Lin Thurber CVM

CME is implementing a programmatic version of the Lin Thurber 3D state-wide CVM, a regional-scale 3D P-wave velocity models. This is for our Northern California model, published in

Thurber, C., H. Zhang, T. Brocher, and V. Langenheim, Regional three-dimensional seismic velocity model of the crust and uppermost mantle of northern California, J.Geophys. Res., 114, B01304, doi:10.1029/2008JB005766, 2009

Formally, the bounding rectangle is approximately given below however, the western edge realistically is the California coastline, and the northern edge is not quite to the Oregon border.

• 42.60, -122.32
• 40.34, -126.27
• 37.74, -117.88
• 35.62, -121.71

The bottom nodes of the model are at 36 km. Node spacing is mostly 10 or 15 km in the NE-SW direction and is uniformly 20 km in the NW-SE direction. Actual model resolution based on checkerboard tests is nominally ~twice the node spacing.

Lin Thurber CVM

This seismic velocity models of the California crust and uppermost mantle using a regional-scale double-difference tomography algorithm. The details are described in:

• Lin, G., C. H. Thurber, H. Zhang, E. Hauksson, P. Shearer, F. Waldhauser, T. M. Brocher, and J. Hardebeck (2010), A California statewide three-dimensional seismic velocity model from both absolute and differential Times, Bull. Seism. Soc. Am., 100, in press.

• FILE FORMAT DESCRIPTION

-117.7230 37.8242 1.00 250.00 0.00 5.0390 109.13 lon lat dep x y vp DWS (derivative weight sum)

Fig 1: Lin Thurber CVM Vp Map at 1km Depth

Fig 3: Lin Thurber CVM Vs Maps at 1km Depth

These preliminary maps are based on querying the model at an elevation offset of -1000.0m from MSL. We will need to add a DEM to UCVM in order to properly query this model by depth. The model is referenced using inverse bilinear interpolation of the original model boundaries.

As seen in the plots, the Vp model is higher resolution (~10km) than the Vs Model (~30km).