Question

****PLEASE ANSWER ALL QUESTIONS****

Question 23 (1 point)

In the 1997 movie Volcano starring Tommy Lee Jones and Anne Heche, a volcanic eruption pours lava all over Los Angeles, California.

Given what you've learned in this section of the lab, assess whether a scenario of volcanic eruptions in Los Angeles, along a continental transform boundary, would seem to be highly plausible (True) or highly implausible (False).

Question 23 options:

	True
	False

Question 27 (1 point)

Which of the following hotspots is beneath the Antarctic Plate?

Question 27 options:

	Lord Howe
	Kerguelen
	Caroline
	Canary

Question 28 (1 point)

The Moai statues of Easter Island, and the island itself, are largely composed of what type of igneous rock?

Question 30 (1 point)

What forms in the gap between separating continents after a continental rift opens?

Question 30 options:

	A new seafloor spreading center.
	A bottomless, fiery chasm of fire.
	A new, third continent will arise.
	A subduction zone.

Question 31 (1 point)

What is the name of a failed arm of a continental-rifting triple junction?

Question 31 options:

	Transduct
	Subplate
	Horst
	Aulacogen

Answer 1

Ans. 23. The given statement is false. This is because transform boundaries are usually associated with the plates moving past each other. So it is a type of motion sideways, and there is no chance of formation of convection cells which can eventually lead to magma upwelling and finally a volcanic eruptions. On the other hand, convergent and divergent boundaries have higher chance of occurrence of volcanic eruptions. The convergent boundaries are associated with subduction of the denser plate, where the subducted plate melts and mixes with the molten material in the subsurface along with water which drives the convection. Finally the steam and molten material come out as lava through eruptions. Only the mid oceanic ridges are associated with the upwelling of the magma and molten material from beneath since the two oceanic plates are moving apart.

Ans. 27. The correct answer is (b) Kerguelen. Its full name is Balleny Erebus Kerguelen. A hotspot is a region of active volcanism irrespective of any plate boundary. Beneath the hotspot plate the upwelling and downwelling of magma take place and they are constantly taking place. Such areas are constantly leading to the formation of volcanoes.

Caroline is a type of tectonic plate and thus is not the correct answer. However there is a Caroline hotspot beneath the Pacific plate. Canary is the hotspot beneath the African plate and thus is incorrect. Lord Howe hotspot is found beneath the Indo Australian plate and thus is incorrect.

Ans. 28. The igneous rock type of the Moai statues of Easter Island, and the island itself is the extrusive igneous rock. Since there is no option available in the question, so this is the correct answer. The extrusive igneous type is mainly basalt.

Ans. 30. The correct answer is (a) A new seafloor spreading center.. When a continental rift starts begins to form a gap results due to the divergence of the plates. This in turn leads to the formation of a new ocean basin. This is why the third option i.e., a continental basin will form is incorrect. Usually a sea is formed in the gap. The second option is incorrect since it cannot lead to formation of a chamber of fire beneath the subsurface since rifting is associated with deformation of crusts. Usually subduction results in rifting. Subplates are the small parts of a pre-existing plate and thus it is a wrong answer. Horst is a type of block of rock which is formed from the normal faulting and thus is the incorrect answer.

Ans. 31. The correct answer is (d) Aulacogen. When a continental plate breaks up into three regions then one of the arms undergoing failure is what is called aulacogen. Transduction refers to the process by which metals are deposited on the crust. So it is wrong answer.