economic activities such as industrialization and manufacturing have caused and put a lot of smog into our air which then makes it way back down to the bottom of the ocean or ground
option 2 most major cities begin next to bodies of water
Answer:
It's the 4th, as third is modified by the man.
Explanation:
- The Third atmosphere was a rearrangement of the plate tectonics and the evolution of atmosphere by the transferring of it to the oceanic basins. As the amount of oxygen in the atmosphere used to be more than 30% around 280 million years ago than the present.
- Rapid development of land plants and animals was caused due to this atmosphere and hence this atmosphere is now less than 21% and due to his influence or modification of man with his technological tools and techniques.
- The atmosphere is rapidly shrinking due to the greenhouse effect and global warming that is leading to the fifth atmosphere that may be like that of mars as devoid of gases and barren and dry with oceans running under the crust.
The lithosphere, which is the rigid outermost shell of a planet (the crust and upper mantle), is broken up into tectonic plates. The Earth's lithosphere is composed of seven or eight major plates (depending on how they are defined) and many minor plates. Where the plates meet, their relative motion determines the type of boundary: convergent, divergent, or transform. Earthquakes, volcanic activity, mountain-building, and oceanic trench formation occur along these plate boundaries. The relative movement of the plates typically ranges from zero to 100 mm annually.[2]
Tectonic plates are composed of oceanic lithosphere and thicker continental lithosphere, each topped by its own kind of crust. Along convergent boundaries, subduction carries plates into the mantle; the material lost is roughly balanced by the formation of new (oceanic) crust along divergent margins by seafloor spreading. In this way, the total surface of the lithosphere remains the same. This prediction of plate tectonics is also referred to as the conveyor belt principle. Earlier theories, since disproven, proposed gradual shrinking (contraction) or gradual expansion of the globe.[3]
Tectonic plates are able to move because the Earth's lithosphere has greater strength than the underlying asthenosphere. Lateral density variations in the mantle result in convection. Plate movement is thought to be driven by a combination of the motion of the seafloor away from the spreading ridge (due to variations in topography and density of the crust, which result in differences in gravitational forces) and drag, with downward suction, at the subduction zones. Another explanation lies in the different forces generated by tidal forces of the Sun and Moon. The relative importance of each of these factors and their relationship to each other is unclear, and still the subject of much debate.
