Tides Flashcards

(39 cards)

1
Q

crest

A

high tide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

trough

A

low tide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

tidal range

A

difference between high/low tide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

tidal period

A

time difference between high/low tide, from 12hrs 25 mins to 24hr 50 min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

measure tides

A

tide stations (floats on sea and measures tides)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

spring tides

A

highest high tide, lowest low tide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

neap tide

A

highest low tide, lowest high tide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what do high tides coincide with

A

storm surges

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

how does coastal flooding occur

A

when high pressure pushes on ocean, if there’s tides it can cause flooding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

diurnal tides

A

one high/low tide a day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

semidiurnal tides

A

two high/low tides a day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

mixed tides

A

two high/low tides a day on unequal tidal range

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

how often do spring/neap tides occur

A

twice a month

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how many tides does earth have a day

A

2 high/low tides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

how are tides formed

A

gravitational force on ocean from moon and part of sun

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how does distance/mass effect pull

A

further away is weaker, heavier is stronger

17
Q

what forms high tide

A

gravitational pull from moon pulls ocean towards it creating high tide, the part that isnt pulled is low tide

18
Q

what time does high tide occur

A

12hr 25, 24hr 50

19
Q

what creates bulges that are positioned opposite to each other

A

gravity and centrifugal force

20
Q

how much more gravitational pull does moon exert

21
Q

centrifugal effect

A

earth pushes water out so can be pulled by moon

22
Q

equilibrium model assumes

A

earth has no land, progressive waves and water is equilibrium with tide generating forces

23
Q

what does equilibrium model mean

A

high latitudes have diurnal, mid latitude has mixed tides, low latitudes have semi diurnal

24
Q

when do spring tides occur

A

when earth/moon/sun aligned in straight line, bulges are larger than usual, equal pulling, greatest pull

25
when do neap tides occur
when earth/moon/sun aligned at 90 degrees, tidal bulges destructive, least pull, lowest bulge
26
why do tides occur 50 mins later each day
due to earth's rotation/moon orbit
27
when does lunar day occur
24hrs 50 min
28
dynamic model
actual earth, as earth rotates it forces water west which piles up and causes pressure gradient, water flows high to low which gets deflected by Coriolis to right and piles to south and builds up, high to low then Coriolis to east side then north etc
29
micro tidal
less than 2m
30
macro tidal
greater than 4m
31
diurnal (model)
1 cycle round basin
32
semi diurnal (model)
2 cycles round basin
33
wave progression
wave progresses over node (no displacement in middle of basin) to antinode (displacement, edge of basin)
34
where is highest tidal wave
furthest from node
35
what does dynamic model result in
rotary wave
36
long/narrow basins
not enough room to rotate to rush in/out, cotidal/corange parallel
37
tidal bore
water surges upriver with advancing high tide in narrow basins
38
factors needed for tidal bore to happen
large tidal range, narrow basin, decreasing depth upriver
39
flood current
water approaching land with high tide