# 1.3

```REVIEW
1. Earth’s major spheres are the ______.
Hydrosphere, atmosphere, geosphere, and
biosphere
2. Which of Earth’s spheres includes the
oceans, groundwater, lakes, and glaciers?
The hydrosphere
3. What theory provides a model to explain
how earthquakes and volcanic eruptions
occur?
Plate tectonics
REPRESENTING EARTH’S
SURFACE
Chapter 1, Section 3
DETERMINING LOCATION
Latitude – the distance north or south of the equator,
measured in degrees
Longitude – the distance east or west of the prime
meridian, measured in degrees
Lines of latitude and longitude form a global grid; allowing
us to state the absolute location of any place on Earth
The equator divides Earth in two; each half is called a
hemisphere (northern and southern)
The prime meridian and the 180º meridian divide Earth into
eastern and western hemispheres
GLOBAL GRID
LOCATING PLACES USING THE GRID
CONCEPT CHECK
How does the global grid divide Earth?
Into hemispheres
MAPS AND MAPPING
No matter what kind of map is made, some portion of
the surface will always look either too small, too big, or
out of place; mapmakers have, however, found ways to
limit the distortion of shape, size, and distance
The Mercator projection is used by many seagoing
navigators, as it uses lines of longitude that are parallel,
making the map rectangular
The Robinson projection shows most distances, sizes, and
shapes accurately, but is distorted around the edges
Conic projections are used to make a map of a smaller
area
Gnomonic projections are used by sailors and navigators
for short distances
PROJECTIONS
CONCEPT CHECK
What major problem must mapmakers overcome?
Representing round Earth on a flat paper causes distortion in shape,
size, and distance
TOPOGRAPHIC MAPS
Topographic Map – a map that represents Earth’s surface in three
dimensions; it shows elevation, distance, directions, and slope angles
Topographic maps differ from other maps discussed so far because
topographic maps show elevation of Earth’s surface by means of
contour lines
Contour Line – line on a topographic map that indicates an elevation;
every point along a contour line has the same elevation
Contour Interval – on a topographic map, tells the distance in
elevation between adjacent contour lines
A map is drawn to scale, where a certain distance on the map is equal
to a certain distance on the surface
A map that shows the type and age of the rocks that are exposed, or
crop out, at the surface is called a geologic map
CONTOUR LINES
GEOLOGIC MAP
CONCEPT CHECK
How do topographic maps indicate changes in elevation?
Contour lines, lines close together indicate a steeper slope
Today’s technology provides us with the ability to more
precisely analyze Earth’s physical properties
Scientists now use satellites and computers to send and
receive data, which are then converted into usable forms
such as pictures and numerical summaries
The process of collecting data about Earth from a
distance, such as from orbiting satellites, is called remote
sensing
We can use this technology in our daily lives too; many
newer cars use the Global Positioning System (GPS) to
provide maps to different destinations
CONCEPT CHECK
What types of advanced
technology are used in mapmaking
today?
Satellites, computers, GPS, sonar,
high-powered telescopes, etc.
```