Answer to Question 1
Tsunamis are caused by the displacement of ocean water. They can be triggered by seismic activity, landslides, volcanic eruptions, and a variety of other events.
These are shallow-water progressive waves that have long wavelengths. They are a fast onrush of water to a shoreline despite their large wave height.
The tsunami in December of 2004 was the worst in recent history. Most of the damage was done to Indonesia, but it also affected India and Africa. There were over 176,000 people killed.
The loss of life and property damage could have been reduced if a tsunami warning system was implemented in the region. These systems use a variety of technology to monitor changes in the shape of the ocean's surface.
Answer to Question 2
Oxygen is very unevenly distributed in the ocean. At the surface, oxygen readily diffuses into the ocean water from the atmosphere. In addition, photosynthesis activity by phytoplankton and other plants and algae releases oxygen. Therefore, the shallow waters of photic zone are rich in oxygen. Oxygen concentration decreases below the sunlit layer because of the respiration of marine animals and bacteria, and because of the oxygen consumed by the decay
of tiny dead organisms slowly sinking through the area. In the deep sea, oxygen levels increase slightly because deep sea water is carried from the surface by deep water currents that originated in the cold, oxygenated surface water of the poles. Additionally, fewer animals are present in the deep seawater to take up oxygen reaching these depths.
The health history can be gathered from many sources
tsunami
Patient health history form.
Climate History
Created Equal: A Social and Political History of the United States, Brief Edition
History Quiz Questions