Using the power of Google Earth, GeoTours take you on flyovers of key locations discussed in the text.
StudySpace student website and ebook icons in each GeoTour connect your to the text and online review materials.
Dialogue boxes accompanying each site include text, figures, photos.
|
|
Geotour 16: Evidence of Groundwater
Irrigation in the Saudi Desert
|
| 1a. Check and double-click polygon Problem 1 in the Problem 1 folder to fly to a region in Saudi Arabia.
What is the trend/orientation of the polygon (and also of the water wells and irrigation circles)?
|
|
|
| 1b. Given that nearby ridges also have this same trend, what is the best explanation for why the water wells and irrigation circles have this trend and are only located in certain “bands”?
|
|
|
Surface and Groundwater flow
|
| 2a. Surface water flow is influenced most directly by elevation differences. Groundwater flow is controlled by elevation differences in the water table, which commonly reflects surface elevations to a degree.
Use the Hand Tool to determine the elevations at the placemarks for Problems 2a-i and 2a-ii. What direction should the surface and groundwater flow? (Confirm this by turning on the “Everglades, FL-Previous Groundwater Flow” overlay).
|
|
|
| 2b. Turn on the “Everglades, FL-Present Groundwater Flow” overlay. What has changed?
part of the swamps have been drained
|
|
|
| 2c. What is causing the dramatic saltwater incursion as seen on the “Everglades, FL-Present Groundwater Flow” overlay?
|
|
|
Hot Springs
|
| 3a. Check and double-click the placemarks for Problem 3a. You will fly to Midway Geyser Basin and see Grand Prismatic Pool, a hot spring, and the nearby Firehole River in Yellowstone NP.
Use the Measuring Tool to measure the width of Grand Prismatic Pool (in m) between the placemarks of Problem 3a.
|
|
|
| 3b. Using the Hand Tool, compare the elevation of Grand Prismatic Pool and of the Firehole River (in m). Does overland flow of water travel from the pool to the Firehole River or from the Firehole River to Grand Prismatic Pool?
|
|
|
| 3c. Check and double-click placemark Problem 3c to fly to Mammoth Hot Springs, an area in the NW corner of Yellowstone NP. This area is different than the silica-based geyser features to the south that are associated with volcanic rocks. Here, hot groundwater circulates in the subsurface to dissolve minerals from the Madison Limestone. What are these terraces of reprecipitated minerals made of?
|
|
|
Karst Features
|
| 4a. Acidic groundwater can dissolve soluble rocks to form fascinating karst landscapes.
Check and double-click placemark Problem 4a to fly to the Mammoth Cave, KY area. This flat area is known as the Pennyroyal Plateau. What are the depressions that dot the landscape called?
|
|
|
| 4b. Check and double-click placemark Problem 4b to fly to an area near Orleans, IN. The placemark points to the Lost River, a stream that flows from east to west in this area. Follow the stream to the west. What kind of stream is it?
|
|
|
| 4c. The Lost River really isn’t “lost”. West of placemark Problem 4b, we see glimpses of the water that has been diverted underground in areas like Elrod Gulf (placemark Problem 4c). Such areas are called karst windows, as they provide a window into the groundwater system. Eventually, the groundwater resurfaces at a resurgent spring near Orangeville and the Lost River flows at the surface again. How is the area between placemarks Problem 4b and 4c best described?
|
|
|
| 4d. What kind of karst landscape is shown in the area around placemark Problem 4d?
|
|
|
| 4e. What kind of karst feature is shown by placemark Problem 4e (see photo in the placemark)?
|
|
|