oceanography Flashcards
(244 cards)
1
Q
origin/meaning of oceanography
A
okeanos - Oceanus
graphia - recording/ describing
2
Q
why oceanography isn’t really a correct term
A
oceanology = study of oceans
3
Q
oceanography as a pure science
A
not. it is a compilation of biology, chemistry, physics, geology.
4
Q
3 broad stages of ocean exploration
A
1,2 Early investigations
3. Modern investigations
5
Q
Early investigations focused on
A
exploring oceans
exploring landmasses
early scientific investigation of ocean
6
Q
Early oceanography, the explorers
A
James Cook
Robert Fitzroy
Wyville Thomson
Fridtjof Nansen
7
Q
Early oceanography, the time
A
1700-1900 CE
8
Q
James Cook
A
1768-1779
3 major voyages
mapped NZ and Aust
data: geo, bio, currents, tides, temps
9
Q
Robert Fitzroy and Charles Darwin
A
1831-1836
HMS Beagle
South America, Galapagos
10
Q
Came out of the HMS Beagles expedition
A
Two major ecological theories
- Atoll formation
- Natural selection
11
Q
Wyville Thomson
A
1872-1876
Circled globe
Explore abyss
data: water chem, temp, currents, biota, sedimentary
12
Q
Major Thomson discoveries
A
Refuted abiotic abyss theory
Recorded 7000+ species down to 9km
First sea-bottom topography charts
13
Q
Abiotic abyss theory
A
Forbes
no species in abyss
14
Q
Nansen
A
1893-1896
circulation of Arctic ocean
Drifted in boat (Fram) for three years locked in sea ice off Siberia, about 2km/yr
15
Q
Nansen discoveries
A
no polar continent
water depths along path
water-mass structure
circulation patterns
16
Q
Modern Oceanography
A
1900+ CE
Marine institutes
German scientists
Collaborations
17
Q
Marine institutes
A
beginning of educating people in oceanography
Scripps, 1903, California
Woods Hole, 1930, Mass.
18
Q
German scientists
A
1925-1927
Survey S Atlantic
Echo sounding
Vertical profiles
19
Q
Major collaborations
A
International geophysical year, 1957-1958
International Indian ocean expedition, 1959-1965
Deep sea drilling project, 1968-1975
20
Q
Major discoveries of deep sea drilling project
A
seafloor spreading
plate tectonics
21
Q
Current/ future research
A
- International efforts (cost)
- Technology
22
Q
Oceanography technology
A
Submersibles (Alvin)
ROV (Jason)
Computers (Modelling)
Satellites (GPS)
23
Q
Earths interior, sections
A
Crust
Mantle
Outer core
Inner core
24
Q
Earth’s crust
A
solid
35-50km, 0.4%
Al, Si, O
25
Earth's Mantle
Solid / plastic
2900 km, 68%
Mg, Fe, Si, O
26
Outer core
Molten
| 2200km thick
27
inner core
Solid
1300km
Fe, Ni
28
Earths divisions based on physical characteristics
```
Lithosphere
Asthenosphere
Mesosphere
Outer core
Inner core
```
29
Lithosphere
Rigid and brittle
| Crust + upper mantle
30
Asthenosphere
Plastic
intermediate mantle
T>P
31
Mesosphere
rigid
lower mantle
P>T
32
Outer core physical state
molten Fe-Ni alloys
| T>P
33
Inner core physical state
solid Fe-Ni alloys
| P>T
34
Earths spheres
Hydrosphere
Atmosphere
Biosphere
35
Hydrosphere
all 'free' water
97% in ocean
10% of total water
36
Atmosphere
gases
| N 79%, O 16%
37
Remaining 90% of water, not in hydrosphere
locked in rocks
38
Biosphere
living and non-living
thin but dynamic
organic - C, H, O
39
Measurement of seafloor topography based on depth
bathymetry
| greatly improved after WWII
40
physiographic provinces
Continental margins
deep ocean basins
midocean ridges
41
Parts of continental margin
continental shelf
continental slope
continental rise
42
Continental shelf
up to 1000km wide
0.5 deg slope
ends at 130-200m depth
43
continental slope
2-3km deep
4 deg slope
steep, v-shape canyons
44
continental rise
up to 500km wide
