Chapter 1 Introduction to Earth Science PDF

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My Notes for Chapter 1 in Earth Science...

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Chapter 1 Introduction to Earth Science Learning Objectives •

1.1 List and describe the sciences that collectively make up Earth science. Discuss the scales of space and time in Earth science.

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1.2 Discuss the nature of scientific inquiry, including the construction of hypotheses and the development of theories.

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1.3 Outline the stages in the formation of our solar system.

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1.4 List and describe Earth’s four major spheres. Define system and explain why Earth is considered to be a system.

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1.5 List and describe the major features of the ocean basins and continents. 1.1 What Is Earth Science?

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List and describe the sciences that collectively make up Earth science. Discuss the scales of space and time in Earth science.

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Earth Science: includes all the sciences that collectively seek to understand Earth and its neighbors in space.

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Includes: –

Geology—literally the “study of Earth,” both physical and historical

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Oceanography—a study of the ocean, “water planet”

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Meteorology—the study of the atmosphere and the processes that produce weather

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Astronomy—the study of the universe

Earth Science Is Environmental Science •

Natural Hazards: Earth processes that adversely impact society

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Resources: formation and occurrence of materials of great practical value

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People Influence Earth Processes: how humans influence Earth

Scales of Space and Time in Earth Science •

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Geologic Time –

Span of time since Earth’s formation

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Earth is 4.6 billion years old

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Concept of “recent” is different

Geologic Time Scale –

Divides history of Earth into different units

1.2 The Nature of Scientific Inquiry •

Discuss the nature of scientific inquiry, including the construction of hypotheses and the development of theories.

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Science assumes the natural world is

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Consistent

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Predictable

Goal of science –

To discover patterns in nature

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To use the knowledge to predict

An idea can become a –

Hypothesis (tentative or untested explanation)

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Theory (tested and confirmed hypothesis)

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Paradigm (a theory that explains a large number of interrelated aspects of the natural world)

Scientific method –

Gather facts through observation

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Formulate hypotheses and theories

1.3 Early Evolution of Earth •

Outline the stages in the formation of our solar system.

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The Universe Begins –

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Starts with Big Bang 13.7 billion years ago

The Solar System Forms –

Earth and the other planets formed at essentially the same time

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Nebular Theory ▪ Solar system evolved from an enormous condensing, rotating cloud of gas and dust 5 billion years ago ▪ Mostly hydrogen and helium ▪ Inner planets form from metallic and rocky clumps ▪ Larger outer planets form from fragments with a high percentage of ices

1.4 Earth as a System •

List and describe Earth’s four major spheres. Define system and explain why Earth is considered to be a system.

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Earth’s Spheres: the separate but interacting parts that affects our dynamic Earth –

Hydrosphere ▪ Ocean—the most prominent feature of the hydrosphere –

Covers 71 percent of Earth’s surface

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Contains 97 percent of Earth’s water

▪ Freshwater—streams, lakes, and glaciers, as well underground ▪ Atmosphere –

Thin, tenuous blanket of air

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One half lies below 5.6 kilometers (3.5 miles)

▪ Biosphere –

Includes all life

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Concentrated near the surface in a zone that extends from the ocean floor upward for several kilometers into the atmosphere

▪ Geosphere –

Solid Earth

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Extends from surface to the center of the planet

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Largest of Earth’s four spheres

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Based on compositional differences, it consists of the crust, mantle, and core

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Divisions of the outer portion are based on how materials behave

1.5 The Face of Earth •

List and describe the major features of the ocean basins and continents.

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Ocean basins

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Average 3.8 kilometers (2.8 miles) below sea level

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Basalitic rocks

Continents –

Flat features that average 0.8 kilometers (0.5 miles) in elevation

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Granitic rocks

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Major Features of Ocean Basins

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Continental Margins –

Portions of seafloor adjacent to major landmasses

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Includes: ▪ Continental shelf—gently sloping platform extending seaward from shore ▪ Continental slope—steep drop off at edge of continental shelf ▪ Continental rise—more gradual incline; continental slope merges with thick accumulation of sediments

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Major Features of Ocean Basins (continued)

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Deep-Ocean Basins –

Between continental margins and oceanic ridges

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Abyssal plains—flat features of deep-ocean basins

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Deep-ocean trenches—deep depressions in ocean floor

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Seamounts—submerged volcanic structures

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Major Features of Ocean Basins (continued)

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Oceanic Ridge –

Also called mid-ocean ridge

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Includes Mid-Atlantic Ridge and East Pacific Rise

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Continuous mountain belt that winds around globe

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Many layers of igneous rock

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Major Features of the Continents

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Mountain Belts –

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Principally the circum-Pacific belt and the Alps/Himalayas

Stable Interior –

Shields—expansive, flat regions of deformed crystalline rock

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Stable platforms—deformed rocks covered by sedimentary rocks...