GRADE 5
Name:
Sea level is the zero height point where the ocean meets the land. The term ‘above
sea level’ generally refers to above mean sea level (AMSL). A mean sea-level
standard is the midpoint between a mean low and a mean high tide at certain
location. Mean sea level is not constant over the surface of the entire Earth.
Exact measurement of a “mean sea level” is difficult to measure due to many factors
that affect sea level, such as constant motion, tides, wind, atmospheric pressure,
local gravitational differences, temperature, salinity and so forth. AMSL is the
elevation (height above sea level) measured
in metres. Heights are usually shown on
maps by contour lines, groups of colour, or
by numbers. Maps that show elevations are
called ‘topographic’ maps.
Elevation influences climate and where
and how people live. Most of the world’s
population live on coastal plains at
elevations of 150 metres or less. Some
cultures have adapted to higher elevations.
Example of topographic map courtesy Planet GIS
I am
on the 0 metre
line. I am standing at
sea level.
0 metre contour line
Did you know?
At sea level, water boils at about 100 º C.
Water boils at a lower temperature as you increase
altitude (e.g., on a mountain).
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Grade 5 Term 1: Social Science: Geography; Physical map of Africa; height above sea level
Height above sea level