| geographic information system (gis) | a computerized system for the collection, storage, and retrieval of geographic data |
|
| geography | literally, writing about the earth, greek. the study of the earth's physical and human features. see "What is geography?" and "definitions of geography" on this site |
|
| geologic time | the calendar of the earth's history since its birth 4.6 billion years ago; geologic time is divided into eras, epochs, and periods |
|
| geology | science of the earth's crust, strata, origin of rocks, etc. |
|
| geomorphology | the study of the landscapes of the earth and their development |
|
| geophagy | eating dirt or clay |
|
| gerrymandering | the process of redistricting voting boundaries to benifit one group over another |
|
| glacier | a large mass of ice thad moves over the land, carving and eroding surfaces as it moves |
|
| global positioning system (gps) | a system of satellites and ground units which enable a user to determine their absolute location |
|
| global warming | the theory that temperature of the atmosphere an increasing due to the increase in gasses such as carbon dioxide |
|
| globe | a spherical model of the earth's surface that includes a map of the earth; also known as a terrestrial globe |
|
| great circle | any hypothetical circle that passes through the center of the earth and divides the planet into two hemispheres. the great circle route, following the arc of a great circle on the earth's surface is the shortest route between any two places on earth. the equator is the only line of latitude that is a great circle. |
|
| green revolution | the effort to introduce highly effective crops to the developin world in the 1960s |
|
| greenhouse effect | the analogy used to describe the ability of gasses in the atmosphere to absorb heat from the earth's surface |
|
| gross national product (gnp) | the value of all goods produced in a given country during a year |
|