Earth Science Studying the Earth Section 1 – Introduction to Earth Science Section 2 – Earth as a System Section 3 – Models of the Earth

The Scientific Study of Earth The scientific study of the earth began with careful observations. Scientists in China began keeping records of earthquakes as early as 780 BCE. The ancient Greeks compiled a catalog of rocks and minerals around 200 BCE. Other ancient peoples, including the Maya, tracked the movements of the sun, moon, and the planets to make observations to create accurate calendars. The invention of the telescope allowed hidden worlds to be found.

Earth Science – the study of the Earth and the Universe around it.

Branches of Earth Science Geology – study of origin, history, and structure of the solid Earth Oceanography – the study of Earth’s oceans that cover ¾ of the surface Meteorology – the study of the Earth’s atmosphere Astronomy – the study of the universe beyond the Earth Environmental Science – a new field of study on the ways humans interact with the environment

Chapter 1 – Section 2 Scientific Method Ask a question. Observation is the process of using the senses of sight, touch, taste, hearing and smell for gathering information. Observations often lead to asking questions. A hypothesis is a possible explanation or solution to a problem. They are based on known facts. Experiments test the hypothesis. Factors that can be changed by the person performing the experiment are independent variables. Dependent variables are variables that change as a result of the change in independent variables.

Conclusions – after many experiments and observations, the scientist comes to a conclusion. If the hypothesis fits the known facts it is accepted as true. If the experimental results differ from what was expected, the hypothesis may be changed or discarded.

Scientific Measurements and Analysis Scientists must gather information. An important method of gathering information is measurement. Scientists use a common system of measurement called the International System of Units or SI. The system includes standard measurements of length, mass, temperature, and volume all based on intervals of 10…the Metric system.

Other Important Issues with Measurement Accuracy – Refers to how close a measurement is to the true value of the thing being measured Precision – Refers to the exactness of the measurement Error – is an expression of the amount of imprecision or variation in a set of measurements Model – a description, representation, or imitation of an object, system, process, or concept.

Chapter 2 – Section 1 The Unique Earth The only known planet in solar system with liquid water on the surface and oxygen in the atmosphere The third planet from the sun 71% of the Earth’s surface is covered with a thin layer of water – the global ocean Not a perfect sphere – actually is an oblate spheroid or flattened sphere. It bulges at the equator.

The Earth’s Interior Crust – the thin, solid outermost zone of the Earth’s surface Mantle – the layer of rock between the Earth’s crust and core; denser than the core. Makes up 2/3 of the Earth’s mass. It has three layers: Lithosphere – made up of a rigid layer 15 to 300 km thick and the crust above it. Asthenosphere – about 200 to 250 km thick; the solid rock in this layer under enormous heat and pressure and has ability to flow – plasticity Mesosphere – the layer of solid mantle rock below the asthenosphere