ML090690209

11/21/2008 Meeting Slides, Summary of Preliminary Findings from the Usgs/Pg&E Hazard Studies for the Central Coastal California Region, Diablo Canyon Power Plant, Unit Nos. 1 and 2, from Pacific Gas & Electric

ML090690209
Person / Time
Site:	Diablo Canyon
Issue date:	11/21/2008
From:	Hardenbeck J, Langenheim V, Watt J Pacific Gas & Electric Co
To:	Office of Nuclear Reactor Regulation
Wang, A B, NRR/DORL/LPLIV, 415-1445
Shared Package
ML090690193	List: ML090690198 ML090690209
References
TAC ME0174, TAC ME0175
Download: ML090690209 (6)

Text

Summary of Preliminary Findings from the USGS/PG&E hazard studies for the Central Coastal California Region Seismicity data from the USGS: J. Hardebeck, Areo-magnetic data from V. Langenheim, Marine-magnetic data from J. Watt

Regional Seismicity Based on Local Velocity Model Double-difference Tomography (tomoDD):

- solves jointly for velocity model and earthquake locations

- absolute and relative arrival times

- improves both absolute and relative earthquake locations Earthquake Data:

- ~1400 earthquakes (exclude San Simeon aftershocks)

- ~26,000 P-wave and ~3000 S-wave absolute arrival times

- ~11,000 P-wave and ~5000 S-wave relative arrival times from waveform cross-correlation

Focal Mechanisms Ray tracing in 3D velocity model.

Black: good quality (A-C of Hardebeck & Shearer) single-event mechanisms.

Grey: lower G l quality lit single-event i l t mechanisms, checked for reasonableness.

DCPP Red: composite mechanisms.

Seismicity Comparison with raw (unprocessed) aeromagnetic data Seismicity Comparison with raw (unprocessed) Marine Magnetic Data