Lecture 02-08-2017 (Post Midterm)

Question 1

What are the 7 categories of earth processes related to natural hazards?

Answer 1

1. Wind action
2. Streams
3. Ice action
4. Marine processes
5. Mass movement
6. Earthquakes
7. Volcanoes

Question 2

What drives patterns of atmospheric circulation?

Answer 2

Solar Radiation

Question 3

What determines the strength of wind?

Answer 3

The range of pressure gradient

Question 4

What is the “deflective force” which affects weather systems?

Answer 4

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.

Question 5

What is the Corollas effect?

Answer 5

1. An effect which causes fluids to curve as they travel across or above earths surface.
2. Caused by earth’s rotation from West to East; and
3. The difference in circumference from North to South.

Question 6

What is deflation or winnowing wind? Where is it of particular concern in Canada?

Answer 6

Deflation - the selective removal of fine grained particles from the earth surface (e.g., Dust Bowl areas)

Question 7

What is abrasion and attrition?

Answer 7

1. Particles are picked up;
2. Collide with each other and against surfaces;
3. Reduce in size and changing in shape; and
4. Modify the surfaces which they come into contact with.

Question 8

What is suspension?

Answer 8

Particles held in fluid.

Question 9

What is saltation?

Answer 9

When particles bounce and jump across a surface.

Question 10

Traction

Answer 10

Particles rolling or dragged across a surface, not changing in trajectory.

Question 11

When did Dust Bowl happen? What erosional force is it associated with?

Answer 11

1930s, deflation.

Question 12

What is loess?

Answer 12

1. Loosely compacted deposit of
2. windblown sediment of
3. which extensive deposits occur, e.g.,
4. in eastern China and the American Midwest.

Question 13

What is Hydrocompaction? What is it associated with, within the context of structures erected within the built environment?

Answer 13

1. 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.
2. Building collapse

Question 14

High pressure = ___ air

Low pressure = ___ air

Answer 14

High pressure = cold air

Low pressure = warm air

Question 15

How does pressure gradient relate to wind velocity?

Answer 15

Bigger pressure gradient = more intense winds

Question 16

Pressure Systems and Pressure Belts:

Answer 16

1. Equatorial Low Pressure Belt or ‘Doldrums’;
2. Sub-Tropical High Pressure Belts or ‘Horse Latitudes;
3. Sub-Polar Low Pressure Belts; and
4. Polar High Pressure Belts.

Question 17

What can be said about climate and weather in regard to the distribution of land and water across earth’s surface?

Answer 17

Discontinuous distribution of land and water sets the stage for variations in weather and climate.

Question 18

What way do hurricanes spin in the Northern Hemisphere?

Answer 18

Counter-clockwise

Question 19

What types of man-made or natural surfaces are:
1. Abrasion; and
2 Deflation
associated with?

Answer 19

1. Abrasion damages man-made structures (e.g., sandblasting)

2. Deflation damages farmland (e.g., Dust Bowl; selective removal of specific particle sizes).

Question 20

Along what lines of latitude are desert conditions found?

Answer 20

1. Tropic of Cancer

2. Tropic of Capricorn

Question 21

Ventrifact

Answer 21

A rock that has been modified by wind-driven erosional forces.

Question 22

Blowout

Answer 22

Blowouts are depressions in a sand dunes caused by the removal of sediments by wind.

Question 23

Desert Pavement

Answer 23

A desert surface covered with closely packed, interlocking angular or rounded rock fragments of pebble and cobble size.

Question 24

Which side of a dune is steeper, leeward or windward?

Answer 24

Leeward, <34 degrees

Question 25

Erg

Answer 25

An erg is a broad, flat area of desert covered with wind-swept sand with little or no vegetative cover. The term takes its name from the Arabic word ʿarq (عرق), meaning “dune field”.

Question 26

Hydrocompaction

Answer 26

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.