Grid Project:   Mortandad Seismic Models

Purpose of Project

Build a small 1500x1500 meter seismic model for the Mortandad Station area. Use the 2015 Earthvision Model WC15c to identify material layers. The area is also characterized by a complex subsurface geology consisting of successive basalts flows, volcanic ash deposits and sedimentary units. Subsurface structure and stratigraphy are rendered by the 2015 WC15c Geologic Framework Model (GFM) developed for LANL Hydrogeologic Modeling.

The Spectral Element Method (SEM) is one of the methods methods for the modeling of full waveform propagation in complex 3D models. SEM uses hexahedra meshes and cannot contain any degeneracies such as zero length edges or zero-volume elements. The mesh is constructed by selecting stratigraphy that form continuous layers without pinching out. All GFM materials are interpolated on to mesh hexahedra cells.

Top Surface Elevation and Model Domain

Small Hex Mesh with Geologic Materials

Image shows ground surface (colored by elevation) Internal box shows the MC station locations Outer box is the mesh boundary Mesh Box Extents (Meters): XMIN 497200 XMAX 498700 YMIN 538400 YMAX 539900 Small Mesh Bottom Z at 500 meters Top is variable with Z from 2000 to 2175 meters

GFM WC15c Geologic Framework Model ID NAME Description 16 Qbt4 Tshirege Unit 4, Bandelier Tuff 15 Qbt3 Tshirege Unit 3, Bandelier Tuff 14 Qbt2 Tshirege Unit 2, Bandelier Tuff 13 Qbt1 Tshirege Unit 1 12 Qct Cerro Toledo Fm. 11 Qbo Otowi Members 10 Tpf3 Puye on top of Cerros del Rio Basalt 9 Tb4 Cerros del Rio Basalts 8 Tvt2 Younger Tschicoma Dacites 7 Tpf2 Puye below Cerros del Rio Basalt, coarse 6 Tjfp Miocene pumiceous sediments, Bearhead age 5 Tb2 Younger Miocene Basalts 4 Tcar Chamita axial river deposits, Santa Fe Group 3 Ttc Tesuque Fm (Chama-El Rito Member) 2 Pal Older Sedimentary from 2005 Basin Model 1 Pc Pre Cambrian from 2005 Basin Model

Mesh V02 Small Mortandad 15m

Mesh with 1500 x 1500m bounding box and 15 meter horizontal spacing. Vertical spacing is variable and conforms to geologic layers with volumes less than 3375m.

Images of V02 1500x1500 15m Mesh

README_v02.txt for Mortandad Mesh

Number Elements:         1480000
Number Nodes:            1519949
Cells per layer:         10000
Cells stacked vertical:  149

Mesh Materials
Exodus blocks 1-14 = material id 3-16

Material  Num_Cells        Material Volume   Fractional Volume        
   16         814          0.2097261E+07     0.000573633
   15        2976          0.7334630E+07     0.002006132
   14        8888          0.2029573E+08     0.005551189
   13       64470          0.1234447E+09     0.033763984
   12       12852          0.2101895E+08     0.005749001
   11       99796          0.2396863E+09     0.065557834
   10       16149          0.3928962E+08     0.010746307
    9       52679          0.1242985E+09     0.033997512
    8        9807          0.2578228E+08     0.007051844
    7       64123          0.1552850E+09     0.042472800
    6       47446          0.1150632E+09     0.031471523
    5      230000          0.5346852E+09     0.146244523
    4      350000          0.6414049E+09     0.175433970
    3      520000          0.1606418E+10     0.439379748

V02 Small Mortandad 15m Mesh Files

/scratch/sft/tam/grid_gen/SPECFEM3D/Mortandad_FEM_15m/output

These files have face sets for all 6 directions:
 1 bottom    HAS      10000 ELEMENTS
 2 top       HAS      10000 ELEMENTS
 3 east      HAS      14800 ELEMENTS
 5 west      HAS      14800 ELEMENTS
 4 north     HAS      14800 ELEMENTS
 6 south     HAS      14800 ELEMENTS

