Transcript Why Study Oceanography? - Glendale Community College

Why Study Oceanography?
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Earth is the water planet
Oceans Modulate the Climate
Human Civilization in Littoral
(waves govern the coastal processes and
habitat)
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Life began in the Oceans, but
ocean biological productivity is
poor
We are caught in a Malthusian
Trap
Earthrise over Smythii impact basin with Schubert impact crater on
horizon. Views like this during Apollo missions made it clear that
Earth is part of a planetary system rather than an isolated sphere,
subject to the same bombardment that battered the surface of the
Moon. (Apollo 11 AS11-44-6551)
The Solar System
Earth, the “Third Rock from Sun” is
also called the “Lonely Planet”
because, to our knowledge as
yet, earth is the only
planet with
evidence of
life and it is
water that
creates this
uniqueness.
NASA - Topex / Poseidon Oceanography
Mission Ends
The joint NASA/Centre
National d'Etudes Spatiales
Topex/Poseidon oceanography
satellite ceased operations
after nearly 62,000 orbits of
Earth. The spacecraft lost its
ability to maneuver, bringing to
a close a successful 13-year
mission.
Topex/Poseidon data have helped in hurricane and El
Nino/La Nina forecasting, ocean and climate research,
ship routing, offshore industries, fisheries...
http://www.youtube.com/watch?v=OvE22AUl-_w
This uniqueness
comes from two
cycles that define
the Earth ...
hydrological cycle;
and
plate tectonics.
A conceptual look at the hydrological
cycle. Notice three aspects of it:
1. Evaporation exceeds precipitation over the oceans,
but precipitation exceeds evaporation on land.
2. Currently, atmosphere transfers by precipitation all
the water it receives by evaporation.
3. Run-off carries excess water as also rock materials
from land to to oceans.
Evaporation
60,000 km3
Evaporation
320,000 km3
Precipitation
285,000 km3
Ocean Storage
1,370,000,000 km3
Precipitation
3
Run-off: 95,000 km
35,000
km3
Mount Annapoorna, 26,545 ft (8,091 m)
Present is the key to the past,
i.e., the geological processes
today are the same as they have
always been.
http://www.ngdc.noaa.gov/mgg/image/relief_slides2.html
Venus
Earth
Mars
Some images
of the Martian
surface
A team of veteran planet hunters - Astronomers Geoffrey Marcy of
the University of California at Berkeley and R. Paul Butler of the
Carnegie Institution of Washington - has discovered two Saturnsized objects orbiting nearby stars – a discovery suggesting that
solar systems with multiple small planets like our own may be far
more common than scientists had assumed. The new objects,
announced
yesterday at
NASA
headquarters,
are one-third
the size of
Jupiter and
maybe
smaller,
suggesting
that "Earthmass planets
are extremely
common in
the galaxy."
www.washingtonpost.com (3/30/2000)
Mount Annapoorna, 26,545 ft (8,091 m)
The World Ocean
Pacific Ocean
Atlantic Ocean
Indian Ocean
Area
(106 km2)
165.2
82.4
73.4
Volume Mean Depth
(106 km3) (km)
4.282
707.6
3.926
323.6
3.963
291.0
Bibi ka Makbara, Aurangabad
Sun setting on Mount Everest (29,028 ft = 8,848 m)
Another view of Mount Everest
Mount Kanchenjunga: 28,169 ft (8,586 m)
http://fs1dgadrv.er.usgs.gov/edu/mearthsw.html
Evaporation
60,000 km3
Evaporation
320,000 km3 Precipitation
285,000 km3
Ocean Storage
1,370,000,000 km
Run-off:
35,000
km3
Precipitation
95,000 km3
3
A conceptual look at the hydrological cycle
A trio of frames from
Polar's Visible Imaging
System (VIS), taken 6
seconds apart on
December 31, 1998,
captures an object
rapidly descending
toward northern
Europe. Because the
camera's filter isolates
emission from hydroxyl
(OH) radicals, the
incoming object must
have contained
abundant water.
http://pubs.usgs.gov/pdf/planet.pdf
NOAA Current SST Anomalies: 2/14/
Tsunami!
