SSCI135 Midterm Review

Geodesy

is the field of people concerned with the precise figure of Earth

Geoid

is the true shape of Earth; is modeled and defined by gravity measurements

Ellipsoid

3D model that contains major and minor axis’

Great Circles

These bisect the core of the Earth and feature the largest circumference possible for a sphere of the Earth

Magnetic North Pole

What we use to navigate using a compass; this field protects us from dangerous radiation

Geographic North Pole

aka true north; this does not change (unlike magnetic) and everything spins around this

Graticules

The lines that make up Earth; parallels are lines of latitude and meridians are lines of longitude

Cartesian Plane

Latitude

Horizontal parallel lines that never intersect that cut the Earth at the equator and situate locations either North or South of the poles (max. value 90)

Longitude

Vertical perpendicular lines that can intersect, these lie along great circles, and help determine a location based off of East-West (max. value 180)

Perpendicular

Lines that can intersect (longitude)

Parallel

Lines that never intersect (latitude)

Prime Meridian

The Y-axis with an assigned value of 0, this runs through Greenwich, England

International Date Line

The other side of the Prime Meridian with an assigned value of 180

Seasons

Changes in relative tilt as Earth orbits the suns determines these

Solstice

Summer: Sun is directly above Tropic of Cancer (North=Summer); Winter: Sun is directly above Tropic of Capricorn (North=Winter)

Equinox

Sun is directly above the equator; everywhere on Earth has approximately 12 hrs. of sunlight

Insolation

Antipode

A point that is the direct opposite of a location (think drilling a hole all the way straight through the Earth)

Trigonometry

State Plane Coordinate System

A system that divides the Earth into 124 zones, each containing their own PM and equator that stay within country boundaries

Map Projection

Geometric transformation of 3D Earth into 2D (flat map surface)

Developable Surface

Cylindrical, azimuthal (planes), and conical shapes used for map projections

Tissot’s Indicatrix

Equal sized circles placed at regular intervals on the Earth’s globe; this reveals distortions on the planet

Conformal Projections

Preserve shape

Cylindrical/Planar/Conic Projections

Three types of developable surfaces that make cylindrical, azimuthal, and conical projections

Compromise Projection

Distributes evenly distortions rather than preserving one and fully distorting others

Line of Tangency

Is where the developable surface touches the globe; also the area of lowest distortion on the map

Tangent Projections

Touches the globe once

Secant Projections

Touches the globe twice (and is generally lower in distortion)

Map Projection Aspect

The orientation of the developable surface: i.e. normal aligns w/ equator, etc.

MAUP

How data is aggregated can and will influence the result and change the outcomes of a map

Scale Effect (MAUP)

What level are we working at? State? County? etc. will altar our outcome

Zonal Effect (MAUP)

What boundary are we working at? Within the scale, what boundaries is our data in will altar our outcome

Gerrymandering

A political manipulation tool that uses the zonal effect to crack and pack populations within boundaries that often benefit the manipulator

Three basic questions of geography

What is where?, Why is it there?, Why does it matter?

Mental Maps

Nodes, Paths, Edges, Districts, & Landmarks

Geodesic Distance

Measured on the curve of the Earth

Euclidian Distance

Measured on flat maps

Mid-Latitude regions use which projections

Conic

Azimuthal

Polar regions use which projections

Equatorial regions use which projections

Cylindrical

Ex: The Lambert Conformal Conic projection helps preserve what feature

Shape (conformal)

Cone

Ex: The Lambert Conformal Conic projections uses which developable surface

Gerrymandering is an example of what type of problem

Zonal effect

“I put your things in a dumpster behind the apartment is an example of what kind of location

Relative location

What kind of force is used to model a geoid

Gravity

What angle is Earth tilted relative to the sun

23.5 degrees

Latitude of the arctic circle

66.5 degrees N

Latitude of the tropic of Capricorn

23.5 degrees S