-rw-r--r--  1 tamiller  sft   96319160 May  9 14:10 hex_allmat_fs6.exo
-rw-r--r--  1 tamiller  sft  161216132 May 10 14:00 hex_allmat_fs6_ascii.exo
-rw-r--r--  1 tamiller  sft  600829012 May  9 14:10 hex_allmat_fs6.exo.avs
-rw-r--r--  1 tamiller  sft  178500064 May  9 14:10 hex_allmat_fs6.exo.gmv

Mesh V01 Small Mortandad 30m

Mesh with 1500 x 1500m bounding box and 30 meter horizontal spacing. Vertical spacing is variable and conforms to geologic layers with volumes less than 27000m. Target seismic waves up to 10Hz. Given a minimum wave speed of 300m/s is a mesh with element size of 30m. (1000m/30m=33 wavelengths).

Images of V01 1500x1500 30m Mesh

Material Table for Mortandad and WC15c Geology (PDF)

README_v01.txt for Mortandad Mesh

Number Elements:         165000
Number Nodes:            174267
Cells per layer:         2500  
Cells stacked vertical:  66

   Mesh Materials
   Exodus blocks 1-14 = material id 3-16

   Material  Num_Cells     Material Volume   Fractional Volume                    
       16         117       0.1802812E+07     0.000493097                        
       15         481       0.7130269E+07     0.001950240                        
       14        1490       0.2033621E+08     0.005562270                        
       13       10834       0.1244548E+09     0.034040320                        
       12        2078       0.2045774E+08     0.005595510                        
       11       14979       0.2398750E+09     0.065609567                        
       10        2071       0.3824186E+08     0.010459747                        
        9        6982       0.1253384E+09     0.034282017                        
        8        1272       0.2536622E+08     0.006938058                        
        7        8555       0.1574117E+09     0.043054546                        
        6        6141       0.1131801E+09     0.030956528                        
        5       27500       0.5346539E+09     0.146236194                        
        4       47500       0.6414312E+09     0.175441447                        
        3       35000       0.1606418E+10     0.439380458               

V01 Small Mortandad Mesh Files

/scratch/sft/tam/grid_gen/SPECFEM3D/Mortandad_FEM/output

These files have face sets for all 6 directions:
 1 bottom    HAS      2500 ELEMENTS            
 2 top       HAS      2500 ELEMENTS            
 3 east      HAS       3300 ELEMENTS            
 5 west      HAS       3300 ELEMENTS            
 4 north     HAS       3300 ELEMENTS            
 6 south     HAS       3300 ELEMENTS       

-rw-r--r--  1 tamiller  sft  10934792 Dec 11 14:45 hex_allmat_fs6.exo
-rw-r--r--  1 tamiller  sft  17028519 Dec 11 15:20 hex_allmat_fs6_ascii.exo
-rw-r--r--  1 tamiller  sft  63089004 Dec 11 14:45 hex_allmat_fs6.exo.avs
-rw-r--r--  1 tamiller  sft  21642684 Dec 11 14:45 hex_allmat_fs6.exo.gmv

Data Sources

Earthvision Model Delivered from Weston, Dan Strobridge 
/scratch/er/lanl_ev_models/weston_WC15c

