Homestake Meeting Minutes, 03/23/17
Attending: Andrew, Daniel, Pat, Ross, Levi, Vuk, Victor, Voon, Gary
Agenda:
Next Meeting: Apr 13
Data analysis topics
Data corrections, frame production (Gary/Daniel/Pat)
Pat observed that some of the channels were swapped (E and N) on some of the stations and not on others.
Daniel: Gary corrected this, will send USB sticks to UMN and Caltech. Pat mailed the sticks to Gary, he should have them by the end of the week. IRIS knows what corrections it needs to apply, but has not done it yet. We should follow up with them in a couple of weeks.
Event catalog (Gary/Ross): no news.
Radiometer updates (Pat)
slides
Total recovered power (in P-experiment) is about 2x too low, and the amplitude in the 90% region is about 20% too low. But position recovered correctly. The issue might have to do with spectral leakage.
When injecting/recovering P+R, there is a bit of leakage from R to P.
Have to think more about assessing the significance of recovered peaks.
Will look at the microseism band, since we can compare with the known directions.
Try recovering with different combinations to gain experience with leakages etc.
Also need to include the bi-exponential Radiometer model. With better model, maybe the leakage would be reduced.
Diffraction limited spot size is about 30 degrees, and this is roughly the size of recovered spots.
Parameter estimation for Rayleigh and Love (Pat/Levi)
(see slides above)
Estimating wave speed along with the bi-exponential spectrum. Could re-run with an externally-determined wave speed, maybe from the transients.
Would also like to use more transient events (currently using 20-30 of them).
Papers
Homestake Array Summary paper:
pdf
Leads: Vuk, Gary, Victor
target: Seism. Research Lett., 6000 words, 10 figures.
topographical plots (Daniel)
Victor added an introduction. Some items could be more detailed.
References to South African mining measurements, but not a detailed discussion. Gary agrees this is sufficient, no discussion needed. Want to make a distinction that these are broadband arrays. Gary will look at the draft.
Gary can add something on the local geology. Perhaps better to include it in sections other than introduction. Make a link to why the mine developed it did, since this has an impact on the geometry of the array. So this may be a natural spot for this discussion (near the topography maps)
For plots: maybe show some examples, and keep the rest for the electronic supplement.
Victor: maybe would be nice to show something that shows the Rayleigh-wave properties. Maybe some of Pat's plots?
Gary: maybe show seismograms to show a transient event, so how clearly you can identify the various components of it. Will try to find a good example(s).
Should also add the topography plots from Daniel.