6th Grade Science Part 2 Plate Techtonics Flashcards
Alfred Wegener
A German scientist, in 1912, theorized that all of the Earth’s continents were once connected together in a single, large landmass. This theory became known as Continental Drift.
compression
the type of stress that occurs when an object is squeezed
continental drift
the first hypothesis proposing large movements of continents. This idea was replaced by the Theory of Plate Tectonics.
convection currents
the circular motion of liquids or gases due to density differences that result from temperature
convergent boundary
an area where two tectonic plates push against each other
divergent boundary
an area where two tectonic plates pull away from each other
earthquake
a sudden movement of the earth’s crust caused by the release of stress which forms along geologic faults or by volcanic activity
fault
a break in the earth’s crust
hot spot
plumes that come from convection currents in the mantle and are stationary compared to the moving plates around them
mid ocean ridge
a long mountain chain that forms on the ocean floor where tectonic plate pull apart. Marks the site where new ocean floor is created as two plates move away from each other.
mountain building
the geological processes such as plate tectonic movement and volcanic activity, by which mountains are formed
ocean basin
the part of the earth’s lithosphere that is covered in salt water and contains the ocean floor, mid ocean ridges, and the lower parts of the continental crust.
Pangea
the supercontinent that began to break apart 250 million years ago to form the present continents
plate boundary
the edge where lithospheric plates touch
volcanic mountain
A mountain that forms when molten rock erupts onto the Earth’s surface
seafloor spreading
an idea that says that new ocean floor is created where two plates move away from one another at mid ocean ridges
subduction
a long, narrow zone where one lithospheric plate slips underneath another
tectonic plates
a piece of the lithosphere that moves around on top of the mantle
tension
the type of stress that occurs when forces act to stretch an object
Theory of Plate Tectonics
the theory that states that the Earth’s lithosphere is broken into plates that move over a flowing layer of the mantle. Plate interactions produce earthquakes, mountains, and volcanoes.
transform boundary
an area where two tectonic plates slide past each other (sliding boundary)
trench
the natural boundary between two lithospheric plates. Becomes deeper as plates pull away from each other.
uplift
the process in which regions of the earth’s crust are raised to a higher elevation
Eurasian Plate
the tectonic plate located under Europe and Asia
African Plate
the tectonic plate located under Africa
Indo-Australian Plate
the tectonic plate located under India and Australia
Pacific Plate
the tectonic plate located under most of the Pacific Ocean
North American Plate
the tectonic plate located under North America
South American Plate
the tectonic plate located under South America
