Serc 1 introd ocean

DR. A.S.N.MURTY
PROFESSOR
DEPARTMFENT OF
METEOROLOGY &
HYDROLOGY
ARBAMINCH UNIVERSITY

Why did Benjamin Franklin make
his map?
 First Postmaster General of U.S.,
he wanted to speed the mails
across the Atlantic.
Benjamin Franklin – 1700’s
– Published map of Gulf Stream based
on fishermen’s and merchants’
experiences
“You may delay but time will not.”
Benjamin Franklin

Benjamin Franklin’s Gulf Stream Map

Benjamin Franklin’s map and
satellite photo of Gulf Stream
“You may delay but time will not wait.”
Benjamin Franklin

The Challenger Expedition
(1872-76)
 Comprehensive scientific expedition
 Naval corvette fitted with laboratories, winches,
and sounding facility and headed by C.Wyville
Thompson
 Circumnavigated whole of the world
 361 sounding stations covered
 Collected large number of deep-sea water samples
 Investigated deep-water motion
 Temperature measurements made at all depths
 Thousands of biological and sea-bottom sediment
samples were collected
 4717 new species were identified
 The analyses of samples collected took several decades
 Mariana’s trench depth was measured first time

Voyage of the Challenger, 1872-1876

Challenger’s expedition-
 The first global oceanographic cruise for scientific study was made
by the British ship, the HMS Challenger during (1872-1876).

Whole of Atlantic ocean first time scientifically
studied by Meteor expedition(1925-27)

Jacques Cousteau
(1910-1997)
Most famous oceanographer of the
20th century
 If we go on the way
we have, the fault is
our greed... if we are
not willing [to
change], we will
disappear from the
face of the globe, to
be replaced by the
insect.
~ Jacques Cousteau


Submersibles- ALVIN &
BATHYSCAPE
were made by Woods Hole
Oceanographic Institution and
can carry 3 passengers to
depths up to 4500m (14,764 ft.),
to explore the ocean, to see the
marine environment physically
and record data.
Jacques Cousteau- Inventor of
Aqualung- today’s SCUBA; he
was a champion to see the
pollution physically in the deep
oceans—and worried about the
man’s exploitation of the earth-
as the destroyer of the marine
environment.

Can you say what it is?
 The picture below is a _____________.submersible

Bathyscaphe -Trieste (the most advanced
submersible of 20th century)

A technological revolution in
today’s Oceanographic studies.
Scripps Institution of Oceanography
developed FLIP (Floating
Instrumentation Platform)- a boat
that turns vertically for research at
different depths and can go
horizontally like a ship
Today’s Oceanography- FLIP
Can you believe when FLIP is in its vertical
position it is extremely stable even under
high storm waves!!.
It is used to study the way water circulates,
how storm waves are formed, how heat is
exchanged between the ocean and the
atmosphere, and the sound made by
underwater marine animals etc.

The Glomar Challenger
Deep Sea Drilling Project Ship
(1968 to 1983)
It has a huge
derrick that
can reach a
previous
pin hole
made at
the sea
bottom at
any time
and is
governed
by
SATNAV

MONEX
 To investigate thoroughly and collect real time
data over the Indian Ocean in 1979,Monsoon
Experiment was conducted
 It was arranged jointly by W.M.O and ICSU
under GARP
 USSR: 5 ships, INDIA: 4 ships& one air
craft,France: 1ship & program for constant level
balloons, USA: 3 air crafts with drop sondes and
1geo stationary satellite (GOES).

See the area influenced by
Monsoon-obtained from Monex

Results of monsoon- See how
monsoon winds are blowing
 These
winds were
derived by
cloud
vectors with
the help of
INSAT- 1 on
5.7.1979 at
600m level
at 10 A.M

Automatic weather station in
Dakshina Gangotri (Antarctica)

Compare the thickness of ocean
with earth’s interior

70.8% of the Earth is
covered by ocean
Oceans contain 97.2% of
water on the surface of
the earth

Major Oceans
 The three major oceans are :
1._______the largest, deepest, coldest and the
least salty.
 2.__________the second largest, shallow,
warm and salty.
 3. _________ intermediate in depth,
temperature and salinity.
 The _______Ocean near the north pole, and the
____________ Ocean near the south pole
contain vast expanses of sea ice.
Pacific
Atlantic
Indian
Arctic
Antarctic

