Shallow Marine Seismic Reflection Survey (see Tab 6) Collect and process 3D shallow marine seismic reflection data to image the geometry of the NI/RC Fault and shallow deformational features associated with the OBT Target area will be based on data obtained from the 2D shallow survey Collect 3D shallow data using P-Cable and perform QA/QC in real-time GeoTrace will process the 3D shallow data with oversight by Scripps and UNR 3D shallow data will identify potential coring targets for the Seafloor Sediment Sampling and Age Dating project 21

22 3D Shallow Marine Seismic Reflection Survey (continued) P-Cable Survey Schematic drawing of the basic P-Cable components during operation 22

23 3D Shallow Marine Seismic Reflection Survey (continued) 30 day maximum cruise 16 x 10 km area max coverage 90 in 3 GI gun source 23

24 Seafloor Surveys (see Tab 7) Collect and process bathymetry, gravity, and magnetic data to image the geometry of the NI/RC and OBT faults Within the 2D deep survey area Performed in conjunction with deep and shallow surveys Fill in the gaps in the California Coastal and Marine Mapping Initiative data Process data and generate maps of seafloor relief, such as ledges, linear gulleys, and undisturbed seafloor High resolution bathymetry and back-scatter data also will help identify targets for follow-on seafloor sampling 24

25 Seafloor Surveys (continued) Seismic surveys will be conducted on R/V Langseth and R/V Melville (each have EM122 swath bathymetry systems) 25

26 Seafloor Sediment Sampling and Age Dating (see Tab 8) Collect organic and sediment samples using gravity, piston, and vibracores to aide in determining the history of the NI/RC and OBT faults Target area is based on the data recovered during 2D/3D shallow seismic reflection surveys Dateable samples will be collected on either side of the faults to determine the age of offset geologic layers imaged by 2D/3D shallow seismic reflection surveys Vibracores will be used in sandy environments on the nearshore shelf Gravity and piston cores will be used along the continental slope and rise where sediment is predominantly silts and clays 26

27 Seafloor Sediment Sampling and Age Dating (continued) 27

28 Seafloor Sediment Sampling and Age Dating (continued) Coring/Geotechnical Cruise R/V Melville Sequence of coring: Gravity core is deployed first Core barrel is 10 ft long Core weight is ~ 500 lbs Larger piston core is on the rail 28

29 Seafloor Sediment Sampling and Age Dating (continued) 10 m Vibracore Guide posts for vibracore head Vibracore head 29

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31 Onshore Projects GPS Monitoring (see Tab 3) Install and monitor continuous GPS stations in the region surrounding SONGS to observe crustal deformation patterns and regional strain accumulation Site selection based on developing a uniform grid of instruments across the region Camp Pendleton Private land New stations will become part of the Southern California Integrated GPS Network (SCIGN) Annual data analysis ( ) 31

32 Onshore Projects GPS Monitoring (continued) Area Surrounding SONGS showing proposed stations on private land and Camp Pendleton 32

33 Onshore Projects Marine Terrace and Coastal Deformation Investigations (see Tab 10) Collect data related to vertical displacement along the southern Orange County and northern San Diego county coastline for use in assessing vertical deformation contributed by the NI/RC and OBT faults Collate existing marine terrace data and perform additional terrace mapping and dating to fill in gaps (e.g., aerial photo analyses, mapping, terrain profile measurements, age date sampling Determine the tectonic/seismic vertical elevation changes of the different marine terraces relative to past sea levels to evaluate vertical components of folding and faulting Use NOAA tide gauge data and NGS geodetic surveys to estimate the vertical movement of the coastline surrounding SONGS 33

34 Onshore Projects Marine Terrace and Coastal Deformation Investigations (continued) Diagram of modern and paleo marine terraces and associated features 34

35 Onshore Projects Paleoseismic Trenching (see Tab 11) Excavate trenches across the RC segment of the NI/RC Fault in San Diego county to measure fault displacement and establish fault history directly from the fault zone Sites selected based on a review of old aerial photographs in comparison with new aerial digital images where fault structures are observed Two to three trenches across and one parallel to the NI/RC fault will be excavated to characterize the three-dimensional geologic setting Samples will provide age information on the fault history 35

36 Onshore Projects Paleoseismic Trenching (continued) Salt Creek Trench 36

37 Onshore Projects Paleoseismic Trenching (continued) Salt Creek Trench 37

38 Onshore/ Existing Onshore and Offshore USGS Investigations (see Tab 9) Obtain recent onshore and offshore USGS geophysical surveys to update the SONGS seismic database Shallow water bathymetry data collected as part of the California Coastal and Marine Mapping Initiative 2D shallow seismic data across the NI/RC and OBT faults 38

39 Onshore/ Seismic Monitoring (see Tab 12) Install and maintain permanent onshore seismographs near SONGS and install and maintain temporary ocean bottom seismometers (OBS) offshore for a three year period Distribution of onshore seismographs is designed in fill in gaps in the CISN Data telemetered real time to the California Institute of Technology Install a single station seismograph at SONGS that will be maintained by the USGS Install, maintain, and eventually remove OBS instruments Three year deployment Download data annually and waveform archived 39

40 Onshore/ Seismic Monitoring (Continued) 40

41 Results Digital results will be provided to the EDD as each project is completed Data will be sent to repositories based on the specific data type Examples of repositories include: Scripps, UNR, Lamont Doherty Earth Observatory, UTIG Real-time onshore seismograph data will be telemetered to Southern California Earthquake Data Center 41