Plate Tectonics Theory Flashcards
The central or inner part of the Earth (inner and outer core)
Centrosphere
also known as the mantle, it lies just below the earth’s crust
Mesosphere
the ductile part of the earth just below the lithosphere, including the upper mantle
Asthenosphere
the outer solid part of the earth, including the crust and uppermost mantle
Lithosphere
Features of the Plates
● A plate is a part of the lithosphere, which includes the uppermost part of the mantle and the crust above it.
● One plate can carry both oceanic and continental crusts. Continental crust-125 km; Oceanic crust -75 km
● A plate is composed of a hard, mechanically strong rock
● A plate floats on the hot plastic asthenosphere and glides horizontally over it.
● Each plate moves as a large intact sheet of rock.
● Earthquakes and volcanoes are common along plate boundaries.
● Tectonic plates move at a very slow rate. They glide over the asthenosphere at a rate of about 1 to 16 cm a year.
proposes that there was once a giant continent. This supercontinent (Pangaea) broke into several pieces that slowly drifted away from one another.
Continental Drift Theory (1912)
hypothesizes that magma from the mantle oozes out to the crust and pushes fragment of the crust away from each other, thus, widening the ocean floor. The rising magma moves by convection. Heat in the earth’s interior creates convection cells within the mantle and the crust moves with the mantle like a conveyor belt system.
The Seafloor Spreading Theory (1960)
The rising magma moves by ???
Heat in the earth’s interior creates convection cells within the mantle and the crust moves with the mantle like a conveyor belt system.
convection
states that the earth’s lithosphere is divided into seven major plates and some
minor ones.
Plate Tectonics Theory (1915)
Jason Morgan
Plate Tectonics Theory
Alfred Wegener
Continental Drift Theory
Harry H. Hess
The Seafloor Spreading Theory
The Seven Major Plates
African
Antarctic
Eurasian
Indo-Australian
North-American Pacific
South-American
The plates move smoothly across the earth at a
rate of about ? to ?? cm a year.
1 to 16
The Plate Tectonics Theory may be used to explain the following
✔ The earth’s surface continues to change through time;
✔ Earthquakes occur in some places,
✔ Certain regions experience volcanic activities;
✔ Mountain ranges are located where they are due to geologic activities.
a part of the lithosphere, which includes the uppermost part of the mantle and the crust above it
Plate
The mechanical and compositional layers of the earth are:
the lithosphere
the asthenosphere
the mesosphere
the centrosphere.
How many plate/s can carry both oceanic and continental crusts?
One plate
composed of a hard, mechanically strong rock
floats on the hot plastic asthenosphere and glides horizontally over it
moves as a large intact sheet of rock
Plate
Common among plate boundaries
Earthquakes and Volcanoes
They move at a very slow rate.
They glide over the asthenosphere at a rate of about 1 to 16 cm a year.
Tectonic plates
proposes that there was once a giant continent
The Continental Drift Theory
This supercontinent broke into several pieces that slowly drifted away from one another.
Pangaea
hypothesizes that magma from the mantle oozes out to the crust away from each other, thus, widening the ocean floor.
The Seafloor
Spreading Theory
