Registration Problems? Please see... Melinda Peterson Geosciences Departmental Office 104 Wilkinson Hall [email protected] 737-1238.

Registration Problems?Please see...

Melinda PetersonGeosciences Departmental Office

104 Wilkinson [email protected]

737-1238

“Water World”“Earth is a unique

planet, possibly one of the few in the

galaxy that has water.Nearly 71% of it’s surface is ocean.

From space, Earth is brilliantly blue, white in places with clouds and ice, sometimes swirling with storms.

At it’s surface the ocean is in constant motion with powerful currents that stretch

for thousands of miles and towering waves. Beneath the ocean’s

surface lie hidden mountain ranges, vast

trenches tens of thousands of feet

deep, immense hot springs, and huge volcanoes spewing

molten rock in massive eruptions.”

-- T. Garrison

Chapter 1

“Just the Facts…” Over 97% of the water on the Earth is in the

ocean. The average depth of the ocean is about

4000 meters. The Mariana Trench is 11,022 m deep, the

deepest spot on the planet.– 8 tons per sq. in.– Mt. Everest is “only” ~8667 m above sea level

“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.– The blue ink representing the ocean on a

paper globe is proportionally thicker.

Why Study the Ocean? Major influence on weather and climate Source of food, energy, medical drugs Transportation Military significance Recreational resource Major influence on the health of the planet Culture and history

Historical Reviewof Oceanography

Roots traced to ocean exploration. Describing the oceans

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)

$1200!

The Voyage of the HMS Beagle

Charles Darwin

Route of the HMS Beagle

Edward Forbes: British naturalist (1815-1854)– Proposed the hypothesis that no life (azoic)

existed in the oceans below 550 m

Historical Reviewof Oceanography

(Cont.)

Matthew Fontaine Maury: U.S. naval officer– Compiled information on winds and

currents– Published The Physical Geography of the

Sea (1855)– “Father of physical oceanography”

Historical Reviewof Oceanography

(Cont.)

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 Disproved Edward Forbes “azoic theory” by

collecting sea life from waters as deep as 9000 m

Historical Reviewof Oceanography

(Cont.)

The Challenger Expedition

Modern Oceanography Major interdisciplinary expeditions e.g., the Meteor

Expedition: German (1925-1927)– Bottom topography– Vertical profiles of salinity, temperature, oxygen

Subsequent growth, World War II, urgent need for information on the physical structure of the oceans

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.

Dec 26, 20049.0 Eq, Sumatra

275,950 killed

Image courtesy of BBC

March 28, 2005 8.7 Eq, Sumatra

290 killed

Image courtesy of USGS

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

Today ocean research is conducted by Today ocean research is conducted by investigators in investigators in specialized marine specialized marine institutionsinstitutions, as well as universities, and , as well as universities, and state and federal agenciesstate and federal agencies

The emphasis is on interdisciplinary, The emphasis is on interdisciplinary, processprocess-oriented research and -oriented research and international cooperationinternational cooperation

Modern Oceanography (Cont.)

19031903www.sio.ucsd.eduwww.sio.ucsd.edu

19301930www.whoi.eduwww.whoi.edu

19491949www.ldeo.columbia.eduwww.ldeo.columbia.edu

Woods Hole Oceanographic InstitutionWoods Hole, MA

Scripps Institution of OceanographyUC-San Diego

Current and Future Oceanographic Research

greater focus on internationalinternational efforts and large scale interdisciplinary expeditions– Many scientists– Many ships

“remote sensing” “unmanned” platforms

New Technology for Probing the Sea

TOPEX/Poseidon satellite launched in 1992.

Seasat-A, the first oceanographic satellite, was launched in 1978.

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