Question 1

The San Andreas system in California is an example of a

Accepted Answer

The San Andreas system is a well-known example of a right-lateral motion in a strike-slip fault.

Question 2

An area that is a seismic gap

Accepted Answer

A seismic gap is an area on a fault where no earthquakes have occurred for a long time, despite being surrounded by active earthquake zones. The longer the time since the last earthquake, the more overdue the area is for another earthquake. Therefore, choice A is the best answer.

Question 3

The area at the surface directly above the subsurface location where seismic waves are initiated is termed the

Accepted Answer

The epicentre is the point on the Earth's surface located directly above the focus or hypocentre, where seismic waves are initiated during an earthquake.

Question 4

The most active tectonic regions of North and South America are on the

Accepted Answer

The western coasts of North and South America are where the most active tectonic regions are located. Both regions are part of the Pacific Ring of Fire, which is known for its volcanic activity and frequent earthquakes. This is due to the movement of tectonic plates along the western boundary of the Americas, where the Pacific Plate is subducting underneath the North and South American Plates.

Question 5

Orogenesis refers to

Accepted Answer

Orogenesis is the process of mountain-building through the thickening of continental crust. It involves folding, faulting, and metamorphism of rocks. Therefore, option B is the correct answer. Option A refers to faulting only, while option D refers to mountain formation without faulting or folding, and option E refers to oceanic processes rather than continental ones. Option C refers to the opposite of thickening of the crust.

Question 6

People often say that California is going to "fall into the ocean,".This idea is totally wrong because the San Andreas fault would have to be a ________ fault associated with ________ forces for this to happen.

Accepted Answer

The answer of People often say that California is going...

Question 7

The Appalachians formed as a result of the

Accepted Answer

The Appalachians formed as a result of the Alleghany orogeny, which occurred during the Late Paleozoic era (between about 325 and 260 million years ago). This orogeny was caused by the collision of the ancient continents of Laurentia (which included present-day North America) and Gondwana (which included parts of present-day Africa, South America, Australia, and Antarctica). The collision caused the sedimentary and volcanic rocks that had accumulated on the continental shelf to be squeezed and folded, forming the Appalachian Mountains.

Question 8

Small areas of high strain along a fault are termed

Accepted Answer

Asperities are small areas of high strain along a fault. These areas are where the most stress builds up and where eventually the fault will break and slip, causing an earthquake.

Question 9

The presence of grabens and horsts indicates the occurrence of

Accepted Answer

Grabens and horsts are associated with the formation of rift valleys, which occur when tectonic plates move apart and create a divergent boundary. This is known as rift activity, making option B the correct choice.  Volcanic activity is associated with the presence of volcanoes, which may or may not be present in regions with grabens and horsts. Collision activity involves the convergence of tectonic plates, which is not associated with the formation of grabens and horsts. Strike-slip activity involves horizontal motion along a fault, while transform faulting involves movement along a transform boundary. Neither of these are directly associated with the formation of grabens and horsts.

Question 10

The Innuitian Mountains formed as a result of the

Accepted Answer

The Innuitian Mountains are located in northern Canada, specifically on Ellesmere Island, and were formed as a result of the Ellesmerian orogeny during the Paleozoic Era.

Question 11

An instrument used to record vibrations in the crust is the

Accepted Answer

The instrument used to record vibrations in the crust is called a seismograph. The seismograph measures vibrations or seismic waves generated by earthquakes, volcanic eruptions, and other seismic activity in the Earth's crust. The resulting data is used to study the Earth's interior and to assess earthquake hazards.

Question 12

Which of the following regions is probably the most tectonically active at this time?

Accepted Answer

The Himalayas are the most tectonically active region due to the ongoing collision of the Indian and Eurasian tectonic plates, which is causing the mountain range to continue to rise. This can be seen through the frequent earthquakes and mountain-building activity in the region.

Question 13

Seismic gap investigations involve

Accepted Answer

Seismic gap investigations involve the study of past earthquake activity along specific plate boundaries, which is done through paleoseismology. This helps in identifying areas where there hasn't been activity for a while, also known as seismic gaps, and assessing the potential for future earthquakes in those areas. The other choices are not related to seismic gap investigations.

Question 14

Foreshocks may be caused by

Accepted Answer

Foreshocks are small earthquakes that occur before the main earthquake. They are caused by small movements that occur when some rocks break in limited areas of a fault plane prior to the main movement.

Question 15

The motion of seismic waves is initiated in a subsurface area along the fault plane called the

Accepted Answer

The focus, also known as the hypocentre, is the point in the subsurface where the movement of tectonic plates initially occurs and seismic waves originate.

Question 16

The relatively young mountains along the western margins of North and South American plates are referred to as the

Accepted Answer

The Cordilleran system refers to the relatively young mountains along the western margins of North and South American plates. The other options either refer to different mountain ranges or are not applicable to the region described.

Question 17

The presence of normal faulting and extensive basalt lava flows indicates

Accepted Answer

Normal faulting and extensive basalt lava flows are indicative of a rift zone. Normal faults result from tensional forces, which are associated with the stretching and pulling apart of the lithosphere. Basalt lava flows are commonly associated with the volcanic activity that occurs in rift zones.

Question 18

Because of the processes responsible for the formation of the Himalayan Mountains,the crust in this region of the world has been

Accepted Answer

The Himalayan Mountains were formed as a result of the Indian Plate colliding with the Eurasian Plate, which caused the crust in the region to be shortened or compressed. This process is known as crustal shortening or compression and is associated with mountain-building events. Therefore, Choice A is the correct answer.

Question 19

Which of the following is produced by normal faulting?

Accepted Answer

The Basin and Range is a region of normal faulting, where the crust has been stretched and pulled apart, resulting in the characteristic alternating valleys and mountain ranges. The Himalayas, San Andreas system, Great Lakes lowlands, and Bay of Fundy are not formed by normal faulting.

Question 20

The seven structural regions of the world

Accepted Answer

The seven structural regions of the world, such as mountains, plateaus, plains, basins, hills, and valleys, are grouped because of shared physical characteristics. These regions have different landscapes, which influence the climate and ecosystems within them.

Quiz 12: Tectonics, Earthquakes, and Volcanism