Campuses:
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| groups:homestake:meetings:20160225 [2016/02/25 09:28] – prestegard | groups:homestake:meetings:20160225 [2016/02/25 11:48] (current) – mandic | ||
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| * Homestake array | * Homestake array | ||
| * status of stations (WTP, Yates, 800) | * status of stations (WTP, Yates, 800) | ||
| - | * planning next visit: | + | * planning next visit: April 15-24 |
| * No access on Apr 11 (Mon) and Apr 22 (Fri). | * No access on Apr 11 (Mon) and Apr 22 (Fri). | ||
| * Replace instruments at 800 and Yates. | * Replace instruments at 800 and Yates. | ||
| * Harvest data from balers. | * Harvest data from balers. | ||
| * Clean out the insulation panels being stored in the room at the #4 Winze wye on the 4850L. | * Clean out the insulation panels being stored in the room at the #4 Winze wye on the 4850L. | ||
| + | * Terry and Pat will go. | ||
| + | * Should have one spare instrument, Pat and Tanner should follow up. Need another Guralp from PASSCAL, Gary to follow up on it. | ||
| + | * Assume to download 4 Balers/day, so need 6 days for the whole array. Checked inventory, looks like we should have 10+ spare balers. | ||
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| * Data analysis updates | * Data analysis updates | ||
| * Results of the Geochemical Analysis of Homestake Wave Speeds {{: | * Results of the Geochemical Analysis of Homestake Wave Speeds {{: | ||
| + | * Victor: should follow up on the minerals for which we don't have data. Levi to email the group about them. | ||
| + | * Velocity does not seem to depend on the depth, so the observed depth dependence of the velocity must come from porosity of the rock, fractures etc. | ||
| * Indiana group results - S velocities and start of event catalog{{: | * Indiana group results - S velocities and start of event catalog{{: | ||
| + | * Shear wave speed measurements at 2000 level: ~3500 m/s in the Homestake formation, ~3300 m/s in Ellison, and ~3700 m/s in the mixed rock environment near Ross. | ||
| + | * Victor: any bias due to being close to the tunnel? Gary: possibly, fracturing is probably higher near the tunnels. | ||
| + | * Gary: looking at anisotropy, but can't tell yet. Need to look at the geology, Levi's work could help with this. Difficult to distinguish anisotropy from heterogeneity in the rock. | ||
| + | * Event catalog: seeing ~10 events per day, mostly mining explosions in the region. Not all are recovered correctly, need a full array analysis for this. | ||
| + | * Many large signals with large S-wave contribution from these mining explosions, although one wouldn' | ||
| * Rayleigh wave planning (Tanner) {{: | * Rayleigh wave planning (Tanner) {{: | ||
| + | * Daniel can help with estimating Rayleigh wave amplitudes, Tanner will follow up with him offline. | ||
| + | * Daniel: probably best to filter the data in a narrow band around a specific frequency, and then do the fitting. In this way you avoid dealing with different speeds at different frequencies. | ||