Mine Safety and Health Administration (MSHA) - Report of ...

Figure 84 - Ventilation System before August 6 Accident .............................................137
Figure 85 - Fan Pressure at the Time of the August 6 Accident ....................................138
Figure 86 - Ventilation Controls after Accidents ............................................................139
Figure 87 – Approx. Time of Useful Consciousness vs. Oxygen Concentration ..........141
Figure 88 – Steel Cables Connected to RocProps ...........................................................160
Figure 89 - New Roof Bolts and New Wire Mesh Installed in the No. 1 Entry ............161
Figure 90 - Sheet of Lexan Suspended from Mine Roof.................................................161
Figure 91 - Initial Location of Seismic Events August 6-16, 2007 .................................163
Figure 92 - Double Difference Locations of Seismic Events, August 6-16, 2007 ..........163
Figure 93 – Bounce or Burst Activity Recorded in Command Center Log Book........164
Figure 94 - No. 1 Entry Rescue Clean-up Progress Plotted by Day ..............................165
Figure 95 - Convergence Measurements..........................................................................167
Figure 96 - How Satellites and Radar Interferometry Detect Surface Movement ......L-1
Figure 97 – Example of Interferogram Color Banding from
USGS Fact Sheet 2005-3025 ......................................................................L-2
Figure 98 - USGS InSAR Image of Subsidence above the Accident Site......................L-3
Figure 99 - Surface Deformation from USGS InSAR.....................................................L-4
Figure 100 - InSAR Vertical Subsidence Contours (cm) from Neva Ridge..................L-4
Figure 101 - Comparison of Vertical Subsidence from Interpreted USGS and
Neva Ridge InSAR Results........................................................................L-5
Figure 102 - InSAR Vertical Subsidence Contours & GPS Subsidence Line Data .....L-6
Figure 103 - Longwall Panels 13 to 15 GPS Surveyed Subsidence Profiles..................L-7
Figure 104 - Mining-Induced Seismicity in Utah ............................................................N-1
Figure 105 - Locations of UUSS Seismographs in the Wasatch Plateau.......................N-2
Figure 106 – Locations of Selected Events showing Progressive Refinements
Using Three Methods.................................................................................N-4
Figure 107 - Observed and Calculated Locations for Events ........................................N-5
Figure 108 - Calculated Double Difference Locations and the Location of Mining Color
Coded by Month.........................................................................................N-6
Figure 109 – Seismic Location of the August 6 Accident and Following Events..........N-7
Figure 110 - P-Wave First Motion Analysis Examples...................................................N-8
Figure 111 - Vertical Component Waveform Data for August 6, 2007 Event..............N-9
Figure 112 - Source Type Plot from Ford et al. (2008).................................................N-10
Figure 113 – Depth Analysis of August 6, 2007 event from Ford et al 2008...............N-11
Figure 114 - General Strain-Softening Element Characteristics...................................U-2
Figure 115 - Traditional Strain-Softening Element Distribution ..................................U-3
Figure 116 - Strain-Softening Element Distribution to Account for
Corner Effects (as Deployed by AAI).......................................................U-4
Figure 117 - North Barrier MSHA 2006 ARMPS Model..............................................W-2
Figure 118 - South Barrier MSHA 2006 ARMPS Model ..............................................W-3
vii