CEE 1030 1st Edition Lecture 1 Outline of Current Lecture I Chapter ONE Reading Notes Current Lecture Geology Greek words geo earth and logos discourse science that persues an understanding of planet earth Earth is always changing Scales of size and space also vary greatly among the phenomena that geologist study Geologists focus on not only the phenomena that are submicroscopic but features that are continental or global in scale Geology is perceived as a science that is done outdoors which is right but it is mostly of observations measurements and experiments conducted in the field Also done in laboratories where they analyze minerals and rocks to provide insight into the process and microscopic study of fossils that unlock clue to the past environments Geology requires an understanding and application of knowledge and principles from physics chemistry and biology Geology seeks to expand knowledge of the natural world and our place in it Physical Geology examines the materials composing earth and seeks to understand what happens beneath and upon the surface This study precedes the study of Earth history because we need to understand who earth works before we attempt to unravel its past Historical Geology understand the origin of earth and its development through time Strives to establish an orderly chronological arrangement of the multitude of physical and biological changes that have occurred in the geological past Geological hazards are natural processes They only become hazards when people try to live where these processes occur Catastrophism the concept that earth was shaped by catastrophic events of a shortterm nature Uniformitarianism what shapes our planet has happened before States that physical chemical and biological laws that operate today have also operated in the geologic past meaning that things we see happening today have been formulating for a very long time Commonly stated as the present is the key to the past James Hutton Scottish physician and gentleman farmer published Theory of the Earth in 1795 Hutton was the first to demonstrate the geologic processes that occur over long periods of time Hutton argued that mountains are sculpted and destroyed by weathering and the work of running water Geology today suggests that we cannot say that geologic processes in the past were the same as those occurring today Hypothesis construction of untested tentative explanation Gathered and principles have been formulated to describe a natural phenomenon investigator try to explain how or why things happen in the manner observed If a hypothesis cannot be tested it isn t scientifically useful The verifications require that predictions be made cased on the hypotheses being considered and that the predictions be tested through comparison against objective observations of nature Theory when a hypothesis beats out other hypotheses after extensive scrutiny well tested and widely accepted view that scientific community agrees best explains certain observable facts Scientific Method researchers gather facts through observations and formulate scientific hypotheses and theories Not a standard recipe that scientists apply in a routine manner to unravel the secrets of out natural world but is an endeavor that involves creativity and insight Scientific investigations involve the following A question is raised about the natural world Scientific data that relate to the questions are collected Questions that relate to the data are posed and one or more working hypotheses are developed that ma answer these questions Observations and experiments are developed to test the hypotheses The hypotheses are accepted modified or rejected based on extensive testing Data and results are shared with the scientific community for critical examination and further testing Continental Drift the idea that the continents moved about the face of the planet This hypothesis contradicted the established view that the continents and ocean basin are permanent and stationary features of the face of Earth Perceived with great skepticism and ridicule Theory of Plate Tectonics is what the Hypothesis moved to be Hydrosphere a dynamic mass of water always on the move in a water cycle Atmosphere gas surrounding the earth Provided air we breathe and the shield that protects us from the sun Biosphere all life of Earth Geosphere the solid earth below hydrosphere and atmosphere System a group of interacting or interdependent parts that form a complex whole Carbon Cycle A subsystem of carbon dioxide in the air and the carbon in living things and in certain sedimentary rocks Hydrologic Cycle a familiar loop of subsystem that represents the unending circulation of Earth s water among the hydrosphere atmosphere biosphere and geosphere Rock Cycle over long time spans the rocks of the geosphere are constantly forming changing and re forming one rock changes to another Scenario 13 7 billion years ago the Big Bang Nebular Theory proposes that the bodies of our solar system evolved from enormous rotating clouds Solar Nebula the rotating clouds that evolved the bodies of the solar system Planetesimals Repeated collisions caused these masses to coalesce into larger asteroidsize bodies Meteorites rocky and metallic pieces that remained in orbit Chemical differentiation established the three basic divisions of Earth s interior the iron rich core thin primitive crust and Earth s largest layer called the mantle Crust thin rocky outer skin continental oceanic Mantle solid rocky shell depth about 2900 km Lithosphere crust and upper mantle earth s cool ridged out shell 250 kilometers thick Asthenosphere soft weak layer beneath the Lithosphere with a depth of 410 kilometers Transition Zone in the upper mantle from about 410 kilometers to about 660 kilometers in depth Lower Mantle from depth of 660 kilometers to the top of the core Depth of about 2900 kilometers Gradually strengthens with depth despite the strength the rocks are very hot Core thought to be composed of an iron nickel alloy with minor amounts of oxygen silicon and sulfur elements that readily form compounds with iron Outer Core liquid layer 92270 kilometers thick Movement of metallic iron within this zone that generates Earth s magnetic field Inner Core sphere that has a radius of 1216 kilometers Despite the higher temperature the iron in the inner core is solid due to the immense pressures that exist in the center of the planet Rock Cycle allows us to view many of the