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The Nature of Science Earth & Space Science Chapter 1, Section 1 The Scope of Earth Science • The scope of Earth science is vast. – Dinosaur bones on display at museums were once embedded in the rocks that make up some of Earth’s cliffs and canyons. – Mining certain rocks produces some of the gold used by jewelers and dentists. – Computer models simulate the flow of the blanket of air that surrounds Earth so that scientists better understand stormy weather. – Ocean-floor exploration has led to the discovery of bizarre creatures that never see the light of day. – The study of objects in space has revealed much about our own planet. The Scope of Earth Science • As you can see, there are many different areas of Earth science. • This broad field can be broken into 4 major areas of specialization: – Astronomy – Meteorology – Geology – Oceanography Astronomy • Astronomy is the study of objects beyond Earth’s atmosphere. • Prior to the invention of sophisticated instruments, such as the telescope, astronomers merely described the locations of objects in space in relation to one another. Today these scientists study the universe & everything in it, including Earth, its neighbors, & other bodes in the universe. Meteorology • The branch of Earth science that studies the air that surrounds our planet is called meteorology. • Meteorologists study the forces & processes that cause the atmosphere to change to produce weather. • They also try to predict the weather & how changes in weather might affect Earth’s climate. Geology • The study of the materials that make up Earth & the processes that form & change these materials • Geologists identify rocks, study glacial movements, interpret clues to Earth’s history, & determine how forces change our planet, among many other things. Oceanography • The study of Earth’s oceans, which cover nearly ¾ of the planet • Oceanographers study the creatures that inhabit salty water, measure physical properties & observe the processes of oceans • Some oceanographers study the effects of human activities on the oceans. The Scope of Earth Science • The study of our planet requires a vast amount of knowledge and the study of many different things. • There are many subspecialties of the 4 major areas of Earth Science Climatology Subspecialty of Meteorology • A climatologist studies patterns of weather over a long period of time and the effects of human activities on weather and climate. Paleontology Subspecialty of Geology • Paleontologists study the remains of organisms that once lived on Earth. • Paleontologists also study ancient environments. Hydrology Subspecialty of Geology • Hydrologists study water flow on and below Earth’s surface. • Also interested in the sources of water and solutions to water pollution. Ecology Subspecialty of Biology • Ecologists study the habitats of organisms and how organism interact with each other and their environments. Geochemistry Subspecialty of Geology & Chemistry • Geochemists study Earth’s composition and the processes that change it. Tectonics Specialty of Geology • A scientist that studies tectonics would also be called a geologist. He/she would be more knowledgeable in the area of plate tectonics than a ―regular‖ geologist. • These scientists study the effects of earthquakes, & mountain building. Earth’s Systems • Scientists who study Earth have identified 4 main Earth systems: – Lithosphere – Hydrosphere – Atmosphere – Biosphere • Each system is unique, yet each interacts with the others. None of Earth’s systems is independent of the others, nor of the global system of Earth itself. The Lithosphere • Earth’s lithosphere is rigid outer shell and includes the crust & the solid, uppermost part of the layer below the crust, the mantle. • There are 2 kinds of crust: continental crust and oceanic crust. The Lithosphere • Earth’s continental crust is made mostly of a rock called granite. • Oceanic crust is mainly basalt, a rock that is denser than granite. • Earth’s mantle is mainly composed of a rock called peridotite. The Lithosphere • Some of Earth’s upper mantle behaves like a rigid solid while other parts of this layer are partially molten and flow like a soft plastic. • This partially molten layer is called the asthenosphere. The Lithosphere • Beneath Earth’s mantle is the core, which can be divided into 2 parts: an outer, liquid part & a solid, inner part. • Earth’s core is thought to be made of iron & nickel. • While Earth’s core & asthenosphere are not parts of the lithosphere, they do interact with this system of Earth to produce many of the features at the planet’s surface. The Hydrosphere • The water in Earth’s oceans, seas, lakes, rivers & glaciers, as well as the water in the atmosphere, makes up the hydrosphere. • About 97% of Earth’s water exists as salt water. The other 3% is freshwater contained in glaciers, lakes & rivers, and beneath Earth’s surface as groundwater. • About ¾ of all freshwater is contained in glaciers and icebergs. • The rest of freshwater is mainly groundwater. • Only a fraction of Earth’s total amount of freshwater is in lakes & streams. The Atmosphere • The blanket of gases that surrounds our planet is called the atmosphere. • Among other things, Earth’s atmosphere is necessary for respiration by most living things, protects Earth’s inhabitants from harmful radiation from the Sun, and helps to keep the planet at a stable temperature. • Earth’s atmosphere contains about 78% nitrogen and 21% oxygen. The remaining 1% of gases in the atmosphere include water vapor, argon, carbon dioxide, and other trace gases. The Biosphere • The biosphere includes all organisms on Earth as well as the environments in which they live. • Most organisms exist within a few meters of Earth’s surface, but some live deep beneath the ocean’s surface, and others live high atop Earth’s mountains. • Earth’s biosphere is unique in that scientists have not found any confirmed evidence of life on other planets or elsewhere in the galaxy. The Biosphere • Earth’s biosphere, lithosphere, hydrosphere and atmosphere are interdependent systems. • Earth’s present atmosphere formed millions of years ago as a result of volcanic activity, respiration and transpiration by ancient organisms & photosynthesis. • Today’s organisms, including humans, continue to change the atmosphere through their life processes and activities. Earth Science in Your Everyday Life • You and the billions of other life forms that live on Earth are part of the biosphere. • Together with many of these creatures, you live on Earth’s crust, which is part of the lithosphere, and breathe the gases in Earth’s atmosphere. • You also depend in many ways on the substance that covers nearly ¾ of Earth— water, which makes up the hydrosphere. Technology • While you might not realize it, the study of science, including Earth science, has led to the discovery of many things that you use every day. • This application of scientific discoveries is called technology. • Freeze-dried foods, ski goggles, micro-fabrics, and the ultra-light materials used to make many pieces of sports equipment are just a few examples of technological advances developed as a result of scientific study. Mapping Our World Earth & Space Science Chapter 2, Section 1 Latitude & Longitude • For thousands of years people have used maps. We still rely on maps for a variety of purposes. • The science of mapmaking is called cartography. • Cartographers use an imaginary grid of parallel lines and vertical lines to locate points on Earth exactly. • In this grid, the equator separates Earth into two equal halves called the northern hemisphere and the southern hemisphere. Latitude • Lines running parallel to the equator are called lines of latitude • Latitude is the distance in degrees north or south of the equator. • The equator, which serves as the reference point for latitude, is numbered 0° latitude. • The poles are each numbered 90° latitude. • Latitude is thus measured from 0° at the equator to 90° at the poles. • Locations north of the equator are referred to by degrees north latitude (N). Locations south of the equator are referred to by degrees south latitude (S). Latitude • Syracuse, New York is located at 43° north latitude (43°N). Latitude • Christchurch, New Zealand is located at 43° south latitude (43°S). Longitude • To locate positions in east and west directions, cartographers use lines of longitude (also known as meridians). • Longitude is the distance in degrees east or west of the prime meridian, which is the reference point for longitude. • The prime meridian represents 0° longitude. • In 1884, astronomers decided that the prime meridian should go through Greenwich, England, home of the Royal Navy Observatory. • Points west of the prime meridian are numbered from 0° to 180° west longitude (W); points east of the prime meridian are numbered from 0° to 180° east longitude (E). Locating Places with Coordinates • Both latitude and longitude are needed to precisely locate positions on Earth. • For example, it is not sufficient to say that New Orleans, Louisiana, is located at 29°N latitude. That measurement includes any place on Earth located along that line of latitude. • New Orleans, LA is located at 29°N 90°W.
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