Laserfiche WebLink
Fall 2019 Subsidence and Geologic Field Observations <br /> Southern Panels Mining Area <br /> 4.0 FALL 2019 SUBSIDENCE OBSERVATIONS <br /> During our fall 2019 field visit, subsidence-related tension cracks were observed above E-seam <br /> Longwall Panels E6 and E7 in the Southern Panels Mining Area along some drilling roads accessed <br /> by USFS Road 711 (Dry Fork Road) and on MVB pads,particularly where they exist above active <br /> mining activities. <br /> Subsidence features were observed at various locations along the established traverses. All new <br /> subsidence features were located west of MVB E8-5 above the recent longwall mining activities <br /> of E-seam Longwall Panel E8 (i.e., areas of maximum expected dynamic subsidence effects). <br /> Details associated with the fall 2019 observation of subsidence features can be found in Sections <br /> 4.3, 4.5, and 4.6 of this report. To date, there have been no subsidence-related features observed <br /> in alluvium even above active longwall mining activities. <br /> Section 4.7 of this report provides observation information associated with new Traverse G-G', <br /> which represents baseline conditions prior to mining of E-seam Longwall Panel SS of the Sunset <br /> Trails Mining Area. <br /> The following sections of this report provide a description of the fall 2019 observations associated <br /> with Traverses A-A' through G-G' (see Maps 1 and 2). Map 1 shows the outline of E-seam mine <br /> workings along with surface topography and other surface features,including the named traverses. <br /> Map 2 shows the same area and detail as Map 1 (minus traverses) along with recently active, or <br /> potentially active, landslide and rockfall areas as delineated from aerial photo research and field <br /> observations. <br /> Some of the numerous photographs obtained during the fall 2019 field visit are included as figures <br /> in the following text. Where these images have notable differences from previous photographs, <br /> the older image has been included for comparison purposes. To reduce the overall size of this <br /> document, narrative text and photographs are excluded for traverses where no noticeable change <br /> was observed. <br /> 831-032.910 Wright Water Engineers, Inc. Page 10 <br /> February 2020 <br />