Sea Level, Tides, & Waves Flashcards
changes in sea level is changes to sea ______
volume
what two main processes affect sea level/sea volume?
- how much water is stored in glaciers and ice sheets
2. fact that water molecules expand in warmer temps and contract in cooler
Expansion/contraction of ocean water in response to ________ changes
temperature
______ temperatures means more meltwater from ______.
higher, glaciers
If there is more meltwater from glaciers, then…
the sea level will raise
If you have colder global climates, sea level will…
drop
why will sea level drop with colder global climates?
because there will be more water frozen into glaciers and ice sheets
water molecules expand in _____ temperatures, and contract in _____ temperatures
warmer, cooler
current sea levels _____ at an average of ____ mm per year
rise, 2.5
which areas are more at risk for sea level rises?
low-level flat coastal areas
what are some effects of sea-level rising?
- more erosion during serve storms
- pushed back beaches
- land subsidence.
- causes decreases in fish and shelfish population
what is land subsidence?
AS soil becomes saturated, the land will sink, and houses will sink along with it or down into it
what are tides?
the rise and fall of sea levels that occur on a daily level
Every _____ hours we see two high tides
24
Every 24 hours we see ____ high ties
2
Every ____ hours we see two low tides
24
every 24 hours we see how many low and high tide?
2 of each 2 high, 2 low
What are tides caused by?
the gravitational attraction of the moon and the sun
AS the Earth rotates on its _____ the moon and the sun are constantly _____ on the waters of the Earth
axis, pulling
The Earth is constantly is rotating through…
the gravitational attraction
As tides moves in and out of coasts they set up tidal _____
currents
As the tide falls and lowers ____ water flows out towards the sea.
more
when the tide falls and lowers more water flows out towards the sea. This is called which current?
ebb current
rising tide creates the _____ current
flood
tidal currents act to remove…
sand piled up by shore processes
Tidal currents _____ and ______ sediment that is rich in organic material, such as dead fish carcasses and seaweed
carry, deposit
a wave is _____ in the ocean
energy
what is a wave caused by?
the energy of the wind
shallower water _____ the wave towards its ____
retardas, base
what is a rip current?
a localized narrow channel of seaweed-flowing water
a localized narrow channel of seaweed-flowing water is called…
a rip current
a rip current can…
carry material far out to sea very quickly
wave energy is a very efficient method of _____
erosion
On ocean shores, the force of the wave energy is _____ enough to break down rock into _____ sized particles
strong, sand
lakes do not have strong enough _____ _____ to break down rocks into sand sized particles
wave energy,
usually pebble sized
waves are efficient at _____ sediment
moving
what are the three pathways/methods that waves move sediment?
beach drift
longshore current
littoral drift
what is beach drift?
the movement of particles in and out of the beach
the movement of particles in and out of the beach is called…
beach drift
beach drift is the movement of _____ in and out of the beach
particles
beach drift moves ______ to the shoreline
perpendicular
the longshore current carries material ______ to the shoreline
parallel
-current moves parallel to the shoreline
beach drift and longshore current combine to form…
littoral drift
the littoral drift transports sediment at _____ angles down the beach.
oblique
