Week 1- Oceanography Flashcards
What is functional biology?
how an organism carries out basic functions eg. reproduction, locomotion, feeding, and cellular processes
What is ecology?
the interactions between organisms and their environments
what is Biodiversity ?
the variety of species
how much percentage of the earths surface is water and how much of that is the ocean?
70% of earths surface is water and 97% of this is ocean
what were the earliest life forms?
methane- producing archaea 4.5 billion years ago
the early ocean was entirely what?
anoxic- in the absence of oxygen
Are resources in the ocean divided equally?
no
how is the ocean split up?
Into zones defined by depth and proximity to continents
what is the earths crust broken up into?
into plates that move up to 100m a year
How many plates are there on the earths crust?
8
Is oceanic crust thicker or thinner than continental crust?
much thinner- on average 100km versus 250km
what is the pacific plate like?
huge and at its fringes interacts with smaller ones around it causing this activity
What is the ring of fire?
a string of volcanoes, substantial seismic activity and earthquakes all caused by plate tectonics
what are the three ways that the plate boundaries move?
- divergent
- transform
- convergent
explain divergent plates?
- they are spreading so moving away from each other
- they are constructive (oceanic lithosphere created)
- create ridges and volcanoes
- eg. mid Atlantic ridge
explain transform plates?
- lateral sliding ( move side by side)
- constructive ( oceanic lithosphere neither created or destroyed)
- no major topography
- no volcanoes
explain convergent plates?
- one plate is pushed under the other (subduction)
- destructive ( oceanic lithosphere is destroyed)
- trench and volcanoes
- eg. mariana trench
what is isostasy?
whereby gravity and buoyancy act on the earths outer layers to bring them closer together
what is bathymetry?
the measurement of ocean depths and the charting of the shape of the ocean floor. First taken by the greeks
what are ocean ridges?
occupy 33% of total ocean floor area and continuously spreading
what are abyssal plains ?
gradients less than 0.05 and are the flattest ocean feature, only interrupted by seamounts. They are covered in deep layers of sediment
what are sea mounts?
most are ocean floor volcanoes that don’t rise above
sea level. Slope angle as great as 25. The Mauno Loa sea mount is as as high as mount Everest. Flat
topped seamounts (Guyots) have been planed off by wave erosion
