Question

Use Google Earth. Paste the location that is given into the "Search" box. Examine each location at multiple eye altitudes and differing amounts of tilt. For any measurements that use the ruler tool, this can be accessed by clicking on the ruler icon above the image. Search for 3645 41.23N 8518 34.22W and zoom out to an eye altitude of \(25,000 \mathrm{ft}\). Although there is no stream present today, the stream channels can be clearly seen. What type of drainage pattern was present in this area? a. Trellis b. Dendritic c. Rectangular d. Radial e. Deranged

Short answer

The drainage pattern is most likely dendritic.

Step-by-step solution

Locate the Coordinates

Open Google Earth and enter the coordinates '3645 41.23N 8518 34.22W' into the search bar. Allow Google Earth to zoom into these coordinates, which is where you will begin your observation.

Set Eye Altitude

Using the zoom-out feature, adjust the view until the eye altitude is approximately 25,000 feet. This height will help you accurately observe the drainage patterns within the terrain.

Adjust Tilt and Perspective

Utilize the tilt feature to view the terrain from various angles. This can help in analyzing the topographical features and consequently the drainage pattern. You may need to switch between different perspectives to get a comprehensive understanding of the pattern.

Identify Visible Drainage Pattern

Examine the patterns formed by the stream channels visible in the terrain. Look for characteristics corresponding to each drainage pattern option: Trellis (parallel lines), Dendritic (branching like a tree), Rectangular (right angles), Radial (divergence from a central point), and Deranged (unorganized).

Conclude with Drainage Pattern Type

Compare the observed stream channels with the defined characteristics for each drainage pattern type. Determine which pattern best matches your observations.

Key concepts

Drainage Patterns

Drainage patterns represent the distinct formations that stream channels take across a landscape. These formations are influenced by the underlying rock structure, topography, and climate. Understanding these patterns allows geologists to infer the geological history of an area. There are several common types:

• **Dendritic:** Mimics the branching pattern of a tree, typically found on uniform rock types where the land slopes gently.
• **Trellis:** Resembles a garden trellis, often observed in regions with alternating bands of resistant and non-resistant bedrock.
• **Rectangular:** Characterized by right-angle bends, often occurring when streams follow fractures in the rock.
• **Radial:** Streams radiate outward from a central high point like a volcano or hill.
• **Deranged:** A chaotic pattern with no clear system, often found in areas that have been disturbed, such as glaciated regions.

Recognizing these patterns on a map or via satellite imagery can provide insights into the geological processes that shaped the landscape.

Google Earth

Google Earth is an incredible tool for visualizing and exploring our planet from a virtual perspective. It allows users to explore detailed geographical data and observe landscapes much like a geologist would in the field. Whether you're zooming into your neighborhood or observing a remote part of the world, Google Earth provides a wealth of information.
Besides the basic navigation, users can utilize various features:

• **Search by Coordinates:** Easily locate specific points using latitude and longitude inputs.
• **Zoom and Tilt Functions:** Provide different perspectives to help understand the topography and drainage patterns.
• **Overlay Options:** Include additional data like political boundaries, roads, and historical imagery to enhance the study.

These features make Google Earth not just a tool for casual exploration, but a powerful resource for education and research in geology.

Topographical Analysis

Topographical analysis involves studying the surface characteristics of an area. It is crucial in understanding the formation and behavior of drainage patterns. Several factors play a role in this form of analysis:

• **Elevation and Relief:** Assessing changes in elevation helps determine the potential flow paths of water across a terrain.
• **Slope and Aspect:** These determine the speed and direction of surface flow, influencing drainage efficiency.
• **Rock and Soil Type:** Affect water absorption and channel formation. Harder rock types may lead to more pronounced drainage patterns.

Through a topographical analysis, one can predict how water will influence and shape the landscape over time. This process employs tools like topographic maps and software like Google Earth to visualize and analyze the terrain.

Ruler Tool Usage

The ruler tool in Google Earth is a simple yet effective feature for measuring distances on a map. Essential for tasks requiring accuracy, such as calculating the length of river segments or the distance between geographic points. The utility of this tool spans across various applications:

• **Distance Measurements:** Calculate straight lines between two points or along a curve to understand the scale of geographical features.
• **Area Calculations:** Determine the area of a polygon by measuring each side, invaluable for land use planning.
• **Depth and Elevation:** While not a direct function of the ruler tool, measuring lengths can assist in interpreting elevation changes when combined with topographical data.

By mastering the ruler tool, professionals and students alike can perform precise geographic analyses, enhancing their understanding of spatial relationships and landscape features.