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WorksheetsDevelopment of a Theory-Lesson 2
Total questions: 15
Worksheet time: 8mins
What device did scientists use in the 1940s to measure ocean floor depths?
Seismograph
Echo sounder
Barometer
Thermometer
What does an isochron map of the ocean floor show?
Ocean currents
Water temperature
Points of equal depth
Points that formed at the same time
Which statement about mid-ocean ridges is correct?
They are found only in shallow water
They are shorter than mountain ranges on land
They contain the youngest oceanic crust
They are where continents collide
What happens to magma when it reaches Earth's surface?
It becomes lava
It turns into granite
It immediately solidifies
It sinks back down
How does the age of oceanic crust change as you move away from a mid-ocean ridge?
It becomes younger
It becomes older
It stays the same age
Age varies randomly
The asthenosphere is:
A completely liquid layer
Part of Earth's core
A solid layer that behaves like plastic due to heat
The uppermost part of the crust
How fast do tectonic plates typically move?
1-9 centimeters per year
1-9 meters per year
1-9 kilometers per year
They don't move at all
The lithosphere includes:
Only the crust
Only the mantle
The crust and uppermost mantle
The entire mantle
Where is the lithosphere thinnest?
Below continents
Below ocean trenches
Below mid-ocean ridges
Below mountains
The Mariana Trench is significant because:
It contains the youngest oceanic crust
It is the deepest landform on Earth
It is where continents first separated
It has the most volcanic activity
The process of seafloor spreading explains:
Why volcanoes form
How earthquakes occur
Wegener's continental drift hypothesis
Why the moon affects tides
What allows tectonic plates to move?
Ocean currents
Earth's magnetic field
The plastic-like asthenosphere
Gravitational forces
The theory of plate tectonics states that:
Earth's interior is completely molten
Continents float freely on the ocean
Earth's surface consists of rigid plates that move
Mountains grow continuously
Where does new oceanic crust form?
At continental boundaries
In ocean trenches
At mid-ocean ridges
In the asthenosphere
What happens to old oceanic crust in the plate tectonics cycle?
It melts and becomes magma
It sinks at ocean trenches
It becomes continental crust
It floats to the surface
