The links below presents the map view and statistics of the Rayleigh wave phase measurements from ambient noise cross-correlation process. Those map views show the data selectio and quality control schemes for the eikonal tomogrpahy develped by Fan-Chi Lin. All map views with better resolution could be viewed by cliking the maps themselves.

The data selection processes include the steps below:

1) the preperation of raw data.

2) SNR removal.

This step is based singal/noise ratio(SNR). The SNR criteria is set to be 10.

3) 2pi correction.

This correction is based on previous phase velocity map created by straight ray tomography. The measurements that cannot be correted by 2pi or integer times of 2pi are eliminated (misfit criteria is 2 sec for this page).

4) Curvature removal.

For measurements which produce curvature > 0.005, we disgard them for next process

5) Stability test.

We interpolateextrapolate the travel time measurements with a minimum-curvature algorithm using two different tension parameters. Fo r area with bad coherence between the 2 schemes, we remove the interpolatedextrapolated values.

6) 4 quadrants criteria.

We compute the slowness from the interpolated/extrapolated travel time surface. For each slowness value, we test if 4 quadrads have stations nearby. If not, it is removed.

7) extradinary slowness value.

We remove slowness value which produce phase velocity > 5 km/sec or < 1.67 km/sec.