Chapter 7 Flashcards
Define Coast
transition zone between land and ocean
Define coastline
Farthest inland extent of storm waves
Define Shore
land between low tide line and coastline
Define shoreline
actual edge of water-changes daily with tides and storms
Define intertidal zone
part of the shore between low tide and high tide
Define backshore
only covered with water during the highest spring tides
Define foreshore
between high and low tide
Define nearshore
between low tide and breaker line-waves interact with the seafloor here-longshore bars and troughs are found here.
What is a longshorebar? In which season are they large?
Shallow sea floor that makes waves break on them because they are shallow.
Summer beaches
•Sand moves onshore•Wide and sandy berm•Smaller or no longshorebar•More deposition than erosion•Smaller and more gentle waves
Winter beaches
•Sand moves offshore•Large longshorebar•Rocky beach•More erosion than deposition•Larger waves
What is wave refraction?
–Waves bend upon entering shallow water–Result of friction–Bend towards shoreline–See Figure to the left•The white lines represent the crest of waves
Describe swash
the breaking wave runs up onto the beach
Describe backwash
the wave flows straight back to the ocean
What is a longshore current?
•Waves (swash) strike the beach at an angle•Backwash leaves beach •Together the swash and backwash make a zigzag path down the beach
What is a long shore drift?
is water or sand or anything drifting because the waves crash at an angle to the shore line.
What is causing the longshore current and longshoredrift to form?
waves coming in at an angle
What is the purpose of a breakwater
Protector harbors from waves
Purpose of Jetties?
Protect mouth of harbor or stream from closing off due to longshoredrift
Purpose of a groin?
Purpose is to widen beach
Purpose of a seawall?
Protect beaches, roads, buildings form waves
How does a rip current form? What should you do if you are caught in one?
Form when there is a break in a longshorebar•Water flows away from the coast in the break
What is a wetland?
Coastal area submerged at least part of the time-usually during high tide
Why are wetlands important?
•Filter pollution out of seawater•Trap sediment and build up land•Nurseries and habitat for coastal marine life•Support salt tolerant grasses and plants •Protects coastal areas from storm wavesChapter
Describe two types of wetlands.
Salt Marsh
Mangrove Swamps
What is an estuary?
Partially isolated body of water where fresh and saltwater mix
Four types of Estuary?
Coastal Plain Estuary
Bar-Built Estuary
Tectonic Estuary
Fjord
What is a tropical cyclone?
a localized, very intense low-pressure wind system, forming over tropical oceans and with winds of hurricane force.
Where do tropical cyclones form?
In the tropics….tropic of cancer to tropic of Capricorn.
Describe a storm surge?
Extreme waves above high tide
Where do hurricanes originate?
Typically form between 5 to 20 °N or S of the Equator
What is the minimum wind speed for a tropical cyclone to be classified as a hurricane?
wind speeds of 74 mph, keeps name given when classified as a tropical storm
What is the eye of the hurricane?
center, winds calm, little or no rain, skies clear
What is the eyewall of the hurricane?
most intense part of storm, highest winds, heaviest rain
What three conditions are necessary for tropical cyclones to form?
- high sea-surface temperatures (>80°F)2. Weak winds aloft3. Coriolis deflection (causes rotation)
What do you call a hurricane in the Indian Ocean?
•“Cyclones” –South Pacific and Indian Ocean
What do you call a hurricane in the West Pacific?
Typhoons north of the equator and cyclones south
Tropical Disturbance progression
low air pressure, group of organized thunderstorms
Tropical depression progression
sustained wind speeds of 23 mph
Tropical Storm progression
wind speeds of 39 mph, given a name at this point
Hurricane progression
wind speeds of 74 mph, keeps name given when classified as a tropical storm
When is it assigned a name? How are they named?
•Start at beginning of alphabet•Alternate male-female names•The next year begins with the opposite gender•2019-Andrea (female), Barry (male), Chantal (female), Dorian (male), Erin (female)•2020-Arthur (male), Bertha (female), Cristobal (male), Dolly (female), Edouard(male)•The next year starts at the top of the new list, even if all the names were not used.
Describe three hazards with hurricanes?
•Storm Surge–Extreme high waves•Flooding•Intense Wind
What is the Saffir-Simpson Scale? What factors is it based on?
•Scale of 1 to 5•Classify hurricanes based on–Air pressure–Wind speed
