Midterm 1 Flashcards
The oceans covers
71% of the earths surface
The average depth of the oceans is
3800m
The deepest depth of the oceans is, and was visited by who?
10,994 meters. By two men in 1960 and by James Cameron in 2012
What percentage of all the Living volume of life is in the oceans
more then 90%
light only penetrates to
100m water depth
bio luminescence is
the most common evolutionary trait of life!
What percentage of all goods are transported across the ocean at some point
90%
Oceanography is divided into sub categories
Geological, Chemical, Physical, Biological
Geological
- Structure of the ocean basins
* Sedimentary processes
* Interpretation of the sediment record
Chemical
- Composition of seawater
* Biogeochemical cycles
* Effects of pollutants
Physical
- Motion of the water
* Ocean circulation
* Ocean mixing
Biological
- Ecology of marine organisms
* Fisheries oceanography, sustainability
* Similar to marine biology, however more focus on ecological aspects
Oceanus
Titan son of Gaia, His realm was the Boundary between the living and the dead
Aristotle
- The first marine scientist.
- Meterologica a number of explanations for how the oceans were formed and why they were salty
- Attempted to explain ocean tides
Polynesian voyagers
First true ocean explorers
* Highly skilled navigators using the sun and stars, there patterns on the surface waves, the flight paths of migratory birds, and even the smell of the water * Originated in the Philippines * Travelled to New Guinea 30,000 years ago * Travelled to Hawaii 1500 years ago
Greeks
- By 900-700BC the ancient greeks ventured as far west as at the strait of Gibraltar (750m)
The Principles of Navigation
- Some idea of scale
* Some idea of location
Eratosthenes of Cyrene
- Accurately calculated the Earths circumference
- Also discovered the Earths tilt within a degree, that there are 365 and 1/4 days in the year, and proposed the addition of leap years
Circumference of the earth
Summer solstice Knew the sun was directly overhead in Aswan, Egypt and was 7* off Alexandria. Knew actual distance. = 25,252 miles
Autumn Equinox
Sun is directly over the equator (0*)
Its rays hit all of the earth equally from pole to pole
Winter Solstice
Three months later (one/quarter a year) later
Sun is directly above the Tropic of Capricorn (23.5S)
The Sun no longer rises in the Arctic Circle (above 66.5N)
The start of winter in the Northern Hemisphere
The shortest day of the year
Vernal (Spring) Equinox
Three months later (one/quarter a year) later
Sun is directly over the equator (0*)
Its rays hit all of the earth equally from pole to pole
Start of Spring in the Western Hemisphere
Summer Solstice
Three months later (one/quarter a year) later
Sun is directly above the Tropic of Cancer (23.5N)
First day of summer in the Western Hemisphere
The sun never sets in the Arctic Circle (above 66.5N)
The longest day of the year
Latitude
- Measured along the North-South axis
- Similar to the y-axis in a graph
- 1 Degree of latitude is an exact distance. It is exactly 1/360 the circumference of the Earth
Important Latitudes
- North Pole 90N
* Tropic of Cancer 23.5N
* Equator 0*
* Tropic of Capricorn 23.5*
* South Pole 90*S
Determining ones latitude
Estimate the angle from the horizon to the Sun (or Polaris) at its highest point (noon) and correct for the time of year, In the northern hemisphere only
This method was used as early as 400AD
Cross staff and the Astrolobe
Longitude
- Measured along the East-West axis
- Similar to the x-axis in a graph
- Longitude is a function of time
John Harrison
Reliable method for determining longitude
by calculating the difference in time between your noon and the time at Greenwich (Prime meridian) and then mutlipy by 15* you get your longitude
John Harrison’s chronometer was accurate to within 1/3 of a second
James Cook
In HMS Endeavour followed Transit of Venus. Found and charted New Zealand and Australia Great Barrier Reef, found the cure to scurry. Killed by Hawaiians
Charles Darwin
HMS Beagle in 1831. Mapping expectation
HMS Challenger
Captain George S. Nares. To investigate the physical and biological condition of the great ocean basins, 3 1/2, Sampled over 350 bottom samples. C. WyvilleThomson
Fridtjof Nansen and Frederick Johansen
Cool Guy 😎. First to cross Greenland ice sheet by dogsled. Arctic ice currents. The Fram. Crew of 13 men stuck in ice for nearly 4 years. Came within 400 m of North Pole.
C. Wyville Thomson
Coined the term oceanography in its present sense
Ronald Nansen
Found the Northwest passage
Remotely Operated Vehicles (ROV)
ROPOS: Remotley operated Platform for Ocean Science
Autonomous Underwater Vehicles (AUV)
The Big Bang
- Occurred 13.8 Billion years ago
* The massive explosion sent matter hurtling out in all directions
Georges Lemaitre
Proposed the idea of the big bang in in 1927
Doppler effect:
As light travels towards us, the wave lengths being emitted will be compressed out will causing it to be blue shifted
As light travels away from us, the wave lengths being emitted will be stretched out will causing it to be red shifted
Visible wavelength spectrum
Purple= 400 Green = 500 Yellow= 600 Red= 700