Name
Area Avg. Depth
10 6 Km2. m.
Pacific Ocean 165.2 4282
Atlantic Ocean 82.4 3926
Indian Ocean 73.4 3963
Southern Ocean 32.0 3930
Arctic Ocean 14.0 1205
Greatest Known Depth
m. Name of Region
11,524 Mariana Trench
9074 Puerto Rico Trench
7338 Sunda Trench
6820 South Sandwich Trench
5536 N/A

Pacific Ocean:
181,34 x 106 km2
Hmed = 4270 m
Lmax = 19800 km
N:Bering Sea& Gulf of
Alaska
S: Antárctica
W: 147E meridion of
Tasmania
E: 1000E merdion of west
coast of N & S America

The ocean's name, derived from
Greek mythology, means the “Sea
of Atlas."
It is the most saline of all the major
oceans; the salinity at the surface in the
open ocean ranges from 33 to 37‰ or (3.3 -
3.7%)
Endangered marine
species are the
manatee,
and the seal (sea
lion)in this ocean.
The Atlantic Ocean is the second-
largest ocean, covering about 1/5
of the Earth's surface.

Oceano Atlântico
(OA):
106,57 x 106 km2
Hmed = 3332 m
2848 km < L < 4830
km
N-S: regions of
Antártica and Árctica
E: Cape of Good
Hope (20E)
W: Cape Horn

The Indian Ocean is the third largest
body of water in the world, covering
about 20% of the Earth's water surface.
The climate north of the equator is affected
by monsoon wind systems causing rainy
seasons that last for 4 months at a time.
The Indian Ocean was the sight of the
underwater earthquake that caused the
devastating Asian Tsunami of 26 Dec 2004.

Indian Ocean:
Area: 74,12 x 106
km2
Hmean = 3890 m
Lmax = 10000 km
N-S: Antártica to
of Asiá
E-W: East Africa
to West Australia

It is the world’s fourth largest ocean
and the least and latest to be studied.
It encircles Antarctica, the highest continent
in the world.
May be the site of large oil and gas fields near
the ocean and continental margin.
Its northernmost boundary is defined as 60° S latitude.

The Southern Ocean ( the width of
the drake passage is only 780 km)

Fresh forming ice - Antarctica

It is the smallest of the world's five
oceans and the shallowest.
Its salinity is the lowest on an average of the
five major oceans, due to low evaporation, as
well as limited outflow of surrounding waters
Endangered marine species include walruses.
The area has a fragile ecosystem which is
slow to change and slow to recover from
disruptions or damage
The Arctic Ocean occupies a roughly circular basin and covers an
area of about 14,056,000 square km. slightly less than
1.5 times the size of the U.S.

Arctic bear: the endangered animal

Methods of Studying the Ocean
The Topex/Poseidon _____________ orbits 1331
km above the Earth, gathering information about
the oceans.
_____________ maps ocean floor topography
by timing how long it takes sound waves to
bounce off the ocean floor.
Underwater vessels called _________________
investigate the deepest ocean trenches.
satellite
Sonar
submersibles

Ocean Zones
Major Zones:
Tidal
Subtidal
Coral Reef
Open Ocean
Abyssal zone
2. Subtidal
3. Coral Reef
4. Open Ocean
5. Abyssal zone ( Ocean bottom)
1.Tidal

Match the following terms to
their correct letter in the
diagram:
A
B
C
D
E
D
F
G
H
Island Arc
Continental shelf
Continental slope
Abyssal plain
Seamount
Continental rise
Trench
Guyot
Seafloor Topography
A.
B.
C.
D.
E.
F.
G.
H.

OCEAN BOTTOM FEATURES
 Seamounts & Trenches. Trenches are found
adjacent & parallel to continents & island chains.

8 major trenches of the world
 a Aleutian
 b Kurile
 c Japan
 d Mariana
 e Philippine
 f Java
 g Tonga,
 h Peru-Chile

Submarine canyon
Extraido da NOAA – Astoria Canyon – Oceano Pacífico

Formation of long Berm wall (1.6
m)due to beach cut at Aryapalli in
Sept

Coconut trees on Black Sand Beach
(Volcanic) & wave breaking in Andamans

Beach with Dunes: naturally formed
accumulation of sand hills which change with
wind movement

A= coral reef, B=Coral island,
C= Atoll
A B
C

Atoll is a ring shaped coral island with a
centre lake in the midst of sea

Another type of Coral Reef Atoll

Coral reefs exist only in these
areas!

