Inversion of group velocity data only. The final models do not vary tremendously. Scatter in the top two layers results from poor resolution at these depths. Even 10 s surface waves "see" a bit deeper than this. Both models show a mild decrease in velocities centered at 25 km depth. There is little variance in the resulting models at mantle depths. In these inversion the mantle has been treated as large blocks. The well defined resulting model implies there is still adequate resolution at these depths to resolve finer details. Other test have been run with more layers at these depths.
The inversaion has no problem fitting the group velocities. The phase velocities (not included in the inversion) show substantial misfit however, particularly in the Qiantang region.
| MODEL PLOT: range of initial models: gray final models: violet mean of final models: black VELOCITY PLOT: Initial group velocity: pale blue Initial phase velocity: pink/gray Final models: black Measured group velocity: blue Measured phase velocity: red |
