Transcript lesson 1 - maps and contemporary tools

Topic: Map Types, Projections and
Distortions
“Maps are the
language of
geography, often
the most direct
and effective way
to convey grand
ideas or complex
theories.” - Harm
de Blij
 Aim: In what ways can maps both tell and distort
the truth?
 Do Now: Is there anything wrong with the map
above? Think about your answer…
Orientation is to the south instead of the north
Standard 1: Human Geography
Use and Think About Maps and Spatial Data:
• Geography is fundamentally concerned with the ways
in which patterns on Earth's surface reflect and
influence physical and human processes. As such,
maps and spatial data are fundamental to the
discipline, and learning to use and think about them
is critical to geographical literacy. The goal is
achieved when students learn to use maps and spatial
data to pose and solve problems, and when they learn
to think critically about what is revealed and what is
hidden in different maps and spatial arrays.
Remember Your Summer
Assignment…
• Do Maps Create or Represent Reality?
What was Hebert’s thesis (argument) about maps?
What did she say their purpose was? What do they
distort and why?
Do Maps Create or Represent Reality?
“The earth, as a physical entity, simply exists. Any
purpose that we see in the world through a map is
one that has been imposed by humans. This is the
sole reason for maps’ existence. They exist to show
us something about the world, not to simply show
us the world. They can illustrate any multitude of
things, from migration patterns of Canadian geese
to fluctuations in the earth’s gravitational field, but
every map must show us something about the
earth upon which we live. Maps lie to tell the truth.
They lie in order to make a point.” ---Laura Hebert
Mental (Cognitive) Maps:
• “A person's perception of the world is known as a mental map. A mental map is an
individual's own internal map of their known world.” - Matt Rosenberg
Mental Map of the World
of a Palestinian high school student
Mental Map Creation:
•You will draw your own mental map of the world on a blank sheet of paper. This
map should NOT be “perfect,” it is just a “pretest” of your knowledge at the start of
the semester. YOU CAN’T LOOSE POINTS FOR INACCURACY, SO PLEASE
DO NOT REFERENCE ANY ACTUAL MAPS TO HELP YOU!
•After drawing the rough outline of the world's land masses, label the
continents. Then create a way to label the following things:
–
–
–
–
–
–
5 Physical features like mountains, rivers, lakes, oceans
5 Political features such as cities and countries
5 Economic features like natural resources, trade goods, etc.
5 Technological features like inventions and ideas, technology
5 Cultural features like works of art, literature, music, religions
5 Movements across space of major migrations of people
 Earliest surviving maps – Babylonian
clay tablets
 Eratosthenes, around 250 BC, made
major contributions to cartography. He
measured the circumference of the
Earth with great accuracy.
Claudius Ptolemaeus (Ptolemy, about
A.D. 85-165). His "world map"
depicted the Old World from about
60°N to 30°S latitudes.
Vesconte’s World Map (1321 A.D.)
Sylvanus, Bernard
(1511)
16th Century
Abraham Ortelius
(1527-1598)
What country did this map come from? Where did the
cartographer position his country on the map?
It seems more likely that the world and all its continents were
discovered by a Chinese admiral named Zheng He, whose fleets
roamed the oceans between 1405 and 1435. His exploits, which
are well documented in Chinese historical records, were written
about in a book which appeared in China around 1418 called
"The Marvellous Visions of the Star Raft".
Physical Geography
Terms
Pangaea: was a supercontinent that existed during the late Paleozoic and
early Mesozoic eras, forming about 300 million years ago. It began to break
apart around 200 million years ago. The single global ocean which
surrounded Pangaea is accordingly named Panthalassa.
What are continents?
How many continents are there?
Name them?
Describe how the following video challenges the ideas you
previously had about continents?
The Geographic Grid:
• Geographic grid is a system of imaginary
arcs drawn in a grid pattern on Earth’s
surface.
– Meridians are arcs drawn between the
North and South poles. Each is
numbered, according to a system
known as longitude.
• Values range from 0º (prime meridian)
to 180º east or west longitude.
– Parallels are arcs drawn parallel to the
equator and at right angles to
meridians. Each is numbered, according
to a system known as latitude.
• Values range from 0º (equator) to
90º north or south.
What are: The Equator, the Prime Meridian, the
‘tropics’, temperate climates?
Maps & Cartography
• Cartography: The science of map making, originally done by
hand but now largely digital
• As a communication tool, a map is the best means for
depicting the distribution of human activities and/or physical
features, as well as reasons for the underlying reasons for a
particular distribution
Two Types of Maps:
1.) Reference Maps
- Show locations of
places and
geographic features
- Absolute locations
2.) Thematic Maps
- Tell a story about the
degree of an
attribute, the pattern
of its distribution, or
its movement.
- Relative locations
Thematic: spatial distribution of one or more
specific themes
Types of Thematic Maps:
• Isoline Maps: use lines of equal value to represent data like
elevation, barometric pressure or temperature
• Choropleth Maps: a thematic map in which a variable is
depicted with shading patterns or colors.
