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groups:homestake:meetings:20160128 [2016/01/28 10:42] – mandicgroups:homestake:meetings:20160128 [2016/01/28 11:06] (current) – mandic
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 Homestake Meeting Minutes, 01/28/2016 Homestake Meeting Minutes, 01/28/2016
  
-Attending: Gary, Ross, Daniel, Levi, Vuk, Tanner, Pat+Attending: Gary, Ross, Daniel, Levi, Vuk, Tanner, Pat, Michael
  
 Homestake wiki: https://zzz.physics.umn.edu/groups/homestake/home Homestake wiki: https://zzz.physics.umn.edu/groups/homestake/home
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 2) data analysis updates 2) data analysis updates
-  * Levi presented the UPDATED Analysis of Depth-dependent Shear Waves {{groups:homestake:updated_analysis_of_depth-dependent_behavior_of_shear_waves.pdf|PowerPoint}}. Found information about rock composition at Homestake, combined with the information on hardness of different minerals, and computed an average hardness of rock in different locations at Homestake. Appears Homestake falls in the "generic rock" category. Gary suggests to repeat the same with P and S speeds, which would give us the baseline speed for unfractured rock. Combined with velocity measurements, we could extract information about fracturing in the rock. Gary will work with Levi on this. +  * Levi presented the UPDATED Analysis of Depth-dependent Shear Waves {{groups:homestake:updated_analysis_of_depth-dependent_behavior_of_shear_waves.pdf|PowerPoint}}. Found information about rock composition at Homestake, combined with the information on hardness of different minerals, and computed an average hardness of rock in different locations at Homestake. Appears Homestake falls in the "generic rock" category. Gary suggests to repeat the same with P and S speeds, which would give us the baseline speed for unfractured rock. Combined with velocity measurements, we could extract information about fracturing in the rock. Gary will work with Levi on this. 
 +  * Gary: use explosions at 4850 to estimate the free-surface amplifications, we should be able to measure it directly.
   * Relevant paper {{:groups:homestake:meetings:arma2013paper493.pdf|}}   * Relevant paper {{:groups:homestake:meetings:arma2013paper493.pdf|}}
 +  * Gary/Ross: processing the reflection line experiment at 2000 level, seeing scattered waves off of mine works. Not clear if the reflection off of the free surface can be observed. Have measurements of shear wave velocities at this level, comparing it now with the geology information. Complementary to the Roggenthen paper linked above.
 +  * Gary also working on the timing information with the weight drop experiment (recall the timing system failed). Measuring cross correlations and trying to estimate the event times from there. Using our array time as a reference. Messy bookkeeping problem.
 +  * Measured peak velocities generated by explosions at Homestake in Dec. Will look at the amplitude fall-off with distance from explosion.
  
groups/homestake/meetings/20160128.1453999356.txt.gz · Last modified: 2016/01/28 10:42 by mandic

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