What is geology?
The scientific study of the earth including the manner in which it was formed, the materials it was made of, the processes (both chemical and physical) that occur on its surface and earth’s interiors and the history of the planets as well as the life forms is what geology is all about. Geology investigates the evolution of the earth in terms of its structure, composition and the nature of processes and developments that might have led to the present state of the earth. It therefore tries to explain how the metamorphosis that the present earths structure, materials processes and organisms might have undergone to arrive at the current form. Geologists therefore work to illustrate the present universe being but are not archeologists who study man’s past activities. The main facets of geology therefore entails petrology, mineralogy, crystallography, structural geology, sedimentology, stratigraphy, paleontology and hydrogeology.
Origin of the universe, galaxies, solar system and the Earth.
Many theories have been proposed, defended as to the origin of the universe. Some of these include the big bang theory which was proposed after close observation of the galaxies moving away from the earth at a terrific speed. It is therefore assumed that the universe once existed together and was compressed into a hot dense mass. The big bang proposes that there was a blast that prompted the universe matter and energy to spring from some ancient energy and the universe expanded with incomprehensible speed to the astronomical scope. The expansion still continues but slower. The solar system began to form more than 4.6 billion years ago through the gravitational collapse of the giant molecular cloud. The collapsed masses collected at the core/center of the universe forming the sun. The rest of the sediments were flattened into a protoplanetary disk which resulted to be planets, moons, galaxies and other bodies (Gorbunov&Rubakov, 2011). This was the nebular model developed in the 18th century
The atmosphere, hydrosphere and lithosphere.
The earths system primarily consists of two main features: the geosphere and biosphere. These two components functions as a system and interact constantly to adjust to the existing internal and external factors. The geosphere entails four subcomponents including the lithosphere that entails the solid earth, the gaseous envelope commonly known as the atmosphere, the liquid water or the hydrosphere and the cryosphere representing the frozen water (Shikazono, 2012).
The hydrosphere is responsible for defining the earth as the only system in the solar system that has a hydrological cycle. The hydrosphere comprises of all waters both salty and fresh that comes from various sources including oceans, fresh water from rivers, lakes and underneath waters as well as from the cryosphere (solid water) that exists in ice sheets, glaciers, and also in frozen grounds. The cryosphere is regarded differently from the hydrosphere but both are vital sources for almost the entire life form and they are the reason as to why the earth is regarded as the water planet.
The atmosphere is usually a thick layer of gaseous particles that circles the earth. It lies within the atmosphere is said to have no boundaries but lies within 97KM of the earth’s zone. It is divided into four distinct layers including the troposphere that exists between 0-10KM, the stratosphere existing after troposphere between 10-45KM latitude. the mesosphere occurring between 45-50Kn latitude as well as the thermosphere forming a layer between 80300Km latitude. The atmosphere comprises of nitrogen, oxygen, argon, carbon dioxide plus some other rare gases. These gases are commonly termed as the greenhouse gases since they delicately balance to ensure that the earth’s temperature is suitable to sustain life. The earth is one of the planets in the solar system that has a favorable atmosphere that can support living as compared to Venus which has 96.5 of its composition being carbon dioxide, 3.5% nitrogen thereby making Venus atmosphere very toxic and inhabitable.
Lithosphere referrers to the rocks and minerals forming the outer part of the earth’s crust and the tectonic plates. The erosion and weathering that takes place in the lithosphere enables the earths system to have minerals. It is indicated that the earth’s lithosphere has been recycled roughly six times. The pedosphere (soil sphere) which is the outermost layer of the earth interfaces the atmospheric, lithospheric, the hydrosphere as well as the biosphereprocesses thereby leading to soil formation necessary to support life in the biosphere.
Biosphere includes all living things, bacteria and plants that existson the earths system. It is believed that biosphere consists of more than 100 phyla that are organized into five kingdoms of living things. Human being belongs to the kingdom Animalia and are one species in a cluster of more than 20-100 species.
Pressure temperature and density of the Earth’s interior.
The earth is spherically layered with the layers being defined by the chemical and rheological characteristics that the layerspossesses. It is believed that these layers formed as a result of a cooling system that led to the heavier denser materials sinking deep at the core of the earth and the lighter remaining at the top. Because of this granite remains at the top while iron and nickel are at the core. These four layers includes the crust, the mantle,the inner core, and the outer core. The crust is the layer we live in and is very thin compare to the other layers. It is broken into plates which moves along steadily but when they stick, pressure builds up causing earthquakes.Themantle is below the crust and is hotter and more pressurized than the crust (Ernst, 2000). This is as a result of the weight of the crust into the mantle. The core (inner and outer) are much hotter with temperatures (may reach 9000degrees) and pressure so high that objects vibrate instead of moving. As one goes deeper into the earth towards the core, the pressure and temperature increases
Ernst, W. G. (2000). Earth systems: Processes and issues. Cambridge: Cambridge University Press.
Gorbunov, D. S., &Rubakov, V. A. (2011). Introduction to the theory of the early universe: Hot big bang theory. Singapore: World Scientific.
Shikazono, N. (2012). Introduction to earth and planetary system science: New view of earth, planets and humans. Tokyo: Springer.