• Dot Map: a thematic map in which a dot represents some
frequency of the mapped variable.
• Cartogram: a thematic map using relative size of political units
to convey a value.
• Proportional symbol: size of the symbol corresponds to the
magnitude of the mapped feature
Dot: each dot represents some frequency
Proportional symbol: size of the symbol
corresponds to the magnitude of the mapped
feature
This topographic
map is an example
of an isoline map.
All of the brown
lines connect
places of equal
elevation.
Choropleth maps: puts features
into classes and then maps classes
for each region
Cartogram
Remember, when
discussing map
scale, the larger
the area, the
smaller the scale
and vice versa!
Large-scale
Small-scale
Reference
Map
Map Projections
and Distortions
1. What is a funhouse
mirror?
2. What does it show?
3. Would you say that
what a funhouse
mirror depicts is
accurate? Why or
why not?
How can you transfer an image of the Earth
onto a flat surface?
Is it possible to create
an accurate map?
Map Projection:
1. Maps are flat and therefore 2 dimensional - this
creates problems of projection, or the scientific
method of transferring locations on Earth’s
surface onto a flat surface.
2. Projections cannot be perfect. They all produce
distortions, particularly when depicting the entire
world.
3. 4 types: shape, distance, relative size, and direction
are all major distortions
4. Let’s take size as an example of how maps lie…
On a standard Robinson Projections (like all the maps you see in school), Africa looks
approximately as large (only slightly larger) than South American, for example…In
reality…
http://flowingdata.com/2010/10/18/true-size-of-africa/
Types of Distortion:
• Earth on a flat piece of paper creates distortions. Four
types of distortions can result:
– The shape of an area can be distorted, so that it
appears more elongated or squat than in reality
– The distance between two points may become
increased or decreased
– The relative size of different areas may be altered, so
that one area may appear larger than another on a map
but is in reality smaller
– The direction from one place to another can be
distorted
The Mercator Projection:
The greatest "inventor" of sixteenth century Europe was map maker Gerhardus
Mercator whose 1569 summary map, publicized by the learned Richard Hakluyt
in his Principal Navigations, Voyages and Discoveries of the English Nation (London:
1589), liberated cartography from dependence on Ptolemy, and included a
projection that allowed navigators to understand the coasts of the New World.
These maps silently promoted a Eurocentric view that privileged the Western
image. Generations of European and American students have been indoctrinated
with the glories of nationalism and colonialism through this map.
The Robinson Projection:
•Tries to correct for the Mercator Projection’s distortions by curving
distorted areas inwards.
•Attempts to balance all distortions by making errors in all four ways:
shape, size, distance, direction
The Peters Projection:
• Focuses on keeping land masses equal in area.
Shapes are distorted.
Comparing
Projections:
Goode’s Projection:
Goode’s
projection interrupts the oceans and tucks Australia and New
Zealand farther west than in reality. Therefore, land masses appear
relatively large compared to the oceans.
Minimized distortion in the shape of the various land masses and the
size of one land mass compared to other land masses.
A World of Projections:
• http://www.flickr.com/p
hotos/sbprzd/sets/7205
7594138628700/
Discussion:
1. What were the
President’s advisor’s
surprised by?
2. What were you
surprised by?
3. What types of
distortions did the
presentation speak
of ?
Contemporary
Geographic Tools:
Global Positioning Systems (GPS):
System that accurately determines the precise position of something
on Earth
• GPS in the U.S. includes three elements
1.
2.
3.
Satellites placed in predetermined orbits
Tracking stations to monitor and control satellites
Receiver that can locate at least four satellites, figure out its distance
from each, and use the information to calculate its precise location
• Applications
–
–
–
Turn-By-Turn directions in vehicles
Navigational aid to pilots and ship captains
Provide location for social media applications in a smartphone
GIS
GIS is a method to visualize,
manipulate, analyze and display spatial
data.
Combines layers of information about
a place to give you a better
understanding of that place.
You chose the layers of information
you combine depending on your
purpose
Examples: finding the best location for
a new store, analyzing environmental
damage, viewing similar crimes in a city
to detect a pattern, and so on.
GIS Geographic information systems store information about a
location in layers. Each layer represents a different piece of
human or environmental information. GIS involves two types of
data: vector and raster. Vector data consists of points (such as
forcities) and lines (such as for highways). Raster data consists of
areas, such as particular landforms.
Remote Sensing
Obtaining information from the Earth by satellite, without the satellite
ever having to touch the earth.
The instruments used for this special technology are known as remote
sensors and include photographic cameras, mechanical scanners, and
imaging radar systems. Regardless of type, they are designed to both
collect and record specific types of energy that impinges upon them.
Gather environmental information (weather patterns, etc.), urban sprawl,
agriculture, etc.