Transcript Extreme Environment - Miami Beach Senior High School

EXTREME
ENVIRONMENT
CHAPTER 7
CHALLENGING ENVIRONMENTS
• Extreme Environments
• Hot, arid environments
• Cold and high altitude environments
Common characteristic: inhospitable to human habitation.
• Global Distribution of Cold and High Altitude
• Mountain range: [longest: Los Andes] [highest: Himalaya]
Mountain
Range’s
distribution
• Glacial areas: a slowly mass or river of ice formed by the accumulation and compaction
of snow on mountains or near de poles.
• Periglacial areas: areas adjacent to glacial areas, and experience repeated freezing
and thawing.
• Why are Cold and High Altitude Extreme Environments?
• First, sun’s rays strike the earth surface at a lower angle near the poles. So solar energy
spreads on a larger area [less energy in polar areas than in equatorial areas]
• Second, sun’s rays must penetrate a greater thickness of atmosphere near de polar [less heat
reaches earth’s surface]
• Third, a great proportion of heat that reaches the surface is reflected back due to albedo
(reflectivity)
• In mountain areas, the main factor causing differences in the landscape is altitude.
The differences that are found globally from latitude 0 to 90 are mirrored by the
differences we see rising from sea level to 9,000 meters elevation, In terms of
geographical variation, the distance from the equator to the poles is the same as from
sea level to the highest point in the world, even though the vertical distance is les than
10,000 meters.
• There is a direct relationship altitude, air pressure and temperature. The tendency for the
atmosphere to become cooler with increasing altitude is the reason for permanently snowcovered caps in countries close to the Equator. To a large extent, the fall in temperature with
increasing altitude mirrors the fall in temperature with increasing latitude.
• As altitude increases , there are decreases in air density, water vapor, carbon dioxide, and
impurities.
• Fall in the air pressure with altitude = boiling point of water decreses
• Higher altitude = higher intensity of ultra-violet radiation
• Temperature, altitude and slope: slopes facing south receive more solar radiation and are
expose to prevailing winds, rising air and soil temperature = differences in vegetation and
land uses on the northern and southern slopes.
• Windward side receives more precipitation than Leeward side of mountains.
• Altitude and its effects on population? Question Bloc 7d
EXTREME ENVIRONMENT LINKS
• https://www.youtube.com/watch?v=EV12TsO2z4E&list=PLgpk1tjLQ5O4ofDo5iEiPS0Ad
QD-FvZAv
WHY ARE ARID ENVIRONMENTS EXTREME?
• Arid environment: potential evaporation exceeds potential precipitation
• Desertification: process whereby desert expand into semi-arid areas or become more
intense.
• Desert
• Traditionally: lack of rain, soil nutrient, vegetation and population
• Now: most desert areas have abundance on vegetation and wildlife
• It is important that aridity is NOT infertility
GLOBAL DISTRIBUTION OF ARID ENVIRONMENT
• Cold winter mid-latitude deserts
• Cause: remoteness from source of atmospheric moisture
• Rainshadow deserts
• cause: orographic effect [precipitation dropped mainly in one side o the mountain, windward]
• Desert of sub-tropical highs
• Cause; equatorial zones receive more constant heating from the sun
• West coast deserts
• Cause: due to the subtropical high-pressure systems and cool ocean currents.