1 deg slope
base up to 4km deep
45
Deep ocean basin
beyond margin
| several bathymetric features
46
bathymetric features
Abyssal plains
abyssal hills
seamounts
deep-sea trenches
47
Abyssal plain
3-5km deep
100-1000m thick
<0.5 deg slope
48
Abyssal hill
domes
<1000m tall
100km wide
volcanic rock
49
Seamount
>1000m tall
| Extinct or active volcano
50
flat-topped seamount
guyot
51
deep-sea trench
3-5km deeper than surrounding
against contin. margin
partially sed. filled
steep-sided
52
Midocean ridges
```
Connected, >60,000km
cover 1/3 of ocean floor
mountain ranges
rift valley
geologically active
volcanoes, earthquakes
transform faults
```
53
max ocean depth
11km
54
earthquake epicentres
midocean ridges
transform faults
deep sea trenches
55
earthquake types
shallow and weak
| shallow-to-deep and strong
56
band of earthquakes in subduction zone
benioff zone
57
benioff zone
45 degrees into earth
| subducting plate and melting
58
after subducting plate melts
molten portion lower density, rises to surface, volcanic arc
59
Predominant subduction zones
Pacific (ring of fire)
| 15-45 cm/yr subduction
60
ocean-ocean convergence produces
andesite
| density btw basalt and granite
61
lithosphere contains
brittle outer shell
crust
upper mantle
62
3 types of plate boundaries
tension
compression
sliding
63
sliding plate boundaries
transform faults
64
tension plate boundaries
divergent zones
65
driving force of plate tectonics
thermal convection
66
thermal convection
heat transfer by fluid motion
heat - lower density - rise - convect
currents- draging of plates
cold edge of subducting
67
slab-pull
subducting plate pulls plate down
68
water molecule
dipole
bent
105 deg between H
covalent bonds
69
covalent bonds
share electrons
70
H2O residual charge
+ at H end
| - at O end
71
most common elements dissolved in seawater
Na+
| Cl-
72
water clusters
irregular grouping of molecules
size decreases w/ increased T
H bonded
73
Ice density
8% less than water
74
Ice
open hexagonal crystals
angle btw H expands to 109.5
chemical bonding
75
water density
max at 3.98 deg C
76
solutes in seawater
```
salt ions
nutrients
gases
dissolved metals
org compounds
```
77
salt ions
major constituents
85.6% Na and Cl
99% w/ sulfate, Mg, Ca, K
78
particles that don't change concentration over large areas on average
conservative
79
salinity
g/ kg seawater
| ppt
80
principle of constant proportion
relative proportions of major constituents are constant
81
use of principle of constant proportion
can determine S by measuring only one ion
82
measuring salinity
conventionally measure Cl- and use principle of constant proportion
83
chlorinity /salinity relation
S = 1.80566 x cholorinity
84
why measure Cl -
halogen
| less reactive
85
sw freezing pt
-1.91 @ 35 ppt
86
sw density
greater than fw
| adding solutes increases atomic mass
87
sw vapor pressure
lower than fw
salinity lowers vp
fw evaporates at higher rate
88
why does salinity lower vp
more molecular bonds
89
isotherms
parallel to latitudes
| vary seasonally
90
characteristic of tropical, temperate oceans
thermocline
91
thermocline depths
200-1000m
92
temperate ocean thermocline
~ inexistent in March
grows during spr-summ
weakens in winter
93
global salinity
highest btw 20-30 deg
| decreases twd poles, equator
94
surface salinity
- dependent on evaporation and precipitation
| - closely follow evap-precip line
95
polar SST
low
| evap and precip both minimal
96
temperate SST
low
evap moderate
precip max
97
haloclines occur
40 deg N - 40 deg S
98
subtropical SST
max
evap max
precip min
99
tropical SST
medium
