Final Study Guide 7

Question 1

What is Coriolis force?

Answer 1

• Mass moving in a rotating system experiences a force perpendicular to the direction of motion. Deflects objects to the right in the northern hemisphere and to the left in the southern hemisphere.
• Not a real force but arises when you are comparing motions in a fixed rotating reference point. Velocity decreases compared to the equator. Example: If at the equator, shooting a cannonball north will cause it to bend to the right. If shooting south in the southern hemisphere, it will bend to the left.

Question 2

What is latent heat?

Answer 2

• Energy absorbed or released by a substance undergoing a change of state at constant temp

Question 3

What controls the path of a hurricane?

Answer 3

• Sea surface temperature as energy source and prevailing wind patterns (imposed by Hadley cells and Coriolis force that gives us general trend of wind patterns)

Question 4

What is a groin and how does it affect beach erosion?

Answer 4

• Groins are man-made structures designed to trap sand as it is moved down the beach by the longshore drift.
• As the longshore drift current approaches the groin, it is forced to slow down and change direction. This chance in velocity causes sand suspended in the current to be deposited on the up-drift side of the groin. As the current then continues around the groin, it becomes turbulent and actually contributes to erosion on the down-drift side of the groin.

Question 5

Why do hurricanes not cross the equator?

Answer 5

• Hurricanes do not cross the equator due to the Coriolis effect. (The Earth’s rotation causes the Coriolis Effect.)

Question 6

What human activities can increase beach erosion?

Answer 6

• Urbanization
• Added structures along the edge (pools and patios)
• Irrigation and other activities

Question 7

What is a storm surge?

Answer 7

• A rise in sea level as a result of low pressure and strong winds associated with a storm.

Question 8

Why does a hurricane need warm sea surface temperatures?

Answer 8

• Hurricanes are fueled by hot humid air found over warm oceans, causing latent heat.
• Warm ocean water leads to evaporation
• Warm, moisturized air rises
• Condensation releases latent heat
• Low pressure sucks in air, increases evaporation

Question 9

How are ocean waves formed?

Answer 9

• Wind blowing over the water produces friction along the air-water boundary. Since the air is moving much faster than the water, the moving air transfers some of its energy to the water, resulting in waves.

Question 10

How does refraction concentrate erosion at headlands?

Answer 10

• Waves bend toward the projecting part of the shore, increasing the wave impact on the headland.
• Wave refraction process:
  > A fast-traveling wave approaches from deep water
  > The part of the wave closest to the beach slows, causing the line of waves to refract toward the beach
  > Waves bend toward the projecting part of the shore, increasing the wave impact on the headland
  > Paths of crests diverge, decreasing the wave impact on the beach

Question 11

Coriolis Force

Answer 11

• a deflection of moving objects when they are viewed in a rotating reference frame; in a reference frame with clockwise rotation, the deflection is to the left of the motion of the object; in one with counter-clockwise rotation, the deflection is to the right
• Due to rotation of Earth plus inertia

Question 12

Latent Heat

Answer 12

• quantity of heat absorbed or released by a substance undergoing a change of state (ice to water etc.), at constant temperature and pressure

Question 13

Convection

Answer 13

• Heat of ocean water causes large scale convection cells that is for the energy for cyclones and hurricanes

Question 14

Refraction

Answer 14

• When the path of a wave is distorted by a change in velocity. Can happen when waves bend because certain parts of the wave reach a lower depth earlier. Important for wave action.
• This is the reason why tsunamis build up along the shoreline the speed of the wave is controlled by the symmetry of the water height
• The part of the wave closest to the beach slows, causing the line of waves to refract toward the beach. Wave bends toward the projecting part of the shore, increasing the wave impact on the headland. The bending of waves (convergence) towards the protruding areas (headlands) and the divergence of waves at the beach or embayment.
• Wave refraction
  > Bending of waves (convergence) towards the protruding areas and the divergence of waves at the beach or embayment

Question 15

Erosion

Answer 15

• Wearing away, abrasion, attrition; weathering; dissolution, corrosion, decay; deterioration, disintegration, destruction. the process of wearing off or being eroded by wind, water, or other natural agents the gradual destruction or diminution of something
• Sea cliff erosion: energy of erosion exceeds supply of sediment à wave and land erosion processes
• Coastal erosion: wearing away of land and the removal of beach or dune sediments by wave action, tidal currents, wave currents or drainage

Question 16

Beach

Answer 16

• is a landform consisting of loose material, such as sand or gravel, that has accumulated by wave action at the shoreline.

