What is latitude? — Horizontal lines (parallels) measuring distance north or south of the Equator in degrees (0°–90°). The Equator is 0°. The North Pole is 90°N and South Pole is 90°S.

What is longitude? — Vertical lines (meridians) measuring distance east or west of the Prime Meridian in degrees (0°–180°). The Prime Meridian (0°) runs through Greenwich, London.

What is the Prime Meridian? — The 0° line of longitude running through the Royal Observatory, Greenwich, London. Divides Earth into Eastern and Western hemispheres. Used as the reference point for all longitude measurements and time zones.

What is the International Date Line? — The 180° meridian — on the opposite side of Earth from the Prime Meridian. Crossing it eastward subtracts one day; westward adds one day. It zigzags to avoid splitting countries.

What are the major lines of latitude? — Equator: 0°. Tropic of Cancer: 23.5°N (Sun overhead at June solstice). Tropic of Capricorn: 23.5°S (Sun overhead at December solstice). Arctic Circle: 66.5°N. Antarctic Circle: 66.5°S.

What is a 4-figure grid reference? — Used to identify a 1 km² grid square on an OS map. Read eastings first (along the corridor/bottom), then northings (up the stairs/side). Example: grid ref 3452 = easting 34, northing 52.

What is a 6-figure grid reference? — Used to identify a 100 m × 100 m point within a grid square. Divide the square into 10 equal parts mentally. Add a third digit to easting and northing. Example: 342521 = easting 34.2, northing 52.1.

What are contour lines on a map? — Lines on a map connecting points of equal elevation above sea level. Close together = steep slope. Far apart = gentle slope. Circular/concentric = hill or valley. V-shapes pointing uphill = valley. V-shapes pointing downhill = ridge/spur.

What is map scale? — The ratio between a distance on the map and the corresponding distance in reality. 1:25,000 means 1 cm on map = 25,000 cm (250 m) on the ground. 1:50,000 means 1 cm = 500 m. Larger scale = more detail.

How do you calculate real distance from a map? — Measure distance on map (cm) × scale denominator = real distance (cm). Convert to km by dividing by 100,000. Example: 3 cm on a 1:50,000 map = 3 × 50,000 = 150,000 cm = 1.5 km.

What is the Mercator projection and its limitations? — A cylindrical map projection that preserves shape and direction — useful for navigation. Limitation: Distorts size at high latitudes. Greenland appears similar in size to Africa, but Africa is ~14× larger.

What is the Peters (Gall-Peters) projection? — An equal-area projection that shows countries in correct proportion by area. Limitation: Distorts shape — countries appear stretched or compressed. Challenged the Eurocentric bias of the Mercator.

What is GIS (Geographic Information System)? — A computer system for capturing, storing, analyzing, and displaying spatially referenced data. Layers different data types (roads, population, elevation) on a map. Used in urban planning, disaster response, and environmental monitoring.

What is the difference between relief and topography? — Relief: The difference in elevation between high and low points in an area (the degree of "roughness"). Topography: The overall shape and physical features of the land, including hills, valleys, rivers, and plains.

What is the bearing of a direction? — A compass direction expressed as a three-digit number clockwise from north. North = 000°. East = 090°. South = 180°. West = 270°. Example: "Travel on a bearing of 045°" means northeast.

What is remote sensing in geography? — Collecting information about Earth's surface from a distance — typically using satellites or aircraft. Used to monitor deforestation, sea ice, flooding, urban growth, and weather. Examples: Landsat, Google Earth.

What is the difference between GPS and GIS? — GPS (Global Positioning System): A satellite navigation system that determines your exact location (latitude, longitude, elevation) using signals from satellites. GIS: A software system for analyzing and visualizing spatial/geographic data. GPS provides data; GIS processes it.

What are OS map symbols for key features? — Blue: Water (rivers, lakes). Green: Woodland/forests. Black: Roads, railways, buildings. Brown: Contour lines. Red: Major roads. Church with tower: ⊤. Campsite: △. Youth hostel: △.

What is a choropleth map? — A thematic map using shading, colors, or patterns to show how a variable (e.g., population density, GDP per capita) varies across geographic areas. Darker shading usually = higher values.

What is the difference between map and atlas? — Map: A diagrammatic representation of an area showing features, boundaries, and spatial relationships. Atlas: A collection of maps, often with thematic, political, and physical maps of the world or regions, with additional statistics.