Junior Cycle Geography Summary and Quizzes

Earth's Layers: Consists of the Crust (outer shell), Mantle (semi-molten magma), Outer Core (liquid), and Inner Core (solid iron and nickel).
Continental Drift: Theory proposed by Alfred Wegener stating that continents were once a single landmass called Pangaea.
Convection Currents: Heat from the core causes magma to rise and sink in the mantle, moving the tectonic plates above.
Plate Boundaries: * Destructive (Convergent): Plates collide (e.g., Nazca and South American plates). Forms mountains and volcanoes. * Constructive (Divergent): Plates pull apart (e.g., Mid-Atlantic Ridge). Magma rises to create new crust. * Passive (Transform): Plates slide past each other (e.g., San Andreas Fault). Causes earthquakes.

Volcano Status: Active (erupts regularly), Dormant (hasn't erupted in a long time but could), Extinct (will never erupt again).
Volcano Features: Vent, Conduit (pipe), Magma Chamber, and Crater.
Earthquake Terms: * Focus: The point deep underground where the earthquake starts. * Epicentre: The point on the surface directly above the focus. * Seismograph: Instrument used to measure tremors. * Richter Scale: Measures the magnitude (strength) of the earthquake from $1$ to $10$ .

Igneous Rocks: Formed from cooled magma/lava. Examples: Granite (plutonic) and Basalt (volcanic).
Sedimentary Rocks: Formed from layers of sediment compressed over millions of years. Examples: Limestone (organic) and Sandstone.
Metamorphic Rocks: Formed when existing rocks are changed by great heat or pressure. Examples: Marble (from Limestone) and Quartzite (from Sandstone).

Course of a River: Upper (Youthful), Middle (Mature), and Lower (Old Age).
Erosion Processes: * Hydraulic Action: The force of moving water. * Abrasion: Stones striking the river bed and banks. * Attrition: Stones colliding and breaking into smaller, smoother pieces. * Solution: Water dissolving certain minerals (e.g., limestone).
Landforms: * Upper Stage: $V-shaped$ valleys, waterfalls. * Middle Stage: Meanders (curves), ox-bow lakes. * Lower Stage: Floodplains, deltas, levees.

Factors affecting Climate: Latitude, distance from sea, prevailing winds, and altitude.
Weather Instruments: * Anemometer: Measures wind speed in $km/h$ . * Wind Vane: Measures wind direction. * Hygrometer: Measures humidity. * Stevenson Screen: White box used to store instruments like thermometers away from direct sunlight.