Question 17

Beach Budget

Answer 17

• Most beaches are in equilibrium — the material removed by erosion is compensated for by deposition
• Beaches contribute to protection of coastline à disappearance of a beach à problem of increased marine erosion

Question 18

Hurricane

Answer 18

• coastal hazard
• latent heat driven
• die down quickly on land
• the weaker the high altitude winds, the stronger the hurricane
• hurricane centers warmer than surroundings
• air in the center of the eye sinks downward
• Counter-clockwise rotation, Does not cross the equator, The spinning wind drives the hurricane but the vertical air force provides the energy, Air will want to move to a low pressure

Question 19

Jetty

Answer 19

• One of the ways to prevent the seasonal variation of beaches, human impact on the beach, considered a hard measure

Question 20

Sea Wall

Answer 20

• a form of coastal defense constructed where the sea, and associated coastal processes, impact directly upon the landforms of the coast; the purpose of a seawall is to protect areas of human habitation, conservation and leisure activities from the action of tides and waves

Question 21

Groin

Answer 21

• One of the ways to prevent the seasonal variation of the beaches, human impact on the beach, considered a hard measure, meant to stop the transport of sediments/ beach erosion

Question 22

Rip Current

Answer 22

• the water does not return as it came in, along the entire shoreline, but is concentrated in narrow zones.
• Horizontal movement of a large volume of sea water. Formed by a series of large waves surging to shore, then the rapid backflow of the piled up water in narrow zones. Large scale zig zag motion; Happens with long shore current, in and outcoming currents; patches of very muddy water because the current takes along more sand in the land flow; Kill more people than hurricanes on average

Question 23

Hadley Cell

Answer 23

• a large-scale atmospheric convection cell in which air rises at the equator and sinks at medium latitudes, typically about 30 degree north or south
• Hot sea floor temperature lead to air that is saturated with water; it then cools and condenses. This is due to the rotation of the earth and effects the general direction that the winds are blowing.
• The Doldrums and the Horse Latitudes are areas around the equator where there is mainly up and down movement this means that there is not enough wind to push boats

Question 24

Sand Budget

Answer 24

• includes transfer of sand between dunes, beach and shore face; it is the balance between the volumes of sand entering and leaving a littoral cell over the long-term that govern the long-term width of the beaches within the cell; scientists use the concept of sand budgets to identify and quantify, to the degree possible, additions and losses of sand that influence beach width
• Inputs:
  > Sediments eroded from backshore cliffs by waves
  > Sediments eroded from up current beach by longshore drift and current
  > Sediments brought in by rivers
• Outputs:
  > Sediments transported to backshore dunes by offshore winds
  > Sediments transported down current by longshore drift and current
  > Sediments transported to deep water by tidal currents and waves

Question 25

Sedimentary Transport

Answer 25

• the process that transports sand along the beach.
• Two components
  > (1) sand is transported along the coast with the longshore current in the surf zone;
  > (2) the up-and-back movement of beach sand in the swash zone causes the sand to move along the beach in a zigzag path.

Question 26

Tide

Answer 26

• The rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon and the Sun and the rotation of the Earth

Question 27

Storm Surge

Answer 27

• an abnormal rise of water generated by a storm, over and above the predicted astronomical tide

Question 28

Longshore Current

Answer 28

• is produced by incoming waves striking the coast at an angle
• Mix between swash pushing sediment onshore in an oblique angle, going back and forth, and drift hitting the shore.

Question 29

Cyclone

Answer 29

• Cyclones are stormy atmospheric systems that have the potential of causing destruction. They are caused due to instability in atmospheric conditions. According to the region and severity of stormy conditions, these storms may be referred to as typhoons or hurricanes.