Understanding Earth's Internal Energy and Plate Tectonics

Energy Flow

Energy moves upward and outward from Earth's interior.

Earthquakes

Natural disasters caused by energy release.

Volcanic Eruptions

Release of energy from Earth's interior.

Plate Tectonics

Movement of Earth's plates causing geological activity.

Solar System Formation

Formation through collisions in a rotating gas cloud.

Immanuel Kant

Proposed Solar System origin hypothesis in 1755.

Rotating Cloud

Initial spherical cloud of gas and dust.

Gravitational Attraction

Force pulling particles together in the cloud.

Nuclear Fusion

Process where hydrogen fuses to form helium.

Solar Radiation

Energy from the Sun felt as sunshine.

Inner Planets

Mercury, Venus, Earth, Mars; rocky due to solar radiation.

Outer Planets

Jupiter, Saturn, Uranus, Neptune; icy bodies.

Impact Origin of the Moon

Hypothesis of Moon's formation from Earth's impact.

Mars-Size Body

Impacting body that formed the Moon.

Earth's Rocky Mantle

Material primarily composing the Moon.

Lesser Iron Abundance

Moon has less iron than Earth.

Dynamic Planet

Earth recycles rocks, obscuring early history.

Rock Recycling

Process that removes Earth's early geological record.

Mass Accumulation

Matter gathers in the center of the disk.

Flattened Disk

Shape formed as rotating mass contracts.

Temperature Increase

Central mass's heat reached about 1,000,000 °C.

Volatile Elements

Gases lost from inner planets due to heat.

Collisions and Fusions

Mechanism for planet formation in the Solar System.

Early Earth

Formed from particles and gases 4.6 billion years ago.

Aggregation Period

Lasted 30 to 100 million years during formation.

Metal-rich Particles

Similar to iron-rich meteorites, contributed to Earth.

Stony Meteorites

Rocks similar to those forming Earth's mantle.

Ices

Composed of water, CO2, and other compounds.

Gravitational Force

Pulled metallic materials toward Earth's center.

Homogeneous Mixture

Initial random collisions created a uniform material.

Planet Formation Heat

Generated from impact energy and radioactive decay.

Impact Energy

Heat from collisions during early Earth formation.

Radioactive Decay

Decay of isotopes contributed to internal heating.

Gravitational Energy

Energy released during material differentiation.

Differentiation

Process that created Earth's layered structure.

Iron Melting Point

Iron melts below 1,000°C (1,800°F) under pressure.

Core Formation

Iron-rich core formed from melted meteorites.

Liquid Iron

High-density liquid pulled to form Earth's core.

Gravitational Energy Release

Increased heat from iron moving inward.

Primitive Crust

Low-density rocks formed on Earth's surface.

Oceans Formation

Large bodies of water formed from melting.

Atmosphere Formation

Denser gases accumulated to create Earth's atmosphere.

Density-Stratified Mass

Earth's materials arranged by density from core outward.

Photosynthetic Bacteria

Life present 3.5 billion years ago.

Plate Tectonics Activity

Outer layers active at least 1.5 billion years ago.

Earth's Core Size

Core diameter approximately 7,000 km (4,350 mi).

Inner Core

Solid mass with diameter 2,450 km (1,520 mi).

Outer Core

Liquid layer generating Earth's magnetic field.

Mantle Composition

Similar to stony meteorites, 2,900 km thick.

Mantle Volume

Comprises 83% of Earth's volume.

Mantle

Layer between crust and outer core, mostly solid.

Lithosphere

Rigid outer layer of Earth, includes crust.

Asthenosphere

Soft plastic layer beneath lithosphere, allows flow.

Mesosphere

Stiff plastic layer below asthenosphere, solid.

Outer Core

Liquid layer surrounding Earth's inner core.

Crust

Earth's outermost layer, low-density rock.

Hydrosphere

All liquid water on Earth's surface.

Atmosphere

Layer of gases surrounding Earth.

Density Stratification

Lower-density materials float above higher-density materials.

Temperature Increase

Causes rock to expand and become less dense.

Pressure Increase

Causes rock to compress and become more rigid.

Continental Crust

Low-density rock layer, floats above mantle.

Oceanic Crust

Denser rock layer beneath oceans.

Geological Time Metaphor

Earth's history compared to a 46-year-old woman.

Earth's Age

4.6 billion years, significant geological events recent.

Earthquake Causes

Differences in material behavior during stress.

Volcano Causes

Material behavior changes lead to eruptions.

Fluid States

Gases and liquids can flow; solids cannot.

Gas Definition

Substance capable of indefinite expansion.

Liquid Definition

Substance with definite volume but no shape.

Rock Behavior

Changes with temperature and pressure variations.

Low-Density Elements

Rise to form continental crust from mantle.

Earth's Volume

Continents constitute only 0.1% of Earth's volume.

Solid

Firm material resisting pressure, not easily changing shape.

Continental Crust

Lower-density crust above the Earth's mantle.

Lithosphere

Rigid outer layer of Earth, includes crust and upper mantle.

Asthenosphere

Soft plastic layer beneath the lithosphere.

Isostatic Adjustment

Land rebounding after weight removal, like ice sheets.

Glacier

Mass of ice flowing under its own weight.

Ice Sheet

Thick glacier covering large land areas, e.g., Antarctica.

Isostatic Downwarping

Land sinking due to weight, like Lake Mead's water.

Negative Anomaly

Gravity measurement indicating less mass than expected.

Uplift

Vertical rise of land after weight removal.

Earthquake

Sudden ground rupture due to stress release.

Rupture

Break in Earth's surface from tectonic stress.

Vertical Movement

Upward or downward shifts of Earth's crust.

Horizontal Movement

Lateral shifts between lithosphere and asthenosphere.

Depth Measurement

Distance below sea level, e.g., Antarctica's 4,470 m.

Thickness of Ice Mass

Ice depth causing land subsidence, e.g., 100 m causes 27.5 m sink.

Rebounding Landmass

Land rising after ice sheet melts.

Viking Ship Discovery

Evidence of land uplift in Stockholm, Sweden.

Earth's Surface Balance

Delicate equilibrium of vertical land movements.

Ground Ruptures

Surface breaks from tectonic activity, can be extensive.

Antarctica's Depression

Land below sea level due to thick ice cover.

Geologic Past

Historical changes in Earth's structure and surface.

Long-term Pressure Yielding

Solids deforming over time under constant pressure.

Impact Energy

Heat generated from colliding celestial bodies.

Gravitational Energy

Heat produced by Earth's gravitational compression.

Radioactive Isotopes

Unstable isotopes releasing energy during decay.

Decay Process

Transformation of radioactive isotopes into stable products.