Sediment Deposition Supports Seafloor Spreading - Story Map Version PDF

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Summary

An in-class assignment. Received an 85% because number 6 was incorrect....

Description

Sediment Deposition & Seafloor Spreading - Student Guide Name: Tristan Gaona

Data Table Use the instructions below the table to complete the data table. Leave the values you add in red. ODP Expedition 168 Site

Velocity of Sound in Water (m/s)

Sonar Travel Time (s)

Depth to Ocean Floor (m)

Sediment Thickness (m)

Depth to Basalt (m)

Distance East of Ridge (km)

Spreading Center

1500

2.80

2100

0

2100

0

1023

1500

3.51

2633

315

2948

22

1024

1500

3.53

2648

342

2990

27

1025

1500

3.55

2663

268

2931

34

1030/1031

1500

3.54

2655

194

2849

41

1028

1500

3.65

2738

139

2877

46

1029

1500

3.65

2738

259

2997

56

1032

1500

3.65

2738

416

3154

76

1026

1500

3.67

2753

324

3077

99

1027

1500

3.67

2753

537

3290

102

Graph

Paste Graph Here:

Summary Questions 1. Assuming a constant rate of sedimentation throughout the study area, what would cause sediment to be thinner near the Juan De Fuca ridge and thicker as you move away? Along the ridge the sediment is very new so it has not had much time to get thick, while the sediment further away from the ridge has been around longer so it has had the time to accumulate and get thick. 2. Where are the oldest sediments? Explain your answer. The oldest sediments are the ones located furthest away from the ridge at the bottom because they were the ones that were deposited first a long time ago. 3. Where do you think the newest crust is? Where is the oldest crust? Why?

The newest crust is near the ridge while the oldest crust is the furthest away from the ridge. This is because the seafloor spreads away from the ridge, so the crust thats further away from the ridge has been around for a longer time. 4. How does the thickness of the sediment support the theory of seafloor spreading? The areas that are further away from the ridge are thicker, meaning that they have been slowly moving away from the ridge and accumulating sediment as they moved. 5. How does the depth of the basalt change as you move away from the spreading ridge? Explain why this change occurs. You should know that this change can be observed at all ridges. The depth of the basalt increases as you move away from the spreading ridge. This is because the sediment accumulates and pushes the basalt further and further down. 6. Finally, draw a bold arrow beneath the graph showing the direction the ocean floor is moving....