evap max
precip max
100
density =
mass per unit volume
| g/cm3
101
density depends on
temperature
salinity
pressure
102
pycnocline layer
corresponds with thermocline and/or halocline
103
outside of pycnocline
surface layer 2% , 100m thick, seasonal
| deep layer 80%
104
tropical pycnocline
corresponds to permanent thermocline
105
temperate pycnocline
coincides with halocline
106
primary regulator of gas [ ] in sw
biotic activity
| photosyn, resp., decomp
107
O2 profile
highest at surface
O min zone
Increases then levels in deep
108
O2 min zone depth
150 - 1500m
109
pH =
-log10[H+]
110
what does pH 7 mean
neutral
| 1/10 million molecules (10^-7) molecules dissociate into H and OH ions
111
addition of CO2 to SW
lowers ph of water
112
H2O+ CO2
- > H2CO3
- > H + HCO3 -
- > CO3 + 2H
113
carbonic acid
H2CO3
114
pH of normal sw
7.8 - 8.2
115
most inorganic C is in the form
bicarbonate
89%
HCO3
116
main source of dissolved ions
rivers
117
solar energy
stratifies water column
| photosynthesis
118
air constituents
N 78
O 21
CO2 + halogens + water vapor +... 1%
119
Pressure =
pgh
| p=ro= density
120
coriolis
In NH deflection to right
121
coriolis becuase
velocity of rotation different at poles relative to equator
122
strength of coriolis dependent on
speed
| location
123
equatorial air currents
divergent
| heat - rising air - high pressure - circulates
124
polar air currents
low pressure - cooled air - sinking - convergence
125
atmospheric cells
hadley - equator
ferrel - mid lats
polar
126
atmospheric air movements
Northeast trades, Hadley
Westerlies, Ferrel
Polar easterlies, polar cell
127
wind-driven current
from frictional drag
| 4% of wind speed
128
midlatitude currents
flows eastward from the westerlies
129
low lat currents
flow westward from trade winds
130
Ekman transport
net flow of water to the right (NH) of the wind 45 deg - drags the layer below - that layer moves 45 deg to the right - drags next layer - .. etc
131
Depth that Ekman transport effects
100-200m
132
net water transport due to Ekman
to the right 90 deg
133
Water movement on east side of continents (NH)
deflected to the right away from continent, deeper water moves up to replace, upwelling
134
NH gyres
water deflected to the right all the way around the gyre - convergence in middle - downwelling
135
series of parallel, counter-rotating circulation cells
langmuir circulation
136
langmuir circulation direction
long axis aligned parallel to wind
137
Langmuir characteristics
- wind >= 3.5 m/s
- 10-50 m wide
- 5-6 m deep
- several km long
138
thermohaline upwells where
pacific and indian
139
classification of organisms (lifestyle)
plankton
nekton
benthos
140
forms of plankton
phytoplankton
zooplankton
bacterioplankton
virioplankton
141
forms of benthic organisms
epifauna
infauna
epiflora
142
classification of organisms (size)
```
megaplankton (jellies)
macroplankton (krill)
mesoplankton (copepod, foramin.)
microplankton (coccolith.)
nanoplankton (diatoms, dinof.)
picoplankton (bacteria)
femtoplankton (viruses)
```
143
classification of organisms (life-history)
Holoplankton
| Meroplankton
144
organisms which are planktic their whole lives
holoplankton
145
distribution of marine species closely follows
isotherms
146
rates of biological activity
double per 10 deg. rise
147
polar organisms
grow slower
reproduce less
live longer
148
physical process where molecules move from areas of high [ ] to low [ ]
diffusion
149
pressure depth relationship
1 atm per 10 m
150
marine fish osmoregulation
body fluid less saline than water
- osmotic water loss
- low urine prod.
