Geology Describe the Paths of Water Through

Geology

Describe the paths of water through the hydrologic cycle. Explain the processes and the energy gains and losses involved in the changes of water between its three states. Operationally, we are often most concerned with what water does when it reaches the solid earth, both on the surface and in the sub-surface. Explain the relationship between the saturated zone, the water table, a groundwater well and the cone of depression, all within the sub-surface.

In the hydrologic cycle, more commonly known as the water cycle, water moves around the world through a series of reservoirs. Water is always moving through the cycle because of evaporation, condensation and precipitation, surface and underground flow and through various other means (Egger 2003).

Water, as with most things, can change states from solid (ice) to liquid (water) to gas (steam). In changing states, the amount of energy in the water particles changes as well. When water changes state, the energy that is in the molecules of water is lost. The surroundings heat the ice cube and as the particles are heated, they move more quickly and subsequently give off energy.

At the point where water reaches the earth, in both the surface and sub-surface, the hydrologic cycle ensures that it still continues to move. There are various levels of water on the surface and sub-surface. The water table is the point at which the pressure of the groundwater is equal to that of the pressure within the atmosphere (Hughes 2012). When the pressure of the water is larger than that of the atmosphere, it has reached the saturation zone. A groundwater well is located beneath the saturation zone while the cone of depression occurs when the water from a well is pumped to the surface. It leaves a space between where there is dirt and where there had once been water pressure.

2. The food chain is a valuable concept in biogeography. Give an example of a specific food chain, labeling the various levels of the food chain. After looking at characteristics of the food chains, explain how a geographer's approach to the study of organisms might be different than biologist's study of organisms; what would each try to emphasize more than the other? What exactly is a biome? Compare / contrast the concept of the biome with that of the zoogeographic region. Compare / contrast the floral characteristics of two of the following biomes: desert, tundra, midlatitude grassland, and boreal forest.

There are three levels of the food chain: producers, consumers, and sometimes decomposers. Each of these levels may feed on members of their own type or on the other two; except for consumers which are able to make their own food and thus do not need to seek out a food source. One example of the food chain is as follows:

Osprey feed on pike

Pike feed on perch

Perch feed on bleak

Bleak feed on shrimp

Shrimp feed on water plants

A geographer's approach to studying the food chain would be different than the perspective of a biologist. Whereas a geographer would be highly focused on the climate and terrain of an individual food chain, the biologist would likely be far more interested with the animals themselves and how they interrelate.

Biomes are "the world's major communities, classified according to the predominant vegetation and characterized by adaptations of organisms to that particular environment" (Campbell 1996). The five established major biomes are: aquatic, desert, forest, grassland, and tundra. A biome is different from a zoogeographic region in that the biome concerns all living matter in the environment whereas the zoogeographic region deals solely with the animal life in a given area. Both deal with life forms which exist in an environment but concentrate differently on the form of life.

Two biomes which have completely oppositional floral characteristics are the desert and tundra. In a desert landscape, plants have had to adapt to regions with very little water and high levels of sunlight and ultraviolet rays from the sun. Roots of plants in the regions grow deep into the ground in order to find ground water. Many plants in the biome are succulents, meaning they can store water and use it sparingly to stay alive (Stetson 2000). Living things struggle in the tundra because of the permafrost which covers the ground. This prevents the roots of plants from growing deeply beneath the ground. Consequently, most plants which grow in the region have shallow roots and do not grow very tall (Whitney 2002). They are primarily low shrubs and trees or various types of mosses.

3. Theorize the difference in soil development in adjoining soils developed on forested, sloped area vs. A grassed flat area. What are the soil-forming factors? Explain the importance of the nature of the parent material to soil formation and type. Then, cite at least two examples in which the influence of parent materials might be outweighed by other soil-forming factors. Explain the "struggle" between the internal and external processes in shaping the Earth's surface. What are the different ways that the surface of the Earth is changed over time?

There are differences in soil formation and development based on the conditions of the ground and the way it is treated. If an area is forested and on a slope, then the soil can be impacted by water runoff caused by rain and melting snow. This can change the chemical content of the soil and alter its ability to grow material. A grassy, flat area will not have this same issue but it will likely be more impacted by winds and soil erosion. Soil-forming factors include: material of the parent plants and ground, time and climate as well as weather conditions, topography, living organisms in the area of the soil, and how the land is used can change the content of the soil (Certini 2007). Examples of biomes wherein parent materials may be overridden by other factors include: deforestation which is an example of land use soil change as well as a change in topography, and also the introduction of a new species of organism into an area can override the parent materials of that location.

