OLLI at AUOceanography 1

101Dr. Kenneth Hinga

Schedule etc.

• Nominal schedule

• Web site

• Objective – a bit of how the world works

• Harvesting slides from some powerpoints and images on webs.

Why a “…graphy” and not an ”…ology”

• History of exploration - what is out there

Based upon the other sciences

Examples of useful information• Distribution of earthquake zones and areas most affected by sea

level rise• Oil & mineral distribution – why & where• Oceans & climate – ozone hole, atmospheric pollution, greenhouse

effect, coral reefs (go see them now!), global warming (and rational debate about)

• Beach erosion & replenishment, sewage disposal, pollution (e.g., detergents and fertilizers)

• Weather & hurricanes• Good fishing & surfing• Why the ocean is warm on the Atlantic beaches and cold on Pacific

beaches• Biological resources – fish, clams, crabs etc.• Management of human discharges - pollution

As my old boss expressed it -

• Oceanography is not the study of the planet’s ocean

• Oceanography is the study of the ocean planet

• Attributed to Dr. Margaret Leinen

The branches of oceanography

Physical Oceanography

Water Movements

Physical Oceanography

• How & why ocean waters move

• Climate & Weather

• Generation of waves by wind

• Heat transfer

• Water cycles

• Waves, tides, currents

Structure and shape of the ocean basin

Geological Oceanography

Geological Oceanography

• Formation processes (seafloor)

• Sediments

• Rocks & minerals

• Geothermal vents

• Properties of rocks such as magnetism

• Occurrence of earthquakes

• Study of earth at edge of ocean

• Paleoceanography

Chemical Oceanography

Composition of sea water and the processing controlling and altering its

composition

Chemical Oceanography

• Seawater processes & interactions

• Temperature, Salinity, Density

• Nutrients

• Dissolved gases

• Pollution

• Trace element distribution

Organisms that live in the ocean and their relationship to the environment

Biological Oceanography

Biological Oceanography

• Ocean Ecology – distribution of organisms in the ocean (space and time)

•Marine biology

•Fisheries biology

A common Adjunct -Atmospheric Chemistry• The makeup of the atmosphere

• Contaminants• Air-sea interactions

• Not weather prediction

• Well, maybe improving weather prediction

Design and installation of oceanographic instrumentation and vehicles

Ocean Engineering

Disciplinary ConnectionsBIOLOGY

BIOCHEMISTRY

OCEANOGRAPHYPHYSICS

GEOLOGY

CHEMISTRY

GEOPHYSICS

BIOPHYSICS

GEOCHEMISTRY

That’s not all – hot topics cross disciplines

• Biogeochemistry – nutrient & chemical transformations and cycles over time

• Geophysics – seismology, paleomagnetics, plate tectonics• Biocomplexity – ecology in the face of chemical & physical constraints• Marine genomics & proteomics – census of marine life; diversity

• Marine Affairs - Legal, economic, management aspects

Other areas of interest

• Archaeology• Law of the sea• Rules of navigation• Resource management – especially fisheries

Nature of this course• More graphs and maps than pictures of fascinating creatures

• For really great imagery I recommend the BBC TV Series, Blue Planet and Blue Planet II (Available on Netflix)

A bit of oceanographic history

Ben Franklin (1770’s)- mapped the Gulf Stream

1996

1786

• collected thousands of biological and sea bottom samples

• traveled in every ocean except arctic• cruise directed by Charles Wyville Thompson• 362 stations, 715 new genera, 5000 new

species• discovered Mariana

Trench and Mindarniad (34,000 ft deep)

Voyage of the HMS Challenger (1872-1876)

Working in the deep sea

• First trans-Atlantic telegraph cable. 1858• Western Ireland to Newfoundland• Failed after three weeks.