- drink SW
- excrete salt through gills
151
terrestrial food chains
ca. 3 links
152
diffusion of water molecules through a semipermeable membrane
osmosis
153
marine food webs
ca. 5 links
154
land vs ocean photosynthesis products
```
L: high light
high nutrient
low CO2
low water
O: opposite
```
155
Diatom size
2 um - 4mm
156
diatom characteristics
10000+ spp.
abundant at high lats
single or chains
157
diatom classification
centric
| pennate
158
diatom body form
hypotheca inside epitheca (frustules)
| chloro., nucleus, oil
159
oil, projections, perforations
increased SA - buoyancy
160
Dinoflagellate size
2 um - 2 mm
161
dinoflag. characteristics
```
1000+ spp.
usually solitary
primitive plastids + secondary pigmants
asexual
-starch and lipids
-mixotrophic
-dont need Si
-low SA:V
-can migrate vertically
```
162
dinoflag. form
- armored or unarmored
- 1+ layers of cellulose
- 2 flagella in grooves
163
dinoflag. flagella grooves
cingulum- encircles, for rotation
| sulcus - displacement
164
dinoflag. pigments
chlorophyll a, c
beta-carotene
peridinin
165
dinoflag. vs diatoms
- advantage over diatoms
| - more abundant in tropic water
166
specialized dinoflag.
zooxanthellae
| HABs
167
zooxanthellae
no flagella
| symbiont in many species (coral, jellies, molluscs)
168
HABs
harmful algal blooms
- produce toxins
- deplete oxygen
- paralytic shellfish poisoning
169
types of Haptophytes
coccolithophores (most)
| haptophyceae
170
haptophyte characteristics
```
370 spp
2-20um
1-2 chromatophore
2 flag.
calcareous plates
auto, hereo, mixotrophic
```
171
haptophytes responsible for
40% of carbonate production in modern seas
172
haptophyte speacilized structure
haptonema
defense or prey capture
sticky tip
173
Cyanobacteria character
prokaryote
blue-green algae
single, colony, filaments
starch, lipids
174
cyanobacteria well adapted to
nutrient-poor open ocean tropics
| -like lots of sun and O2
175
cyanobacteria pigments
```
chlorophyll a, b
beta-carotene
xanthophylls
phycoerytherin
phycocyanin
```
176
carotenoids
beta-carotene (yellow)
| xanthophylls (brown)
177
phycobilins
phycoerythrin (red)
| phycocyanin (blue)
178
Nitrogen fixation
conversion of atm N into useable form
179
Nitrification
conversion of ammonia from waste and detritus to nitrate ions
180
Heterocyst
- contain specialized enzymes
- cyanobacteria
- N fixation / nitrification
181
Foraminiferan
```
zooplankton
pseudopods
multi-chamber test
consume diatoms, bacteria
sexual and asexual
```
182
foramin pseuodopods
form reticulopods - net-like structures
183
foramin limitations
2000 m
| CCD
184
radiolarian
Actinopoda
- benthic grazer or planktonic suspension
- long needle-like pseudopods
- Si skeleton and spines
185
copepod
<1mm - few mm
- jerky motions
- large antennae
- complex life cycle
186
copepod feeding
create water stream w/ head appendages - moves particle down ventral surface - capture with 2nd maxillae - brought to mouth
187
copepod life cycle
6X Nauplii
| 5X copepodid
188
Major zooplankton
```
krill
cladoceran
foraminiferan
radiolarian
ctenophore
arrow worm
scyphozoan (jelly)
siphonophore (MoW)
```
189
amount of E lost at each transfer
80-95%
190
C =
energy ingested
= A + F
= E assimilated + E lost Feces
191
A =
E assimilated
= P + R + U
= 2dary product. (growth) + E loss respiration + E loss nitrog. waste
192
P =
growth =
C - R - U - F
= food - respiration - urea - feces
193
force required to separate water molecules allowing organism to pass
viscosity
194
viscosity, T
negatively correlated
195
viscosity, S
positively correlated
196
SR =
```
sinking rate =
(W1 - W2) / R V
W1 = org density
W2 = SW density
R = surface of resistance
V = viscosity of SW
```
197
why phytopl. should float or sink
nutrients
sunlight (good and bad if too high)
dont get stuck under thermocline
198
why zoopl. should float or sink
follow the phyto
199
flotation mechanisms
weight reduction
∆ surface of resistance
exploit water movement
200
reduction of weight, flotation
alter body fluid comp. (ammonium chl)
gas-filled floats
use lighter fluids (lipids)
201
changes in surface resistance, flotation
small (higher SA:V)
flattened shape
spines, projections
202
why smaller size more important for tropical plankton
higher T = less dense water
| also more serious thermocline to watch out for
203
exploitation of water movement, flotation
langmuir convection
204
how langmuir works
day - heat, night - cool, T-driven convection cells
local (m's - 100s m's)
wind > 3 m/s
205
langmuir upwelling
convergent cells
206
tropic plankton pattern
low and relatively even all year
| very little lag or difference
207
polar plankton pattern
one peak for each in summer
| lag between phyto., zoop
208
Intensity of light at depth, I_z
= I_0 e ^ -kz
I_0 = light at surface
k = extinction coeffic.
