Different models in segments#
Slabs and faults can be heterogeneous in depth, and this is very easy to represent in the world builder. The segments we just added allow for defining temperature and compositional models, which overwrite the temperature and compositional models for the whole feature. You can think of it this way: you set the feature models for each segment in the feature (line 54 and 55) and then you overwrite that feature model in the segments where you want something else.
In this case we want to have two layers in the first segment, where the upper layer is the same as the upper layer of the oceanic plate and the lower layer is the same as the rest of the subducting plate. This layout is mainly chosen to highlight how the transition between the oceanic plate can both be seamless and sharp.
43 {
44 "model":"subducting plate", "name":"Slab", "dip point":[0,0],
45 "coordinates":[[1500e3,1000e3],[1600e3,350e3],[1500e3,0]],
46 "segments":
47 [
48 {"length":300e3, "thickness":[100e3], "angle":[0,60],
49 "composition models":[
50 {"model":"uniform", "compositions":[3], "max distance slab top":50e3},
51 {"model":"uniform", "compositions":[2], "min distance slab top":50e3}]},
52 {"length":500e3, "thickness":[100e3], "angle":[60,20]}
53 ],
54 "temperature models":[{"model":"plate model", "density":3300, "plate velocity":0.02}],
55 "composition models":[{"model":"uniform", "compositions":[2]}]
56 }
1{
2 "version": "1.0",
3 "coordinate system":{"model":"cartesian"},
4 "features":
5 [
6 {
7 "model":"mantle layer", "name":"upper mantle", "max depth":660e3,
8 "coordinates":[[-1000e3,0],[-1000e3,1000e3],[3000e3,1000e3],[3000e3,0]],
9 "composition models":[{"model":"uniform", "compositions":[4]}]
10 },
11 {
12 "model":"oceanic plate", "name":"Overriding Plate", "max depth":100e3,
13 "coordinates":[[0,0],[0,1000e3],[1500e3,1000e3],[1600e3,350e3],[1500e3,0]],
14 "temperature models":
15 [
16 {"model":"half space model", "max depth":100e3, "spreading velocity":0.04,
17 "ridge coordinates":[[[400e3,-1],[-100e3,2000e3]]]}
18 ],
19 "composition models":[{"model":"uniform", "compositions":[0], "max depth":50e3}]
20 },
21 {
22 "model":"continental plate", "name":"Passive margin", "max depth":[[200e3]],
23 "coordinates":[[-1000e3,0],[-1000e3,1000e3],[0,1000e3],[0,0]],
24 "temperature models":
25 [
26 {"model":"linear", "max depth":[[100e3],[200e3,[[-250e3,0],[-750e3,1000e3]]]]}
27 ],
28 "composition models":
29 [
30 {"model":"uniform", "compositions":[3],
31 "max depth":[[100e3],[200e3,[[-250e3,0],[-750e3,1000e3]]]]},
32 {"model":"uniform", "compositions":[1],
33 "min depth":[[100e3],[200e3,[[-250e3,0],[-750e3,1000e3]]]]}
34 ]
35 },
36 {
37 "model":"oceanic plate", "name":"Subducting Oceanic plate", "max depth":100e3,
38 "coordinates":[[2000e3,0],[2000e3,1000e3],[1500e3,1000e3],[1600e3,350e3],[1500e3,0]],
39 "temperature models":[{"model":"linear", "max depth":100e3}],
40 "composition models":[{"model":"uniform", "compositions":[3], "max depth":50e3},
41 {"model":"uniform", "compositions":[1], "min depth":50e3}]
42 },
43 {
44 "model":"subducting plate", "name":"Slab", "dip point":[0,0],
45 "coordinates":[[1500e3,1000e3],[1600e3,350e3],[1500e3,0]],
46 "segments":
47 [
48 {"length":300e3, "thickness":[100e3], "angle":[0,60],
49 "composition models":[
50 {"model":"uniform", "compositions":[3], "max distance slab top":50e3},
51 {"model":"uniform", "compositions":[2], "min distance slab top":50e3}]},
52 {"length":500e3, "thickness":[100e3], "angle":[60,20]}
53 ],
54 "temperature models":[{"model":"plate model", "density":3300, "plate velocity":0.02}],
55 "composition models":[{"model":"uniform", "compositions":[2]}]
56 }
57 ]
58}
Basic Starter Tutorial section 14. The top part of the figure shows where the composition as been assigned as an object. Currently is shows composition 0 as green, composition 1 as yellow, composition 2 as purple and composition 3 as blue. Composition 4 is not shown to be able to see the slab. The front half of the overriding plate (composition 1) has also been removed to be able to better view the slab. The bottom part shows the temperature as seen slightly from below where only temperatures between 300K and 1600K are shown.#