What features would you expect to find at an ocean-ocean divergent plate boundary?

By

Lab 3 Plate Tectonics
Required materials
Pencil
Colored pencils
Computer with Google Earth software loaded
Pre-lab reading and quiz
Read Chapter 2 of “Earth Science”, and review your lecture notes on plate tectonics.
How do the lithospheric plates move at a divergent margin?
Give an example of a present day oceanic divergent margin.
What features would you expect to find at an ocean-ocean divergent plate boundary?
Give an example of a present day continental divergent margin.
How do the lithospheric plates move at a convergent margin?
Give an example of a present day convergent margin.
What features would you expect to find at an ocean-continent convergent plate boundary?
How do the lithospheric plates move at a transform margin?
Give an example of a present day transform margin.
In-class lab exercises
Part 1 Plate processes
The diagram below is a simplified representation of an ocean-ocean divergent margin.
Label the oceanic lithosphere, the asthenosphere and the zone of melting, and the mid-ocean ridge.
Draw arrows on the plates to indicate the directions in which they are moving.
Draw a second set of arrows to show the direction of flow in the asthenosphere.
What feature would you find at the center of the mid-ocean ridge?
The diagram below is a simplified representation of an ocean-continent convergent margin.
Label the oceanic lithosphere, the asthenosphere and the zone of melting. Indicate the regions where earthquakes may occur.
Draw arrows on the plates to indicate the directions in which they are moving.
Draw a second set of arrows to show the direction of flow in the asthenosphere.
Draw and label the locations of the trench and the accretionary wedge.
The diagram below is a simplified representation of a hot spot.
Draw arrows on the plate to indicate the direction of movement.
Label which island is the oldest and which is the youngest.
What information do hotspots like this give us about past plate movements?
Part 2 Calculation of Plate movement
Look at the map of the age of the seafloor in figure 2.17 of “Earth Science”.
From your initial observation, do you think the Mid-Atlantic Ridge is spreading faster or slower than the East Pacific Rise?
Explain why you think this.
Looking at the North Atlantic…
What age is the seafloor immediately off the coast of NYC?
Using the ruler tool in Google Earth, what is the shortest distance (in km) of the edge of the continental shelf off NYC to the Mid-Atlantic Ridge?
Using the equation rate = distance / time, how fast had North America moved away from the Mid-Atlantic Ridge (in cm/year)?
Looking at the East Pacific…
South America is moving away from the East Pacific Rise at approximately 8.6 cm/year.
Do these rates agree with your initial assumption? Explain why.
Part 3 Worldwide Plate Boundaries
On the present day world map on the next page use color to mark the divergent, convergent and transform plate boundaries. Choose a different color for each type of plate boundary, and show these colors in a key.
Are there more convergent or divergent boundaries, or are their total lengths about the same?
Why is this?
Where are most of the transform boundaries located?
Why?

How to create Testimonial Carousel using Bootstrap5

Clients' Reviews about Our Services