Dynamic Earth: Chapter 1

Topography

Arrangement of land surfaces + landscape (Ex: mountains)

Earth’s layer organization

Layers are organized based on desnity (m/v=D) Crust, Mantle, Liquid Core, Solid Core

Continental Crust

Less dense, thicker, higher elevation

Oceanic Crust

Denser, thinner, smaller elevations (by comparison to land mountains)

Core Composition

Primarily Iron

Mantle + Crust Composition

Primarily oxygen, silicon, calcium, magnesium and aluminum

Minerals found in upper layers of the Earth

Silicate minerals (Ex: Quartz)

99% of Earth’s Mass

8 Elements (Sulfur, Nickel, Oxygen, Silicon, Iron, Magnesium, Calcium, and Aluminum)

90% of Earth’s Mass consists of

4 elements (Iron, oxygen, silicon, and magnesium)

Dynamic Planet

A planet with constant changes both internally and externally (Volcanoes, hurricanes, earthquakes, glacial cycles, landscape changes, etc.)

Earth’s Patterns are influenced by internal and external energy sources

The Sun (external) and Earth’s inner heat engine (powered by trapped heat at Earth’s origin and internal radioactive decay)

Solar Energy

Responsible for influencing our climate + weather patterns and in driving processes in the atmosphere, hydrosphere, and biosphere + development of landforms.

Release of Heat

Balances the input of the Sun’s energy and the Earth’s internal heat engine

Meteors

When mass + minerals from outer space enter and burn up in Earth’s Mesosphere

Internal Heat Generation

Remaining heat from Earth’s formation + natural decay of radioactive minerals (Ex: uranium)

Convection

Transfer of heat through the movement of heated liquids/gases

Subduction

Sinking of cooler + denser rock into the Earth’s mantle under another piece of hotter, less dense rock

Convection of Earth’s Mantle

Plate tectonics + continental movement

Electrical Fields

Convection of electrically conductive, molten iron core induces electrical fields

Purpose of Electrical Fields

As long as convection of molten core continues the electrical field will continue to deflect harmful charged particles from solar wind that originates from the sun

Undulations

Continuous rise/fall or smooth wave-like motion (movement of electrical fields)

Magnetic Disturbances

Ripples in the ionosphere can generate disturbances (particularly powerful geomagnetic storms - sun expels large amounts of charged particles that are funneled to the poles)

Solar Wind

Ionized gases blown towards Earth at 400km/s (varies in intensity based on the sun’s surface activity and rate of hydrogen-based nuclear fusion)

Hydrological Cycle

Movement of water on, above, and below Earth (powered by energy from the sun + gravity)

Internal + External energy systems are linked

Plate tectonics move - form mountains - affect the climate

Geodynamo

Interaction between inner + outer core that maintains and creates the magnetic field (occurs deep inside the planet)

Troposphere (0-12km)

Weather happens here (temp decreases w/ height)

Stratosphere (12-50km)

Ozone layer that protects us from harmful UV rays

Mesosphere (50-85km)

Coldest layer, meteors burn up here

Thermosphere (85-600km)

Very hot, auroras + satellites here

Exosphere (600-10,000km)

Outermost layer, merges into open space

Atmosphere

Composed of gases, held by gravity (creates breathable air) [weather & UV protection)

Hydrosphere

All water on Earth, their cycles and influences

Biosphere

Global zone containing all living organisms

Asthenosphere

Weak, flexible, and semi-fluid layer of Earth’s upper mantle (right below the rigid lithosphere)

Lithosphere

Upper 100km, “rigid skin”, includes the crust & upper mantle

Subduction Zones

Region where the denser (cooler) plate sinks below the less dense (hotter) plate

Continental Collision

When the lithosphere disappears far beneath the mantle, it causes continental crust to collide forming things like mountains