Earth Science: Layers, Plate Tectonics, Weather, and Soil

What are the three main layers of the Earth?

Crust, Mantle, Core.

What drives tectonic plate movement?

Convection currents in the mantle.

What are the three types of plate boundaries?

Divergent, Convergent, Transform.

What forms at divergent boundaries?

Mid-ocean ridges, continental rifts, and new crust.

What forms at convergent boundaries?

Subduction zones, trenches, volcanoes, and mountains.

What forms at transform boundaries?

Strike-slip faults and earthquakes.

What is a hot spot?

A mantle plume pushing magma through the crust (e.g., Hawaii).

What causes earthquakes?

Sudden release of built-up pressure along faults.

What creates Earth's magnetic field?

Movement of liquid metal in the outer core.

What are the three rock types?

Igneous, Sedimentary, Metamorphic.

What is mechanical weathering?

Physical breakdown of rock without chemical change.

What is chemical weathering?

Breakdown of rock through chemical reactions like oxidation and hydrolysis.

What is sedimentation?

Deposition and accumulation of rock particles.

What is soil?

A mixture of minerals, organic matter, air, water, and organisms.

What is the ideal agricultural soil composition?

45% mineral, 25% air, 25% water, 5% organic matter.

What is humus?

Decomposed organic matter that enriches soil nutrients.

What is soil texture determined by?

Percentages of sand, silt, and clay.

What is loam?

Ideal mixture of sand, silt, and clay.

What is the O Horizon?

Organic layer with leaf litter and decomposers.

What is the A Horizon?

Topsoil with organic matter + minerals; most fertile.

What is the E Horizon?

Leached layer depleted of nutrients.

What is the B Horizon?

Subsoil rich in clay and minerals.

What is the C Horizon?

Weathered parent material.

What factors influence soil formation?

Parent material, climate, topography, biological activity, time.

What organisms improve soil fertility?

Bacteria, fungi, earthworms, and insects.

What is soil erosion?

Removal of soil by wind, water, or ice.

What are the major types of water erosion?

Sheet, rill, gully, stream bank.

What increases wind erosion?

Monoculture, removing windbreaks, overgrazing, exposed fields.

What is desertification?

Conversion of productive land into desert due to overuse.

Name three soil conservation methods.

Contour plowing, terracing, crop rotation.

What are the six soil quality management concepts?

Increase organic matter, reduce tillage, manage pests/nutrients, prevent compaction, keep ground covered, diversify crops.

What are the four main layers of Earth's atmosphere?

Troposphere, Stratosphere, Mesosphere, Thermosphere.

What occurs in the troposphere?

Weather and greenhouse gas activity.

What is the ozone layer's role?

Absorbs UV radiation.

What is the tropopause?

Boundary limiting mixing between troposphere and atmosphere above.

What drives atmospheric convection?

Uneven heating of Earth.

What is the Coriolis Effect?

Deflection of moving air due to Earth's rotation.

What direction do winds rotate in hemispheres?

Northern = clockwise; Southern = counterclockwise.

What are jet streams?

Fast upper-level winds influencing weather patterns.

What is the difference between weather and climate?

Weather is short-term; climate is long-term patterns.

What is a monsoon?

Seasonal wind shift causing wet/dry seasons.

What is a cold front?

Cold air pushing warm air upward, causing storms.

What is a warm front?

Warm air sliding over cool air, causing drizzle.

What powers hurricanes and cyclones?

Warm, moist air releasing latent heat.

What forms tornadoes?

Colliding warm/humid air with cold/dry air.

What is El Niño?

Warm water moves east, weakening trade winds; wetter U.S. South, warmer/drier North.

What is La Niña?

Stronger trade winds push cold water upward; U.S. is drier and storm tracks shift north.

What causes seasons?

Earth's axial tilt affecting solar angle.

What is albedo?

Reflectivity of a surface.

What are high-albedo surfaces?

Snow and ice (80-90%).

What is the solar constant?

~1,361 W/m² at top of atmosphere.

What is the greenhouse effect?

Atmospheric gases trap heat radiation, warming Earth.

What are the main greenhouse gases?

CO₂, methane, nitrous oxide, water vapor.

What human activities increase CO₂?

Burning fossil fuels and deforestation.