Slide 1

Slide 2 Introduction to Earth Science Chapter 1 Slide 3 Essential Questions 1.What does an Earth Scientist study? 2.What information do various maps give to an Earth Scientist? 3.How do Earth Scientists (and all scientists) seek knowledge? Slide 4 Overview of Earth Science Earth science is the name of the group of sciences that deals with Earth and its neighbors in space. Earth science is divided into four broad categories: Slide 5 The Earth Sciences Geologythe study of the solid Earth Oceanographythe study of the Earths oceans Meteorologythe study of the Earths atmosphere Astronomythe study of the Earths place in the universe Slide 6 Formation of Earth The Nebular Hypothesis suggests that bodies in our solar system evolved from an enormous rotating cloud called the solar nebula. Mostly hydrogen and helium, with some heavier elements. Slide 7 Differentiation As the newly formed Earth cooled layers formed through a process called differentiation. Denser elements (iron and nickel) sink to the Earths core. Lighter rocks and materials migrate outward forming the mantle and crust. Slide 8 A View of the Earth Earth can be thought of as consisting of four major spheres: Hydrosphere Atmosphere Geosphere Biosphere Slide 9 Earths Major Spheres The hydrosphere includes all liquid water on Earthboth saltwater and fresh water. The atmosphere consists of the gaseous envelope surrounding the Earth. Although the atmosphere extends more than 100km up, 90% is within 16km of the surface. Slide 10 Earths Major Spheres The biosphere includes all life on Earth. The biosphere is concentrated in a zone that extends from the ocean floor upward several kilometers in the atmosphere. The geosphere consists of the solid parts of the planet and is not uniform. Based on differences in composition it is divided into three main regions, the core, the mantle, and the crust. Slide 11 Slide 12 Geosphere Divisions The dense core has two parts; a solid inner core and a liquid outer core. The rocky mantle is divided into an lower mantle and upper mantle. The rock in the upper part of the upper mantle is somewhat flexible and pliableits called the asthenosphere (weak sphere). Slide 13 Geosphere Divisions The outer crust is divided into continental crust and oceanic crust. This rigid outermost layer is called the lithosphere (rock sphere). Slide 14 Slide 15 Plate Tectonics The lithoshpere is broken into several sections called plates. The Theory of Plate Tectonics states that earthquakes, volcanoes, mountain building, and the movement of continents are the result of the movement of lithospheric plates. Slide 16 Earth System Science Earth system science aims to study the Earth as a system made up of numerous interacting parts, or subsystems. A system can be any size group of interacting parts that form a complex whole. Slide 17 Earth as a System The Earth system is powered by two sources of energy: The Sun which drives external processes in the atmosphere, hydrosphere, and at the surface. The Earths interior heatwhich drives plate tectonics. Slide 18 Each system affects the other. The actions of nature and people produce changes in all of the other parts of the Earth system. Resources (some renewable, some not), population, pollution, global warming, species extinction, etc. are some examples. Slide 19 Scientific Inquiry All science is based on two big assumptions: 1.The universe behaves in a consistent and predictable manner. 2.Through study, we can understand this behavior. Slide 20 Hypothesis Once observations have been made and data gathered, scientists try to explain how or why things happen in the manner observed. They state a possible explanation called a scientific hypothesis. Slide 21 Theory Once further observations have been made and/or tests performed, scientists either accept, modify, or reject their hypothesis. The hypothesis is elevated to a Scientific Theory once it has been well tested and accepted by the scientific community as the best explanation of observable facts. Slide 22 Representing Earths Surface MAPPING Specifying a location on Earths surface is done using a grid system of latitude and longitude. Latitude is the distance north or south of the equator (measured in degrees). Longitude is the distance east or west of the prime meridian (also in degrees). Slide 23 The Global Grid Slide 24 Slide 25 Slide 26 Because lines of latitude never meet they are also known as Parallels: circles around the globe N or S of the Equator Each degree consists of 60 equal parts called minutes. Each minute is divided into 60 equal parts called seconds. Slide 27 Because lines of longitude never meet they are also known as Meridians: semicircles running from pole to pole. As with latitude, there are minutes and seconds: Slide 28 Great Circle: any circle that cuts the Earth into a perfect half. any 2 lines of longitude directly across from each other on opposite sides of the globe, or the Equator (the only parallel of latitude that forms a great circle) Slide 29 Great Circle: any circle that cuts the Earth into a perfect half. Slide 30 Using Coordinates Both latitude and longitude are needed to locate positions on Earth precisely. When giving coordinates, latitude is always given first. Slide 31