The science that deals with understanding earth’s structure is called geology
Earth's interior is characterizedby a gradual increase intemperature & pressure as itgets deeper
Crust
The thinnest and the outermost layer of the Earth
Oceanic Crust
Rocks of the oceanic crust as Sima which stands for silicate and magnesium, the most abundant minerals in oceanic crust
It makes up the seafloor. It's thinner, denser, and simpler in structure than the continental crust
It composed of dark, igneous rock called basalt
Continental Crust
Also called as Sial because its bulk composition is richer in aluminium silicates (Al-Si) and has a lower density compared to the oceanic crust
It is composed of granitic rocks, which have even more silicon and aluminum than the basaltic oceanic crust and are less dense than basalt
Subduction
When an oceanic plate converges with a continental plate, the oceanic crust will always subduct under the continental crust; because oceanic crust is naturally denser
Mantle
The mostly solid bulk of Earth's interior. The mantle lies between Earth's dense, super-heated core and its thin outer layer, the crust
Upper Mantle
It is mostly solid, but it's more malleable regions contribute to tectonic activity
Two parts are the lithosphere and the asthenosphere
The lithosphere includes both the crust and the brittle upper portion of the mantle. The lithosphere is both the coolest and the most rigid of Earth's layers
The asthenosphere is the denser, weaker layer beneath the lithospheric mantle
Lower Mantle
The lower mantle is hotter and denser than the upper mantle and transition zone
The lower mantle is much less ductile than the upper mantle and transition zone
Mantle convection
Transfers heat from the white-hot core to the brittle lithosphere. The mantle is heated from below, cooled from above, and its overall temperature decreases over long periods of time
Core
The very hot, very dense center of our planet. The ball-shaped core lies beneath the cool, brittle crust and the mostly solid mantle
Outer Core
It is mostly composed of liquid iron and nickel
The liquid metal of the outer core has very low viscosity, meaning it is easily deformed and malleable. It is the site of violent convection. The churning metal of the outer core creates and sustains Earth's magnetic field
Inner Core
It is a hot, dense ball of (mostly) iron
Its intense pressure—the entire rest of the planet and its atmosphere—prevents the iron from melting
Some geophysicists prefer to interpret the inner core not as a solid, but as a plasma behaving as a solid
It rotates a little differently than the rest of the planet. It rotates eastward, like the surface, but it's a little faster
Lithosphere
Sphere of rock. It includes the crust and uppermost mantle, 100 - 250 km thick
Asthenosphere
Lies beneath the lithosphere in the upper mantle, soft, comparatively weak layer
Mesosphere
Lies between 660 and 2900 km. It is more rigid layer
Continental Drift Theory
Earth's continents are came from a single large landmass
"Pangaea" means supercontinent or large landmass. It is also translated as "all Earth"
Proposed by Alfred Wegener
Panthalassa: a large and vast bodies of water that surrounds the supercontinent
As the supercontinent drift, it forms two great landmasses called "Eurasia" and "Gondwana"
Plates
Primary Plates - Pacific, North America, Eurasia, Africa, Indo-Australian, Antarctica, and South America
Secondary Plates - Caribbean, Cocos, Juan de Fuca, Nazca, Philippines Sea, Scotia
Tertiary Plates - microplates – very small in size and global presence
Asthenosphere
Solid upper mantle material that is so hot that it behaves plastically and can flow. Plays an important role in plate tectonics
Lithosphere
The outermost mechanical layer. Behaves as a brittle and rigid solid. Rides on the asthenosphere
Plate boundaries
Divergent (moving apart) - also known as constructive boundaries, often forms a mountainchain known as a ridge, forms as magma escapes into the space between the spreading tectonic plates, involves the process of spreading
Convergent (moving together) - also known as destructive boundaries. happens when one tectonic plate dives underneath the other. involves the process of subduction
Transform (moving side by side) - occurs when two plates slide past each other, it forms transform fault, involves the process of lateralsliding