exam2 Flashcards
Why does water have unusual properties?
- Bend in geometry 2. Give slight pos charge on H side and neg on O2 side 3. Causes Polarity
What makes water the Universal Solvent?
Partial pos and partial neg charges can easily tug apart anything with opposing charges.
List the properties that result from Hydrogen Bonding.
- High solubility of chemical compounds 2. Unusual thermal properties, high spec heat 3. Adhesive properties 4. Cohesive properties 5. High surface tension 6. Blue color of water 7. Solid liquid and gas states on Earth’s surface
What is temperature?
The average kinetic energy of the atoms and molecules in a substance.
What is heat?
The total kinetic energy of atoms and molecules in a substance.
What is the latent heat of vaporization and latent heat of fusion for water?
- Latent heat of vaporization is 540 cal/g/deg C 2. Latent heat of fusion is 80 cal/g/deg C
Waters high heat capacity does what?
- Used as coolant 2. Moderates coastal temperatures 3. Allows ocean currents to spread heat around the globe
What is the land temp range and ocean temp range?
- Land: 100°C from -50 to 50°C 2. Water: 30°C from -2 to 28°C
Why does San Francisco’s temperature fluctuate less than Norfolk, Virginia?
Wind patterns move west to east. The wind heading towards Norfolk is carried over land, while the air arriving in San Francisco travels over the Pacific, which moderates temperature.
Why does ice float?
When water freezes, it forms a crystal lattice due to hydrogen bonding, making ice less dense than liquid water.
What is cohesion?
The ability of water molecules to stick together (hydrogen bonds).
What is viscosity?
Resistance to motion.
In what two ways is Tuvalu experiencing sea level rise?
- Ice caps melting 2. Thermal expansion of the oceans
How do ions enter the ocean?
- Rivers 2. Hydrothermal vents 3. Volcanic activity 4. Groundwater 5. Decay of organisms
How do ions leave the ocean?
- Chemical entrapment at ridges 2. Sea spray 3. Uptake by organisms 4. Incorporated into sediments or subduction.
How much salinity is in the ocean?
3.5% or 35 ppt or 35g per kg
What is the most abundant ion in seawater?
Cl- (Chloride)
What are the major nutrients in the ocean that are trace elements?
Nitrogen and Phosphorus
What are the three ways to determine salinity?
- Chlorinity 2. Refractometry 3. Conductivity
What is a conservative constituent?
An element that occurs in constant proportion in seawater (Cl, Na, Mg).
What is a non-conservative element?
An element whose proportion in seawater varies over time due to biological demand or chemical activity (e.g., N, P, Fe, Al, Si, O2, CO2).
Describe a few ways to increase or decrease salinity.
- Freshwater decreases salinity (runoff, precipitation, melting ice). 2. Evaporation and ice formation increase salinity. 3. Hydrothermal vent deposits decrease salinity. 4. Salt spray, biological uptake, and evaporites decrease salinity.
Where does ocean salinity not vary?
Deep ocean stays constant at 35 ppt.
Salinity at the equator vs the poles ?
- Polar regions: Lower salinity (33 ppt) 2. Equatorial regions: Higher salinity (37 ppt)
What is the depth of the halocline (rapid salinity change)?
300–1000m
How does increasing salinity affect freezing and maximum density?
It decreases the temperature of maximum density and freezing.
How do you remove salt from seawater?
- Distillation (solar, artificial heat) 2. Electrolysis 3. Reverse osmosis 4. Freeze separation
What is the pH of the ocean?
8.1
How does ocean pH stay stable?
CO2 in seawater forms carbonic acid, which dissociates into bicarbonate (HCO3-), acting as a buffer.
Explain why CO2 and O2 vary with depth.
- Surface: Photosynthesis removes CO2 and produces O2. 2. Deeper: Less photosynthesis, but respiration still occurs, consuming O2 and releasing CO2. 3. Oxygen minimum zone exists where more oxygen is used than replaced.
What are the major nutrients for plant growth in the ocean?
- Nitrate 2. Phosphate 3. Silicate
How are nutrients brought to the ocean?
Freshwater runoff from continents.
How do nutrient levels decrease?
Increase in biological productivity (organisms consuming nutrients).
How do nutrient levels increase?
Population decline—death and decay release nutrients into the water.
What is the photic zone?
The uppermost layer of the ocean where marine life is richest and photosynthesis occurs (90% of marine life lives here).
What is the depth range of the photic zone?
- Clear open ocean: ~100m (max 600m) 2. Coastal ocean: 15–40m
What affects the depth of the photic zone?
- Riverine input 2. Wind mixing 3. Phytoplankton densities
What is the color of benthic algae at different depths?
- Green near surface 2. Brown at moderate depth 3. Red at deeper depths
Where is the SOFAR channel?
~1000m (velocity minimum zone).
What factors contribute to the SOFAR channel?
- Temperature 2. Pressure 3. Salinity
How does pressure change in the ocean?
1 atm at 0m, 2 atm at 10m, 3 atm at 20m.
How deep can sperm whales dive?
Up to 2250m.
What three things occur at the photic zone?
most O2 is generated here, supports higher trophic levels, receives the most heat.
