2008/5/26

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Oceanography,Marine Science

Dr. Ryuichiro Nishi

Oceanography also called oceanology or marine science, is the branch of Earth Sciences that studies the Earth's oceans and seas. It covers a wide range of topics, including marine organisms and ecosystem dynamics; ocean currents, waves, and geophysical fluid dynamics; plate tectonics and the geology of the sea floor; and fluxes of various chemical substances and physicalfluxes of various chemical substances and physical properties within the ocean and across its boundaries. These diverse topics reflect multiple disciplines that oceanographers blend to further knowledge of the world ocean and understanding of processes within it: biology, chemistry, geology, meteorology, and physics.

Sub-Categories;

Marine biology or biological oceanography, the study of the plants, animals and microbes (biota) of the oceans and their ecological interaction;

Chemical oceanography or marine chemistry, the t d f th h i t f th d it h i lstudy of the chemistry of the ocean and its chemical

interaction with the atmosphere;

Marine geology or geological oceanography, the study of the geology of the ocean floor including plate tectonics;

Physical oceanography studies the ocean's physical attributes including temperature-salinity structure, mixing, waves, tides and currents;

Marine engineering involves the design and building of oil platforms, ships, harbors, and other structures that allow us to use the ocean wisely [1]allow us to use the ocean wisely. [1]

These branches reflect the fact that many oceanographers are first trained in the exact sciences or mathematics and then focus on applying their interdisciplinary knowledge, skills and abilities to oceanography.[2]

Japan Sea

East China Sea Pacific Ocean Pacific Ocean

East China Sea

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Trade Wind

Jet Stream

Jet Stream

Clockwise circulation and counter clockwise circulation

Oyashio (Kuril) current

Tsushima current

Cold current

T i

Japan

Kuroshio currentWarm current

Philippines

Taiwan

Plate tectonics

Continental plate

Ocean plate

Earthquake, Tsunami

Blue planet; 70% water surface

Diversity of ocean topography, active plate

S=1600,000,000km2

V=723,700,000km3

have=4280mhmax=11,022m

Pacific Ocean

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Wind waves; Sea and SwellOcean wave breaking (120°, 1/7)H=f(F,D,V)

F; Fetch, D; Duration, V; Velocity

Tanh(x) = 1; x>>1 (Deep water)=tanh(x) x; transition zone= x; x<<1 (Shallow water)

C=L/T

Coast, nearshore, offshore

Fresh water

Grand banksLabrador and Gulf stream

Kuroshio and Oyashiocurrent

Off of PeruUpwelling

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Q：年平均流（漂）砂量

砂防　Qm

砂防ダム

水利ダム

河川　Qr

↓ Qdis

= Qr - Q

d

⇒ Qc ( Q

dis × α

ef )≈

海岸（沿岸漂砂量）, αef：有効漂砂量係数

Qoff

= Qdis - Qc

沖合いへの細砂成分流出

砂採取　Qrd

河口

bbsbsbg xHaaCHQ )2cos2sin()( 21

2

∂∂θθ −=

山地（Qmount)→Qin 砂防ダム Qout→QB,in河 川

(水利ダム）

(=(1-α)Qout)(E) (B)

( =(1-β)QB,out

)

河口部（海岸入口)QB,out→QA,in

(A)

QA,out=Qdis

浚渫；Qｒｄ( =α・Q

B,out)浚渫；Q

sd( =β・Q

out)植生緑化効果； γQ

m

α; 河川浚渫係数

Qoff

Qc

12

Qc

12

β; 砂防浚渫係数γ; 植生緑化係数

⎥⎥⎥

⎦

⎤

⎢⎢⎢

⎣

⎡

⎟⎟⎟

⎠

⎞

⎜⎜⎜

⎝

⎛−++

⎟⎟

⎠

⎞

⎜⎜

⎝

⎛+

=Δ

ΔΔ +

+

+

VQVt

QQQV

ttV Aininin

in

At

t

eA

tt

t

eA

t ˆ̂21ˆ̂ˆ̂

ˆ̂12 ,

1

1

,

1

⎥⎥⎦

⎤

⎢⎢⎣

⎡

⎭⎬⎫

⎩⎨⎧ +−+

⎭⎬⎫

⎩⎨⎧ −−

×⎪⎭

⎪⎬⎫

⎪⎩

⎪⎨⎧−=

2

2

2

2

2

2

2)(exp

2)(exp

2exp

)(2),,(

zz

yzy

zHzH

yU

QzyxC

σσ

σσσπ

A－P関係式の模式図

A; インレット（感潮狭口）の断面積

P; タイダルプリズム

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10000

100000

onal

are

a (m

2 )

Japan China U.S.A. New Zealand Vietnam India

106 107 108 109

100

1000

Cro

ss s

ectio

Tidal prism (m3)

図－7 各国のインレットデ－タの関係

1000

10000

100000

ctional

are

a (m

2 )

A = 1.75×10-4P0.952

P = 9116A1.054

106 107 108 109

100

1000

Cro

ss s

ec

Tidal prism (m3)

Inlet data for this project A =

R = 0.94

図－8 本研究における汎用インレットA-P関係

Please carefully observe a photograph below and find a marine animal ?

Question 1

Dr. R. NishiEngineers and scientists need capability to find something different and new in nature !

A baby sea turtle is coming out from sandy beach and will across the Pacific Ocean!

Ans. 1

Dr. R. Nishi

What kind of marine animal is in this photograph?

Question 2

Dr. R. Nishi

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Ans.2;  Marine turtle after a nesting (loggerhead)

Dr. R. Nishi

What kind of marine creature is in this photograph?

Question 3

Dr. R. Nishi

Ans. 3;   Hermit crab

Dr. R. Nishi

What kind of marine species caused this damage ?

Question 4

Dr. R. Nishi

Ans.4 ； ‘Habu’ Jellyfish(Chiropsalmus quadrigatus) 

Dr. R. Nishi