• Second cable much more successful in 1866

Rich ocean “hobbyists”

• Prince albert 1st (1848-1922) Extensive collections on his private yacht. Established the Musée Océanographique de Monaco

• Alexander Agassiz (1835-1910) – Set up Harvard’s Museum of Comparative Zoology

• William K Vanderbuilt – largest private fish collection in US - 1932

Pioneers in oceanographic topicsSir John Murray (1841-1914) – Challenger reports

Matthew Fontaine Maury (1806-1873) – published The physical Geography of the Sea in 1855

Fridtjof Nansen (1861-1930) – Arctic exploration

Vagn Ekman (1874-1954) – currents and instrumentation

Matthew Fontaine Maury

American navel officer

Called “Father of Modern Oceanography and Naval Meteorology”“Scientist of the Seas”

The Physical Geography of the Sea (1855), the first such extensive and comprehensive book on oceanography to be published.

1836

First publishedmap of oceanbathymetry

Other expeditions & ships • HMS Endeavour (1768-1771) – discovering islands

• British Beagle expedition (1831-1836) – Darwin - postulated on coral reefs

• Galathea Expedition 1845-1847 (Danish)

• Second Galathea Expedition (1950-1952) – Deep Sea Studies

• USFC Albatross (1882 -1897 &1899-1921) Fisheries research

• Dana expedition (1928-1930) – biological collections

• Carnegie (1909-1921 & 1928-1929) geomagnetic studies

https://oceanexplorer.noaa.gov/history/timeline/timeline.html

How deep is the water?

1800s. Various mechanical devices

Circa 1850 first transatlantic telegraph cable.

Typical time for a sounding- 3 hours

Meteor Expedition (1925)- introduced modern optical and electronic equipment (echo sounder)

More modern connections

• Jacques Costeau

• The Silent World (1953)

• Developed Aqua-lung (SCUBA)

• Ship RV Calypso, & “diving saucer” Denise (1959)

• Depth limit 400 meters

More modern connections

• Marie (Bobbie) Poland Fish

• Bioacoustics Research (For the Navy - distinguish enemy submarines from wildlife)

• Sounds of Western North Atlantic Fishes: A reference File of Biological Underwater Sounds

More modern connections

• John Steinbeck and Ed Rickets

• The Log from the Sea of Cortez (1951)

• Cannery Row (1954) • Sweet Thursday (1954)

More modern connections

•Bob Ballard

• Pioneer in Deep Submergence

• https://nautiluslive.org

Some basic observations

Where did the water come from?

Earth is 4.5 billion years old. Earliest “oceans” about by 4 billion years ago

• Internal sources- since origin of earth- out gassing as earth cooled• Dehydration of minerals• vulcanism

• Extraplanetary sources – added later• Meteoroids • Comets

Earth consists of a series of concentric layers or spheres which differ in chemistry and physical properties.

ChemicalLayers Physical

Layers

All Earth's water, liquid fresh water, and water in lakes and riversSpheres showing:(1) All water (sphere over western U.S., 860 miles in diameter)(2) Fresh liquid water in the ground, lakes, swamps, and rivers (sphere over Kentucky, 169.5 miles in diameter), and(3) Fresh-water lakes and rivers (sphere over Georgia, 34.9 miles in diameter).Credit: Howard Perlman, USGS;

If the Earth were a smooth spheroid, how deep would the ocean be?

• About 2,600 m or 1.6 miles

Image Source: USGS

If Greenland ice sheet melted, sea level would rise about 6 meters (20 Feet)

If Antarctic ice sheet melted, sea level wold rise by amout 60 meters (200 feet)

Source NSIDC

The problem of vertical exaggeration –Pictures are often deceptive

About a 10x Vertical exaggeration

Source: USGS Imaging the Seafloor (1995) https://pubs.usgs.gov/bul/2079/report.pdf

The hypsographic curve 3,729 meters = 2.3 miles

Granite and Basalt• Both igneous rocks – cooled from magma

• Granite continental bedrock

• Basalt – ocean floor bedrock

• Density g/cm3

• Granite – 2.6-2.7 • Basalt - 2.8 – 3.0• Mantle – 3.0 -3.4

Lead-in to our next section on geology