Earth's Layers
What is the outermost layer of Earth?
Crust
Plates move apart at this type of boundary.
Divergent
Where does seafloor spreading occur?
Mid-ocean ridges
What was the name of the supercontinent that existed 250 million years ago?
Pangea
What is the theory that Earth's plates are constantly moving?
Plate Tectonics
What is the layer is the center of the Earth?
Inner Core
Plates push together at this type of boundary
Convergent
Where are the youngest oceanic rocks found?
At the mid-ocean ridge
What kind of evidence did Alfred Wegener use to support continental drift?
Fossil evidence, geologic structures, tectonic plates
Which type of crust is older- continental or oceanic?
Continental
What layer is made of solid rock that flows slowly and drives plate motion?
Mantle
Plates slide past each other at this boundary
Transform
What pattern in the ocean floor provides evidence of seafloor spreading?
The peaks and trenches
Mesosaurus
What process happens when an oceanic plate sinks beneath a continental plate?
Subduction
Which layer is solid due to intense pressure?
Inner Core
The Himalayas formed at this type of boundary
Convergent
Which boundary is seafloor spreading associated with?
Divergent boundary
What type of rock layer evidence shows Earth’s history?
Sedimentary rock layers (strata)
What do scientists study to learn about Earth's geologic history?
Fossils and rock layers
Name the two parts of the Earth that make up the lithosphere.
Crust and upper Mantle
At a convergent boundary where oceanic crust meets continental crust, what two features usually form?
A deep-ocean trench and a chain of volcanoes (volcanic arc)
Who discovered evidence of seafloor spreading in ocean the ocean?
Harry Hess and others in the 1960s
Why are similar fossils found on continents separated by oceans?
Continents were once joined together
Name one natural event caused by plate tectonics
Earthquakes, volcanoes, or mountain building