Question

1. what does the theory of plate tectonics suggest?
2. how is the ocean - floor topography different from the topography of exposed land areas?
3. what is the difference between a synclinal and a seamount?
4. how are mid - ocean ridges formed?
5. how did the continental shelf form?
6. how did submarine canyons form?

Explanation:

1. The theory of plate tectonics suggests that Earth's lithosphere is divided into tectonic plates that move relative to each other, causing geological features like mountains, earthquakes, and ocean - floor spreading.
2. Ocean - floor topography is different from exposed land areas as the ocean floor has features like mid - ocean ridges, trenches, and abyssal plains. Exposed land has mountains, valleys, plains etc. with different elevation and formation processes.
3. A subduct is when one tectonic plate moves under another, often at convergent plate boundaries. A seamount is an underwater mountain. The main difference is that a subduct is a process and a seamount is a geological feature.
4. Mid - ocean ridges are formed by seafloor spreading. Magma rises from the mantle at divergent plate boundaries, solidifies, and creates new oceanic crust, pushing the existing crust apart and forming the ridges.
5. The continental shelf forms as a result of the edge of a continent being submerged under relatively shallow water. It is a gently sloping extension of the continent and is formed through processes like sediment deposition and sea - level changes.
6. Submarine canyons form through a combination of processes including turbidity currents (fast - moving mixtures of water and sediment) that erode the continental slope and shelf, as well as the influence of tectonic activity and sea - level changes.

Answer:

1. The theory of plate tectonics suggests that Earth's lithosphere is divided into moving tectonic plates which cause various geological phenomena.
2. Ocean - floor topography has features like mid - ocean ridges and trenches, different from exposed land's mountains and valleys.
3. A subduct is a process of one plate moving under another, while a seamount is an underwater mountain.
4. Mid - ocean ridges are formed by seafloor spreading at divergent plate boundaries.
5. The continental shelf forms as the submerged, gently sloping edge of a continent with sediment deposition and sea - level change influences.
6. Submarine canyons form from turbidity currents, tectonic activity, and sea - level changes.