Lecture 02-08-2017 (Post Midterm) Flashcards
(26 cards)
What are the 7 categories of earth processes related to natural hazards?
- Wind action
- Streams
- Ice action
- Marine processes
- Mass movement
- Earthquakes
- Volcanoes
What drives patterns of atmospheric circulation?
Solar Radiation
What determines the strength of wind?
The range of pressure gradient
What is the “deflective force” which affects weather systems?
The Coriolis Effect. For example, an object flying from the equator to the north pole would end up somewhere right of it’s intended path; the earth spins from West to East.
What is the Corollas effect?
- An effect which causes fluids to curve as they travel across or above earths surface.
- Caused by earth’s rotation from West to East; and
- The difference in circumference from North to South.
What is deflation or winnowing wind? Where is it of particular concern in Canada?
Deflation - the selective removal of fine grained particles from the earth surface (e.g., Dust Bowl areas)
What is abrasion and attrition?
- Particles are picked up;
- Collide with each other and against surfaces;
- Reduce in size and changing in shape; and
- Modify the surfaces which they come into contact with.
What is suspension?
Particles held in fluid.
What is saltation?
When particles bounce and jump across a surface.
Traction
Particles rolling or dragged across a surface, not changing in trajectory.
When did Dust Bowl happen? What erosional force is it associated with?
1930s, deflation.
What is loess?
- Loosely compacted deposit of
- windblown sediment of
- which extensive deposits occur, e.g.,
- in eastern China and the American Midwest.
What is Hydrocompaction? What is it associated with, within the context of structures erected within the built environment?
- The process of volume decrease and density increase that occurs when moisture-deficient deposits compact as they are wetted for the first time since burial.
- Building collapse
High pressure = ___ air
Low pressure = ___ air
High pressure = cold air
Low pressure = warm air
How does pressure gradient relate to wind velocity?
Bigger pressure gradient = more intense winds
Pressure Systems and Pressure Belts:
- Equatorial Low Pressure Belt or ‘Doldrums’;
- Sub-Tropical High Pressure Belts or ‘Horse Latitudes;
- Sub-Polar Low Pressure Belts; and
- Polar High Pressure Belts.
What can be said about climate and weather in regard to the distribution of land and water across earth’s surface?
Discontinuous distribution of land and water sets the stage for variations in weather and climate.
What way do hurricanes spin in the Northern Hemisphere?
Counter-clockwise
What types of man-made or natural surfaces are:
1. Abrasion; and
2 Deflation
associated with?
- Abrasion damages man-made structures (e.g., sandblasting)
2. Deflation damages farmland (e.g., Dust Bowl; selective removal of specific particle sizes).
Along what lines of latitude are desert conditions found?
- Tropic of Cancer
2. Tropic of Capricorn
Ventrifact
A rock that has been modified by wind-driven erosional forces.
Blowout
Blowouts are depressions in a sand dunes caused by the removal of sediments by wind.
Desert Pavement
A desert surface covered with closely packed, interlocking angular or rounded rock fragments of pebble and cobble size.
Which side of a dune is steeper, leeward or windward?
Leeward, <34 degrees
