Terrestrial Environments and Climate

Terrestrial Environments

• Earth's landscapes are categorized as terrestrial (on continents), marine (ocean floor), and transitional (shores).
• Marine environments cover most of Earth's surface.
• The study focuses on terrestrial environments.

Climate and Terrestrial Environments

• Temperature and Humidity:

  • The equator is hot and humid due to the equatorial low pressure.
  • Areas around 30° latitude are hot and arid due to subtropical highs.
  • Regions around 60° latitude are cold and humid due to subpolar lows.
  • Polar regions are cold and arid due to polar highs.

• Terrestrial Landscapes by Latitude:

  • The equator has tropical forests (Amazon, Congo, Indonesian rainforests).
  • Around 30° latitude, hot deserts exist (Sahara, Arabian, Gobi, Great Australian).
  • Northern hemisphere 60° latitude has boreal forests (taigas).
  • Poles are permafrost areas covered with continental ice sheets (Antarctica, Greenland).

• Progression of Terrestrial Landscapes (Humid to Arid):

  • Landscapes range from humid forests to arid deserts, passing through woodlands, shrublands, grasslands, and steppes.

• Landscape Progression by Latitude:

  • Transitions illustrate the effect of latitude on climate and landscape. For example, from equator to deserts, tropical environments change to hot steppes and deserts.

• Seasons:

  • Mid-latitudes experience summer (more direct sunlight) and winter (less direct sunlight).
  • Equatorial latitudes have a high-sun season and a low-sun season.
  • Polar latitudes have a daytime season and a nighttime season, each lasting for half the year.

• Shifting Climates: Climate factors like humidity and aridity shift with the Sun's apparent movement, influencing the boundaries between environments.

• Factors Affecting Climate: Latitude is a primary factor; ocean currents, continental effects, and orographic effects are secondary factors.

• Elevation and Latitude: Elevation changes on a mountain mimic the effect of latitude, showing a progression of landscapes from the base to the summit.

Geomorphology

• Definition: The study of how landscapes and environments change over time.
• Geomorphic Agents: Forces that reshape landscapes:
  • Most significant: Fluvial processes (running water).
  • Other agents: Wind, gravity, underground water, glaciers.
• Geomorphic Processes:
  • Degradation (weathering): Breaking down landscapes.
  • Erosion: Moving sediments.
  • Aggradation: Building new landscapes with sediments.

Weathering

• Mechanical Weathering: Breakdown without compositional changes.
  • Examples: Exfoliation, frost wedging, salt wedging.
• Chemical Weathering: Breakdown with compositional changes.
  • Examples: Carbonation, oxidation, hydrolysis.
• Acids and Bases: Different theories define acids and bases (Arrhenius, Brønsted-Lowry, Lewis). pH measures acidity or basicity.
• Biological Weathering: Breakdown by living organisms.
• Differential Weathering: Uneven breakdown of different landscape parts. Examples: Inselbergs, volcanic necks.

Soil Science

• Regolith: Layer of sediment covering Earth's surface.
• Soil: A specific regolith type vital for agriculture.
• Pedosphere: All soils; an intersection of the geosphere, hydrosphere, atmosphere, and biosphere.
• Soil Composition: Inorganic minerals, water, air, and organic material.
• Sediment Size (Wentworth Scale): Sediments are categorized by size.
• Soil Texture: Soil texture is determined by inorganic mineral components.
  • Coarse, fine, or intermediate (loam).
• Water in Soil: Forms of water in soil include free water, cohesive water, adhesive water, and combined water bound to soil.
• Soil Processes:
  • Eluviation: Degradation of one part of the soil.
  • Leaching: Erosion of degraded material.
  • Illuviation: Aggradation from leached material.
• Soil Horizons: Layers of soil resulting from eluviation, leaching, and illuviation.
  • Examples: O horizon, A horizon, B horizon, C horizon, and R horizon.
• Soil Productivity Factors:
  • Parent material (composition).
  • Climate (most important).
  • Topography (slope).
  • Bioturbation (soil mixing from life forms).
• Crop Rotation: Alternating crops to maintain soil health.
• Soil Taxonomy: Classification of soils into orders (Entisols, Andisols, etc.); the most agriculturally productive are Alfisols and Mollisols.

