Question

What causes sudden movements of the earth?
A.Volcano
B.Folding
C.Flood plain
D.All of the above

Answer 1

Hint: The continental drift theory proposed by Alfred Wegener in 1912 says that all the continents were originally one single continental mass or supercontinent called Pangea which was surrounded by a mega ocean called Panthalassa. This supercontinent broke up about 200 million years ago to form two giant continents, Gondwana and Laurasia that then continued to break into several smaller continents that exist today. Plate tectonics is a theory (that stems from the continental drift theory) proposing that all large scale motions and geological activities on earth are caused by the tectonic plates that exist in the earth’s lithosphere.

Complete answer:
Option A: is correct. Volcanic activity is one of the sudden movements of the earth’s crust caused by the convergence or divergence of the tectonic plates. It can occur both on land due to the convergence of tectonic plates like the Pacific Ring of Fire and in the oceans due to the divergence of tectonic plates like the Mid-Atlantic ridge.
Option B: is incorrect. Fold mountains are formed due to the convergence of tectonic plates in the earth’s crust. At the boundaries where the tectonic plates collide, rocks and debris are formed as a result of compression and it is folded into rocky hills, mountains, and ranges. However, this process is very slow and takes thousands of years to form.
Option C: is incorrect. Flood plains are the lowland areas where alluvial soil is brought down and deposited by the river flowing through it. It has nothing to do with the movements in the earth’s crust.
Option D: is incorrect.

So, the correct answer is option A.

Note: There are seven major tectonic plates located in the region after which they are named— the African Plate, the Antarctic Plate, the Eurasian Plate, the Indo-Australian Plate, the Pacific Plate, the North American Plate and the Latin American Plate. The movement of the tectonic plates creates three types of boundaries—convergent in which the plates move into one another; divergent in which the plates move apart from each other; and transform in which the plates move sideways from each other.