The Ocean Flashcards
What are the 5 main oceans?
Pacific (largest)
Arctic (smallest)
Atlantic
Indian
Southern
The oceans cover ~___% of the earth’s surface
- Does it cover more in the N or S hemisphere?
70
more ocean in the southern hemisphere (80%) than in the northern hemisphere (61%)
What’s the deep sea challenger?
A submersible that went to the bottom of the Marianas Trench in 2012 (in 2.5hrs!)
Marginal Seas=
a small part off of a main ocean, affected by regional climate
Give 3 examples of marginal seas and list some things they’re affected by
- Straight of Georgia
- Gulf of Mexico
- Mediterranean Sea
- regional climate
- precipitation- evaporation balance
- river input (fresh water and dissolved solids)
- limited exchange with open ocean (eg sill)
- geological history
Continental slopes have a __ degree slope and are full of ______
- explain their characteristics and what they’re important for
1 degree
sedimentation
- they’re long and shallow (300m) and an important area for organisms and our harvesting
What are sills?
a barrier on the seafloor that can prevent exchange between the open ocean and an enclosed area of water (like a lip)
Earth’s surface is divided into ___, and the borders of these are ___ systems and ____
ridges
ridge systems
faults
Oceanic ___ is formed at ___, moved laterally, and destroyed by ____ (which forms trenches)
This is called:
crust
ridges
subduction
seafloor spreading
T/F
Continents are embedded in ocean crust
true
that’s why there’s continental drift
List 3 pieces of evidence for continental drift
- fossils of similar fauna are found on different continents
- seafloor mapping and radiometric dating found the seafloor younger than the continental crust (= there’s new crust forming)
- magnetic anomalies
- magnetic stripes on the ocean floor near spreading ridges show movement of the oceanic crust
Asymmetry of charge distribution on the water molecule causes ___. What does that do?
polarity
- increases its ability to form bonds with other ions
- makes water a good solvent
Explain the bond types in the water molecule
- H-O bonds: strong covalent bonds between H and O
- Weaker hydrogen bonds between water molecules (H20-H20)
- gives water ‘sticky’ property (meniscus)
- can form and unform, strength differs (water, ice gas)
What are the 4 main water properties
- excellent solvent (b/c it’s polar)
- High heat capacity
- it takes a lot of energy to break the hydrogen bonds
- energy transported in the ocean is huge
- water has a large thermal buffer capacity and acts as a climate buffer - High Heat of Vaporization
- lots of energy needed to change liquid at its boiling point into gas - High heat of fusion
- requires a huge amount of heat to change ice to water at 0 degrees
- eg requires a huge amount of energy to melt an iceberg
What are some implications linked to water properties?
- lands heats and cools faster than adjacent water bodies, so land temps near water bodies are moderated
- northern land masses do not necessarily experience arctic climates because of warm water currents (eg Norway)
- water transports heat/ cold over huge distances, so a temp change in Arctic can affect Antarctic water
T/F
The temperature range for deep water is greater than the temperature range for surface waters
false
large latitudinal range for surface waters, little range for deep water
what’s the thermocline layer?
a layer of water just below the surface where temperature decreases rapidly with increasing depth
Explain the differences in the thermocline in an open tropical ocean vs shallow temperate ocean (winter/ summer)
- open tropical ocean (eg Hawaii)
- thermocline layer is very deep (~1000m) - shallow temperate ocean in the summer
- very shallow thermocline because the heat from the sun doesn’t penetrate very much (ends at ~5m deep) - shallow temperate ocean in winter
- lacks a thermocline (the entire vertical column of water will be at the same temp, just above 0 degrees)
