Geography Tools and Methods

Geography Skills We use them daily to make personal decisions Geographers use them to understand and explain concepts about the Earth Cartographers, or mapmakers, use them to create maps and globes Map: Two-dimensional representation that shows more detail than a globe Globe: Three dimensional representation of the Earth showing area, distance and direction accurately

Map Projections Projections: Cartographers project the round Earth onto a flat surface. The purpose of the map determines the type of projection used. Planar: Often used for maps of the poles Most accurate at its center Cylindrical Projection: Projection of a globe into a cylinder Most accurate near the Equator Shapes and distances are distorted near the Poles Conic: Comes from placing a cone over part of the globe. Best for showing limited east-west areas that are not too far from the Equator

Common Map Projections Winkel Tripel: Most general reference maps Provides a good balance between size and shape of land areas Robinson: Has minor distortions as the polar areas are flattened

The World: A Robinson Projection

Getting It All On the Map The World: Mercator Projection In 1569, a geographer named Gerardus Mercator created a flat map to help sailors navigate long journeys across the globe. The Mercator projection, or method of putting a map of the Earth onto a flat piece of paper, is used by nearly all deep-sea navigators. The Mercator projection shows correct shapes, but not true distances or sizes.

Common Map Projections continued… Goode’s Interrupted Equal-Area: Resembles a globe that has been cut apart and flattened Shows true size and shape, but distances are distorted Mercator: Distorts size and shape as it moves farther from the Equator Accurately shows true directions and shapes of landmasses Useful for sea travel

The World: Three Projections Interrupted Projection There are many ways to show a globe on a flat map. The interrupted projection map, on the left, shows real sizes and shapes of continents. The equal area map , below left, shows size accurately. The Peters projection, below, shows land and oceans areas and correct directions accurately Peters Projection Equal-Area Projection OwlTeacher.com

Mercator Projection vs. Peters Projection

Determining Location Absolute Location: Latitude: Longitude: Precise location using a coordinate system Latitude and longitude most common Measured by geographic positioning systems (GPS) Latitude: Also known as parallels, Measures distance north and south of the Equator (0 degrees latitude) Longitude: Also known as meridians Measure distance east and west of the Prime Meridian (0 degrees longitude), which runs through Greenwich, England The opposite side of the Prime Meridian is the International Date Line at 180 degrees longitude

How Latitude and Longitude Form the Global Grid

Determining Location continued… Global Grid: A series of latitude and longitude coordinates across the earth that help us to find absolute locations Hemispheres: The Equator separates the Earth into Northern and Southern Hemispheres The Prime Meridian separates the Earth into Eastern and Western Hemispheres

The Hemispheres

Reading a Map Scale Bar: Shows the relationship between map measurements and the actual distances on Earth. Compass Rose: Shows the four cardinal directions: north, south, west and east. Map Key: Lists and explains the symbols, colors, and lines used on a map. Sometimes called a legend.

Scale Scale: a consistent, proportional relationship between the measurements shown on the map and the measurement on the Earth’s surface. Small-Scale Maps: Shows a large area with little detail Large-Scale Maps: Shows a small area with a great amount of detail

The Power of Scale Influence of processes operating at different scales Context of a phenomenon in what is happening at different scales Political use of scale to change who is involved or how an issue is perceived

Why Are Geographers Concerned with Scale and Connectedness? Scale: Territorial extent of something Varying scales of observations Local Regional National Global

Local National Global

Types of Maps Reference: Political: Shows the boundaries and locations of countries, states, counties, cities, or towns. Most are human made features. Physical: Shows location and topography (the shape) of the Earth’s features including water features, landforms, and relief and elevation

Types of Maps Continued Thematic: Emphasize a single idea or particular kind of information Qualitative: Uses colors, symbols, lines, or dots to show specific information related to an idea. Often shows historical information Flow-Line (flow vector): Illustrate movement of people, animals, goods, and ideas, as well as physical processes like hurricanes and glaciers Arrows are used to represent the flow or direction of movement

Why Do Geographers Use Maps, and What Do Maps Tell Us? Types of maps Reference maps Locations of places and geographic features Absolute locations Thematic maps Degree of an attribute Pattern of distribution Information/data Movement Relative locations

Reference Map

Thematic Map

Determining Location continued… Relative Location: Location in relation to something else Changes over time with changing circumstances

Mental Maps Maps we carry in our minds of places we have been and places we have heard of Activity Spaces The places we travel to routinely in our rounds of daily activity

Geographic Information System (GIS) Computer hardware and software that permit storage and analysis of layers of spatial data

Geographic Information Systems GIS: Software and hardware used by cartographers Data from various sources such as maps, satellite images, printed text, and statistics are entered and the GIS converts the data to a digital code The information is then processed into layers to produce maps. This system allows cartographers to make maps and change them quickly and easily

Area of impact and destruction Remote Sensing and GIS Satellite image (direct observation) Hurricane Katrina, 2005: Area of impact and destruction