Geomorphology Questions and Answers

Answer: B

The key takes option B: W.J. Morgan, who is the one named among the options as having postulated the concept of plate tectonics. Morgan put forward the idea of rigid plates moving on the earth's surface in 1967, and Le Pichon and others worked out the plate model soon after. Tuzo Wilson is known for the transform fault and for the hot spot, so the other names stand for other parts of the same set of ideas. The answer follows the key. The other options name places, people or terms that the subject does not connect with this question, so only the keyed option stands.

Answer: A

Both statements are true and the reason is the correct explanation, option A. There is a close relationship between volcanoes and plate margins, and the reason gives the evidence for it: about 80 per cent of the world's volcanoes are associated with the convergent plate boundaries, where one plate sinks into the mantle and melts. Options B, C and D deny either the truth of a statement or the link between them. Each statement is judged on its own first, and only then is it asked whether the reason accounts for the assertion, which keeps the choice between the four codes clear.

Answer: A

Knick points are associated with river rejuvenation, option A. When a river is rejuvenated, as by a fall of the base level or an uplift of the land, the river cuts down again from the mouth, and the place where the new profile meets the old one is a sharp break of slope, the knick point. Glacial erosion, aeolian deposits and karst topography are not connected with knick points. The other options name places, people or terms that the subject does not connect with this question, so only the keyed option stands.

Answer: A

Peninsulas make up most of Italy and Denmark, option A. Italy is the boot shaped peninsula of southern Europe, and Denmark is made up of the Jutland peninsula and a number of islands. Poland and France, Ireland and Great Britain, and Austria and the Czech Republic are made up mainly of mainland or of islands, so options B, C and D are wrong. The other options name places, people or terms that the subject does not connect with this question, so only the keyed option stands.

Answer: A

The Atlantic Ocean is spreading due to plate tectonic movement, option A. The Mid-Atlantic Ridge is a divergent boundary where new crust is made, and the Atlantic gets wider by a few centimetres every year. The Pacific is shrinking, since it is ringed by subduction zones, and the Indian Ocean spreads at its own ridges, but the Atlantic is the standard example of a spreading ocean in the key. The other options name places, people or terms that the subject does not connect with this question, so only the keyed option stands.

Answer: A

Landscapes produced by a single dominant geomorphic process are called simple landscapes.

In this terminology a simple landscape owes its form to one main process, such as running water or glacial action, acting over a long time. A compound landscape, by contrast, shows the work of two or more processes acting together or in turn.

Monocyclic and multicyclic landscapes (options C and D) are named for the number of cycles of erosion that the area has passed through, not for the number of processes. Compound landscapes (option B) are the opposite of what the question asks.

Answer: A

Flat-topped sand ridges that lie parallel to the prevailing wind are known as whalebacks.

Whalebacks are large, low and broad sand ridges of arid regions with flat tops and no clear slip faces, running along the wind direction.

Seifs (option B) are long, sharp-crested longitudinal dunes. Barchans (option C) are crescent-shaped dunes with horns pointing downwind. Sand drifts (option D) are small accumulations of sand behind obstacles and do not form ridges of this kind.

Answer: C

River valleys whose courses are controlled by factors that cannot be determined are termed insequent.

An insequent stream develops on a rock surface with no obvious relation to its structure or to the original slope, as with dendritic streams on uniform rock.

A consequent stream (option A) follows the original slope of the land. A subsequent stream (option B) is guided by weak rock belts or structure. A resequent stream (option D) flows in the direction of the original slope but at a lower level than the original consequent stream.

Answer: A

The correct match is Principles of Geomorphology with W.D. Thornbury, The Study of Landforms with R.J. Small, The Unstable Earth with J.A. Steers and Morphology of the Earth with L.C. King, so ii iii iv i.

Thornbury's textbook is a standard work of American geomorphology, Small wrote The Study of Landforms, Steers wrote The Unstable Earth on coastal and earth movements, and King wrote Morphology of the Earth on the cycle of pediplanation.

The other codes give these titles to the wrong authors, such as Morphology of the Earth to Steers or Principles of Geomorphology to King.

Answer: C

The slope replacement model was propounded by Walther Penck.

Penck held that a slope is replaced by a new, gentler one as the base level falls and slope elements retreat in sequence, which led to his theory of parallel retreat and slope replacement, in contrast to Davis's slope decline.

Wood (option A) is known for a model of slope development with free faces and debris slopes, Davis (option B) for the geographical cycle with slope decline, and Strahler (option D) for dynamic equilibrium and quantitative geomorphology.