shoreline
the line that marks the contact between land and see
shore
the area that extends between the lowest tide level and the highest elevation on land that is affected by storms
foreshore
the area that is exposed when the tide is out (low tide) and submerged when the tide is in (high tide)
baskshore
___________ is landward of the high tide shoreline
nearshore
zone that lies between the low tide shoreline where waves break at low tide
offshore
zone is seaward of the near shore zone
beach
an accumulation of sediments found along the landward margin of the ocean or lake
inland
the coast extends _________ from the shore as far as ocean related features are found
coastal zone
wild beach with relatively flat platform
berm
composed of sand and marked by a change in slope at seaward edge
the wind
waves derive their energy and motion from
crest
top of the wave
trough
low area between waves
wave height
the vertical distance between a trough and a crest
wave length
the horizontal distance between crests
wave period
the time interval between the passage of two successive crests
the trough and crest
wave height is the distance between
crests
wave length is the distance between
crests
wave period is the time interval between the passage of two
wind speed
length of time
the fetch (distance)
length of time
the fetch (distance)
height, length and period of a wave depend on three factors:
wave of oscillation
this wave occurs in open sea in deep water
energy, the water
in the wave of oscillation ______ moves forward, NOT ______
wave of translation
this waves begins to form in shallower water
fetch
distance that the wind has traveled across open water
wave of oscillation
circular motion of particles, energy moves, not water
wave of translation
enery and water moves
trough is low area crest is top of the wave
difference in a trough and a crest
true
true or false; wave of oscillation transmits energy not water
time between two successive crests
how do we measure wave period
oblique
bent waves are called
wave impact and pressure
abrasion by rock fragments
abrasion by rock fragments
wave erosion is caused by
deposition of sediments in bay areas
over time wave erosion straightens an irregular shoreline
longshore currents
currents in the surf zone flow parallel to the coast
longshore currents
rip currents
concentrated movements of water that flow in the opposite direction of breaking waves
beach drift
waves that reach the shoreline at an angle (oblique waves) cause the sediment to move along a beach in a zigzag pattern called
rip currents
wave movement that can be hazardous to swimmers
rocks along the shore (hard v soft)
currents (strong v weak)
wave intensity
coast type (stable, sinking, or rising)
currents (strong v weak)
wave intensity
coast type (stable, sinking, or rising)
shoreline features vary depending on these factors:
wave-cut cliffs
shoreline feature caused by wave erosion that originates in the cutting action of the surf against the base of coastal land
wave cut platforms
shoreline feature that is a flat, bench like structure
marine terraces
shoreline feature that is a wave cut platform that stays above sea level
wave refraction (longshore current)
bending of a wave causes waves to arrive nearly parallel to the shore
wave cut platform
a relatively flat bench like surface that is left behind by a receding cliff
marine terrace
if a wave cut platform is uplifted above sea level by tectonic forces it becomes a
marine terrace
the fall of sea level due to a global cooling event will result in elevated position of wave cut platform making it a
spits
elongated ridges of sand extending from the land into the mouth of an adjacent bay
wave generated currents
often the end of a spit hooks landward in response to
baymouth bar
a sand bar that completely crosses a bay
spit
“hook” shape ridge of sand
baymouth bar
tombolo
a ridge of sand that connects an island to the mainland or another island
tombolo
barrier islands
low ridges of sand that are parallel to the coast
barrier islands
the atlantic and gulf coasts
barrier islands are mainly along
jetties
built in pairs to develop and maintain harbors
jetties
built to prevent deposition
groins
built to maintain or widen beaches
right angle
groins are constructed at a __________ to the beach to trap sand
breakwater
protects boats from the force of large breaking waves
offshore, parallel
breakwater barrier is built _______ and ________ to the coast
seawall
built very close to or on the beach to protect property
parallel to the shore
seawall barrier is
jetties
______ are always in pairs
trap sand upstream and cause erosion downstream
jetties and groins both
atlantic and gulf coasts
gently sloping, wide, tectonically quiet region
the barrier islands
in atlantic and gulf coats development of wave activity occurs mainly on
open ocean
barrier islands face the
atlantic and gulf coasts
which coast receives the full force of storms?
pacific coast
narrow coast, backed by steep cliffs and mountain ranges
narrowing of many beaches
a major problem with the pacific coast is
straighter coast
stable coast: if the shoreline remains stable, the result of shoreline erosion and deposition is to eventually produce a
emergent coasts
develop b/c of uplift of an area or a drop in sea level due to global cooling event
wave cut cliffs and wave cut platforms
most characteristic features of an emergent coast:
submergent coast
caused by subsidence of land adjacent to the sea or rise in sea level
irregular shoreline
estuaries
estuaries
most characteristic features of a submergent coast:
estuaries
drowned river mouths
tides
daily changes in the elevation of the ocean surface are called
moon and lesser the sun
tidal bulges are caused by the gravitational forces of the
spring tides
occur twice a month, during new and full moons
neap tides
occur during the first and third quarters of the mood (moon and sun act on earth at right angles)
spring tide
large daily tidal range
neap tides
daily title range is less
diurnal
a single high tide and single low tide each tidal day
semidiurnal
two high tides and two low tides each tidal day
tidal currents
horizontal flow of water accompanying the rise and fall of the tide
flood current
landward moving water advances into the coastal zone a the tide rises
ebb current
seaward moving water as the tide falls
tidal flats
areas affected by the tidal currents are called
