week 8 Flashcards
what is an ocean
saline water occupying earths surface. this inclues all seas and lakes
covers 72%
what are the properties of the ocean
salts, dissolved gases, organic matter and water
Cl, Na, Mg, S, Ca, K, Br
what is the avg salinity of the ocean? which ocean has the highest salinity
3.5g/L (%)
dead sea
what are the 5 oceans
pacific
Arctic
Atlantic
Indian
Antarctic
describe the pacific
largest and deepest ocean and contains many islands
contains the ring of fire - lots of volcanic activity (subduct zones)
subject to many tropical cyclone (typhoons)
describe the Atlantic
2nd the largest ocean that is fed by many large rivers
contains the mid-Atlantic ridge= diverging plates/ spreading
contains many shallow seas (Caribbean, Mediterranean, gluf of Mexico_
subject to hurricanes
describe Indian ocean
3rd largest
warmest ocean
subject to monsoon
what is a monsoon
regional wind patterns that change seasonally. these commonly bring string precipitation patterns
the change in seasonal winds and associated precipitation patterns
describe the antarctic
2nd smallest
Intense low-pressure systems = storms!
mobile ice pack (95% coverage in winter and 15% in summer)
describe the artic
smallest and shallow
mobile ice pack that can change ice concentration 50% between summer and winter
this can open the northwest passage
which ice sheet is important for maintaining climate and why
arctic ice
-imparts a strong albedo as well as drive ocean water circulation. (gyre)
what drives oceans’ surface circulation
Gyre and wind friction
gyre moves warm water to the poles and cold water to the equator
what is welling
the rise or fall of deep ocean water promoting the circulation of water to the continental shelf. this help circulate nutrient-dense water from below to the surface
what dictates deep ocean currents
density gradients/ thermohaline circulation
overall temp and salinity of the water will impact the density of the water (influenced by sea ice)
what are the most productive ocean areas
coastal zones and upwellings from the deep ocean (nutrient-rich) promote Photosynth activity
what is the most caught fish
alaskan pollok
what are the threats to ocean ecosys
over fishing
climate change
pollution
what implications does overfishing impart?
a rate of catching fish faster than they can reproduce
have increased levels of bycatch (non-targeted fish that cannot be kept or sold (commonly killed))
anadromous
a fish life cycle that takes pace in both fresh water and salt water
spawn in the fresh water and livein the oceans for 1-7 years
what is open-net salmon farming
deploying large (deep) nets of the coast (in similar habitats of wild salmon.
open-net fish farming commonly introduced diseases and paradise into the farmed fish
- many also use chemicals/ toxins into the water
escapement of the farm fish is also common. this challenges the wild salmon in their ecosystem by inc competition for resources
how is climate change harming aquatic ecosys
the melting of glaciers (eustasy), alters seas level, temp and composition (nutrient density)
on coastal regions warming of the water causes leeching of the coral as the symbiotic algae are expelled
how are inc lvl of CO2 (climate change) harming coean eco sys
imparting ocean acidification. this lowers the pH and lowers the number of carbonate minerals in the water
this hinders the ability for shell formation, leaving orgs to be vulnerable to predators
how is pollution impacting the ocean ecosys
sources from runoff and point sources (toxic material and nutrients)
plastic (80% from land activities)
more than 8 million tones of energy the ocean each year where approx 99% skins to the bottom and /or biodegrades to micro plastics.