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Geography: free practice, theory and problems
Maps are simplified pictures of reality. Geographers use maps, coordinates and digital tools (GIS) to find patterns, for example where people live or where floods may occur.
Contents
- Maps and geographic tools
- Earth's interior and plate tectonics
- Climate and weather
- Population and migration
- Natural hazards and resources
1. Maps and geographic tools
What is it about?
Maps are simplified pictures of reality. Geographers use maps, coordinates and digital tools (GIS) to find patterns, for example where people live or where floods may occur.
Concepts and formulas
- Scale: the ratio between distance on the map and in reality. 1 : 50,000 means 1 cm = 500 m.
- Latitudes run east–west and measure distance north/south of the equator (0° to 90°).
- Longitudes run north–south and measure east/west of the prime meridian through Greenwich (0° to 180°).
- Map projection: Earth is round, the map is flat. Every projection distorts something. Mercator makes land near the poles far too big.
- Contour lines show height. Close contours = steep terrain.
- GIS (geographic information systems): maps in layers with data, such as population, flood zones and roads.
- Time zones: Earth rotates 360° in 24 hours, i.e. 15° per hour.
Example
Oslo lies at about 60° north and 11° east. Further north, the Arctic Circle crosses Norway at about 66.5° north.
2. Earth's interior and plate tectonics
What is it about?
Earth's crust is divided into large plates floating on the viscous material beneath. Where plates meet, we get earthquakes, volcanoes and mountain ranges.
Concepts and formulas
- Earth's layers: crust, mantle, outer core (liquid) and inner core (solid).
- Divergent boundary: plates move apart. New seafloor forms, as along the Mid-Atlantic Ridge (Iceland).
- Convergent boundary: plates push together. The heavier one dives down (subduction), forming volcanoes and deep trenches. Continent against continent gives high mountains, like the Himalayas.
- Transform boundary: plates slide sideways past each other, like the San Andreas Fault in California.
- Earthquakes are measured on the moment magnitude scale. Each step means about 32 times more energy.
- The Caledonian mountain range, of which Norway's mountains are remnants, formed around 400 million years ago.
Example
Iceland lies on a divergent boundary. The island grows a few centimetres a year because the North American and Eurasian plates are moving apart.
3. Climate and weather
What is it about?
The Sun heats Earth unevenly: most at the equator, least at the poles. The differences drive winds and ocean currents and create different climate zones.
Concepts and formulas
- Climate zones: tropical (warm all year), subtropical, temperate (clear seasons, as in Norway) and polar.
- The Gulf Stream (the North Atlantic Current) carries warm water north and makes Norway much milder than other places at the same latitude.
- Types of precipitation: orographic (air forced up over mountains, typical of western Norway), frontal (warm and cold air meet) and convective (warm air rises, giving showers and thunder).
- Low pressure often brings clouds and rain. High pressure often brings fine, stable weather.
- The lee side of a mountain is drier than the windward side (rain shadow).
- Climate graphs show temperature (line) and precipitation (bars) through the year.
Example
Bergen gets over 2000 mm of precipitation a year because moist air from the sea is forced up over the mountains. East of the mountains, in the rain shadow, it is much drier.
4. Population and migration
What is it about?
Earth has over 8 billion people. The population grows fast in some countries and shrinks in others. Geography explains why, and why people move.
Concepts and formulas
- Birth rate and death rate: the number of births and deaths per 1000 inhabitants per year.
- Natural increase = birth rate − death rate.
- The demographic transition model: countries go from high birth and death rates (stage 1) via a falling death rate (rapid growth) to low rates (stages 4–5).
- Population pyramid: shows the age distribution. A wide base = many children (young population). A narrow base = ageing population.
- Migration: push factors (war, poverty, climate) drive people away. Pull factors (jobs, safety, family) draw them to a place.
- Urbanisation: more and more people live in cities. Over half of the world's population now lives in cities.
Example
A birth rate of 12 and a death rate of 8 give a natural increase of 4 per thousand, i.e. 0.4 % a year.
5. Natural hazards and resources
What is it about?
People live off natural resources, but nature can also be dangerous: landslides, floods, storms and drought. Climate change makes many of these hazards greater.
Concepts and formulas
- Renewable resources (water, forest, fish) can be renewed if they are not overexploited. Non-renewable ones (oil, gas, minerals) run out.
- Landslides in Norway: rockfalls, avalanches, clay slides (quick clay) and debris flows.
- Quick clay is marine clay that can liquefy when disturbed, as at Gjerdrum in 2020.
- Floods often come with snowmelt or heavy rain. Asphalt and sealed surfaces increase runoff.
- Vulnerability: how hard a hazard hits depends on how many live there, buildings, preparedness and wealth.
- The resource curse: countries rich in natural resources can end up with weaker economies. Norway avoided this partly through its sovereign wealth fund.
Example
An earthquake of the same strength can kill many more people in a poor country than in a rich one, because buildings are weaker and preparedness poorer.
Example problems with solutions
Here are some of the problems in geography. In the app, calculation problems get new numbers every time, so you can practise until it sticks – and take a graded practice exam before the real one.
Maps and geographic tools: What does latitude measure?
Answer: Distance north or south of the equator
From 0° at the equator to 90° at the poles.
Earth's interior and plate tectonics: What type of plate boundary is Iceland on?
Answer: Divergent
The plates move apart along the Mid-Atlantic Ridge.
Climate and weather: Why is Norway milder than other places at the same latitude?
Answer: The Gulf Stream carries warm water north
The North Atlantic Current gives mild coastal winters.
Population and migration: Birth rate 30 and death rate 10 per 1000. What is the natural increase in percent?
Answer: 2 %
per thousand = 2 %.