Earth Science Oceanography

“Water World”

Oceanography

“The application of science to the study of phenomena in the oceans”.

Oceanography is a broad Science

4 Disciplines Geological Oceanography

– Structure of the sea floor Chemical Oceanography

– Chemical composition and properties of seawater

Physical Oceanography– Waves, tides, currents

Biological Oceanography– Oceanic life forms

Why Study Oceanography?

Oceans comprise 71% of the Earth’s surface

Oceans contain 97.2% of the water on or near the Earth’s surface

Source of Food Transportation and Travel Weather Shoreline

– Interface between land and ocean

CLIMATE

WEATHER

Shoreline – Waves Baby

Food & Marine Life

The 5 Oceans Pacific Ocean

– Largest and deepest ocean– Mariana Trench: 11 km., 36,000 ft.

(Mt. Everest 29,000 ft.)

Atlantic Ocean– About ½ the size of the Pacific

Indian Ocean– Southern hemisphere

Arctic Ocean– ¼ as deep, much smaller, sea ice

Southern Ocean– South of 50 deg. South latitude

“Just the Facts…” Mauna Kea on the Big Island of Hawaii,

measures ~10,600 m from the ocean floor, making it the tallest mountain on the planet (surpassing even Mt. Everest).

If the Earth’s contours were leveled to a smooth ball, the ocean would cover it to a depth of 2686 m.

“Just the Facts…” The ocean contains some 5 trillion tons

of salts– If dried and spread evenly, that mass would

cover the entire planet to a depth of 45 m. On a planetary scale the ocean is

insignificant.– Its average depth is a tiny fraction of the

Earth’s radius.

Historical Reviewof Oceanography

Roots traced to ocean exploration. Describing the oceans

Herodotus (ca 450 BCE)Where is …. ?

Historical Reviewof Oceanography

The 18th century was marked by– Improvements in navigation and

mapping

– Accumulation of data for charts Temperature, currents

In the United States, Benjamin Franklin (1769-1770) published the first chart of the Gulf Stream

Historical Reviewof Oceanography

(Cont.)

In Britain, James Cook (1768-1779)

– Constructed charts of coastlines especially for the South Pacific

– Secondary discovery the Hawaiian Islands

Historical Reviewof Oceanography

(Cont.)

Historical Reviewof Oceanography

(Cont.)

In the 19th century curiosity about the oceans increased and voyages for scientific purposes were initiated

Charles Darwin: British naturalist– Voyage of the Beagle (1831-1836), studied

geology and biology of the South American coastline

Developed theory of organic evolution based on natural selection

Published On the Origin of the Species (1859)

The Voyage of the HMS Beagle

Charles Darwin

Route of the HMS Beagle

C. Wyville Thompson: British explorer– Directed the Challenger Expedition (1872-1876)

First major scientific expedition Globe-encircling voyage Chemical, physical, and biological measurements

and collections

Historical Reviewof Oceanography

(Cont.)

The Challenger Expedition

What is Oceanography Today?

Geological Oceanography(Marine Geology)

Study of rocks and sediments & processes responsible for their formation.

Marine Geophysics

Study of rock structure in the ocean basin, properties of rocks such as

magnetism, occurrence of earthquakes.

Physical Oceanography

How and why ocean currents flow, air-sea interactions such as the generation of

waves by the wind.

Chemical Oceanography

Composition of sea water and the processes controlling and altering its

composition, including marine pollution.

Biological Oceanography(Marine Biology)

Organisms that live in the oceans and their relationships to the environment.

Ocean Engineering

Design and installation of

oceanographic instrumentation and vehicles

Summary:What is Oceanography?

Broad science focused on the oceans– Geology/geophysics, chemistry, physics,

biology, engineering Highly interdisciplinary Also highly collaborative We are still exploring (!) but … Feeds also into ocean policy,

management, and conservation