Activity 12.5 Floridan Aquifer System Name: Course/Section: Date: Refer to Figs. 12.10 (Sulphur Springs Quadrangle) and A12.5.10 55 55 50 do 50 45 - - -- 1 mi Boundary of topographic map WHBO radio tower Poinsettia Sinks - - - - - - - - - - - Spillway Sulphur Springs Hillsborough Lowry Spring Figure A12.5.1 A. On Fig. A 12.5.10 mark the elevations of water levels in the lakes (obtain this information from Fig. 12.100). The elevations of Lake Magdalene and some lakes beyond the boundaries of the topographic map are marked already for you. B. Contour the water-table surface (use a 5-foot contour interval) on Fig. A 12.5.1 Draw only contour lines representing whole fives (40, 45, and so on). Do this in the same manner that you contoured land surfaces in the topographic maps lab. to indicate C. The flow of shallow groundwater in Fig. A12.5.10 is at right angles to the contour lines. The groundwater flows from high elevations of the water table to lower elevations, just like a stream. Draw three or four flow lines with arrows on Fig. A 12.5.1 the direction of shallow groundwater flow in this part of Tampa. The southeastern part of Fig. 12.10 shows numerous closed depressions but very few lakes. What does this indicate about the level of the water table in this region? D. Note the Poinsettia Sinks, a pair of sinkholes with water in them in the southeast corner of the topographic map (Fig. 12.100). Next, find the cluster of five similar sinkholes, called Blue Sinks, about 1 mile northwest of Poinsettia Sinks (just west of the WHBO radio tower). Use asterisks (*) to mark their locations on Fig. A 12.5.10, and label them Blue Sinks. London Burre 1 km ake Platt Lake 49 North C Contour Interval 5 ft U Wamps Pond Lake Magdalene 2004 47 O naine weetwatelsat SA Lake Vlake t ak Noreast Lake ) Lakes Lipse Lake 3. Poinsettia Sinks White Trout Lake Figure 12.10 Topographic map in a karst area. Portion of the Sulphur Springs, Florida, 7.5-minute topographic quadrangle map by the USGS (2015). The center of this map is located approximately at 28.068°N, 82.472 W. Water-surface elevations for several of the lakes are indicated in feet above sea level. The grid squares are 1 km2 We've updated our read aloud featur