Introduction to Earth Science
BRANCHES OF EARTH SCIENCE
Geology – The study of the materials that make up Earth and the processes that form and change these materials is the branch of Earth science known as Geology. Geologists identify rocks, study glacial movements, interpret clues to Earth’s 4.6 billion-year history, and determine how the forces change our planet, among many other things.
Oceanography – The study of Earth’s oceans, which cover nearly ¾ of the planet, is called oceanography. Oceanographers study the creatures that inhabit salty water, measure different physical and chemical properties of the oceans, and observe various processes in these bodies of water.
JOBS IN EARTH SCIENCE
Climatology, Ecology, Paleontology, Geochemistry, Hydrology, Tectonics
EARTH SCIENCE
In this unit you will learn about Earth and the processes and forces that change it, the materials from which it is made, its long history, and its place in the universe.
The Scope of Earth Science
Earth science has a vast scope.
What do you think of when you hear Earth Science?
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 a blanket of air that surrounds the Earth so that scientists better understand stormy weather. Ocean floor exploration has led to the bizarre creatures that never see the light of day, while the study of objects in space has revealed much about our planet.
BRANCHES OF EARTH SCIENCE
JOBS IN EARTH SCIENCE
As you can see from the previous slide there are many different areas of Earth science. The broad field of Earth science can be broken into four major areas of specialization;
Astronomy, Meteorology, Geology, and Oceanography.
Astronomy – is the study of objects beyond Earth’s atmosphere. Before the invention of sophisticated instruments, such as the telescope, many astronomers merely described the locations of objects in space in relation to one another.
Meteorology – This is the branch of Earth science that studies the air that surrounds the planet. Meteorologists study the forces and processes that cause the atmosphere to change to produce weather. These Earth scientists try to predict the weather and how changes in the weather might affect Earth’s climate.
Climatologists - study patterns of weather over long periods of time; effects of human activities on weather and climate
Ecologists – study the habits of organisms and how organisms interact with each other and their environments.
Paleontology – study the remains of organisms that once lived on earth, and ancient environments.
Geochemists – study Earth’s composition and the processes that change it.
Hydrologists – study the flow of water on and below the Earth’s surface; sources of and solutions to water pollution.
Tectonic Scientists – study the effects of internal processes on Earth’s surface, including earthquakes and mountain building.
EARTH SYSTEMS
Beneath Earth’s mantle is the core, which can be divided into two parts: an outer, liquid part and a solid, inner part. Earth’s core is thought to be made of mostly iron and nickel. While Earth’s core and asthenosphere are NOT parts of the lithosphere, they do interact with this system of Earth to produce many features at the planets surface.
Hydrosphere – The water in Earth’s oceans, seas, lakes, rivers, and glaciers, as well as the water in the atmosphere, makes up the hydrosphere. About 97% of Earth’s water exists as salt water; the remaining 3% is freshwater contained in glaciers, in lakes, and rivers, and beneath Earth’s surface as groundwater. About ¾ of all freshwater is contained in glaciers and icebergs, like the one shown below.
The Atmosphere – The blanket of gases that surrounds our planet is called the atmosphere. 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 temperature suitable for life. 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 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 appears to be unique in that scientists have not yet found any confirmed evidence of life on other planets in our solar system or elsewhere in the galaxy.
EARTH SYSTEMS
Earth scientists have identified 4 main Earth systems: the lithosphere, the hydrosphere, the atmosphere, and the biosphere. Each system is unique yet interacts with the others. NONE of Earth’s systems are independent of the others, nor the global system of Earth itself.
The Lithosphere – Earth’s lithosphere is the rigid outer shell of the planet and includes the crust and the solid, uppermost part of the mantle, which is the layer below the crust. There are two kinds of crust: continental crust and oceanic crust. 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 comprised of a rock called periditite. Some of the 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 the asthenosphere.
EARTH SCIENCE IN YOUR EVERYDAY LIFE
EARTH SYSTEMS
As seen in the picture below , Earth’s biosphere, lithosphere, hydrosphere, and atmosphere are interdependent systems. Earth’s present atmosphere, for example, formed millions of years ago as a result of volcanic activity, respiration and transpiration by ancient organisms, and photosynthesis. Today’s organisms, including humans, continue to change the atmosphere through their life processes and activities. You will explore interactions among Earth’s biosphere and other systems , both past and present.
EARTH SCIENCE in YOUR EVERYDAY LIFE
You and 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 the Earth, water, which makes up the hydrosphere. In what other ways is Earth science a part of your everyday life?
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. The application of scientific discoveries is called technology. Freeze-dried foods, ski goggles, micro-fabrics, and the ultra-light materials used to make pieces of sports equipment are just a few examples of technological advances developed as a result of scientific study.
Technology is transferable, which means that it can be applied to new situations. The technological developments just described were first developed for use in space, and later adapted for use by everyone.
Christopher A. Ervin
Vista Grande High School
Earth Science