Stemscopes 7.E.6.5 Seafloor spreading

What evidence helps scientists show how sea floor spreading occurs?

• Ocean Floor Material

• Magnetic Stripes

• Drilling Samples

• All of the Above

What happens when Subduction occurs?

• Parts of the crust fall into the mantle

• Parts of the crust fall into the core

• Parts of the crust fall into space

• None of the Above

What are Mid-Ocean Ridges?

• A chain of underwater waterfalls 

• A chain of underwater volcanos

• A chain of underwater mountains

• A chain of underwater rocks

___________ help explain why Earth is not getting any larger even though the tectonic plates are always moving.

• earthquakes

• subduction zones

• fossils

• volcanoes

Where does molten material rise and erupt to make new sea floor?

• deep ocean trench

• subduction

• mid ocean ridge

• continental crust

Old oceanic crust is more dense than new oceanic crust because it is

• hot

• cool

• moving

• close to a continent

What process adds more crust to the ocean floor?

• suction

• sea-floor spreading

• subduction

• magnetic stripe

Which process or processes change the size and shape of the oceans?

• subduction only

• sea-floor spreading only

• both subduction and sea-floor spreading

• both  drilling for samples and subduction

What features form the longest mountain ranges on Earth?

• the mid-ocean ridges

• the deep ocean trenches

• the Rockies

• the Andies

The farther from a mid-ocean ridge a rock sample is taken the ______________ the rock is.

• hotter

• softer

• younger

• older