Page 266 - (DK) The Ultimate Visual Dictionary 2nd Ed.

GEOLOGY, GEOGRAPHY, AND METEOROLOGY

Mapping the Earth EXAMPLES OF MAP PROJECTIONS

THE EARTH’S SURFACE FEATURES can be represented in various ways, such as
on maps and globes. The earliest know map of the whole world dates back to
between 750–500 BCE. The first globe was constructed in the mid-2nd century
BCE, about 100 years after ancient Greek astronomers established that the Earth was
spherical. Advances in mathematics, science, and geography—combined with
CYLINDRICAL CYLINDRICAL-
an increasing number of people exploring the world—have meant that Earth’s
PROJECTION PROJECTION MAP
surface features have been mapped with increasing accuracy throughout history.
In modern times, advances in technology have revolutionized the mapping 180o
150o
process. In 1972, NASA launched the first civilian remote-sensing vehicle 120o
Great Bear 90o
into Earth’s orbit, which allowed the Earth to be mapped by satellite for the Great Slave Lake Lake
Lake Superior
first time. Today, the surface of the Earth is surveyed every day by Greenland
thousands of satellites, which send mappable data back to Earth to be Bering
analyzed and used by a range of people, from cartographers to Sea Hudson
Alaska Bay
scientists. The ability to use satellites has substantially sped up Range Baffin
Island
data collection—areas that would have once taken months or
Rocky
even years to survey can now be mapped within minutes. Mountains
However, even with these advances in map-making, Sonoran NOR TH Lake Huron
Desert AMERICA
globes remain a more accurate way to represent the Lake Ontario
Earth’s surface features. This is because only a Lake Erie
Lake Michigan
globe can correctly represent areas, shapes, sizes, Sierra Appalachian
Madre
and directions, as there is always distortion Chihuahuan Mountains
Desert
when a spherical surface like the Earth’s is Gulf of
Mexico
Hawaiian
projected on to the flat surface of a map. Islands Mississippi- ATLANTIC
A map projection is therefore always a Missouri River Caribbean OCEAN
compromise: it shows some features Sea Guiana
Highlands
accurately but distorts others. Even Amazon
River
satellite mapping does not produce
Brazilian
completely accurate maps, although Highlands
they can show physical features
with great clarity. PACIFIC SOUTH
OCEAN AMERICA
Andes
Atacama
Desert
SATELLITE MAPPING OF THE EARTH Gran
Chaco
Mato
Satellite takes Solar panel Parana Grosso
photographs of Earth’s River
the Earth
rotation
Pampas
Antenna
Earth
Patagonia
Polar orbit
of satellite
Area of Earth’s Composite picture of Earth
surface on each created from thousands of 120o 90o
photograph separate images 150o WEST OF GREENWICH
180o
MERIDIAN
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