GLG102 Summary Test 1

GLG102 Summary Test 1 - S umma ry Chapter 1 Scientists view...

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Summary Chapter 1 Scientists view Earth as a system of interconnected components that interact and affect each other. The principal subsystems of Earth are the atmosphere, hydrosphere, biosphere, lithosphere, mantle, and core. Earth is considered a dynamic planet that continually changes because of the interaction among its various subsystems and cycles. Geology, the study of Earth, is divided into two broad areas: Physical geology is the study of Earth materials, as well as the processes that operate within Earth and on its surface; historical geology examines the origin and evolution of Earth, its continents, oceans, atmosphere, and life. The scientific method is an orderly, logical approach that involves gathering and analyzing facts about a particular phenomenon, formulating hypotheses to explain the phenomenon, testing the hypotheses, and finally proposing a theory. A theory is a testable explanation for some natural phenomenon that has a large body of supporting evidence. Both the theory of organic evolution and plate tectonic theory are theories that revolutionized biology and geology, respectively. The Universe began with the Big Bang approximately 14 billion years ago. Astronomers have deduced this age by observing that celestial objects are moving away from each other in an ever-expanding universe. Furthermore, the universe has a pervasive background radiation of 2.7 K above absolute zero (2.7 K = -270.3°C), which is thought to be the faint afterglow of the Big Bang. About 4.6 billion years ago, our solar system formed from a rotating cloud of interstellar matter. As this cloud condensed, it eventually collapsed under the influence of gravity and flattened into a counterclockwise rotating disk. Within this rotating disk, the Sun, planets, and moons formed from the turbulent eddies of nebular gases and solids.
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Earth formed from a swirling eddy of nebular material 4.6 bill ion years ago, accreting as a solid body and soon thereafter differentiated into a layered planet during a period of internal heating. Earth is differentiated into layers. The outermost layer is the crust, which is divided into continental and oceanic portions. The crust and underlying solid part of the upper mantle, also known as the lithosphere, overlie the asthenosphere. A zone that behaves plastically and flows slowly. The asthenosphere is underlain by the solid lower mantle. Earth’s core consists of an outer liquid portion and an inner solid portion. The lithosphere is broken into a series of plates that diverge, converge, and slide sideways past one another. Plate tectonic theory provides a unifying explanation for many geological features and events. The interaction between plates is responsible for volcanic eruptions, earthquakes, the formation of mountain ranges and ocean basins, and the recycling of rock materials. The central thesis of the theory of organic evolution is that all living
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GLG102 Summary Test 1 - S umma ry Chapter 1 Scientists view...

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