Quad surfaces from EV WC15c

01_Bedr_ev_interp.out.txt:   elev      -1.078324487E+03 -9.645696057E+02 1.137548814E+02      2601  
04_Tb1b_ev_interp.out.txt:   elev      -1.523995982E+03 -1.523995982E+03 9.094947018E-13      2601  
06_Tb2b_ev_interp.out.txt:   elev       1.305153252E+03  1.506287166E+03 2.011339141E+02      2601  
07_Tb2_ev_interp.out.txt:    elev       1.517807196E+03  1.671343731E+03 1.535365352E+02      2601  
08_Ttc_ev_interp.out.txt:    elev       1.167422845E+03  1.257497226E+03 9.007438086E+01      2601  
10_Tcar_ev_interp.out.txt:   elev       1.680630800E+03  1.775282850E+03 9.465204961E+01      2601  
15_Tjfp_ev_interp.out.txt:   elev       1.743783412E+03  1.820515364E+03 7.673195157E+01      2601  
16_Tpt_ev_interp.out.txt:    elev       1.531776902E+03  1.607042177E+03 7.526527500E+01      2601  
20_Tvt2_ev_interp.out.txt:   elev       1.764923354E+03  1.950913854E+03 1.859904992E+02      2601  
22_Qta_ev_interp.out.txt:    elev       1.526962682E+03  1.635176989E+03 1.082143070E+02      2601  
24_Tpf2_ev_interp.out.txt:   elev       1.811845530E+03  1.913187850E+03 1.013423203E+02      2601  
25_Tb4_ev_interp.out.txt:    elev       1.879964814E+03  1.937199869E+03 5.723505469E+01      2601  
26_Tpf3_ev_interp.out.txt:   elev       1.916700550E+03  1.960049377E+03 4.334882695E+01      2601  
27_Qbog_ev_interp.out.txt:   elev       1.931140348E+03  1.969253071E+03 3.811272344E+01      2601  
28_Qbof_ev_interp.out.txt:   elev       2.021113769E+03  2.070784561E+03 4.967079141E+01      2601  
29_Qct_ev_interp.out.txt:    elev       2.029873758E+03  2.072957313E+03 4.308355469E+01      2601  
30_Qbtt_ev_interp.out.txt:   elev       2.030731455E+03  2.073341020E+03 4.260956563E+01      2601  
31_Qbt1g_ev_interp.out.txt:  elev       2.063161397E+03  2.101214264E+03 3.805286719E+01      2601  
32_Qbt1vc_ev_interp.out.txt: elev       2.072076681E+03  2.118096720E+03 4.602003867E+01      2601  
33_Qbt1vu_ev_interp.out.txt: elev       2.099112285E+03  2.127557701E+03 2.844541641E+01      2601  
34_Qbt2_ev_interp.out.txt:   elev       2.113855232E+03  2.144000042E+03 3.014480938E+01      2601  
35_Qbt3_ev_interp.out.txt:   elev       2.118133834E+03  2.164925705E+03 4.679187070E+01      2601  
36_Qbt3t_ev_interp.out.txt:  elev       2.098212905E+03  2.163219039E+03 6.500613359E+01      2601  
37_Qbt4_ev_interp.out.txt:   elev       2.107158628E+03  2.157317626E+03 5.015899843E+01      2601  
Topo_smort_ev_interp.out.txt: elev      2.057830231E+03  2.175153055E+03 1.173228240E+02      2601  

Quad Surfaces from 2005 Basin model

basin_tsf_ev_interp.out.txt: elev       4.650423761E+02  5.429197359E+02 7.787735982E+01      2601  
basin_tf_ev_interp.out.txt:  elev       1.303302460E+03  1.721466297E+03 4.181638367E+02      2601  
basin_pc_ev_interp.out.txt:  elev      -3.048000000E+03 -3.048000000E+03 1.818989404E-12      2601  
basin_pal_ev_interp.out.txt: elev      -1.355017532E+03 -1.126217708E+03 2.287998234E+02      2601  

Meshing Method

Initial strategy is the selection of basin surfaces that do not intersect or pinch-out. These surfaces are used to create a stacked hex mesh that follow the shape of surfaces used. The GFM materials are interpolated on to the hex mesh elements. These first prototypes will have coarse vertical resolution and materials will stair-step along all interfaces except those that were used in the stacking of the layers.


Step 1. Select horizon surfaces that do not pinchout.

Step 2. Construct layers between surfaces and stack.

Step 3. Fill layers with hexahedral elements.

Step 4. Interpolate Full set of GFM materials on to hex elements.

Grid Team Contacts