Homestake Meeting Minutes, 06/01/17

Attending: Andrew, Gary, Levi, Pat, Ross, Victor, Vuk, Daniel, Michael

Agenda:

• Next Meeting: June 29
• Data analysis topics
  • Data corrections, frame production (Gary/Daniel/Pat)
    • final checks (Pat/Gary/Daniel)
    • Pat created frames at UMN, doing checks, looks done now. Should be at CIT early next week, will discuss with admins there on the details.
    • Will discuss with Gary how to handle calibration records (instrument response gain). Using files Daniel and Gary got from IRIS.
  • Event catalog (Gary/Ross)
    • Gary will try to use slowness for location recovery. Working on code for this.
  • Radiometer updates (Pat, Levi)
    • Pat: looking for a different pixelization on sphere, looking at how to assess how well the recovery is done. Transferring a technique from gravitational-wave field.
  • Parameter estimation for Rayleigh and Love (Pat/Levi)event r-wave check
    • This is a check/confirmation that the injected wave is really Rayleigh.
  • Gary: checked the results on near-surface effects presented in the past, confirmed it is OK with the new data. Effects like P-waves being transverse, or S-waves having strong variations - probably near surface effects.
  • Teleseismic events and Wiener filtering (Daniel, Michael)
    • Michael able to produce reconstructions of wavefield using Wiener filtering. Should get together to think how to use this, but the concept works. This would be an alternative to the pure physics approach, where we model reflections etc.
    • Michael: already saw that we can improve the Wiener filter approach if we use input from the physics approach. Wiener filter alone had trouble with how to fit waveforms on top of each other, i.e. figuring out the correct phase shifts.

• Papers
  • Homestake Array Summary paper: pdf
    • Leads: Vuk, Gary, Victor
    • target: Seism. Research Lett., 6000 words, 10 figures.
    • Vuk: made changes to reflect discussion from last week. Things to do:
      • References - Victor will add the ones in the introduction.
      • Brief local geology discussion in introduction?
      • Figure updates? At least Figure 4, maybe others.
      • Further discussion of Figures 6 and 7?
    • Victor: would like to have a better motivation/introduction to the Event Data Analysis section. Not quite representative of the future work we want to do.
    • Victor: suggest to replace the 3 bullet points in pg 11 with a brief discussion of what we are planning to do.
    • Gary will need to update Figure 5.
    • Gary/Victor: improve visibility of Fig 3.
    • Vuk: suggest to improve the visibility of the event locations for Fig 4.
    • Gary: could use color, remove country boundaries.
    • Vuk: Printing charge?
    • Victor: $700 flat for first 6 pages, $150 per page for pages 7-12, $250 per color print page (online color is free).
    • To do list:
      • Victor to write the section of future analyses, and add references
      • Gary to finish the discussion of Figs 6 and 7, and update Fig 4
      • Vuk/Pat to finish Figs 2 and 3.
      • Aim to finalize the draft by next time we meet.

• Active excitation overview paper
  • Leads: Gary, Ross
  • Others: Victor, Daniel,…
  • Will try to add a draft by Apr 13.

• Surface Active Excitation
  • Leads: Victor, Boise
  • Others: Gary, Ross

• Underground Active Excitation:
  • Lead: Gary, Ross

• Parameter estimation for the Rayleigh and Love eigenfunctions (amplitude vs depth dependence).
  • Leads: Pat, Daniel
  • Also contributing: Victor, Vuk, Levi

• Estimating directional and modal composition of the seismic noise. (Pat, Levi, Vuk)
  • Leads: Pat, Vuk, Levi

• Wiener filter application
  • Leads: Jan, Michael

• Teleseismic EQs and near-surface scattering
  • Leads: Daniel, Victor

• Time-variable velocity changes
  • Lead: Victor, not started yet

• Very low frequency harmonics (Ross)