Term | Definition |
Volcano | a vent in the surface of Earth through which magma and associated gases and ash erupt. |
Earthquake | a sudden motion or trembling in Earth caused by the abrupt release of slowly accumulated strain. |
Geology (geologic) | the study of planet Earth: the materials of which it is made, the processes that act on these materials, the products formed, and the history of the planet and all its forms since its origin. |
Earth Structure | a definable shape formed by geologic activity. |
Latitude | a north-south measure of a point on Earth’s surface relative to the Equator. It is measured in degrees (0º to 180º) north or south from the Equator. |
Longitude | the east-west position of a point on Earth’s surface, relative to the Prime Meridian. It is measured in degrees (0° to 180°) east or west from the arbitrary line. |
Equator | an imaginary line around the middle of Earth that is an equal distance from the North and South Pole. |
Prime Meridian | an imaginary line chosen on Earth’s surface that stretches from the North Pole to the South Pole and passes through Greenwich, England. |
Geologist | A scientist who studies the origin, history, and structure of Earth. |
Topography | the general arrangement of a land surface, including its relief (height and slope) and the position of its natural and human-made features. |
Elevation | the vertical distance (height) from sea level to a point on Earth’s surface. |
Depth | distance below sea level of a point on Earth’s surface. |
Sea level | the average height of the surface of the oceans; it is used as a reference point for the measurement of elevation and depth. |
Topographic Map | A map showing the natural and human-made configuration of a land surface. |
Contour line | A line on a map that connects points of equal elevation of the land surface. |
Contour interval | Difference in elevation between contour lines. |