Lesson 5- sea-floor-spreading
1. How does sea-floor spreading occur?
a.new materials are being added to the asthenosphere
b.earthquakes break apart the ocean floor**
c.sediments accumulate at the area of spreading
d.molten material beneath earths crust rises to the surface
2. which features form the longest mountain range on earth?
a.the mid ocean ridges**
b.the deep ocean trenches
c.the rockies
d. the andes
3. how does subduction change the ocean floor?
a.subduction causes magma to accumulate on the ocean floor
b.subduction causes oceanic crust to break into pieces
c.subduction causes the ocean floor to sink into deep ocean trenches*
d.subduction causes metamorphic rocks to form
4. how are ocean trenches formed?
a.ocean trenches are formed when oceanic plate cools and moves to the surface of the ocean
b.ocean trenches are formed when the denser oceanic plates sink**
c.ocean trenches are formed when the molten rock cools and solidifies
d.ocean trenches are formed when magma accumulates on the ocean floor.
Please check my answers! Thank you!
1.d
2.a
3.c
4.b
Your answers are almost all correct! Great job. Just one correction needed:
Question 1: How does sea-floor spreading occur?
Your answer: b. earthquakes break apart the ocean floor ** (Incorrect)
Correct answer: d. molten material beneath Earth's crust rises to the surface
Explanation: Sea-floor spreading occurs when molten material from the mantle rises to the surface along mid-ocean ridges, creating new oceanic crust. As the material cools and solidifies, it spreads away from the ridge, pushing older crust aside. The process is driven by the movement of tectonic plates.
Question 2: Which features form the longest mountain range on Earth?
Your answer: a. the mid-ocean ridges ** (Correct)
Question 3: How does subduction change the ocean floor?
Your answer: c. subduction causes the ocean floor to sink into deep ocean trenches * (Correct)
Question 4: How are ocean trenches formed?
Your answer: b. ocean trenches are formed when the denser oceanic plates sink ** (Correct)
Great job overall! If you have any more questions, feel free to ask.