Waves-Currents-Tides Flashcards
Waves propagate __ not water
energy
Shallow-water waves are called shallow because…
The depth of the wave-base is greater than the depth of the water
Deep-water waves are considered deep water because…
The depth of the wave-base is much less than the depth of the water
What is the velocity of deep water waves?
(v)deep = 1.25sq.rt length
What is the velocity of shallow water waves?
(v)shallow = 3.13sq.rt depth
Describe the wave orbit of deep-water waves.
Deep-water wave orbit are consistently circular throughout their depth
Describe the wave orbits of shallow-water waves.
waves orbits of shallow-water waves are more oval shaped as height increases
Define cat’s paw.
cat’s paw is a term used to describe the clashing of multiple waves stemming from different directions; forming no definite wave shape
Which factors influence wave height(h), energy (e), length(l), and duration(t)?
- wind speed
- wind duration
- fetch/ open distance over water
Name of the machine that harness wave energy to create electricity.
Pelamis machine
List the types of coasts.
- transgressive
- regressive
- emergent
- submergent
List the types of depositional landforms
- beaches and coastal dunes
- barrier islands
- deltas and marshes
- spits and bay mouth-barriers
- tombolos
List the types of erosional landforms
- sea arches
- sea stacks
- sea cliffs
- platforms
Define submerged coasts.
Submerged coasts are coastal regions of land that are in the process of being submerged due to rising sea levels
What does the acronym LUST stand for?
L = landward
U= upward
S = space
T = time
What does the acronym LUST refer to?
LUST refers to the movement of water landward and upwards causing erosion on one side of the land and deposition on the other side of land over time
A delta can only survive if…
the amount of reiver sediments is deposited at a rate faster than the sea-level rises
What is the first action that leads to a tsunami?
abrupt vertical movement of the sea floor
What is the second action that leads to a tsunami?
the tsunami radiates from the bottom of the sea floor into all directions
What is the third action that leads to a tsunami?
from the deep water, the tsunami travels quickly but is small
What is the fourth action that leads to a tsunami?
as the tsunami arrive in shallow water, the energy is compressed creating a taller tsunami
What is the fifth action that leads to a tsunami?
at the shire the tsunami expends its energy as alternating surges and withdrawls
How many tides do all locations (except the poles) have per day?
all locations have two high tides and two low tides per day
Are all tides the same height?
no. neither the two high tides or the two low tides are the same height due to positional changes in the sun and moon
What determines the monthly and yearly cycles of tidal ranges?
changes in the distance of the sun and moon from the earth
How often should there be changes in the alternating spring and neap tides?
every week
How many spring and neap tides should there be every lunar month?
two spring tides and two neap tides
What is the machine called used to harness tidal energy?
underwater turbines
What are the causes of sea-level fluctuations?
- climate change (malenkovich cycle)
- techtonics and crustal rebound since ice age
- humans (deforestation, greenhouse gasses/ globals warming, and oil/ groundwater extraction)
List ways to protect against coastal erosion.
- understand the geologic processes and act accordingly
- follow setback rules
- seawall and recurved walls
- wave breakers or submerged break water
- rip-raps (rock armor) and stablers
- beach nourishment
- groin and jetties
