Global warming is a phenomenon that refers to increase in temperature of the earth surface as a result of the concentration in the amount of greenhouse gases in the atmosphere. Greenhouse gases like carbon dioxide, methane, water vapour in their normal amount helps to trap some part of solar radiation which is useful for all life on earth. If the proportion of these gases increase beyond normal, more radiation will be trapped and a surge in surface temperature results. This increase in temperature leads to:
Extreme weather conditions: Hurricanes, tornadoes becomes more prevalent as there is more heat in the atmosphere.
Polar ice begins to melt as a result of increase in the temperature of the earth surface.
Due to surge in the amount of carbon dioxide on the earth, the ocean dissolves the gases and this leads to the formation of weak carbonic acid.
The distribution of earthquakes defines the boundary of the earth tectonic plates as earthquakes have the seismic energy that gets transferred to the landscape and as result to this the transform, divergent and convergent boundaries along the plate margins can be found.
Deep focus earthquakes are those that have shallow bases and origin in trenches where the lands are subdued under the plates and are associated with prominent oceanic features like the mid-oceanic ridges, deep-sea ridges, and seamounts, guyots and canyons, etc.
The ocean floor of convergence that creates the deep-seated earthquake as being collided with land and an oceanic plate or being collided with an oceanic and oceanic plate boundary. Physical features are faults and rift valleys.
The tonga trench is located near the tonga island and in the southwestern pacific ocean, is the second deepest trench on earth. Pacific plate is being subdued under this tench with an in convergence rate of 15 cm/year. Thus the rigid slab of lithosphere plate is being pulled towards this zone of convergence.
