Leads: Jan, Michael
Latest version:
wiener.pdf. Needs minor modifications of figure 6, and still need to rewrite conclusions.
Vuk: Why can't you measure seismic speed below 1.2 Hz.
Jan: Not clear, the method should work, it looks like there is a lot of variability around 1Hz, potentially different wave modes.
New point in the paper: evidence of the presence of body waves at 0.2 Hz, based on the speed measurement. Body waves seem to dominate on some days. In fact, it seems there is a continuous body wave background and on some weeks a stronger Rayleigh background overcomes it. Important for GW detectors.
Vuk: suggest to emphasize this to Victor and Gary via email, their response could help place this result in existing geo literature. ALso suggest to plot Fig 6 as a scatter plot, which should appear as -45 degree line.
Daniel: where would body waves come from?
Jan: not sure.
Jan: also have very good Wiener subtraction. Should we try a more visible journal, like Nature geophysics?
Vuk: worth considering, depends on what is known about body vs Rayleigh background. Also, it seems we don't need the depth aspect of this array is not needed for Fig 6.
Jan: correct, could try another array like Sweatwater.
Vuk: Could we use an estimate of Rayleigh wave speed from elsewhere? And plot lambda/4 on the Figure 5.
Ross/Pat: could try to estimate the speed from mining blast data. Pat working on this now, Ross did a study in the past.
Jan: Could use shear wave speed, which was measured, and convert based on some assumption on the poisson ratio. This could be a value for now, that could be updated later from other analyses.
Gary: could use the mine blasts. Have very solid data on shear wave speed from the active excitation at 2000. But this is on the scale 10-100m, but don't know it at a larger scale, but wouldn't expect it to very much. You can also get uncertainty on these velocity measurements.
Jan will send an email summarizing these results. We should discuss how to proceed via email, if necessary we'll schedule another call before the winter break…