ESS130 chapters 4-6
The average salinity of typical sea water
3.5%
Judge the following sentence according to the criteria given below: Biogenous sediment usually contains abundant calcite below the calcite compensation depth BECAUSE it readily dissolves above the calcite compensation depth.
Both the assertion and the reason are incorrect.
What is the most abundant negatively charged component of seawater?
Chloride
What is continental crust?
Continental crust is thicker, less dense, and lighter in color than oceanic crust, and its average composition is the igneous rock granite.
Describe the differences between passive and active continental margins and how these features relate to plate tectonics.
Continental margins are shallow-water areas close to the continents and can either be classified as active or passive, depending on their proximity to plate boundaries. Passive margins are embedded within the interior of lithospheric plates and are therefore not in close proximity to any plate boundary. Passive margins usually have broad continental shelves, slopes, and rises. In contrast, active margins are associated with lithospheric plate boundaries and thus have a high degree of tectonic activity. Active margins can be either classified as convergent or transform depending upon how the plates are moving relative to each other.
Why does a map of worldwide earthquakes closely match the locations of worldwide plate boundaries?
Earthquakes are sudden releases of energy usually caused by the movement of lithospheric plates or volcanic eruptions. The global distribution of earthquakes indicates that most occur along oceanic trenches, reflecting the energy released during the process of subduction. Other earthquakes occur along divergent plate boundaries at seafloor spreading centers along the global oceanic ridge system. Comparison of earthquake activity with the boundaries of plates indicates a high degree of correspondence.
Judge the following sentence according to the criteria given below: Marine sediment accumulations are interesting to oceanographers BECAUSE they often contain microscopic fossils that provide clues to the past geographic distributions of marine organisms.
The assertion and the reason are both correct, and the reason is valid.
Judge the following sentence according to the criteria given below: Microscopic biogenous ooze is common on the deep-ocean floor BECAUSE there is so little lithogenous sediment deposited at great distances from the continents that could dilute the biogenous material.
The assertion and the reason are both correct, and the reason is valid.
Judge the following sentence according to the criteria given below: Thick sediment accumulations occur on the continental shelves and rises, especially near the mouths of major rivers BECAUSE these locations are close to major sources of lithogenous sediment.
The assertion and the reason are both correct, and the reason is valid.
Judge the following sentence according to the criteria given below: Water is able to dissolve nearly everything BECAUSE water molecules interact with other water molecules and other polar molecules
The assertion and the reason are both correct, and the reason is valid.
Latent heat is the quantity of heat gained or lost as a substance undergoes
a change in state
Manganese nodules are an example of
hydrogenous sediments
Many of the unique properties of water are attributed to the fact that water
is a polar molecule
As salinity increases, what happens to density?
it increases
The study of how the ocean, atmosphere, and land have interacted in the past to produce changes in ocean chemistry, circulation, biology, and climate is called
paleoceanography
Diatoms contain what chemical compound?
silica ( SiO2 )
The principle of constant proportions states that
the relative concentrations of major ions in seawater does not change
What process increases seawater salinity?
Evaporation
What is a biogenous sediment?
a sediment produced by plants and animals in the sea
A beaker contains a mixture of ice and pure liquid water at 0 degrees celsius. What happens to the temperature of the liquid water as heat is added?
It remains constant until the ice melts, and then it begins to rise
What is oceanic crust?
Oceanic crust is thinner, denser, and darker in color than continental crust and is composed of the igneous rock, basalt.
List the major constituents dissolved in seawater in decreasing concentration.
Over 99% of the dissolved solids in seawater that exist in ionized form are chloride, sodium, sulfate, magnesium, calcium, and potassium.
What sediments are produced in areas of high primary productivity?
Radiolarians & diatoms
What is a lithogenous sediment?
Sediments derived from preexisting rocks on land
How is the age of the ocean sediments related to the distance from a mid-ocean ridge?
Since mid-ocean ridges are divergent plate boundaries where new crust is formed as the plates separate, the newest crust is at the spreading center in the mid-ocean ridge (ridge axis) and as one moves away from the ridge axis toward the continent, the age of the ocean sediments increases.
What is heat capacity?
The amount of heat energy required to raise the temperature of a substance by 1 degree Celsius.
Judge the following sentence according to the criteria given below: Density decreases as temperature increases BECAUSE the molecules lose energy and slow down with increasing temperature.
The assertion is correct, but the reason is incorrect.
How is the carbonate compensation depth (CCD) related to the worldwide distribution of calcareous oozes?
The destruction of calcium carbonate varies with depth. At the warmer surface and in the shallow parts of the ocean, seawater is generally saturated with calcium carbonate, so calcite does not dissolve. In the deep ocean, however, the colder water contains greater amounts of carbon dioxide, which forms carbonic acid and causes calcareous material to dissolve. The higher pressure at depth also helps speed the dissolution of calcium carbonate. The depth in the ocean at which the pressure is high enough, and the amount of carbon dioxide in deep-ocean waters is great enough, to begin dissolving calcium carbonate is called the lysocline. Below the lysocline, calcium carbonate dissolves at an increasing rate with increasing depth until the calcite compensation depth (CCD) is reached. At the CCD and greater depths, sediment does not usually contain much calcite.
Describe the characteristics and features of the oceanic ridge system, including the difference between oceanic ridges and oceanic rises.
The global mid-ocean ridge is a continuous, fractured-looking mountain ridge that extends through all the ocean basins. The mid-ocean ridge results from sea floor spreading along divergent plate boundaries. The enormous mid-ocean ridge forms Earth's longest mountain chain, extending across some 75,000 kilometers (46,600 miles) of the deep-ocean basin. The width of the mid-ocean ridge averages about 1000 kilometers (620 miles). The mid-ocean ridge is a topographically high feature, extending an average of 2.5 kilometers (1.5 miles) above the surrounding sea floor. The mid-ocean ridge contains only a few scattered islands, such as Iceland and the Azores, where it peeks above sea level. Remarkably, the mid-ocean ridge covers 23% of Earth's surface. Segments of the mid-ocean ridge called oceanic ridges have a prominent rift valley and steep, rugged slopes, and oceanic rises have slopes that are gentler and less rugged. As explained in Chapter 2, the differences in overall shape are caused by the fact that oceanic ridges (such as the Mid-Atlantic Ridge) spread more slowly than oceanic rises (such as the East Pacific Rise).
What is a biogenous sediment?
any types of oozes, they are sediments that come from biological materials
Foraminiferans contain what chemical compound?
calcium carbonate ( CaCO3 )
Calcite dissolves more readily in seawater that is ________ in temperature and ________ in pressure
colder; higher
