MIDTERM 1
All of the following are true about conservative elements in the ocean except __________.
a) they are biologically active
b) they have long residence times
a) they are biologically active
The three types of tectonic plate boundaries include:
divergent, convergent, and transform
What percent of the worlds water is in the oceans?
97%
What are the four most abundant dissolved ions that make up seawater?
Chloride, Sodium, Sulfate, Magnesium
Waves that continue to propagate beyond the area of strong storm winds are known as _______.
A) Swell
B) Sea
C) Surf
D) Breakers
A) Swell
One of the major removal mechanisms for the Mg ion in the ocean is______________.
a) The formation of gypsum deposits
b)formation of carbonate skeletons
c) high temperature alteration at hydrothermal vents
c) high temperature alteration at hydrothermal vents
Features of the suturing stage of the Wilson cycle include:
a)Island arches and trenches around the basin
b)Ocean basins with continental margins
c)Narrowing seas with matching coastlines
d) young to mature mountain belts, like the Himalayas
d) young to mature mountain belts, like the Himalayas
A good example of the MATURE stage (Stage C) of the Wilson Cycle is: (select the best choice)
a) Himalya Mountains
b) Atlantic Ocean
c) Red Sea
d) Pacific Ocean
e) Andes Mountains
b) Atlantic Ocean
What is the best explanation for the contrasts between dissolved solutes in river and ocean water?
a) Dissolved elements coming into the ocean from rivers are removed from ocean in different ways and at different rates
b) The much higher concentration of dissolved solutes in the ocean reflect the rapid evaporation of water relative to the residence time of major salts in seawater
c) There are additional sources of dissolved solutes into the ocean besides rivers (e.g., hydrothermal fluids, dust)
d) All of above
e) A and C
f) B and C
g) A and B
d) All of above
Based on your knowledge about the Arctic and Antarctic regions and the information in lectures, identify which of the statements comparing them is/ are accurate?
a) The Arctic is an ocean surrounded by land masses; the Antarctic is a land mass surrounded by ocean
b) The ocean currents in the Arctic connected with other oceans, the ocean currents in the Antarctic isolate it from other oceans
c) Both Arctic and Antarctic regions include continental ice sheets that connect with the ocean via glaciers
d) Both Arctic and Antarctic regions have sea ice that is comparable in overall area and thickness
e) A, B, and D
f) A, B, and C
g) A and B
h) B and C
i) A and D
j) B and D
f) A, B, and C
The theory of plate tectonics helps explain the location of volcanoes and earthquakes. Which of these also describes the current theory of plate tectonics?
a) it combines elements of continental drift and seafloor spreading.
b) it suggests that the lithosphere is divided into pieces, called plates.
c)denser ocean crust sinks below less-dense continental crust along subduction zones.
d) A and B
e) B and C
f) A and C
g) All of the above
g) All of the above
Which of the relationships of temperature, salinity, and density of seawater is true?
a) As temperature increases, density decreases
b) As salinity increases, density increases
c) As salinity decreases, density increases
d) As temperature changes, salinity doesn't change
e) a and b
f) b and c
g) a and c
h) a, b, and c
i) a, b, and d
i) a, b, and d
What change in the earth's magnetic field is recorded in lava as it cools?
polarity of the magnetic field
The main reason for the differences in the types of tides that are seen between the equator (semidiurnal tides), mid-latitudes (mixed tides) and high-latitudes near the poles (diurnal tides) is ____________.
d) The Moon-Earth gravitational axis is tilted at a 23.5 degree angle relative to the Earth’s equator
Decreasing sea ice cover in the Arctic Ocean is likely to lead to:
a) a rise in sea level
b) an acceleration in the rate of sea ice melting
b) an acceleration in the rate of sea ice melting
Water is a powerful solvent: A solvent is a substance that dissolves a solute (a chemically different liquid, solid or gas), resulting in a solution. Not everything dissolves equally in water. However, substances that are most easily dissolved are held together by _____________.
ionic bonds
Based upon the Earth's surface elevation histogram (hypsometric curve), what percent of the earths surface is land that is 0-1000 km high.
What is a seafloor isochron?
seafloor of equal ages
The concept of residence time (RT) for a dissolved ion brought into the ocean by rivers can be most easily visualized in comparison to the residence time of river water using the following equation:
RT(any ion in ocean) = RT(river water) x Concentration (ion in ocean)/Concentration (ion in river)
Given that
RT(river water) = 35,000 years
Concentration of SiO2 in river = 13.1 mg/liter
Concentration of SiO2 in ocean = 3.0 mg/liter
True or False:
The residence time of SiO2 in the ocean is slightly less (about 30,000 years) compared to river water
False: The residence time of SiO2 in the ocean (about 8000 years) is considerably less compared to river water
Ships departing from the OSU ship dock, aim to depart at this tidal phase:
at slack tide
You are on a ship off the coast of Oregon and are mapping the sea floor using soundings. Your 'chirp' took 2.4 s to travel to and from the seafloor. How deep is is the ocean floor beneath you?
1800
What is the average density and average composition of continental crust?
a) 2.7 g/cm3; granite
b) 2.9 g/cm3, basalt
c) 2.7 g/cm3, basalt
d) 2.9 g/cm3, granite
a) 2.7 g/cm3; granite
You are marine geological oceanographer mapping the seafloor off the coast of Oregon using soundings. Your sound 'ping' takes 0.6s to travel from and return to the ship. How deep is the seafloor beneath you?
450m
Spring tides occur every roughly every 2 weeks (14.8 days) because:
a) The Moon and the Sun are aligned with the Earth four times per month and result in constructive gravitational interference
b) The Moon and the Sun are at 90-degree angles with the Earth two times per month and result in constructive gravitational interference
c) The Moon and the Sun are aligned with the Earth two times a month and result in constructive gravitational interference
d) The Moon and the Sun are aligned with the Earth two times a month and results in destructive gravitational interference
c) The Moon and the Sun are aligned with the Earth two times a month and result in constructive gravitational interference
Antarctic sea ice is retreating ____________ compared to the arctic because ______________.
slower; because heat transport to the southern ocean is impeded by the ACC