Mass Wasting

• Definition: Movement of material downhill due to gravity.
• Triggers: Heavy rain, snowmelt, earthquakes, fires, or steepened slopes.
• Angle of Repose: The maximum slope a given material can have without mass wasting.
• Types:
  • Falls (fastest).
  • Slides & Flows.
  • Creep/Solifluction (slowest).
• Other Terms: Avalanche, Lahar, Talus slopes, and Escarpments (steep cliffs).

Fluvial Processes

• Hydrologic Cycle: The continuous movement of water.
• Watercourses: Rills, brooks, creeks, streams, and rivers; tributaries feed larger watercourses.
• Drainage Patterns: Dendritic, radial, rectangular, trellis, and interior.
• Rivers:
  • Perennial rivers flow year-round.
  • Ephemeral rivers are temporary.
  • Watersheds/Drainage Basins, Drainage Divides, and Continental Divides.
• River Gradient: The vertical drop per horizontal distance decreases from the river head to mouth.
• River Discharge: The volume of water per unit time; typically increases from river head to mouth.
• River Load: Material (sediment) transported by a river.
  • Bed load, suspended load, and dissolved/solution load.
• River Competence & Capacity: The river's ability to transport different-sized and total amount of material.
• Longitudinal Profile: Graph illustrating river gradient.
• Base Level: The river's lowest point.
• Downcutting, Waterfalls & Rapids, and Lateral Profiles: Concepts related to river erosion and channel formation.
• Floodplain Protection: Natural features, like levees.
• Flood Control: Techniques such as artificial levees and channelization. A major cause of flood deaths are car accidents.

Groundwater Processes

• Groundwater: Water beneath the Earth's surface.
• Porosity & Permeability: Properties of rocks that affect groundwater flow.
• Phreatic & Vadose Zones: Zones of saturated (phreatic) and unsaturated (vadose) ground.
• Water Table: The boundary between the water-saturated zone and the unsaturated zone.
• Aquifers & Aquitards: Layers through which groundwater flows easily or not.
• Confined Aquifers: Aquifers trapped between layers.
• Karst Topography: Landscapes shaped by groundwater (caverns, sinkholes, springs).
• Speleology & Speleogenesis: The study of caverns and how they form.
• Speleothems (cave formations): Stalactites, stalagmites, and columns.

Aeolian Processes

• Aeolian Processes: The movement of land surfaces by wind.
• Desert Composition: Includes hamadas (solid rock), regs (gravel), and ergs (sand).
• Aeolian Landforms: Ventifacts, yardangs, and the degradation of plateaus to mesas to buttes.
• Aeolian Load: Bed load (sand) and suspended load (silt).
• Aeolian Aggradation: Loess and dunes.

Glaciology

• Cryosphere: All ice on Earth.
• Glaciers: Alpine (mountain) and continental (ice sheets).
• Ice Age: A period with widespread glaciation.
• Glacier Formation: Stages of ice formation.
• Glacial Anatomy: Parts of a glacier. Example: Zone of Accumulation and Zone of Wastage.
• Glacial Movement: Advancing, retreating, and stationary.
• Glacial Weathering: Abrasion and plucking.
• Glacial Aggradation: Till and stratified drift.
• Moraines: Sediment deposits from glaciers (lateral, medial, end, and ground moraines).
• Post-Glacial Features: Tarns (glacial lakes) and paternoster lakes.
• Glacial landforms: V-shaped valleys becoming U-shaped valleys, Fjords, Arêtes, and Glacial Horns.

Explore the characteristics and climates of various terrestrial environments across different latitudes. This quiz covers the unique landscapes such as tropical forests, deserts, boreal forests, and polar regions. Test your knowledge on how temperature and humidity influence these environments.