Plate Tectonics Flashcards
Inner Core
800 miles thick (iron & nickel in solid state)
Outer Core
1,400 miles thick (iron and nickel in liquid state)
Mantle
1,800 miles thick (flows with consistency of asphalt)
Continental Plate
5-25 miles thick
Oceanic Plate
3-5 miles thick
Divergent Plate Margin
Spreading Motion - Constructive Effect - Ridge Topography - Volcanic Activity
Convergent Plate Margin
Subduction Motion - Destructive Effect - Trench Topography - Volcanic Activity and Earthquakes
Transform Plate Margin
Lateral Sliding Motion (Slides Paralel) - Conservative Effect - No Major Topography - No Volcanic Activity but Earthquakes are present within crust
Deep Sea Trench
in the deepest parts of the ocean; these are long, narrow depressions along the sea floor which are formed due to tectonic activity (the movement of the Earth’s lithosphere)
Volcanic Arc
a LONG chain of many volcanoes that forms above a SUBDUCTION ZONE.
Ring of Fire
a large area around the Pacific Ocean that has active earthquakes, volcanic eruptions and tectonic plate boundaries that fringe the Pacific Basin.
Subduction Zone
a convergent plate boundary where the Earth’s crusts meet and one expands underthe other because it’s denser.
Fold Mountains
mountains that are formed by two or more tectonic plates when they are pushed together by the Earth’s crusts.
Block Mountains
a mountain formed by natural faults in the Earth’s crust. A mountain formed when crustal plates move away from each other.
Plate Boundaries/Margins
the boundary of one of the plates that forms the upper layer (lithosphere) and together cover the surface of the Earth.
Two types of Layers That the Earth is Made of
Compositional (chemical) & Mechanical Layers
Three Mechanical Layers
Lithosphere - Asthenosphere - Mesosphere
Creator of Plate Tectonics Theory
Alfred Wegener
Pangea
a notion that around 335 millions years prior to now, there existed an ancient supercontinent based off the evidence of continental drift and fossil evidence.
Plate Tectonics Theory
a notion that the outermost mechanical layer (the lithosphere) or Earth’s crust is divided into many plates which shift across the earth’s surface
Evidence of the Plate Tectonics Theory
Our planet is always forming and reshaping itself from beneath ( magma rising )
The locations of earthquakes and volcanoes around the world follow a similar pattern to that of which Wegener theorised, an outline of the plates beneath us
Fossils of tropical species for example were found in less than tropical areas of the world, proving Wegener’s point of the world being one supercontinent at a time in prehistory.
Three Types of Plate Boundaries
Convergent
Divergent
Transform
Sima
The lower layer of the Earth’s crust, it is dense and heavy
Sial
Found on the upper part of the earth’s crust and is very light.
