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 does this type of drainage pattern indicate about the area? a. rocks in the area are homogeneous and/or flat lying b. rocks in the area are alternating resistant and non-resistant, forming parallel ridges and valleys c. stream channels radiate outward like wheel spokes from a high point d. stream channels flow randomly with no relation to underlying rocks or structure

Short answer

Option b is correct: rocks are alternating resistant and non-resistant, forming parallel ridges and valleys.

Step-by-step solution

Enter Coordinates

Open Google Earth and enter the coordinates 3645 41.23N 8518 34.22W into the search box. Press Enter or click the search icon to go to the location.

Zoom Out to 25,000 ft

Once you reach the location, zoom out to an eye altitude of 25,000 feet. You can adjust the zoom level using the zoom slider or your mouse scroll wheel.

Examine the Landscape

Observe the landscape for the visible patterns of stream channels. Note any obvious patterns such as parallel lines, radial patterns, or random distribution of channels.

Determine the Drainage Pattern Type

Compare the observed stream channel patterns with common drainage patterns: dendritic, trellis, radial, and random. Match the observed pattern to one of these types.

Match Observation to Given Options

Based on the stream pattern observed, determine which option is correct. If the channels form parallel ridges and valleys, it corresponds to option b. If radial, option c is correct, and so on.

Key concepts

Drainage Patterns

Drainage patterns are crucial in studying geology because they reveal much about the underlying rock types and structures of an area.
When using Google Earth to analyze these patterns, you might notice various formations.

• Dendritic Patterns: Resemble the branches of a tree. This pattern usually forms in regions where the rocks are uniformly resistant to erosion.
• Trellis Patterns: Characterized by parallel streams with short tributaries entering at right angles. This pattern often forms in areas with alternating resistant and non-resistant rock layers, creating ridges and valleys.
• Radial Patterns: Streams move outward from a central point, typical of volcanic cones or domes.
• Random Patterns: Not related to any specific underlying rock formations, but are influenced by surface conditions.

By identifying drainage patterns, you can conclude the geological history of the landscape you are examining.

Landscape Analysis

Landscape analysis involves evaluating natural features to understand the region's geological processes.
When you observe a landscape using Google Earth, you can spot various physical structures. Analyzing landscapes provides insights into:

• Topography: Study the shapes and features of the surface, such as mountains, valleys, and plains.
• Vegetation: Different plant distributions can suggest certain soil types or climates.
• Water Features: Observe how rivers, lakes, and streams are distributed and what that indicates about the terrain.

Through careful study of landscapes, geologists can predict weathering patterns, erosion processes, and identify natural resources.

Geographical Coordinates

Geographical coordinates are essential for precisely locating a place on the Earth's surface. They consist of latitude and longitude, expressed in degrees.

• Latitude: Measures north-south position between the poles. Ranges from 0° at the Equator to 90° at the poles.
• Longitude: Measures east-west position. The Prime Meridian at 0° allows measurement up to +180° east and -180° west.

When using Google Earth or any mapping service, coordinates help users traverse to exact points on Earth's surface.
Understanding these coordinates is fundamental to tasks like mapping geological features or navigating unfamiliar territories.

Stream Channel Identification

Stream channel identification involves recognizing the physical paths water has carved into the landscape. Even if streams aren’t present, their channels tell a story.

• Shape of the Channels: Indicates the type of flow and erosion patterns.
• Arrangement of Channels: Helps decipher the geological history of an area.

In areas where active streams no longer exist, like the one located at 3645 41.23N 8518 34.22W, you can still see these historical channels using satellite imagery.
This identification is key in predicting areas prone to flooding, soil erosion, and in implementing soil conservation strategies.