Physical properties of
sea water

Temperature structure with depth in
the open ocean
 Warmer at top, cooler with depth
 Thermocline – region of rapid
change of temperature;
permanent
seasonal
diurnal
 Higher temperature, lower density

Depth of certain
isotherms as a
function of month
Vertical
temperature
profiles month by
month

Salinity
 Total amount of solid material dissolved in water- Traditional
definition
 Typical salinity is 3.5% or 35o/oo
o/oo or parts per thousand (ppt) = grams of salt per kilogram of water
g/Kg
Six elements make up 99% of dissolved solids in seawater
Fig. 5.12

Ocean Chemistry and Currents
I. Chemistry of Ocean Water
96.5% Water
Common salts: chlorides, sulfates
Sodiumions(Na+)-31%
Magnesiumions(Mg2+)-4%
Calciumions(Ca2+)-1%
Potassiumions(K+)-1%
Chloride ions(Cl-)-55%
Sulfateions(SO4
2-)-7%
Salts come from erosional
forces, runoff from the
continents
3.5% Salts

Salinity
Can you fill the gaps about ocean salinity?
The average salinity of seawater is _____ ppt. Therefore, for
every 1,000 ml water, there are ___ grams of dissolved salts.
The most abundant salt in seawater is ________, but
there are many other salts present in the form of ions.
Near the equator salinity is __________ than average due to
___________________.
Near the poles salinity is __________ than average due to
_______________.
In the Mediterranean the salinity is __________than
average due to __________.
NaCl
35
35
lower
greater precipitation
lower
melting sea ice
higher
evaporation

How much is
the
salinity
here ?
A. 35 ppt
B. 34 ppt
C. 36 ppt

Conductivity-Temperature-Depth (CTD)
 T accuracy: ±0.001°C
 C accuracy: 0.0003 S/m
~ 0.0024 on PSS
 Response time: Time
required for instrument to
respond to temperature of
a new environment.

Surface ocean variation of salinity
 Polar regions: salinity
is lower due to lots of
rain/snow and runoff
 Mid-latitudes: salinity is
higher due to high rate of
evaporation
 Equator: salinity is
lower due to lots of rain

Variation of T,S & σT with latitude

Deep
ocean
salinity
is
almost
same

Vertical distribution of salinity

Density of water
Density of water increases as
temperature decreases
Density of ice is less than density of
water
From 4oC to 0oC density of water
decreases as temperature decreases

Density of seawater in polar
oceans
Salinity has greatest influence on
density in polar oceans
Polar ocean is almost isothermal

A TS-diagram showing densities at
different depths

Relation of Density and salinity
 1.022 to 1.030 g/cm3 surface seawater
 Ocean layered according to density
 Density seawater controlled by
temperature, salinity, and pressure
 σt = -0.093 + 0.8149 S –0.000482 S2 +
0.0000068 S3
 σt = -0.069 + 1.4708 Cl –0.001570 Cl2 +
0.0000398 Cl3

Label the three ocean layers in the diagram below.
Mixed layer
Thermocline
Bottom layer

Can you guess the origin of bottom
water in low latitudes?

Reversing thermometers & Nansen
Reversing water bottles

Nansen reversing water bottles

Expendable Bathythermograph
Accuracy = ±0.1°C (??)

ARGO Program
 Up to 3000 floats in
upper 2000 m of
ocean
 International
collaboration of about
23 countries
 Used with Jason
satellite

Current Velocity- ADCP
 Current meters
 Acoustic Doppler Current Profiler
(ADCP)

Chapter Review
1. What is the average salinity of seawater?
2. What is the deepest area of the seafloor?
3. What is the largest ocean?
4. Why is the ocean “blue”?
5. What is the force responsible for surface currents?
6. What causes density currents?
7. What causes tides?
8. List the 3 tidal patterns.
9. What is the highest part of a wave called?
10.Name the most saltiest ocean .
35 ppt
trench
Pacific
shorter wavelengths not absorbed
wind
differences in temperature and
salinity
gravity of the sun and moon
diurnal, semidiurnal, mixed
crest
Atlantic

Serc 1 introd ocean

More Related Content

What's hot (20)

Similar to Serc 1 introd ocean (20)

Recently uploaded (20)

Serc 1 introd ocean