Oceanography - Reading Assignment 1

Reading assignment 1 broken down into studyable bites.

The Five Major Oceans

Atlantic Ocean, Pacific Ocean, Indian Ocean, Arctic Ocean, & Southern Ocean

Percent of surface water made up by the Ocean

97\.5%

Percent of surface water made up by Fresh Water

2\.5%

Four Major Fresh Water Reservoirs

Atmosphere & Surface Water, Permafrost, Ground Water Glaciers

Percent of Fresh Water: Atmosphere & Surface Water

0\.4% (Lakes & Rivers)

Percent of Fresh Water: Permafrost

0\.8% (Top soil & sediment layer that has been frozen for 2 Yrs)

Percent of Fresh Water: Ground Water

30\.1% (Water beneath the surface, in rocks & soil)

Percent of Fresh Water: Glaciers

67\.8% (Body of dense ice)

Weather

Short-term changes in the atmosphere

Climate

Regional averages of atmosphere/weather over a long time period

Importance of the oceans

Supports diverse ecosystems, transportation and global connections, major source of water, source of food, & major force of weather & climate.

Average Ocean Depth (meters)

3,682 m (≈4,000 m)

Average Ocean Depth (kilometers)

3\.682 km (≈4 km)

Average Ocean Depth (miles)

3\.2 miles

Average Ocean Depth (feet)

12,144 ft

Average Elevation Above Sea Level (meters)

840 m

Average Elevation Above Sea Level (feet)

2,756 ft

1 km = ____ miles

0\.621 miles

1 mile = ____ ft

2,756 ft

1 km = ____ m

1,000 m

1 km = ____ cm

100,000 cm

1 m = ____ cm

100 cm

1 cm = ____ mm

10 mm

Scientists who study formation & mobility of the ocean crust, characteristics of seafloor sediments, distribution of minerals, & history of the ocean.

Marine Geologists

Scientists who study & observe waves, tides, ocean currents, & ocean-atmosphere interaction.

Physical Oceanographers

Scientists who study seawater composition, sources and sinks of dissolved solids & gases, pH of seawater, & chemical exchange between seawater & the ocean crust.

Chemical Oceanographers

Scientists who study the types and distribution of marine organisms, the health of marine organisms, isolation of drugs from marine species, marine fisheries, & marine aquaculture.

Marine Biologists

The 4 Gas Giants

Jupiter, Saturn, Uranus, Neptune

The 4 Terrestrial Planets

Mercury, Venus, Earth, Mars

Common Elements Composing The Gas Giants

Hydrogen (H), Helium (He), Methane (CH_4), Ammonia (NH_3)

Common Elements Composing The Terrestrial Planets

Iron (Fe), Oxygen (O), Silicon (Si), Magnesium (Mg)

What does "Ga” Mean?

Giga Anum (Billion Years)

Approximate Age of the Earth

4\.6 Ga

Approximate Age of the Moon

4\.4 Ga

Importance of the Moon

Controls the ocean tides & helps stabilize the tilt of Earth's axis (prevents wobbling)

Formation of the Moon

Slightly larger than Mars sized object collected with the young Earth (≈0.2 Ga). The objects rocky mantle was ejected & formed a ring around Earth, the core combined with Earth's core. The ejected material condensed becoming the moon.

Most abundant gases in the first atmosphere

Hydrogen (H), Helium (He), small amounts of Methane (CH_4) & Ammonia (NH_3)

Most abundant gases in the second atmosphere

Carbon Dioxide (CO_2) & Water Vapor (H_2O)

Origin of second atmosphere gasses

Volcanic Outgassing (Volcanic eruptions)

Two most abundant gases in today's atmosphere

Nitrogen & Oxygen (99% of molecules in the air today)

What percent of today's atmosphere is made up by Nitrogen?

78%

What percent of today's atmosphere is made up by Oxygen?

21%

What was the Oxygen Revolution?

A dramatic increase of oxygen in the atmosphere from the earliest plant photosynthesis.

When did the Oxygen Revolution begin?

2 Ga

Two Causes of the Oxygen Revolution

Early plant photosynthesis & oxidized minerals dissolved in the ocean and surface sediment leaving additional oxygen to defused into the atmosphere

Photosynthesis

6CO_2 + 6H_2 O —sunlight—> C_6 H_2 O_6 + 6O_2

Where did most water on or near Earth’s surface originate?

Earth's interior & volcanic outgassing

Secondary source of Earth's water

Asteroids & Comets colliding with Earth (until 3.8 Ga ago)

Evidence Supporting Secondary Water Source

Isotopic ratios suggest water found in asteroids match the water found in Earth's ocean (better than comets)

Climate change on Earth began…

At the start of Earth's history

What element is life on Earth made up by?

Carbon (C)

Where did Earth's carbon supply come from?

Earth's interior, Comets, Asteroids, Metros, & Inter-planetary dust particles crashing into earth during its formation

Where did life on Earth begin?

Deep-sea Hydrothermal Vents (hot springs on the ocean floor, at mid-ocean ridges)

Why were Deep-sea Hydrothermal Vents suitable for biosynthesis?

