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Home , Antarctic Circle, Arctic Circle, Tropic of Capricorn

GEOG 100 Physical Geography Welcome to GEOG 100: Physical Geography!

• Syllabus

• Canvas

• Course Expectations Geography

• Term comes from “geo” – and “graphien” – to write • Literally means to “describe the earth”

• 2 Main Branches: Physical and Human Branches of Geography THE FIVE THEMES OF GEOGRAPHY

• Location

• Place

• Human Environment Interaction

• Movement (Migration)

• “Where”

• Where are you from? El Centro? The Imperial Valley? California? The Southwest? America? Mexico?… all of these places?

• The answer depends on who is asking

• Places have connotations Location

• Absolute location: exact geographic coordinates … 32.8° N, 115.5°W Location

• Relative location: with reference to other or locations

• Can we define regions on campus? Space

• Geometric: Lines, Grids, and Degrees • Defines areal extents… units • Measurement • Location • Spatial… Place

• Space with layers of social meaning • Answers the question of where? • Campus… safety, familiarity, and function Territory

• Space under control (borders) • Space of action, power, and consequences • Lines of inclusion and exclusion • Territory can be place Sense of Place

• We perceive information from and about places • Perceptions overlap with values, forming attitudes • Attitudes overlap, forming cultural stance/world view • One’s surroundings become context for emotion Physical Geography is all about landscapes!

• Systems and processes in spheres of the Earth • Lead to landscape change over time and space Sphere’s of the Erath

• Atmosphere • Hydrosphere • Lithosphere • Cryosphere • Sphere’s Interact

• Multiple spheres are involved in the landscape Earth is in the “Sweet Spot”

• Liquid water!!! Relief

• Measuring vertical distance • Highest Point – Mt. Everest • Lowest Point – Mariana Trench Great Circles

• Shortest distance is a straight line • Factor N/S as well as E/W Geographic Grid & Location

• Locations are found using a geographical grid called & longitude

• On a map, the grid is similar to an algebraic grid

• Made of interconnecting circles Latitude

• Horizontal Lines: Latitude (Parallels) - Lines of latitude run east and west

- They are parallel to one another

- Point of reference is the

- A location’s latitude describes how far or south it is from the equator - Min 0°, -Max is 90°N or S Important Parallels

• Circle • Circle • Equator • • Longitude

• Vertical Lines: Longitude (Meridians) - Lines of longitude run north and south - They converge at the poles

- Point of reference is the Prime : established in 1851, Royal Observatory in Greenwich. In 1884 it was voted as the international standard.

- A location’s longitude describes how or west it is from the PM

-Min 0°, Max 180°E or W The Grid Latitude and Longitude

-Latitude and Longitude are measured in degrees (°).

-For latitude, each degree is about 69 miles (111 km) apart.

-At the equator, longitude degrees are also about 69 miles apart but proceed to get closer together as they grow near the poles.

-Degrees(°) can be further subdivided into minutes(‘) and seconds(‘‘)

-There are 60 minutes in every degree, and 60 seconds in every minute.

-Using degrees, minutes, and seconds, a location can be pinpointed on Earth within 100 ft. (30.5 m). Earth’s Rotation

• Speed is fastest at the Equator

• Speed is slowest at the poles What have we learned?

• Angular distance! • Long = 0 – 180 degrees E or W of • Lat = 0 – 90 degrees N or S of Equator • Lines are called Meridians • Lines are parallel, that’s • Every Meridian goes from the why they are called N pole to the S pole Parallels • Physical distance between • Distance of lines gets meridians is smaller as you shorter as you get higher get higher in latitude

• The Geographic Grid defines our location! Earth Relationship: and Seasonality

• The Earth’s axis is tilted at 23.5 degrees…

• Makes days get longer in summer and shorter in winter

• Affects the amount/angle of insolation (solar radiation)

• Means more for places at high Basic Earth-Sun Relationships

• The Sun is about 110 x larger than Earth

• At any given time ½ of the Earth is always illuminated by the Sun

Circle of Illumination The World at Insolation – Electromagnetic Energy

• The Sun constantly emits huge quantities of energy… this is the energy that inherently drives Earth’s Systems!

• The energy that hits the Earth and provides us with light and heat is called:

Insolation

• The total amount of energy coming to Earth is the same at all latitudes

• Why are the poles cold? Diffusion

• Because of Earth’s curved surface, energy that hits the poles is diffused over a larger ground area. Energy at the equator is more concentrated. Seasons & the Sub Solar Point (SSP)

• Concentrated Energy = SSP (Intersection of the Plane of the Ecliptic)

• The SSP migrates north when the is oriented towards the Sun

• The SSP migrates south when the is oriented towards the Sun Important Lines of Latitude (Parallels)

• Specific lines of latitude mark specific geometric relations with the Sun

• 0° Equator

• 23.5° N – Tropic of Cancer

• 23.5° S – Tropic of Capricorn

• 66.5° N –

• 66.5° S – vs. Equinox

• A solstice marks the day when the SSP (Plane of the Ecliptic) reaches its most northerly and southerly position.

