Difference between revisions of "SW4 Mesh Development"
Line 80: | Line 80: | ||
-113.59525 34.44267 (x= 460.000 y= 672.000) | -113.59525 34.44267 (x= 460.000 y= 672.000) | ||
-116.52591 31.13175 (x= 0.000 y= 672.000) | -116.52591 31.13175 (x= 0.000 y= 672.000) | ||
+ | |||
+ | == Sim Volume CyberShake Site s3446 == | ||
+ | The yellow box we looked at on the call - the volume for site s3446 - has the following specs: | ||
+ | |||
+ | Dimensions: 460.8 x 774.4 x 50.56 km | ||
+ | Rotation angle: 36 degrees counterclockwise | ||
+ | Corner points: | ||
+ | -126.18649, 39.75063 (W) | ||
+ | -121.85281, 42.27791 (N) | ||
+ | -116.72395, 36.56162 (E) | ||
+ | -120.90294, 34.22243 (S) | ||
== Query points with missing Data == | == Query points with missing Data == |
Revision as of 21:54, 22 April 2024
Goal: Create NorCal CyberShake Mesh for SW4
Contents
Mesh Region
Region should match the SFBR model https://www.usgs.gov/programs/earthquake-hazards/science/3-d-geologic-and-seismic-velocity-models-san-francisco-bay
- ne_coord (-122.562365, 39.174505)
- nw_coord (-123.858493, 38.424179)
- sw_coord (-121.922036, 36.320331)
- se_coord (-120.644051, 37.050062)
- 140km x 290km
Config Script
- input 4 corners (and projection) and spacing
- calc rotation angle
- distance between points
- calculate nx, ny, nz based on spacing
Define Region
- origin
- rotation angle
- distance x
- distance y
- distance z
- spacing
Low Res UCVM2Mesh Configuration for SFBR Model
To test our mesh formats for SW4, we will test with a low resolution
- rot=-53.9
- x0=-123.858493
- y0=38.424179
- z0=0.0
- spacing=500.0
- Dist x = 140,000
- Dist y = 290,000
- Dist z = 40,000
- nx=280
- ny=580
- nz=80
Full Res UCVM2Mesh Configuration for SFBR Model
- rot=-53.9
- x0=-123.858493
- y0=38.424179
- z0=0.0
- spacing=25.0
- Dist x = 140,000
- Dist y = 290,000
- Dist z = 60,000
- nx=
- ny=
- nz=
SF CVM
These are the coordinates of the detailed USGS SFBA VM:
ne_coord (-122.562365, 39.174505) nw_coord (-123.858493, 38.424179) sw_coord (-121.922036, 36.320331) se_coord (-120.644051, 37.050062)
Regarding the azimuth of the velocity model in the SFBA, we use a rotation of 143.638º, assuming an initial rectangle aligned with the geographical coordinates and anchor at the south-west corner. After applying this rotation, this point at the origin becomes the north-east corner of the domain.
can you discretize the mesh in 100 m in horizontal and 25 m in vertical, following a cube? Eventually at larger depths the discretization is coarser which will allow to same mamory, but I do not know yet how the model is defined in depth (I think at a some points the blocks are defined every 200 m in depth, but I haven't explored this feature of the velocity model).
Example from CyberShake
We don't actually generate a ucvm2mesh config file as part of the process of creating CyberShake meshes, but I've created what I think is the correct ucvm2mesh file for USC. The rotation angle is -55 degrees, and the 4 corners should be about:
-122.46716 34.52173 (x= 0.000 y= 0.000) -119.66138 37.97316 (x= 460.000 y= 0.000) -113.59525 34.44267 (x= 460.000 y= 672.000) -116.52591 31.13175 (x= 0.000 y= 672.000)
Sim Volume CyberShake Site s3446
The yellow box we looked at on the call - the volume for site s3446 - has the following specs:
Dimensions: 460.8 x 774.4 x 50.56 km Rotation angle: 36 degrees counterclockwise Corner points: -126.18649, 39.75063 (W) -121.85281, 42.27791 (N) -116.72395, 36.56162 (E) -120.90294, 34.22243 (S)