From this point of view you will see the Tanana River and the valley which it meanders through. On a clear day you can see across to the other side and the mountain range on that side. Standing at the posted coordinates and looking out at 158.91 degrees you might be able to see the group of mountain ranges which has Mount Hess at 11,940 feet, Mount Skarland at 10,315 feet, Mount Giddings at 10,180 feet, Mount Geist at 10,720 feet, Mount Balchen at 11,140 feet, and so on, but that is 85.52 miles away. (Alaska)
Mount Hess and the others visable off in the far distance.
The Tanana River is a 584-miles long and is a tributary of the Yukon River. According to William Bright, the name is from the Koyukon (Athabaskan), which literally means "trail river". The river's headwaters are located at the confluence of the Chisana and Nabesna rivers just north of Northway in eastern Alaska. In the marsh regions it is joined by several large tributaries, including the Nenana (near the city of Nenana) and the Kantishna. It empties into the Yukon approximately 70 miles downriver from the village of Manley Hot Springs, near the town of Tanana. Ice on the river begins to accumulate in October or November. Each winter the river has an average maximum thickness of 43 inches at Nenana. Over the years, the break-up date has varied from April 20 to May 20. (Alsaka)
Valley
A valley is an extended depression in the Earth's surface that is usually bounded by hills or mountains and is normally occupied by a river or stream. Because valleys are usually occupied by a river, they can also slope down to an outlet which can be another river, a lake or the ocean.
Valleys are one of the most common landforms on the Earth and they are formed through erosion or the gradual wearing down of the land by wind and water. In river valleys for example, the river acts as an erosion agent by grinding down the rock or soil and creating a valley. The shape of valleys varies but they are typically steep-sided canyons or broad plains, however their form depends on what is eroding it, the slope of the land, the type of rock or soil and the amount of time the land has been eroded.
There are three common types of valleys which include V-shaped valleys, U-shaped valleys and flat floored valleys. (Victor R. )
V-Shaped Valley
A V-shaped valley, sometimes called a river valley, is a narrow valley with steeply sloped sides that appear similar to the letter "V" from a cross-section. They are formed by strong streams, which over time have cut down into the rock through a process called downcutting. These valleys form in mountainous and/or highland areas with streams in their young stage. At this stage, streams flow rapidly down steep slopes. (Victor R. )
Source: http://www.quia.com/files/quia/users/fleach/Landforms/landforms-V-shaped-valley
U-Shaped Valley
A U-shaped valley is a valley with a profile similar to the letter "U." They are identified by steep sides that curve in at the base of the valley wall. They also have broad, flat valley floors. U-shaped valleys are formed by glacial erosion as massive glaciers moved slowly along. U-shaped valleys are found in areas with high elevation and in high latitudes, where the most glaciation has occurred. Due to their large size and weight, glaciers are able to completely alter topography, but it is the alpine glaciers that formed most of the world's U-shaped valleys. This is because they flowed down pre-existing river or V-shaped valleys during the last glaciation and caused the bottom of the "V" to level out into a "U" shape as the ice eroded the valley walls, resulting in a wider, deeper valley. For this reason, U-shaped valleys are sometimes referred to as glacial troughs. (Victor R. )
Source: http://geoscience.wisc.edu/~chuck/Classes/Mtn_and_Plates/Images/C124glaciated_valley.gif
Flat-Floored Valley
The third type of valley is called a flat-floored valley and is the most common type in the world. These valleys, like V-shaped valleys, are formed by streams, but they are in their mature stage. The valley floor gets wider. Because the stream gradient is moderate or low, the river begins to erode the bank of its channel instead of valley walls. This eventually leads to a meandering stream across a valley floor. Over time, the stream continues to meander and erode the valley's soil, widening it further. With flood events, the material that is eroded and carried in the stream is deposited which builds up the floodplain and the valley. During this process, the shape of the valley changes from a V or U shaped valley into one with a broad flat valley. (Victor R. )
Source: http://geography-site.co.uk/pages/physical/glaciers/images/trough.jpg
What is Erosion?
Erosion is the process by which soil and rock are removed from the Earth's surface by natural processes such as wind or water flow, and then transported and deposited in other locations. In this particular area at GZ, Water has caused most of the Erosion here.
Types of Erosion:
Splash Erosion: Small soil particles are detached and sent airborne through the impact of raindrops on soil.
Sheet Erosion: Raindrops break apart the soil structure and it's moved down-slope by water that flows overland as a sheet rather than definitive channels. This occurs frequently during cloud bursts.
Rill Erosion: This process develops small, short-lived, concentrated flow paths. These paths create a sediment source and delivery system for hill-slope erosion. Areas where precipitation rates exceed soil infiltration rates are more prone to this type of erosion.
Gully Erosion: Water flows in narrow channels during or directly following heavy rains or melting snow. The gullies can erode to considerable depths.
Valley or Stream Erosion: Continual water flow alongside land (along a linear feature) creates this type of erosion. It extends downward, deepening a valley, and head-ward, extending the valley into the hillside. This occurs most frequently in times of flooding.
Bank Erosion: Over time, banks of rivers and streams are naturally worn down.
Freezing and thawing: Cold weather causes water trapped in tiny rock cracks to freeze and expand, breaking the rock into several pieces.
Glaciers: erode predominantly by three different processes: abrasion/scouring, plucking, and ice thrusting. In an abrasion process, debris in the basal ice scrapes along the bed, polishing and gouging the underlying rocks, similar to sandpaper on wood. Glaciers can also cause pieces of bedrock to crack off in the process of plucking. In ice thrusting, the glacier freezes to its bed, then as it surges forward, it moves large sheets of frozen sediment at the base along with the glacier.
Source: (water)
Sources
**Logging requirements**
DO NOT POST ANSWERS IN YOUR LOG.
Send the following answers to me via email.
- The text "GC5D56X Alaskan Valley View" on the first line
- How wide is this valley? (see waypoint)
- What is the elevation here?
- Now subtract the elevation of the valley floor of 418 feet, how high up are you from the valley below?
- What type of valley are you seeing in front of you?
- What caused this valley?(the river is not the primary cause for the creation of this valley)
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