Earth Science: FULL COURSE

Earth Science

An interdisciplinary field that studies Earth and its surroundings, combining geology, oceanography, meteorology, and astronomy.

Geology

Studies Earth's materials and its history.

Oceanography

Examines ocean water, movements, and marine life.

Meteorology

Investigates weather and climate.

Astronomy

Focuses on space and Earth's place in the universe.

Dynamic Earth

Earth is dynamic, with changes occurring slowly (e.g., erosion, plate tectonics) or rapidly (e.g., earthquakes, volcanic eruptions).

Closed System

Earth operates as a closed system, driven by solar and internal energy.

Hydrosphere

The sphere of water on Earth.

Atmosphere

The sphere of gases surrounding Earth.

Biosphere

The sphere of life on Earth.

Geosphere

The solid Earth.

Nebular Hypothesis

The theory that Earth formed ~4.5 billion years ago via the coalescence of dust and gas into planets.

Core

The innermost layer of Earth, consisting of inner solid and outer liquid iron.

Mantle

The layer of hot, flexible rock between the core and the crust.

Crust

The outermost layer of Earth, consisting of continental and oceanic layers.

Lithosphere

The rigid outer layer of Earth that floats on the semi-fluid asthenosphere.

Renewable Resources

Resources that can be replenished, such as solar and wind energy.

Non-Renewable Resources

Resources that cannot be replenished, such as fossil fuels and metals.

Scientific Method

A systematic approach used in Earth Science involving observation, hypothesis, experimentation, and analysis.

Earth Scientists

Professionals who study Earth, working in labs, offices, and the field.

Mineral

A naturally occurring, inorganic solid with a definite chemical composition and an orderly crystalline structure.

Five Key Characteristics of Minerals

1. Naturally occurring, 2. Inorganic, 3. Solid, 4. Crystalline structure, 5. Definite chemical composition.

Mohs Scale

A scale measuring hardness from 1 (talc) to 10 (diamond).

Silicates

The most abundant mineral group, built from the silicon-oxygen tetrahedron.

Non-Silicates

Less abundant but economically important minerals, including carbonates, sulfates, and halides.

Rock Cycle

Explains how Earth's rocks transform over time between three major types: igneous, sedimentary, and metamorphic.

Igneous Rocks

Formed from molten rock (magma or lava) that cools and solidifies.

Intrusive Rocks

Plutonic rocks that form below ground and cool slowly, resulting in large crystals (e.g., granite, gabbro, diorite).

Extrusive Rocks

Volcanic rocks that form at the surface and cool quickly, resulting in small or no crystals (e.g., basalt, rhyolite, andesite).

Phaneritic Texture

Coarse-grained texture indicating slow cooling of igneous rocks.

Aphanitic Texture

Fine-grained texture indicating fast cooling of igneous rocks.

Porphyritic Texture

Mixed grain sizes in igneous rocks indicating cooling at two rates.

Glassy Texture

Texture of igneous rocks that appears glassy (e.g., obsidian).

Vesicular Texture

Texture of igneous rocks that contains vesicles (e.g., pumice, scoria).

Felsic Composition

Light-colored, silica-rich composition of igneous rocks (e.g., granite).

Mafic Composition

Dark, iron/magnesium-rich composition of igneous rocks (e.g., basalt).

Ultramafic Composition

Very dark composition of igneous rocks, typically from mantle rocks.

Intermediate Composition

Composition of igneous rocks that is between felsic and mafic (e.g., andesite, diorite).

Sedimentary Rocks

Formed from sediment that compacts and cements over time (lithification).

Clastic Sediments

Broken fragments of other rocks (e.g., sandstone, shale).

Chemical Sediments

Sediments formed from dissolved materials precipitating out of water (e.g., rock salt, gypsum).

Organic Sediments

Sediments formed from remains of organisms (e.g., limestone, coal).

Metamorphic Rocks

Formed from existing rocks through heat and pressure.

Contact Metamorphism

Metamorphism that occurs from nearby magma heating rock.

Regional Metamorphism

Metamorphism that occurs from large-scale tectonic forces, such as mountain building.

Foliated Texture

Banded or layered texture in metamorphic rocks (e.g., slate, schist, gneiss).

Non-foliated Texture

Texture in metamorphic rocks that has no layers (e.g., marble, quartzite).

Weathering

Breaks down rock physically and chemically.

Erosion

Transports materials via water, wind, ice, or gravity.

Mass Wasting

Downhill movement of rock and soil due to gravity.

Drainage Basin

Land area contributing water to a river.

Streamflow Types

Laminar = smooth, straight paths; Turbulent = swirling, chaotic motion.

Sediment Transport

Movement of sediment in water, categorized into dissolved load, suspended load, and bed load.

Oxbow Lakes

Former meander loops cut off from the main stream.

Alluvial Fans

Cone-shaped deposits at canyon exits.

Floodplains

Flat areas near rivers, formed and shaped by flooding.

Natural Levees

Built-up ridges along riverbanks.

Deltas

Form where rivers deposit sediment into low-energy bodies of water.

Mississippi River Delta

An example of a delta.

Groundwater

Found in pore spaces in soil/rock, crucial for water supply.

Porosity

Water-holding capacity of soil/rock.

Permeability

Flow ability of water through soil/rock.

Aquifers

Water-bearing layers that allow flow.

Aquitards

Layers that block water flow.

Water table

Top of the saturated zone.

Springs

Natural flow at surface.

Wells

Extract groundwater; must reach saturation zone.

Artesian Wells

Self-pressurized flow from confined aquifers.

Caverns

Formed by the dissolution of rock, especially limestone.

Sinkholes

Depressions formed when the ground collapses.

Dripstones

Mineral formations that develop in caverns.

Stalactites

Dripstones that hang from the ceiling of a cavern.

Stalagmites

Dripstones that rise from the floor of a cavern.

Karst landscapes

Irregular terrain created by dissolution of soluble rocks.

Glaciers

Large, slow-moving ice masses that form over centuries from compacted snow.

Valley Glaciers

Glaciers found in mountainous regions that flow slowly through valleys.

Ice Sheets

Vast continental-scale glaciers found today in Greenland and Antarctica.

Zone of Fracture

Upper brittle layer of a glacier with dangerous cracks (crevasses).

Zone of Accumulation

Area where snow builds up and turns into ice.

Zone of Wastage

Area where glacier loses ice through melting or calving (icebergs break off).

Plastic flow

Movement of glaciers through internal sliding.

Basal slip

Movement of glaciers sliding over ground.

Budget

The balance between accumulation and wastage that determines if glaciers advance or retreat.

U-shaped Valleys

Valleys reshaped from original V-shaped river valleys by glacial erosion.

Cirques

Bowl-shaped erosional features created by glaciers.

Arêtes

Sharp ridges formed between cirques.

Horns

Sharp peaks formed between cirques.

Hanging Valleys

Smaller valleys perched above main glacial valleys.

Striations

Scratches caused by glacial abrasion.

Polish

Smoothing of rocks caused by glacial abrasion.

Till

Poorly sorted sediment left by melting glaciers.

Moraines

Ridges of till left by glaciers.

Outwash Plains

Sorted sediments from glacial meltwater.

Erratics

Large, misplaced boulders dropped by ice.

Kettles

Depressions left by melting ice blocks.

Kettle Lakes

Lakes formed in depressions left by melting ice blocks.

Loess

Fine windblown silt deposits.

Dunes

Mounds of sand with steep slip faces and cross-bedding from wind action.

Continental Drift

The theory that continents were once part of a supercontinent called Pangaea.

Pangaea

The supercontinent that existed approximately 200 million years ago.