z = depth
209
light attenuation curve
exponential decrease with depth
210
depth where
| respiration = photosynthesis
compensation depth
no growth
(based on light)
phytopl. must remain above
211
temperate plankton pattern
two phyto. peaks (spring, fall)
spring peak bigger
zoop lag
212
depth of light penetration
```
absorption
wavelength
reflection
scattering
latitude
season
```
213
peak wavelength penetration in water
blue
214
compensation depth depends on
```
latitude
season
sea surface conditions
water clarity
type of PP
position relative to shore
```
215
strong thermocline all year
tropics
216
nekton selection
- mobility
- nervous, sensory systems
- fast swimming
- camouflage
- floatation
217
no connection or duct between the swim-bladder and the intestinal tract
physoclistous
218
physoclistous air control
specialised structures called the gas gland and ovale respectively
219
rete mirabile means
'wonderful net'
| latin
220
Fish with a connection (pneumatic duct) between the gas bladder and the esophagus
physostomus
221
rete mirabile is
counter-current exchange
cappillaries
allow gas uptake in fish with swim bladder
222
causes diffusion in rete mirabile
oxygen tension greater in venous than arterial blood
223
physostomus air control
via the mouth
224
nekton adaptations for buoyancy
- swim bladder
- swim fast
- gas filled cavity
- lipids
225
nekton, swimming fast
avoid sinking
streamlined
strong tail
226
EX. nekton quick swimmer
bonito
| mackerel
227
nekton with gas-filled cavities
mammals (seals)
| birds
228
nekton with lipids
```
fast fish (lipid-filled liver of shark)
mammals (blubber)
```
229
nekton adaptations to surface of resistance
streamlined
| long, thin
230
resistance to movement
frictional resistance
form resistance
induced drag
231
minimal frictional resistance
in spherical objects
232
minimal form resistance
in long thin object
| proportional to cross-sectional area
233
induced drag increases
with speed or size
234
why does induced drag increase
laminar flow disrupted
| forms vortices, eddies
235
Aspect ratio =
Height of caudal fin^2 / Area of caudal fin
236
fastest fishes caudal fin
high AR
| therefore tall but narrow
237
Nekton adaptations, defense
Ventral keel
| cryptic coloration
238
ventral keel
sharp angeled ventral edge allows light to illuminate ventral side and reduce shadow and visibility
239
nekton adaptations, sensory systems
lateral lines
ampullae of lorenzini
vision, hearing, olfaction
240
lateral line
canals length of fish body and over head
| -detect pressure (movement)
241
ampullae of lorenzini
organ that can detect electrical signals in water (sharks, cartilagenous fish)
242
nekton need adaptations for body heat because
water has a higher thermal conductivity than air
243
nekton adaptation, heat
large (SA:V)
fat (blubber)
modified circulatory system
244
nekton modified circulatory system
warm arterial blood transfers heat to cooler venous blood; recycles heat; keep heat in organism core
