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🌊 GLG 120 – Quiz 11 Study Guide

Ocean Currents & Circulation

  • Surface ocean currents are driven by wind, the Coriolis Effect, and are deflected by continents.

  • Ekman Spiral: Wind + Coriolis Effect + friction cause surface water to move at ~90° from the wind direction; deeper layers spiral.

  • Ocean gyres: Large circular systems of surface currents powered by wind; transfer warm water poleward and cold water equatorward; regulate climate.

Wave Action & Coastal Processes

  • Wave refraction: Waves bend around headlands, concentrating energy and causing erosion.

  • Headlands erode over time, forming features like sea stacks and arches.

  • Longshore currents: Flow parallel to shore, move sediment—create spits and barrier islands.

  • Breakers form as waves slow and steepen near shore (wave base meets bottom).

Coastal Features

  • Erosional: sea stacks, marine terraces, headlands.

  • Depositional: beaches, spits, barrier islands.

  • Submergent coasts: due to rising sea level; often have barrier islands/spits.

  • Emergent coasts: due to land uplift; terraces and wave-cut platforms form.

Tides

  • Caused mostly by the Moon's gravity.

  • Spring tides: Large tidal range (Sun + Moon aligned).

  • Neap tides: Small tidal range (Sun + Moon at 90°).

Waves

  • Wavelength: distance between two wave crests.

  • Wave base: depth where water movement caused by a wave stops (~½ wavelength).

Beach Sediment

  • Dynamic—constantly moved by waves, currents, and storms.

  • Structures like jetties, groins, seawalls, and breakwaters are human-made to manage sediment and protect coastlines.

Atmosphere & Weather vs. Climate

  • Weather: short-term atmospheric conditions (days).

  • Climate: long-term trends (decades+).

Atmospheric Layers

  • Troposphere: weather occurs here.

  • Stratosphere: contains ozone layer.

  • Mesosphere & Thermosphere: higher layers.

  • Magnetosphere: contains Van Allen belts (not ozone or greenhouse gases).

Ozone Layer

  • Found in the stratosphere.

  • Blocks UV radiation (not infrared).

  • Most depletion occurs at the poles, not the equator.

Lapse Rate

  • Standard lapse rate: 6.5°C drop per 1,000 meters.

  • Use for calculating temperature changes with elevation.

Seasons & Solar Position

  • Tropic of Cancer + Sun overhead = Northern Hemisphere summer (around June 21).

  • Equator + Sun overhead on Sept 21 = start of fall in Northern Hemisphere.

Heat Transfer

  • Conduction: direct contact.

  • Convection: fluid movement (liquids/gases).

  • Radiation: electromagnetic waves (no medium required).

Radiation & Earth's Energy Budget

  • Hotter objects emit shorter wavelength radiation.

  • Good absorbers = good emitters.

  • Earth absorbs most incoming solar radiation (especially at surface).

  • Albedo: % of radiation reflected. Higher albedo = more reflection.

Greenhouse Effect

  • Caused by CO₂, H₂O vapor, CH₄.

  • Traps longwave (infrared) radiation.

  • Enhanced by fossil fuels and some natural sources (e.g., volcanoes).