Coastal Hazards - Hazards and Mitigation

Question 1

Most coastal hazards are related to ________ because this is when both _______ and _______ energy are at their highest.

Answer 1

storm events; wind and wave

Question 2

refer to large, rotating low pressure storm systems that originate in tropical oceans

Answer 2

tropical cyclones

Question 3

Exceptionally strong tropical storms are called ________, ________, or _______ depending on where they form in the Tropics

Answer 3

typhoons, hurricanes, or cyclones

Question 4

Tropical cyclone develop over the __________
parts of oceans where a low pressure disturbance can become amplified into a gigantic, rotating storm composed of __________ and ___________

Answer 4

warm tropical ; high winds and intense precipitation

Question 5

Winds and low pressure within a
hurricane produce a rise in sea level
called a __________ and will also produce
heavy rains that commonly lead to _________

Answer 5

storm surge ; river flooding

Question 6

what causes storm surges?

Answer 6

winds and low pressure within a hurricane

Question 7

cyclones, hurricane, or typhoons can produce winds with speed of:

Answer 7

> 150 miles/hr

Question 8

How are hurricanes formed?

Answer 8

Hurricanes form around low pressure disturbances as evaporation removes heat energy and water from tropical waters. The resulting convection combined with Earth’s spinning motion produces a rotating system centered about the low pressure
area of the eye.

Question 9

Hurricanes form around ____________ as evaporation removes_______ and _______ from tropical waters.

Answer 9

low pressure disturbances ; heat energy and water

Question 10

________, _______, and ________cause major damage to coastal areas

Answer 10

Intense winds, rains, and wind action

Question 11

The unusually strong winds associated with
hurricanes result from the circulating air
masses within the storm.

Answer 11

high winds

Question 12

The unusually strong winds associated with
hurricanes result from

Answer 12

circulating air masses within the storm

Question 13

Different hurricanes are ranked based on
their__________, with the lowest
category having winds of at least ____________ anything less is called a ___________.

Answer 13

sustained winds ; 74 miles/hr ; tropical depression/storm

Question 14

used to rank hurricanes based on their wind speed

Answer 14

Saffir-Simpson scale

Question 15

t or f: the area of low pressure
beneath a hurricane exerts less weight
on the ocean surface, allowing it to rise

Answer 15

t

Question 16

The rotating eye of a hurricane is an
area of ____________

Answer 16

abnormally low pressure

Question 17

This dome shaped water will literally
move or surge up onto land as the
hurricane makes landfall, producing a
rapid rise in sea level called a __________

Answer 17

storm surge

Question 18

storm surges can go up to ___________ rise in seal level

Answer 18

9 meter

Question 19

This rapid rise in sea level, called a __________, is greatest on the __________ side of the eye as the ___________ rotating system pushes water up against the shoreline.

Answer 19

storm surge; northeastern ; counterclockwise

Question 20

explain how storm surges are formed

Answer 20

The decrease in air pressure toward the eye of a
hurricane allows the sea surface to rise, creating a dome of water that follows the storm inland. This rapid rise in sea level is called a storm surge

Question 21

explain how storm surges are formed

Answer 21

The decrease in air pressure toward the eye of a
hurricane allows the sea surface to rise, creating a dome of water that follows the storm inland. This rapid rise in sea level is called a storm surge

Question 22

t or f: tropical depression is stronger than tropical storm

Answer 22

F

Question 23

what category of hurricane swept over Galveston Island, Texas, in 1900?

Answer 23

hurricane 4

Question 24

__________ commonly leads to inland flooding far from
where a storm makes landfall.

Answer 24

intense precipitation

Question 25

In addition to a storm’s precipitation rate, another key factor affecting the level of flooding is a storm’s _____________ as it moves over land.

Answer 25

forward speed

Question 26

what are considered a "slow moving storm"?

Answer 26

less than 10 miles/hr (16 km/hr)

Question 27

t or f: slow moving storm are particularly more dangerous since more rain will fall on a given area compared to a storm that passes more rapidly

Answer 27

t

Question 28

t or f: Rainfall intensity will increase when an ocean storm moves inland and encounters rugged or mountainous terrain

Answer 28

t

Question 29

explain how an ocean storm increases intensity when encountering mountainous terrain

Answer 29

the humid air masses within the storm will rapidly gain elevation, thereby resulting in faster cooling rates which in turn increase the condensation and precipitation rates

Question 30

what is the oldest form of mitigation strategy for storm hazards?

