WorksheetsSea Floor Spreading Quiz
Total questions: 15
Worksheet time: 15mins
What is sea-floor spreading?
The process of ocean water expanding due to heat
The theory that new ocean floor forms at mid-ocean ridges and moves away from the ridge
The sinking of old ocean floor into trenches
The movement of fish across ocean basins
What is a mid-ocean ridge?
A deep valley in the ocean floor
An underwater mountain range where new ocean floor is created
The edge of a continent underwater
A flat area on the ocean bottom
What does the term "magnetic reversal" mean?
When compasses stop working properly
When Earth's magnetic field changes direction over time
When magnets lose their power
When ocean currents change direction
What are magnetic stripes on the ocean floor?
Painted lines used by ships for navigation
Patterns of normal and reversed magnetic polarity in ocean rocks
Areas where metal objects have fallen into the ocean
Cracks in the ocean floor
What is oceanic crust?
The top layer of ocean water
The layer of rock that forms the ocean floor
Salt deposits on the ocean surface
The deepest part of the ocean
What does "basalt" refer to in sea floor spreading?
A type of ocean animal
A dark volcanic rock that makes up most of the ocean floor
A measurement of ocean depth
A type of ocean current
What is a divergent boundary?
Where two tectonic plates move toward each other
Where two tectonic plates slide past each other
Where two tectonic plates move away from each other
Where tectonic plates stop moving
What does "symmetrical pattern" mean in relation to sea floor spreading?
The ocean floor is perfectly round
Magnetic stripes on both sides of a ridge are mirror images
All ocean ridges are the same height
Ocean trenches are evenly spaced
Who developed the theory of sea floor spreading?
Alfred Wegener
Harry Hess
Charles Darwin
Marie Curie
What is the asthenosphere?
The ocean's surface layer
The partially molten layer of Earth's mantle beneath the lithosphere
The deepest part of ocean trenches
The magnetic field around Earth
What does "pillow lava" indicate about underwater volcanic activity?
Lava that is soft like a pillow
Rounded lava formations that occur when lava cools rapidly underwater
Lava that floats on water
Lava that forms only on land
What is the lithosphere?
Only the ocean floor
Earth's rigid outer layer, including crust and upper mantle
The atmosphere above the ocean
The liquid center of Earth
How does the age of ocean floor rocks change as you move away from a mid-ocean ridge?
Rocks become younger
Rocks stay the same age
Rocks become older
Rock age changes randomly
What evidence supports sea floor spreading theory?
Only magnetic stripe patterns
Only the age of ocean rocks
Magnetic stripes, rock ages, and symmetrical patterns around ridges
Only the depth of ocean trenches
What can scientists conclude about Earth's magnetic field based on sea floor spreading evidence?
It has always pointed in the same direction
It only affects ocean rocks
It has reversed direction many times throughout Earth's history
It doesn't affect rocks at all
