Specific heat is the heat required to raise the temperature of one unit substance (e.g., gram) through a particular temperature interval (1oC, for example). The specific heat of water is 1 calorie/gram °C = 4.186 joule/gram °C which is higher than any other common substance on Earth.

For years, geographers have used aerial photographs to study the Earth’s surface

Earth orbiting satellites, control and monitoring stations across the Earth, and GPS receivers owned by individuals.

Latitude and longitude comprises a grid system of lines encircling the globe and is used to determine the locations of points on the earth. Lines of latitude, also called parallels, run east - west. Latitude lines always run parallel to each other, and hence, they are always an equal distance apart. Latitude lines never converge or cross.

A model is simply a representation of a real thing. You have seen and used models in the past, like a globe which is a model of the earth. Geographers construct models to analyze geographic processes because the real object of study may be too large to examine, the processes which created it operate over too long of a time frame, or experimentation might actually harm or destroy it.

Large scale maps, such as 1:24000 scale maps show a smaller area in great detail. Small scale maps have the least detail but show large areas.

An isoline is a line that connects points of equal value. For instance, the brown contour lines on United States topographic map connect points of equal elevation.

The information collected to create a map is called spatial data. Any object or characteristic that has a location can be considered spatial data. Maps can depict two kinds of data. Qualitative map data is in the form of a quality and expresses the presence or absence of the subject on a map, like the kind of vegetation present occupying a region. Quantitative map data is expressed as a numerical value, like elevation in meters, or temperature is degrees celsius.