Chapter 13, Problem 1GST

a)

To determine

The continental slope, continental rise and continental shelf and shelf break among the given points in the diagram.

Answer to Problem 1GST

• Point-B: Continental shelf
• Point-D: Continental shelf break
• Point-A: Continental slope
• Point-C: Continental rise.

Explanation of Solution

Continental margins are the outer margins of the continents where the continental crust transitions to oceanic crust. These are one of the prominent provinces of the ocean floor. The major features accompanying these margins are as follows:

Continental shelf: It is the gentle sloped submerged surface which extends from the shoreline to the deep ocean basin. It is composed of continental crust. The average inclination of the shelf is about one-tenth of a degree. Its width greatly varies from ocean to ocean.

Continental slope: The seaward edge of the continental edge is known as continental slope. It the boundary between the continental crust and oceanic crust and is relatively steep with an average of 5 degrees.

Continental rise: The extension of continental slope with the thick accumulation of sediment down the slope is known as continental rise. The deep sea fans produced by the canyons merge together to form a continuous wedge shape at the base of the slope. This is termed as continental rise.

b)

To determine

The comparison of the size of continental shelf of surrounding Florida to the surrounding size of Florida peninsula.

Answer to Problem 1GST

The size of continental shelf of surrounding Florida is larger when compared to the surrounding size of Florida peninsula.

Explanation of Solution

Continental shelf is the gentle sloped submerged surface which extends from the shoreline to the deep ocean basin. It is composed of continental crust. The average inclination of the shelf is about one-tenth of a degree. Its width greatly varies from ocean to ocean.

From the accompanying map, it can be observed that the size of the Florida is much smaller when compared with the size of the continental shelf surrounding it. The presence of the major part of Florida much below the sea level also proves the same.

c)

To determine

The reason for the absence of deep-ocean trenches on the given map.

Answer to Problem 1GST

The given map has no convergent boundaries present and hence there are no deep-ocean trenches.

Explanation of Solution

Deep-ocean trenches are the long, narrow deep trenches located at the deepest parts of the ocean. These are the prominent features of the convergent plate boundaries. These are formed when he slabs of oceanic slab subducts under the other plate boundary, and plunge into the mantle. It results in the volcanic activity due to the energy released by the scrap of the plate.