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Fall 2019 Subsidence and Geologic Field Observations <br /> Southern Panels Mining Area <br /> A new subsidence crack with elevation offset was observed during our spring 2019 field visit on <br /> the road leading to MVB E6-14 about 1,000 feet south of the pad(Location 2). Details associated <br /> with our follow-up visit to this location during our fall 2019 field work are provided below. <br /> 4.3.1 Location 1 <br /> Two parallel subsidence cracks were observed approximately 300 feet south of the E7-12 MVB <br /> pad during our fall 2018 field work (Figure 1). These cracks had a N60OW orientation and an <br /> offset of about 13 feet. Observational evidence at that time (i.e., sharpness of crack edges) <br /> suggested that the cracks had not formed at the same time. The northern crack had rounded edges <br /> while the southern crack edges were sharp. E-seam overburden thickness at this location is about <br /> 800 feet. <br /> Observations made during the fall 2019 field visit found that the northern crack had no significant <br /> depth (i.e., it was filled with sediment) while the southern crack still had a measurable width and <br /> depth (Figure 2). Both cracks showed signs of healing and weathering. Maximum measurements <br /> of the southern crack were 10 inches in width and 34 inches in depth. <br /> _m <br /> Figure 1. Southeastward view during the fall 2018 field visit of two parallel <br /> subsidence cracks that appeared as a result of longwall mining beneath the area at <br /> that time. The closest crack showed more rounded edges than the farthest crack, <br /> suggesting the latter had most recently formed at the time of the observation. <br /> 831-032.910 Wright Water Engineers, Inc. Page 13 <br /> February 2020 <br />