Key Concepts in Earth Science, Culture, and Global Politics
Fundamental Concepts and Definitions
Physical Geography and Earth Science
Geography
The study of the distribution and interaction of physical and human features on the Earth’s surface.
Topography
The combined characteristics of landforms and their distribution in a region.
Relief
The difference in elevation between the highest and lowest points in a specific area.
Uplands
Areas of high elevation, often characterized by very low mountains or hills.
Continental Divide
A line that separates river systems flowing eastward from those flowing westward.
Drainage Basin
An area drained by a major river and its tributaries.
Runoff
Rainfall or melted snow that is not absorbed by the soil and flows over the surface.
Biodiversity
The variety of organisms within an ecosystem.
Humus
Dark, organic material in soil formed from decomposed plant and animal matter.
Loess
Wind-blown silt and clay deposits that result in very fertile soil.
Atmosphere
The layer of gases surrounding the Earth.
Hydrosphere
All the water comprising the Earth’s surface.
Biosphere
The part of the Earth where plants and animals live.
Lithosphere
The solid rock portion of the Earth, including the crust and upper mantle.
Core
The Earth’s center, primarily composed of iron and nickel.
Mantle
A thick rock layer about 1,800 miles thick, located between the crust and the core.
Crust
The thin, outermost rock layer of the Earth.
Magma
Molten rock material beneath the Earth’s surface.
Lava
Magma that has reached the Earth’s surface.
Fault
A fracture in the Earth’s crust where movement has occurred.
Weathering
Physical and chemical processes that break down rocks and minerals.
Sediment
Small pieces of rock, soil, or organic matter deposited by water or wind.
Glaciation
The process of changing landforms by slowly moving glaciers.
Moraine
A ridge or hill of rock and sediment carried and deposited by a glacier.
Climate and Weather
Weather
The condition of the atmosphere at a particular location and time.
Climate
The typical weather conditions at a particular location over a long period of time.
Convection
The transfer of heat in the atmosphere by the circulation of heated matter.
Mistral
A cold, dry wind blowing from the north.
Sirocco
A hot, steady south wind that blows from North Africa across the Mediterranean Sea.
Prevailing Westerlies
Global winds that blow consistently from west to east in the middle latitudes.
Taiga
A nearly continuous belt of evergreen forests across the Northern Hemisphere; also known as boreal forest.
Human Geography and Culture
Urban Geography
The study of how people use space in cities.
Urban Sprawl
Poorly planned development that spreads a city’s population and infrastructure over a wider area.
Culture
The total of knowledge, attitudes, and behaviors shared by and passed on by members of a specific group.
Society
A group that shares a geographic region, a sense of identity, and a culture.
Diffusion
The spread of cultural elements or patterns of behavior to different societies.
Innovation
Taking existing elements of society and creating something new to meet a need.
Acculturation
The cultural change that occurs when individuals in a society accept or adopt an innovation.
Yurts
A portable, round tent used by nomads in Asia.
Quechua
The language of the Inca Empire, still spoken in parts of the Andes.
Inca
A member of the Quechuan peoples of South America who built a great civilization in the Andes Mountains.
Siberia
A vast region of central and eastern Russia.
Beringia
A land bridge thought to have connected what are now Siberia and Alaska during the Ice Age.
Silk Road
The 4,000-mile ancient trade route connecting China with the Mediterranean region.
Political and Economic Systems
State
A specific territory and political entity.
Nation
A large group of people who share a common culture, language, or history.
City-State
A political unit made up of a city and its surrounding territory.
Republic
A form of government where citizens elect representatives to rule on their behalf.
Oligarchy
A form of government run by a few powerful persons.
Feudalism
A political system prevailing in medieval Europe in which nobles held lands from the Crown in exchange for military service.
Nationalism
The belief that people should be loyal mainly to their nation—that is, to the people with whom they share a culture and history.
Coalition
A temporary alliance of political parties or states for joint action.
Czar
The emperor of Russia (before 1917).
Free Enterprise
An economic system in which private individuals own most of the resources and determine what to produce.
Informal Economy
An economic system of trade and exchange that is not regulated or taxed by the government.
Postindustrial Economy
An economic phase where manufacturing no longer plays a dominant role, replaced by services and information technology.
Multinationals
A corporation that engages in business worldwide (Multinational Corporation).
Historical and Infrastructure Terms
Crusade
A series of religious wars launched by European Christians in the Middle Ages.
Holocaust
The Nazi program of mass murder of European Jews and other groups during World War II.
Anti-Semitism
Discrimination against or prejudice toward Jewish people.
Seaworks
A structure used to control the sea’s destructive impact on human life and property.
Terpen
High earthen platforms built in low-lying areas, often associated with seaworks.
Locks
A section of a waterway with closed gates where water levels are raised or lowered, allowing boats to pass.