• Occurs once a year in both the northern and southern hemispheres

• An equinox occurs when the SSP (Plane of the Ecliptic) is located at the Equator

• Occurs twice a year as the SSP migrates north and south Seasons 1 Revolution (Year)

• 365.25 days (winter)

• December 21st/22nd

• Shortest day of the year in the NH

• Arctic Circle receives 24 of darkness

• Antarctic Circle receives 24 of daylight

• The SSP is located at the Tropic of Capricorn

• Sun appears directly overhead at 23.5° S March Equinox (Spring)

• March 21st

• All latitudes receive 12 hours of daylight and 12 hours of darkness

• The SSP is located at the Equator

• The Sun appears directly overhead at the 0° (summer)

• June 21st/22nd

• Longest day of the year in the NH

• Arctic Circle receives 24 hours of daylight

• Antarctic Circle receives 24 of darkness

• The SSP is located at the Tropic of Cancer

• Sun appears directly overhead at 23.5° N September Equinox (fall)

• September 21st

• All latitudes receive 12 hours of daylight and 12 hours of darkness

• The SSP is located at the Equator

• The Sun appears directly overhead at the 0° Sun Dial 1:00 am on a Saint Petersburg July night Tropical Areas Time zones

• People like it when the sun rises in the morning and sets in the evening

• The World has 24 time zones to stagger the Earth’s rotation around the Sun

• What would California be like if we had to live on New York Time? On Beijing Time??? Time Zones of the World Time Zones of Time zones can get complicated… Finding Locations on Earth

• How has it been done in the past?

• Mental maps and local knowledge

• Latitude and Longitude: coordinate system used to describe locations on Earth

• Global Positioning System Maps

• A map is a two-dimensional or flat-scale model of Earth’s surface, or a portion of it.

• Cartography is the science of mapmaking.

• Maps serve two purposes… 1. As a reference tool to identify an object’s absolute and relative location. 2. As a communications tool to convey the distribution of human activities or physical features. Early Mapmaking

• Earliest maps were reference tools—simple navigation devices to show a traveler how to get from Point A to Point B.

• First world map prepared by Eratosthenes(276– 194 B.C.) • Improvements to world map later made by Ptolemy.

• After Ptolemy, advancements in cartography primarily made outside of by Chinese and Islamic world. • Mapmaking revived during the Age of Exploration and Discovery. Early Map Eratosthenes’s World Map Ptolemy's World Map MAP BY ORTELIUS, 1571 Maps

• Displaying a 3D Spheroid (Earth) on a 2D surface

• limited amount of detail…

• Choose projections carefully!!! Mercator Projection Robinson Projection Goode’s Interrupted Projection Maps

• All maps are distorted • A globe is always the best… 3D to 3D

• 2 major map projections • Conformal – less distortion with shape • Equivalent – less distortion with size Maps

• Conformal Projection • Shapes of land masses are correct • Size is exaggerated near the poles

• The Mercator Projection Conformal Projections Maps

• Equivalent Projection • Size is correct • Shape is distorted

• Mid latitudes are most accurate • Albers Equal-Area Projection Map Scale

• Scale is the ratio of the real world to that of a given map • Representative Fraction • 1:24,000 (unitless)

• Verbal Scale • “1 inch represents 1 mile”

• Bar Scale Large Scale vs. Small Scale

• Large Scale • Small Scale • Shows less area • Shows more area • Large amount of detail • Small amount of detail • Denominator in representative • Denominator in representative fraction is small number fraction is a big number • 1 : 24,000 • 1 : 10,000,000 • Looks “zoomed in” • Looks “zoomed out” Which one is large scale? Which one is small scale?

North America Lawrence, Kansas Isolines

• Lines of equal value

• Commonly used isolines: • Isobars – air pressure • Isotherms – air temperature • Isohyets – precipitation • Isopachs – sedimentary thickness

• Contour lines – elevation Contour Lines

• Point elevations

• Determine where contours would lay, between known elevation points

• Draw elevation contours Thematic Maps

• Any map that is focused on showing differences in a dataset, or among datasets

• Population density • Agricultural productivity • Poverty • Tree cover One Area – 4 Themes

Digital Technology

• Remote sensing • Global Positioning System (GPS) • Geographic Information Systems (GIS) Maps are Created for a Purpose! What have we learned?

• Scale is the relationship between the Earth’s surface and the map

• Maps are based on the Geographic Grid

• Map projections have issues

• Maps are made by people, and reflect all of their issues