The "Goldilocks Principle," as applied to the origin of water on Earth suggests that:
Earth has just the right position in the solar system -not too close to the Sun and not too far away
On average, and particularly in the tropics, the temperature and salinity of ocean deep water is very similar to that of shallow, surface water.
Water molecules have polar (unequally distributed) charge that leads to many of water's unusual characteristics
Rachel Carson suggested that rain and other factors weather the continents and that rivers deliver dissolved rock (including elements such as Na, Ca and Cl) to the world ocean.
When scientists carry out investigations, they typically:
A.) Make observations and collect data B.) Test hypotheses by trying to disprove them C) Make predictions using hypotheses and test these against existing data and new observations
An example of latent heat is
A) the energy required to change the temperature of fresh water B) the energy required to raise the temperature of 1 kg of water by 1 degree Celsius C) the energy released when water cools D) the energy required to heat liquid water from 0 to 100 degrees E) None of the above (ANSWER)
There is less dissolved carbon dioxide in deepwater of the ocean than in ocean's surface waters because:
A) Photosynthesis occurs primarily in deepwater B) Organisms that respire produce CO2 in deep water C) Photosynthesis in surface water uses C02 D) Deepwater is colder than shallow water and the solubility of CO2 is higher for colder water. E) None of the above, the above statement about C02 is incorrect (ANSWER)
This plot shows four points (crosses) labeled 1 through 4. Which of the following is/are correct?
2 has σt (sigma_t) of 23
Ocean water most likely formed:
A) In the past 10,000 years B) From emission (degassing) of materials (volatiles) from Earth's interior (ANSWER!!) C) From melting of glaciers and polar ice caps D) A and C E) A and B
The latent heat of fusion (melting) for water is 80 cal per gram. How much heat energy is required to melt 1 gram of ice?
A) 80 calories (ANSWER) B) 540 calories C) 800 calories D) 54 calories
Which of the following is/are true about residence time of an element in seawater:
A) It can be calculated from the total amount of the element present in coral reefs and the amount in salt deposits B) It can be calculated from the amount in Earth's interior. C) It is given by the ratio of the total amount of the element in seawater divided by the input rate. (ANSWER!!) D) All of the above
Which of the following is/are true?
A) Freshwater reaches maximum density at the freezing point B) Saltwater is less dense than freshwater C) Seawater density is determined primarily by salinity and temperature (ANSWER!) D) All of the above E) B and C
Many elements are dissolved in seawater, but Cl is the most abundant and Na is the second most abundant.
According to this plot, which requires the largest amount of heat input?
A) Melting 10 grams of Ice (ANSWER!) B) Boiling 1 gram of liquid water at 100 degrees C (that is, turning it into vapor) C) Raising the temperature of 1 gram of water from 0 to 100 degrees C (heat capacity is 1 cal/gm °C) D) Raising the temperature of 1 gram of ice from -20 to 0 degrees C. (heat capacity of ice is 0.5 cal/gm °C)
Ocean chemistry is influenced by
A) inputs from river water. B) outputs such as gypsum, halite and other evaporites C) interaction of seawater with the seafloor D) all of the above (ANSWER!) E) none of the above.
The average salinity of the world ocean is ___ parts per thousand (o/oo)
A) 50 B) 35 (ANSWER!) C) 17 D) 144
The terms sensible heat and heat capacity refer to the heat necessary to change the temperature of a substance, whereas latent heat refers to the heat necessary to change the phase of a substance, for example from solid to liquid.
Which of the following is/are true?
A) Water has higher heat capacity than land (ANSWER!) B) Water has higher temperature than air at all latitudes C) Seawater generally has more Ca than Na D) none of the above
For gases dissolved in seawater, solubility
A) is higher in colder water B) increases as salinity increases C) decreases as temperature rises. D) A and C (ANSWER!) E) none of the above
The average chemical composition of river water is the same as that of seawater.
The course web site has a link about greenhouse gasses and global warming and that link makes the point that Earth receives most of its energy, called radiation, from the Sun.
Which of the following list of elements or molecules represents the correct rank order from highest to lowest concentration in seawater?
A) SO4, Na, Ca, Mg, Cl, K B) Cl, Mg, SO4, Na, Ca, Na C) Cl, Na, SO4, Mg, Ca, K D) Na, Cl, Mg, K, Ca, SO4 (ANSWER!) E) None of the above
The density of seawater
A) increase as it cools from 30 deg C to 5 deg C. B) increases as salinity decreases from 35 to 33 ppt. C) is minimum at 4 deg C, independent of salinity D) increases as temperature falls and salinity rises. E) A and D (ANSWER!)
Which of the following is/are correct?
A) Of the 17 billion Earth-sized worlds lurking in the Milky Way, most are so close to their stars that they would be far too hot for life as we know it. B) When you gaze up on a clear night at the starts, at least 70 percent of stars we see have a planet, whether it is a small rocky planet or a gas giant. C) In the Milky Way galaxy, Earth-sized planets are quite rare D) All of the above E) A and B (ANSWER!)
A hurricane builds energy as it moves across the ocean, sucking up warm, moist tropical air from the surface and dispensing cooler air aloft.