Protection from UV radiation (disrupts organic particles), stable environment (consistent temperature), & metal rich energy sources (hydrothermal fluids).

How old are the oldest fossils to date?

3\.85 Ga

What organisms made the oldest fossils?

Bacteria

When did the ocean form?

4 Ga ago

When did the first fish appear?

510 million years ago

When did the first marine mammals appear?

50 million years ago

When did the first humans appear?

3 million years ago

What are charts?

Maps of bodies of water & related information

Information recorded on charts

Water depths, Hazards (rocks, sunken ships, etc), Ocean currents (tides),& Navigational Buoys

People who make charts are called ____.

Cartographers

When were the first charts made?

800 B.C.E

What did the first charts depict?

The Mediterranean Sea

How did the Library of Alexandria contribute to Marine Science?

Held copies of charts made by sailors, made access to said charts easier to access & update with new information

What happened to most of the documents stored within the Library of Alexandria?

Burned when the library was set alight by a mob.

Who was the first person to calculate the circumference of the Earth?

Eratosthenes of Cyrene

How was the Earth's circumference first determined?

Measuring the angle of a shadow in Alexandria when it was noon in Syene (no shadows, straight sun beam), 785 km. Angle of Alexandria's shadow was ≈7° (1/51.4 of a circle). Circumference calculated with basic geometry.

When was Eratosthenes's calculation made?

230 B.C.E

How accurate was Eratosthenes compared to today's accepted circumference?

Within 8% of the current accepted value

The circumference of the Earth around the equator is ____?

≈40,000km (29, 901 miles)

Who was the first person to use latitude and longitude lines on maps and chart?

Eratosthenes of Cyrene

What were the first lines of latitude and longitude drawn through?

Important places

Who invented the modern latitude and longitude grid?

Hipparchus

When were the modern latitude and longitude lines invented?

165-127 B.C.E

Degrees of latitude are equal to the angle between ____ & ____.

a line from the center of the Earth to the equator & a line from the center of the Earth to a specific location on the Earth's surface.

Degrees of longitude are equal to the angle between ____ & ____.

a line from the center of the Earth to the Prime Meridian & a line from the center of the Earth to the meridian of a specific location on the Earth's surface.

How did early seafarers (like Columbus) determine their ships's latitude?

Measuring the angle between the horizon and Polaris (North Star)

How did early seafarers (like Columbus) determine their ships's longitude?

By keeping track of the time on ship and the time in Greenwich, England (and comparing the two).

What is a chronometer?

A clock or time piece

Who invented the first chronometer? When?

John Harrison, in 1728

Why was the chronometer important to marine exploration?

Allowed for precise determination of time, and therefore longitude.

When was Captain James Cook's expedition on the “HMS Endeavor”?

1768-1771

What was the primary purpose of Captain James Cook's 1768-1771 expedition?

To assert British presence in the South Seas

What were some accomplishments of the 1768-1771 “HMS Endeavor” Expedition?

Observation of Venus eclipsing the Sun, verified calculations of planetary orbits, charted coast of New Zealand, charted Great Barrier Reef, noted positions of small islands, & recorded information on natural history & human habitations.

When were Captain Jame's Cook's expeditions on the “Resolution” and “Adventure"?

1772-1775

What were the accomplishments of Captain James Cook's 1772-1775 expeditions?

Charted Tonga & Easter Islands, discovered Caledonia in the Pacific & South Georgia in the Atlantic, & first navigations of the world at high latitudes.

What latitudes did James Cook circumnavigate the world on during his 1772-1775 "Resolution” and "Adventure” expeditions?

North of 60°N & South of 60°S (near the arctics)

When was Captain James Cook's expedition on the “Resolution” and "Discovery"?

1776

What was the purpose of Captain James Cook's 1776 expedition?

To find a Northwest passage around Canada and Alaska or a Northeast passage above Siberia (Failed expedition).

What were the accomplishments of the 1776 "Resolution” and “Discovery” expeditions?

Investigated Hawaiian Islands & charted east coast of North America

Captain James Cook is considered the first Marine Scientist. Why?

Provided accurate charts of locations, wrote detailed observations, look samples of marine life, islands, and coastlines, & he recored and interpreted his observations in a systematic way.

Who led the United States Exploring Expedition?

Lieutenant Charles Wilkes

When was Lieutenant Charles Wilkes United States Exploring Expedition?

1838

What were the major goals of Lieutenant Charles Wilkes 1838 expedition?

Showing the flag (concurring land), whale scouting, mineral gathering, charting, observing, & disproving the Earth is hollow and could be entered through holes at either pole.

What were the major accomplishments of the 1838 United States Exploring Expedition?

Charted east coast of Antartica and proved it to be a continent, explored Hawaii, collected scientific specimens and artifacts, & confirmed Darwin’s hypothesis for coral atoll formation.

What did the 1838 United States Exploring Expedition help establish?

The natural sciences (including oceanography)

What did Lieutenant Charles Wilkes write because of his expedition? When was it published?

A 19 volume report, in 1842

Who published a chart of the Gulf Stream in 1769?

Benjamin Franklin