Properties of water; currents and tides Flashcards
(43 cards)
What does temperature reflect in terms of molecular movement?
Average speed of molecules
Higher temperature means faster molecular movement.
What type of bonds hold water molecules together?
Hydrogen bonds
These bonds constantly break apart and reform.
What happens when a water molecule moves fast enough?
It breaks free from hydrogen bonds and evaporates into gas.
What is the density relationship between ice and water?
Ice is less dense than water, so it floats.
What is a key part of global water circulation?
Sinking of cold, dense seawater.
What structure do hydrogen bonds create in frozen water?
A fixed 3D lattice (crystal).
What is heat capacity?
The amount of heat required to raise a substance’s temperature.
What is unique about water’s heat capacity?
Water has one of the highest heat capacities of any known substance.
What are the high latent heats of water?
Latent heat of fusion and vaporization.
How does water’s heat absorption affect temperature stability?
Water can absorb a lot of heat for a small temperature increase, stabilizing temperature.
What does salinity measure?
Amount of salt dissolved in water.
How was salinity traditionally measured?
By the amount of salt left after seawater evaporated.
What is the modern method of measuring salinity?
Via the conductivity of seawater.
What is the rule of constant proportions?
Oceans are remarkably well mixed.
What is the typical salinity of oceanic water?
~35 parts per thousand.
What factors can cause salinity changes?
- Addition/removal of water
- Changes across estuaries
- Fluctuations in rockpools.
What determines the density of seawater?
Temperature and salinity. Temperature main controller of density of seawater
What happens to seawater density as it gets saltier and colder?
It gets denser.
What gases dissolve in ocean water?
- Oxygen
- Carbon dioxide
- Nitrogen.
How does temperature or salinity affect oxygen levels in water?
Oxygen decreases as temperature or salinity increases.
Which gas is more soluble in water, CO2 or O2?
CO2.
How does hydrostatic pressure change with depth?
Increases linearly.
What happens to light intensity as it penetrates water?
It declines with depth.
Which wavelengths of light are absorbed first in water?
Red light.
