week 1-lily Flashcards
what is oceanography?
scientific study of all aspects of the oceans
how much of the earth surface is covered by water
71%
how much of earths water contained in the oceans and salty
97%
how much of the 97% water fresh water?
3%
how much of earths water is useable
0.3%
where is the freshwater typically located
90% in icecaps, glaciers, deep groundwater
what is an ocean
vast body of saline water occupying deepest depressions on the earths surface
- artificial divisions/boundaries
what are the 5 oceans
- pacific
- Atlantic
- Indian
- arctic
- southern/Antarctic
sometimes there are how many oceans
7
- north/south atlantic
- north/south pacific
concept of 1 world ocean
they are all connected
what is the difference between sea from ocean
- related to island, plate tectonics
- smaller bodies of water
- on the peripheries of oceans
- enclosed by land (ridges, rises, island chains)
- often not always over continental margins
total surface area of ocean
361,132,000km2
total volume of ocean
1,335,000,000km3
average depth of ocean
3,688m
deepest part of ocean
10,935+-6m
pacific ocean basin
earths largest feature
challenger deep
deepest point of the Mariana trench
- the deepest part of the ocean
how deep is the challenger deep?
variable depths
10,903-10989m
why is the depth so variable?
high precision measurement is hard to do under that deep of water
how did they find challengers deep?
HMS challenger (1872-1876)
how many people have been to challenger deep?
27
who has been to challenger deep
- piccard and walsh 1960
- cameron, 2012
- Fen Dou Zhe, 2020
- “limiting factor” 2019-current
ocean exploration
- oceans did not prevent spread of humanity, they played key roles
- drove ancient civilizations to explore, study and travel
main things of ocean exploration
- food
- increase access
- nutritional advantage
- economic advantage
- politics/power
- money
- quest for knowledge
ocean exploration- mediterranean sea- phoenicians
- exploration of mediterranean
- circumnaviation of africa 590 BCE
- from 2000 BCE
- trade routes throughout region
- different ship styles for trade and war
- travelled into the atlantic, red sea, indian ocean
ocean exploration- Mediterranean sea- ancient greek and Egyptians
- use of Mediterranean, Nile River & Red Sea
- cartography
ocean exploration- mediterranean sea- ancient greeks
- early fishing vessel
- greek bireme-warship
- greek cargo ship
ocean exploration- ancient Greeks- library of Alexandria
- 3rd century BCE- alexander the great
- repository of scientific knowledge
- beginning of marine science
ancient “Greeks” contributions
latitude and longitude
pytheas
used latitude to travel N
- based off angle of north star to horizon
hipparchus
current grid system we use
eratosthenes
- 2nd librarian at alexandria
- confirmed earth is round
- 230BC calculated circumferences 40,000km vs actual 40,032km
- used shadows, day of year, and trigonmet
eratosthenes how did they calculate circumference
used shadows, day of year, and trigonmetry
Ancient “Greeks and Romans” contributions
Claudius Ptolemy
Claudius Ptolemy
150 AD- publishes Geography- compilation of geographical knowledge
- Updates Erastosthenes circumference
Ptolemy and his circumference
- he get is wrong (29,000Km): wrongly used posidonius circumference value
- 1500 years later his data led columbus to believe he would reach parts of Asia and not the americans/caribbean
ocean exploration- pacific- polynesians
- oceanian culture
- “Easiet” island colonzied 1st- led to overpopulation and resource depletion
- religious warfare
- led to an outward spreading, colonization even further away (Rapa Nui, Hawai)
ocean exploration and the polynesians
technological advances
navigational techniques (wayfinding)
ocean exploration- antarctica
- 601 to 700 CE
- recorded in oral history
antarctica exploration- Ui-Te- rangiors
led fleet of Waka Tiwai (canoes) south until they reached “a place of bitter cold where rock-like structures rose from a solid sea”
what is Te tai-uka-a-pia
the frozen ocean
when was there a little ice age
during the 7th century BC
where did sea ice migrate
considerably further north (or large pack ice broke of an drifted north)
ocean exploration- Chinese
- pacific and beyond
- Admiral Zheng He
- 7 voyages - 1405 to 1433
- fleet > 300 ships (treasure ships)
chinease technical innovations
- the compass
- central rudder- easy to maintain course on long voyage
- waterlight compartments- confine damage, less sunken ships
- sail on multiple masts
what were the Chinese technical advances/innovation good for
- could stay at sea for 4 months distilled seawater, grew fresh vegetables on board
- “collected” and cataloged cultural artifacts and scientific specimens
- helped big ships stay and go through sea
ocean exploration- vikings: ships
fast, stable and strong, excellent for sea voyages, especially in stormy north Atlantic
ocean exploration- vikings, iceland
reached iceland and greenland- ships blown off course by storms
- erik “the Red” thorvaldson
- settled in vinland (995 AD), established a settlement- L’Anse aux meadows
- Leif “the lucky” Erikson
who are the 4 major players in euro age of discovery
- french
- english
- spanish
- portuguese
why did people explore
NOT for the thrill usually goals/motives
people of euro age of discovery
- Christopher Columbus
- Prince Henry the Navigator
- Ferdinand Magellan
one of Magellan 5 ships
completed first circumnavigation of globe in 1522
(he did during this journey)
ocean exploration- james cook
- establish/ maintain englands presence
- sailed to new sealand, hawaiian islands, austrialia
- explored west coast of north america
- Start of scientific oceanography
- first to land and stay on the island australia
the voyages of james cook
1st (1768-71)
2nd (1772-75
3rd- (1776-80)
what did james cook do
- abundance of scientific discoveries and contributions
- accurate navigation and creation of charts