There are many different ways that the surface of the earth can be altered and changed, either through internal or external processes. Internal processes are those which come from the earth itself earthquakes whereas external processes are those which have impacted the earth from outside sources, such as manmade lakes or canals and also erosion of rock because of water. The earth's surface is very different now from what it once was, according to geologists and other earth scientists (Landscapes 2010). At fault lines, the earth is constantly moving towards, away from, or sliding to create new land forms and split old ones. The most obvious example of this is the idea of Pangaea, that the seven continents we now know were originally one large land mass which has broken away over the millennia.

4. Describe the general sequence of events in continental drift since the time of five separate continents 450 million years ago. What is the difference between the older continental drift theory by Wegener and the more recent plate tectonic theory? Plate tectonics theory explains many seemingly unrelated phenomena. Explain how the patterns of volcanoes and earthquakes related to plate tectonics. Explain several pieces of evidence that combine to make the theory of plate tectonics the one that is generally accepted.

450 million years ago, the Earth's continents were all part of one enormous land mass known as Pangaea. This continent was surrounded by one large ocean which has been called the Panthalassic Ocean (Van Wagner 2012). Over time, this large mass of land broke up and the newly-formed smaller land masses moved slowly into their present geographical positions. First, Pangaea broke into two continents called Gondwanaland and Laurasia during the Jurassic Period. This breaking up continued until the Cretaceous Period when the continents took what would their present locations.

Alfred Wegener's theory of continental drift is not completely different from the more recent and more universally accepted theory of plate tectonics. Wegener postulated that parts of the Earth's crust slowly drift because they sit atop a liquid core. He did not know what force was behind the movement of what he termed crustal plates. The theory of plate tectonics uses scientific evidence to suggest that it is the convection currents within the earth's mantle which is what drives the movement of the various plates. Further, plate tectonics explains how various geological phenomena can be seen in different parts of the world (Pratt 2000). Volcanoes and earthquakes occur along fault lines, that is to say the boundaries where the crustal plates meet. When two plates meet they can do one of three things, crash together or converge which forms mountain ranges and volcanic activity, move apart or diverge which tends to cause earthquakes, or they can slide up or down from one another. There is plenty of evidence which serves to prove the viability of the plate tectonic theory. These include: the fact that the continents look like their shapes would fit together into a larger whole, that fossils which have been found in regions such as South America and Africa indicate that similar if not indeed the same types of animals lived on that landscape at one time, that seismic and volcanic activity occur frequently along believed plate boundaries, and sea floor spreading which shows that new land is being formed because of volcanic activity at the boundaries.

5. Provide a reason why some scientists believe the Pleistocene is over and a reason why other scientists believe we are now in an interglacial stage. Some believe, for example, that since areas of pack ice and glacial ice still exist we are still in an ice age. Others, on the other hand, seeing the rapid retreat of ice and snow pack in many areas, believe that this period of glaciation has ended. So, using some other justifications, why do we see some differences in interpretation? Is there some scientific data available that can support both sides view? If so, provide it. Why hasn't this controversy been solved? What impact does this division of views have on the public policies that are enacted by state, national and international bodies?

Scientists have debated about the current period of world history and what type of age it is that we currently live in. Some believe that what is known as the Pleistocene Period is over has been over for 11,000 years now. After the last ice age and the emergence of Homo-sapiens, this new era began. These folks refer to the present era as the Holocene epoch. Since the end of the Pleistocene Era, the earth has warmed and during the era, the world was not a continual ice age. Throughout that time, there were periods of warming and cooling which may have lasted millennia. Given this information, it is possible to theorize that this is in fact another interglacial period (Cartmill 2009,-page 13). Others argue that this is in fact not a true era, but an interglacial period between the last ice age and the next one that is to come. Scientists have defined historical eras as those in which it can be proven that animal life ceased to exist and then all new forms of animal life came to be. One of the reasons that scientists have become reluctant to accept this as a new era in world history has to do with the continued presence of species which have been in existence since the Pleistocene Era (Hall 2002). The large number of animals on the endangered species list gives further evidence that the era is on the way to ending but has not yet reached that point.