EALS - Lesson 3

subsystems

Earth as a system is composed of numerous interacting parts or ___

Earth Subsystem

The physical environment of our Earth is traditionally divided into three major spheres: the water portion (the hydrosphere), the gaseous envelope (the atmosphere), and the solid part (the geosphere).

Hydrosphere

a dynamic mass of water that is continuously moving, evaporating from the oceans to the atmosphere, precipitating to the land, and returning to the ocean.

Atmosphere

It is the layer of gases that surround the Earth. It provides us with air that we breathe. It also protects us from the sun’s dangerous ultraviolet radiation.

change

“Tropos”

Troposphere

This layer is closest to the sun.

tropopause

boundary between Stratosphere and Troposphere

layer

“Strat”

stratosphere

This layer contains a thin layer of Ozone O3 molecules which forms a protective layer and absorbs harmful ultraviolet (UV) radiation from the Sun.

stratopause

transition boundary which separates mesosphere to the stratosphere

middle

“Meso”

mesosphere

It has fewer air molecules that absorb electromagnetic radiation from the Sun. Most meteors burn up in this atmospheric layer.

hot

“Thermo”

thermosphere

The thickest layer in the atmosphere Only the lightest gases—mostly oxygen, helium and hydrogen are found here.

mesopause

boundary between the mesosphere and thermosphere. It is the coldest part of Earth’s atmosphere

outside

“Exo”

exosphere

it is the outermost layer of Earth’s atmosphere. Atoms and molecules escape into space

thermopause

boundary between the thermosphere and exosphere

geosphere

It is the solid part of the Earth that consists of all rock and the soils and sediments on the Earth’s surface.

biosphere

It contains all life, including plants, animals, and other organisms in water and air. It is composed of living organisms and nonliving factors.

biotic and abiotic

other term for living organisms and nonliving factors

the crust, mantle, and core.

Earth’s compositional differences resulted in the formation of three layers

crust

It is the thin, topmost layer of the Earth.

Sial and Sima

two layers of crust

Silicon and Aluminum

elements found in sial (uppermost layer)

Silicon and Magnesium

elements found in sima (lower crust)

continental and oceanic

two types of crust

continental crust

averages about 35 km thick and exceeds 70km in mountainous regions. It consists of granite.

oceanic crust

roughly 7 km thick and composed of dark igneous rock basalt.

mantle

Has the 84% of Earth’s total volume. It is made of 45% silicon, 22% oxygen, and 23% magnesium. - Iron, aluminum, calcium, sodium, and potassium make up the remaining parts.

Mohorovicic discontinuity or “Moho”

boundary between the crust and the mantle

Andrija Mohorovocic

he is a croatian scientist, that discovered Mohorovicic discontinuity in 1909.

core

The composition of the ___ is an iron-nickel alloy with minor amounts of oxygen, silicon, and sulfur elements

Gutenberg Discontinuity

boundary between Mantle and core.

outer core

Liquid layer 2,200 km thick. It is the movement of this zone that generates of Earth’s magnetic field.

inner core

a sphere with a radius about 1250 - The iron in the core is solid due to the immense pressures that exist in the center of the planet.

Lehmann Discontinuity

boundary between the solid inner core and the liquid outer core