Answer 30

avoiding locating large settlements directly on the coasts

Question 31

ways to mitigate storm hazards

Answer 31

1. avoiding locating large settlements directly on the coasts 2. Development of early warning systems such 3. weather satellites continuously tracking the storms’ location 4. forecasting models 5. elevate a building above the expected storm surge level 6. Metal straps to secure the roof to the main structure

Question 32

t or f: tsunamis are formed by wind

Answer 32

F (it is formed by earthquakes, volcanic eruptions, landslides, and meteorite impact)

Question 33

typical wavelengths of a tsunami

Answer 33

6-300 miles (10-500km)

Question 34

height of tsunami waves in deep water

Answer 34

less than a meter

Question 35

typical speed of tsunami waves

Answer 35

over 500 miles per hour (800 km/ hr )

Question 36

One of the most effective mitigation strategies relies of mitigating tsunami hazards

Answer 36

early warning system and public education

Question 37

early warning system involves utilizing a network of ________________ for detecting subduction zone earthquakes that have a potential for generating a tsunami

Answer 37

seismograph stations

Question 38

this instrument detect passing tsunami waves based on their unusually long wave length and high velocity.

Answer 38

deep ocean buoys

Question 39

japan tsunami engineering controls

Answer 39

large gates and walls

Question 40

are strong currents that flow away from shore

Answer 40

rip currents

Question 41

how does rip currents form?

Answer 41

when backwash from the surf zone funnels through a break in underwater sand bars

Question 42

create a narrow, but powerful current that flows toward deeper waters

Answer 42

rip current

Question 43

what to do if you get caught in a rip current

Answer 43

stay calm and swim parallel to shore

Question 44

Solid walls made of resistant materials such as concrete, rocks, or wood built parallel and on the coast.

Answer 44

sea walls

Question 45

what is the downside of a sea wall?

Answer 45

as waves break against the sea wall, the energy is directed to the bottom of the sea wall creating a strong backwash that erodes the base of the sea wall, making it unstable and eventually collapse

Question 46

Solid walls usually made of granite built of and parallel to the coast, or with one end attached to the coast

Answer 46

Breakwaters

Question 47

breakwaters are usually made of________

Answer 47

granite

Question 48

breakwater creates a zone of _______ behind them which encourages ___________ and ________ of beaches

Answer 48

calm waters ; deposition and formation

Question 49

downside of breakwaters?

Answer 49

only the zones behind them are protected while those otherwise are not

Question 50

Solid walls usually made of granite or wood built on and perpendicular to the coast.

Answer 50

groynes / groins

Question 51

groins are usually made of

Answer 51

granite or wood

Question 52

Absorbs or reduces wave energy and encourages deposition on the side of the groyne facing _____________

Answer 52

longshore drift

Question 53

this term refers to a series of groins

Answer 53

Groin field

Question 54

what is the downside of groins?

Answer 54

down drift beaches (other side of the groin) become starved, causing shoreline retreat to accelerate.

Question 55

barriers made of large rocks and are installed at the mouth of an inlet to keep sediment from longshore current to clog channels, and thereby reducing dredging costs

Answer 55

Jetties

Question 56

t or f: longshore currents will periodically reverse from their dominant direction

Answer 56

t

Question 57

why do jetties come in pair?

Answer 57

because longshore currents will periodically reverse from their dominant direction

Question 58

what is the downside of using jetties?

Answer 58

causes down drift areas to experience rapid shoreline retreat as beaches there are starved of sand.

Question 59

Wire cages filled with small rocks piled up and placed along the coast.

Answer 59

Gabions

Question 60

downside of gabions

Answer 60

only offer short term protection as the rocks are easily eroded away and the cages corrodes easily.

Question 61

the only real solution to beach starvation is to manually add sand to the beach in a process called

Answer 61

beach nourishment

Question 62

The most cost effective way of nourishing a beach is usually by

Answer 62

pumping sand up onto the beach from offshore sand deposit

Question 63

t or f: beach nourishment disrupt the longshore current

Answer 63

F (does not)