Raphael (Raffaelo Sanzio: 1483-1520): “School of Athens”
The Oceans
cover ~71% of earth’s surface and
have an average depth of ~3.8 km;
carry most (80-97.5%) of the
hydrospheric water supply;
evolved ~4 Ga ago, in an event
that created the atmosphere, the
hydrosphere and the biosphere;
The Earth
evolved ~4.7 Ga ago, together with
the rest of the Solar System, from a
hydrogen-helium dust cloud;
is largely spherical, with ~6371 km
average radius, an equatorial bulge
and polar flattening;
is a multilayered body, with core,
mantle and the crust;
is unique in having water; and
has a hemispherically asymmetric
distribution of land and oceans.
Continental shelf and
slope (11.4%)
Continental
mountains
(10.3%)
Continental
rise (3.8%)
Continental
platforms
(18.9%)
Ocean
ridges
(22.1%)
Ocean
basin floors
(29.8%)
Island arcs,
trenches, guyots etc. (3.7%)
http://www.worldatlas.com/aatlas/imageg.htm
Surface Area (million km2)
90o
N
5
10
15
20
Whole Earth
Latitude
60o N
Land
30o N
0o
30o S
60o S
90o S
Oceans
25
Whole Earth’
Universe Earth s
Crust
Hydrogen H 74.500
Helium He 23.840
Oxygen O
Carbon C
Nitrogen N
Silicon
Neon
Magnesium
Iron
Sulphur
Aluminum
Calcium
Nickel
Sodium
Argon
Chromium
Phosphorous
Manganese
Chlorine
Potassium
Other elements
Si
Ne
Mg
Fe
S
Al
Ca
Ni
Na
Ar
Cr
P
Mn
Cl
K
0.8200 29.8
0.3750
0.0910
46.6
15.6
27.7
13.9
33.3
2.1
5.0
1.5
1.8
2.0
0.2
8.1
3.6
0.0830
0.0550
0.0570
0.1040
0.0380
0.0066
0.0074
0.0092
0.0033
0.0030
0.0032
0.0009
0.0011
0.0006
0.0003
The whole earth is
richer in Fe, Mg and
Ni, and poorer in Si,
K and Al, than what
is found on the
earth’s surface.
Crust
Mantle
Outer
core
2.8
Inner
core
1.9
2.6
1.5
Whole Earth density = 5.5 gm/c
Density of the crust = 2.7 gm/cm
r pole
req
Earth has an equatorial
bulge and polar flatenning,
the equatorial radius (req)
being ~21 km
greater than the polar
radius (rpole) . The radius (r)
of an equivalent sphere
Equivalent
is 6,371 km.
sphere
Based on satellite mapping,
the earth is now known to
be
truly pear-shaped, in that,
added
to facts of earth’s equatorial
bulge and polar flatenning,
10 m
- 30 m
How much water in the
hydrosphere ?
An average person needs ~300,000 gallons of water per
year (1 metric ton = 263 gallons), including 250,000
gallons for growing food. Indeed, nations with <150,000
in trillion face
metric
tons
gallons annual per Hydrospheric
capita watermass
availability
severe
limits to economic
growth.
Including
all the land and Excluding the
marine sedimentary coastal marine
formations worldwide* sediments
Oceans 1,370,000 80.8% 1,370,000 97.5%
10,000 0.7%
Pore water in sediments 300,000 17.7%
25,000 1.5%
25,000 1.8%
Glacier and polar icecaps
300 0.018%
300 0.02%
ace water (rivers, lakes)
13 0.0008%
13 0.0009%
Atmospheric moisture
* Based on Karl Turekian: GLOBAL ENVIRONMENTAL CHANGE (Prentice
A panoramic view of the
Martian surface, as seen
by the Pathfinder