Ground motions used as tsunami sources

As part of the Cascadia CoPes Hub project, a new set of 36 ground motions have been computed using 3D simulations. The surface deformation from these ground motions have been used as sources for tsunami simulations.

%matplotlib inline

from pylab import *
import os,sys
sys.path.insert(0,'../src')
from CHTuser import CHTtools

#from importlib import reload
#reload(CHTtools)

Short and long names¶

For labelling tsunami simulation results, we use short versions of the names describing each of the 36 sources, using the following scheme:

CHTtools.name_conversions(markdown_table=True)

|event number | event | long name |
| ---: | :---: | :--- |
|   1  |  BL10D  |  buried-locking-str10-deep |
|   2  |  BL10M  |  buried-locking-str10-middle |
|   3  |  BL10S  |  buried-locking-str10-shallow |
|   4  |  BL13D  |  buried-locking-mur13-deep |
|   5  |  BL13M  |  buried-locking-mur13-middle |
|   6  |  BL13S  |  buried-locking-mur13-shallow |
|   7  |  BL16D  |  buried-locking-skl16-deep |
|   8  |  BL16M  |  buried-locking-skl16-middle |
|   9  |  BL16S  |  buried-locking-skl16-shallow |
|  10  |  BR10D  |  buried-random-str10-deep |
|  11  |  BR10M  |  buried-random-str10-middle |
|  12  |  BR10S  |  buried-random-str10-shallow |
|  13  |  BR13D  |  buried-random-mur13-deep |
|  14  |  BR13M  |  buried-random-mur13-middle |
|  15  |  BR13S  |  buried-random-mur13-shallow |
|  16  |  BR16D  |  buried-random-skl16-deep |
|  17  |  BR16M  |  buried-random-skl16-middle |
|  18  |  BR16S  |  buried-random-skl16-shallow |
|  19  |  FL10D  |  ft-locking-str10-deep |
|  20  |  FL10M  |  ft-locking-str10-middle |
|  21  |  FL10S  |  ft-locking-str10-shallow |
|  22  |  FL13D  |  ft-locking-mur13-deep |
|  23  |  FL13M  |  ft-locking-mur13-middle |
|  24  |  FL13S  |  ft-locking-mur13-shallow |
|  25  |  FL16D  |  ft-locking-skl16-deep |
|  26  |  FL16M  |  ft-locking-skl16-middle |
|  27  |  FL16S  |  ft-locking-skl16-shallow |
|  28  |  FR10D  |  ft-random-str10-deep |
|  29  |  FR10M  |  ft-random-str10-middle |
|  30  |  FR10S  |  ft-random-str10-shallow |
|  31  |  FR13D  |  ft-random-mur13-deep |
|  32  |  FR13M  |  ft-random-mur13-middle |
|  33  |  FR13S  |  ft-random-mur13-shallow |
|  34  |  FR16D  |  ft-random-skl16-deep |
|  35  |  FR16M  |  ft-random-skl16-middle |
|  36  |  FR16S  |  ft-random-skl16-shallow |

The function CHTtools.shortname may be useful for converting older file names:

CHTtools.shortname('buried-random-str10-middle')

'BR10M'

One problem we’ve had in the past is that dashes and underscores have not been used consistently in the long file names, so the shortname function accepts all combinations, e.g.

CHTtools.shortname('buried_random-str10_middle')

'BR10M'

Conversely, you can convert from a short name to a long name:

CHTtools.longname('BR10M')

'buried-random-str10-middle'

By default the delimiter is dash, but you can specify and arbitrary delimiter:

CHTtools.longname('BR10M', delimiter='_')

'buried_random_str10_middle'

# print a table of conversions alphabetized by long name:
#CHTtools.name_conversions_long_to_short()

Logic tree¶

The names are based on a logic tree that follows the National Seismic Hazard Model logic tree, which weighted buried events 0.75 and frontal thrust 0.25, and then the following weights for the downdip limits: Deep: 0.2, Middle: 0.5, Shallow: 0.3. Within each of these 6 branches there are 6 events that have equal weights, since both the slip distribution and magnitude-area relationship branches are equally weighted.

If one wants to assign conditional probabilities to each of these events, this might be done by assigning a weight equal to the product of weights on the branches leading to it, e.g. BR16D would have weight 0.75 * 0.2 * (1/6) = 0.025.

Accessing ground motion data on DesignSafe¶

Ground motion data published in Dunham et al. (2025) can be accessed on DesignSafe JupyterHub in directory ~/NHERI-Published/PRJ-5885, which contains:

bgrid_bb/   bgrid_im_files/  model/    pnsn_det/
bgrid_det/  logfiles/        pnsn_bb/  pnsn_im_files/

ls ~/NHERI-Published/PRJ-5885  # only works on DesignSafe

ls: /Users/rjl/NHERI-Published/PRJ-5885: No such file or directory

GeoClaw dtopo files¶

Explain where these or located on DesignSafe / TACC...

References¶

Dunham, A., Wirth, E., grant, alex, & Frankel, A. (2025). CSZ Full-Margin Megathrust Earthquake Scenarios. Designsafe-CI. 10.17603/DS2-DQRM-DH11