- they were very accurate that they used over 160 year later by Allied forces furing WWII invasion of pacific islands
the onset of Trans-Atlantic slave trade
- discovery of the “new world” and the resources colonial powers setup to extract required workers
- west african slave traders (african or afro-eurpean descent) captured peoples of various ethnicity and sold them to European slavers
who completed the first trans Atlantic slave voyage
portuguese slavers to Brazil in 1526
- other nations rapidly followed suit
how many slaves were transported from Africa to the americas
12.5 million
impact on the indigenous people: doctrine of disovery
pope of roman catholic chruch
- endoctrinated colonial powers with the “legal” and moral justification to claim land “not populated by Christians”
in Canada what was the pre-colonial pop
est. 350,000-500,00
what did the pre-colonial population decline to
125,000 by 1867
tactics of asserting control and power:
impacts on indigenous people
- conflict, genocides, culture and language loss/suppression
- “old-world” virus often most devastating weapon
HMS challenger (British NAVY)
- first true “scientific” expedition
- organized by Charles Wyville Thomson and John Murray
- first used term OCEANOGRAPGY
when did the HMS challenger set sail
december 21, 1872
- 4 year voyage around the world
what played a critical role in western oceanographic research
naval research
oceanographic voyages
technically ambitious and expensive
Heroic age of Antarctic exploration
- late 19th century to early 20th century
- 17 major exploration missions to anatarctic between 1887-1922
- some are stratgic mission during WWII
who were the hero age of Antarctic exploration by
- Belgians
- British
- Germans
- Swedes
- French
- Japanese
- Norwegians
- Australians
Glomar Challenger
- specifically designed in the late 1960s for the purpose of drilling into and taking core samples from the deep ocean floor
ocean exploration- 1900’s to present
development of new technology and ships designs for specific tasks- international
example of new ships designed for specific task in present
JOIDES resolution- 1985-deep sea drilling
R/V Chikyu- 2007
what is Bedford Institute of Oceanography
- BIO
- is the largest ocean research station in Canada and is located in darthmouth (city of halifax), nova scotia, research ships include the CCGS Hudson
Sylvia Earle- The Sturgeon General
- chief scientist - NOAA
- Aquanaut, conservationist
- Pioneer- SCUBA, deep sea subs
- > 7000 hours underwater
- she did some of the deepest dives
Asha de Vos
- Marine biologist
- Blue whale research, northern indian ocean
- oceanswell/ blue project
- oceanography for developing nations
- whale poop
what do stars have to do with the ocean?
- most substances on the earth, including the ocean, and all living things are made of particles created by stars
- nuclear fusion reactors of the universe
- many elements heavier than hydrogen and helium originated in starts; dispersed by supernova
where did it all start?
the BIG BANG
Big bang
- used to describe the beginning of the universe
how long ago did the big bang happen
14 billion years ago
big nag; the first picosecond
- the “plank epoch” (pre the law of physics)
- establishment of the 4 fundamental forces (gravity, weak and strong nuclear forces)
big bang; by seconds to minutes
subatomic particles–> light ions start forming
big bang; 10,000-100,000 yrs
first proper atoms –> first molecules
big bang; 370,000 years
universe becomes transparent
- first atoms reach “ground state” by releasing photons
what did ‘ground state’ by releasing photons cause?
microwave background radiation
100 million years ago
- first stars begin to form
- gravity starting to take over
- sun was not one of the first stars
- collapse of dust cloud & injected materials from supernova into the sun
how did the sun form
100 million years ago
- sun formed after supernova of a previous star
when did earth form + how
4.5 to 4.6 billion years ago
- by accretion
earth’s 1st atmosphere
- very little atmosphere in Haden (too hot, too many collisions)
- mostly hydrogen, helium and other hydrogen gases (leftover from contracting nebula)
- 4.6 ish billion years ago
what does the earths first atmosphere not have
- no magnetic felid, solar winds (electrons, protons, alpha-particles) blew earth’s first atmosphere away
formation of earth’s second atmosphere
- 4.2 to 3.8 billion years
- mainly CO2, water vapour (H,N and sulfur-based gases)
- formed when gases trapped in earth were ‘burped’ to the surface (outgassing)
- gases are hot- rise and eventually condense into clouds
- many volcanic islands
- sun only 80-85% as bright
- volcanic like atmosphere (H2o, Co2, So2, CH4)
why did the gases escape in the earth’s second atmosphere?
- gravity, chemistry of magnetic field formation
how does the oceans get salty in the earths second atmosphere
- from minerals running offland into ocean
magnetic field what does it do?
protects us to survive from radiation of outer space
when did oceans form?
between 3.8 to 4.2 billion years
how did oceans form
- water vapour cools and forms droplets, rain falling to earth- fills depression
- physico-chemistry of water critical to this
great oxidation event
2.4 billion years
- is earths 3rd atmosphere
- cyanbacteria appears
when/where did life likely originate?
- in the early ocean, at hydrothermal vents
- deep ocean - stromatolites
for the creation of life steps
- take simple organic molecules (amino acids & nucleotides)
- combine into complex molecules
- replicate/reproduce
- don’t forget to add water and heat (energy)
what are the 3 theories of where life started
- hydrothermal vent hypothesis
- lighting and surface water filled with building blocks of life (organic molecules)
- nuclear geysers
hydrothermal vent hypothesis
- fossil records of stromatolites 3.5 billion year old on deep sea floor
- hydrothermal vents have a cocktail of chemical building blocks
nuclear geysers
decay of radioactive elements (more common in early earth) in surface water
