The Earth Subsystem: Hydrosphere PDF

The Earth Subsystem: Hydrosphere Objective: Explain what the natural water are. The Hydrosphere The hydrosphere encompasses all the waters found on Earth. This includes water in various forms whether in ice, liquid, or vapor found on the surface of Earth, and in the atmosphere (in gaseou...

The Earth Subsystem: Hydrosphere Objective: Explain what the natural water are. The Hydrosphere The hydrosphere encompasses all the waters found on Earth. This includes water in various forms whether in ice, liquid, or vapor found on the surface of Earth, and in the atmosphere (in gaseous form). Water covers about 70% of Earth’s surface, and most of it water that makes up the oceans. The importance of water Water has been associated with the existence of life. When water or traces of water are found in other planets, then possibility of life is always speculated. Water is a substance that is necessary for the sustenance of life on Earth. It is also critical component of most organisms; so drying up would also mean dying. Properties of water that makes it vital Water could be in liquid form, not just solid Because it flows, water can travel to different places and reach organisms. As it travels, it picks up nutrients and other materials that is need to survive. Its being liquid also make it easy to circulate in the internal body system of organisms. Water has a neutral pH Because is neither acidic or alkaline (or basic), it can readily be tolerated by organisms without any harmful reactions to the various acidity levels that make up their organ system. Water is a good conductor of heat and energy The ability of water to transfer heat and energy has help regulate the overall temperature of Earth. Heat is distributed to organisms through water which makes up 70% of Earth. Water has a high specific heat Specific heat relates to the amount of heat necessary for any object to raise its temperature. Imagine if water has low specific heat; liquid water would suddenly boil when heat applied. Water’s high specific heat properly important to organisms as it gives them time to adapt to any changes in atmosphere heat, say due to climate change. Water is a universal solvent Some minerals or substance needed by organisms as part of their life processes may be dissolved by water. Hydrological cycle Water circulates everywhere on Earth. This circulation is made up by the interaction of energy and matter that allows the transformation of water from one phase to another, allowing it to circulate and travel to different regions of Earth. Because of water cycle, water and life processes are maintained. Evaporation Evaporation is the process of a liquid's surface changing to a gas. In the water cycle, liquid water (in the ocean, lakes, or rivers) evaporates and becomes water vapor. The water cycle's evaporation process is driven by the sun. As the sun interacts with liquid water on the surface of the ocean, the water becomes an invisible gas (water vapor). Evaporation is also influenced by wind, temperature, and the density of the body of water. Condensation Condensation is the process of a gas changing to a liquid. In the water cycle, water vapor in the atmosphere condenses and becomes liquid. Condensation can happen high in the atmosphere or at ground level. Clouds form as water vapor condenses, or becomes more concentrated (dense). Clouds at ground level are called fog or mist. Precipitation Precipitation describes any liquid or solid water that falls to Earth as a result of condensation in the atmosphere. Precipitation includes rain, snow, and hail. Fog is not precipitation. The water in fog does not condense sufficiently to precipitate, or liquefy and fall to Earth. Fog and mist are a part of the water cycle called suspensions: They are liquid water suspended in the atmosphere. Precipitation is one of many ways water is cycled from the atmosphere to the Earth or ocean. Distribution of waters on Earth All the waters found on Earth are natural but not everything is considered safe for drinking. In fact, only less than 3% of the world’s water is considered potable. The water on Earth are divided into two groups: surface water and ground water. Surface water and ground water differ in the types and amount of mineral founds in them. Surface water Surface water may be marine water or fresh water. Marine water has a higher salt content and is found in larger bodies of water such as ocean, seas, bays, and gulf.  Freshwater, on the other hand are those in lakes, rivers, spring and falls which, because of the lower salt content, is the best source of drinking water for all organism. While it is evident that water is found almost everywhere on Earth, most of it is salty, and therefore not readily fit for drinking. This is where processed water comes in. People have invented ways on how to make marine water potable by using technology. Marine water, for instance, may be desalinated make it safe for drinking. However, desalination technology require financial consideration. Groundwater Groundwater, on the other hand, is the water found beneath Earth’s surface where there are spaces in the soil or fractures in rocks. The underground layer of water- bearing rock is called an aquifer. An aquifer acts as reservoir for ground water and may contain large amount of minerals such as magnesium, calcium, etc.  If ground water is used for drinking, distillation may be required to avoid health problems.  It should be noted that there is a limit to the amount of minerals that can be tolerated by the body. If intake of mineral nutrients exceed the tolerable amounts, certain health problems may encountered such as kidney strain which may lead to the formation of kidney stones