ocean 100 sacramentogrilo exam
3
what are the parts of the coastal region? - -1. coast
2. offshore
3. beach
4. berm
5. wave-cut platform
6. notch
- Coastal region - -land adjacent to the beach and affected by the ocean
(marine layer)
- coast - -land extending inland as far as marine influence is seen
- coastline - -base of cliff, think of the literal line that connect the bottom of
a cliff to the sand berm
- offshore - -extends from breakers to edge of continental shelf
- beach - -shore + nearshore (area between coast & shore); very active
- berm - -dry area at the foot of the coastal cliff - > sand
- tsunami, high tide, storm surge (flood the berm)
- wave-cut platform - -flat, eroded bedrock by wave energy, shallow
sand/sea floor that we are able to walk on in the shallow ocean
- notch - -cave cut into sea cliff by waves
- what does wave energy do to a coastal cliff over time? how? - -erodes it;
crashing waves push air and water into tiny rock crevices, repeated buildup
and release of pressure can weaken and fracture the rock
- Rivers and cliff erosion- sand to the berm? - -River: sediment on a beach
has been moved for long distance by rivers or ocean currents to its present
location; providing sand to the berm
Cliff: particles may fall from the cliff above and accumulate at the shoreline
- what can you say about the southern california sand supply? - -
LONGSHORE DRIFT: movement of sediment, along the coast driven by wave
action
mostly comes from cliff erosion
, Net southward transport of material along CA coast exceeds 230,000 meters
per year
Rivers, cliff erosion
70% of supply of sand comes from cliff erosion
- Longshore Drift occurs in 2 ways - -Wave-driven movement of sand along
the exposed beach
Current driven movement of sand in the surf zone offshore
- what are the principal sources of sand to the beach? - -1. erosion of cliffs
2. river run-off
- what are the 3 ways the berm can be flooded? - -1. tsunamis
2. high/spring tides
3. great storm surges
- Berm - -accumulation of sediment that runs parallel to shore and marks
the normal limit of sand deposition by wave action
- Summer season BERM - -wave energy is LOW
long, low waves push sand up to shore
creates LARGE BERM (wide berm sandy area)
- Winter season BERM - -wave energy is HIGH
short, high waves that brigs sand below sea level (sand bar)
creates a ROCKY beach with a NARROW BERM
algae on berm in winter (bad)
- longshore current - -movement of water in surf zones
approach beach at an angle
- Longshore drift - -transport of sediment due to winds (which direct the
waves) parallel to coasts
movement of sand grains
- what direction does the longshore current flow? - -parallel to the shore
- what direction does the longshore current go in Southern California? why? -
-north to south (towards La Jolla)
waves approach at an angle, current flow parallel to the shore, pushes sand
perpendicular because of the wind from the NORTH the WESTERLIES
- what are the 2 types of coasts? - -1. erosional
2. depositional
- erosional coast - -Coast eroded from wave energy
3
what are the parts of the coastal region? - -1. coast
2. offshore
3. beach
4. berm
5. wave-cut platform
6. notch
- Coastal region - -land adjacent to the beach and affected by the ocean
(marine layer)
- coast - -land extending inland as far as marine influence is seen
- coastline - -base of cliff, think of the literal line that connect the bottom of
a cliff to the sand berm
- offshore - -extends from breakers to edge of continental shelf
- beach - -shore + nearshore (area between coast & shore); very active
- berm - -dry area at the foot of the coastal cliff - > sand
- tsunami, high tide, storm surge (flood the berm)
- wave-cut platform - -flat, eroded bedrock by wave energy, shallow
sand/sea floor that we are able to walk on in the shallow ocean
- notch - -cave cut into sea cliff by waves
- what does wave energy do to a coastal cliff over time? how? - -erodes it;
crashing waves push air and water into tiny rock crevices, repeated buildup
and release of pressure can weaken and fracture the rock
- Rivers and cliff erosion- sand to the berm? - -River: sediment on a beach
has been moved for long distance by rivers or ocean currents to its present
location; providing sand to the berm
Cliff: particles may fall from the cliff above and accumulate at the shoreline
- what can you say about the southern california sand supply? - -
LONGSHORE DRIFT: movement of sediment, along the coast driven by wave
action
mostly comes from cliff erosion
, Net southward transport of material along CA coast exceeds 230,000 meters
per year
Rivers, cliff erosion
70% of supply of sand comes from cliff erosion
- Longshore Drift occurs in 2 ways - -Wave-driven movement of sand along
the exposed beach
Current driven movement of sand in the surf zone offshore
- what are the principal sources of sand to the beach? - -1. erosion of cliffs
2. river run-off
- what are the 3 ways the berm can be flooded? - -1. tsunamis
2. high/spring tides
3. great storm surges
- Berm - -accumulation of sediment that runs parallel to shore and marks
the normal limit of sand deposition by wave action
- Summer season BERM - -wave energy is LOW
long, low waves push sand up to shore
creates LARGE BERM (wide berm sandy area)
- Winter season BERM - -wave energy is HIGH
short, high waves that brigs sand below sea level (sand bar)
creates a ROCKY beach with a NARROW BERM
algae on berm in winter (bad)
- longshore current - -movement of water in surf zones
approach beach at an angle
- Longshore drift - -transport of sediment due to winds (which direct the
waves) parallel to coasts
movement of sand grains
- what direction does the longshore current flow? - -parallel to the shore
- what direction does the longshore current go in Southern California? why? -
-north to south (towards La Jolla)
waves approach at an angle, current flow parallel to the shore, pushes sand
perpendicular because of the wind from the NORTH the WESTERLIES
- what are the 2 types of coasts? - -1. erosional
2. depositional
- erosional coast - -Coast eroded from wave energy
