Mountain are called- ridges
Valley are call- depression and tranches
Lithosphere- the solid outer part of earth
In 1912, Alfred Wegener, a German meteorologist put forward a theory know as continental drift.
Alfred Wegener theory- millions of years of years ago the continent that we know were joined together
into a super continent called Pangea. And Pangea formed about 299 million years ago and over time it
split into smaller land messes
Evidence supported his theory- Similar animal fossils and rock type, mountain ranges and matching
fossil remains were found on different continents. (ice ae at the same time)
Mountain belts ocean trenches/ ridges, volcanoes, earthquake mostly form along tectonic plate
Boundaries.
Lithosphere refers to the Solid (rigid) part of Crust Mantle.
The edges of tectonic plates are called “Tectonic Plate boundaries “
Tectonic Plates- are large, broken sections of (lithosphere) which is made up of solid part of Crust and
Upper Mantle
Tectonic Plates (Lithosphere Plates): Large sections of lithosphere (Solid part of crust and Mantle)
Tectonic Plate Boundaries: Where the tectonic plates meet
Destructive (Convergent) Plate Boundaries- Two plates move toward each other ---> has (3) different
types.
Type 1) Oceanic vs Continental plates – IF one plate is oceanic and other continental, the heavier
oceanic goes down, pushing continental plate up--> earthquakes, volcanoes, mountains, ocean trenches.
Type 2) Continental vs Continental Plates- If both plates are continental, they both go up, creating fold
mountains --> earthquakes, but No volcanoes.
Type 3) Oceanic vs Oceanic plates ---> if both plates are oceanic, the older plate subducts (goes down)
under the younger plate ---> earthquakes, volcanic eruption
Constructive (Divergent) Plate Boundaries- Two plate move apart each other --> magma rises,
constructing new land (Ice land on Mid-Atlantic Ridge)
At these boundaries you will get volcanic eruptions and earthquakes.
Conservative (transform) boundaries- Two plates slow move toward each other. Friction causes the two
plates to stick together and pressure builds up. When the Friction is over come, the sudden movement
at the boundary creates a severe earthquake As crust is neither created nor destroyed. There is no
volcanoes at theses boundaries
Convection Currents: Process by which heat is transferred in fluid like air or water up and down.
Why do Tectonic plates move?(2 theories- Convection heat currents, Slab pull Ridge push with Gravity)
Earth internal heat creates Convection currents in the mantle transferring heat, which rises and cools
back down in a circular motion which move tectonic plates above.
Slab Pull//Ridge push
Plates are extremely heavy so gravity acts upon them pulling them apart. (older(denser) part of the
plate goes down the rest follows due to gravity.
A fault/Fault line= Plate boundaries where two tectonic plates pass each other.
Seismic Waves= Wavs of energy causes by earthquakes/ measured in Magnitude (0-10)(9.5 highest)
Shock From an earthquake= Foreshocks(before) ---> Mainshock(during) ---> Aftershock(after)
Earthquake In Nepal 2015 (Magnitude 7.8) 9000 dead 22000 inured, 75% of city damaged, avalanche on
Mount Everest.
High income countries – Strict building codes(laws) ---> safter building materials
Make earthquake resistant buildings
Urbanization controlled
Citizens are more prepared and educated.
Fact about Unit (11.2, 11.3)
Theory -often have evidence
Us navy find out ocean floor is not flat during WW II when they were mapping ocean floor.
Mid-Ocean-Ranges – (mountain ranges on ocean floor)
Mountain Belt- (Very long mountain ranges)