Earth Science 101Earth Science 101

Instructor : Pete Kozich

Introduction to Earth Science

Chapter 1

Earth ScienceEarth Science

Encompasses all sciences that seek to understand• Earth • Earth's neighbors in space

Earth is a dynamic body with many interacting parts and a long complex history

Earth ScienceEarth Science

Earth Science includes• Geology - literally the “study of Earth” • Oceanography – a study of the ocean,

youngest and newest study• Meteorology - the study of the atmosphere

and the processes that produce weather • Astronomy - the study of the universe, oldest

discipline

Geology-”study of Earth”Geology-”study of Earth”

• Physical geology: examines the material composing Earth and seeks to understand the many processes that operate beneath and upon the surface– Mountain building, volcanoes, erosion,

earthquakes

• Historical geology: understand the origin of Earth and the development of the planet through its 4.6 billion-year history

OceanographyOceanography

• Application of all sciences in a comprehensive interrelated study of oceans in all their aspects– Chemistry, physics, geology, and biology (old)– Oceanography is now becoming legitimate in

its own right via fluid dynamics and modeling.

• Study of composition and movement of seawater, coastal processes, seafloor topography and marine life.

MeteorologyMeteorology

• Study of the atmosphere and all the processes that produce weather and climate

• Involves the application of other sciences into an integrated study of the atmosphere

• Many disciplines within the whole such as synoptic, mesoscale, boundary layer, turbulence, and climatology

People and the environment People and the environment

Environment • Surrounds and influences organisms or

“small” entities• Physical environment encompasses water,

air, soil, and rock

People and the environment People and the environment

Resources • An important focus of the Earth sciences • Includes water, soil, minerals, and energy• Two broad categories

• Renewable – can be replenished (examples include plants and energy from water and wind)

• Nonrenewable – metals, fossil fuels, for example

People and the environment People and the environment

Population • Population of the planet is growing rapidly • Rate of mineral and energy usage has

climbed more rapidly than the overall growth of population

• As population expands, the demand for resources expands too

Environmental problems• Local, regional, and global

People and the environment People and the environment

Environmental problems• Human-induced and accentuated

• Urban air pollution• Acid rain• Ozone depletion• Global warming (probable)

• Natural hazards • Earthquakes • Landslides

People and the environment People and the environment

Environmental problems• Natural hazards continued

• Floods• Hurricanes

• World population pressures• Increased rate of mineral and energy usage• US ~ 5% of world population and uses 25%

annual production of mineral and energy resources.

Scientific inquiry Scientific inquiry

Science assumes the natural world is • Consistent• Comprehensible through careful,

systematic study• Because of this, science is Predictable

Goal of science • To discover patterns in nature• To use the knowledge to predict

Scientific inquiry Scientific inquiry An idea can become a

• Hypothesis (tentative or untested explanation) • Theory (tested and confirmed hypothesis) • Paradigm (a theory that explains a large number

of interrelated aspects of the natural world)

Scientific method • Gather facts through observation • Formulate hypotheses that may eventually

become theories

Scientific inquiry Scientific inquiry Scientific knowledge is gained through

• Following systematic steps (Scientific Method)• Collecting facts• Developing a hypothesis • Conduct experiments • Re-examine the hypothesis and accept, modify, or reject

• Theories withstand examination • Totally unexpected occurrences a challenge-> is hypothesis correct

as is?

Scientific Law – a basic principle that describes nature’s behavior and is narrow in scope • Consistent with observations and measurements• Rarely discarded

Earth's “Spheres"Earth's “Spheres"Hydrosphere

• a dynamic mass of liquid that is always on the move from the oceans to the atmosphere precipitating back onto the land, then running back to the oceans again.

• Water makes the earth unique• Ocean – the most prominent feature of the

hydrosphere • 71% of Earth's surface • 97% of Earth's water • Average depth ~4000 m

• Also includes fresh water found in streams, lakes, and glaciers, as well as that found underground

Earth's “Spheres"Earth's “Spheres"

Atmosphere• Thin envelope of gases surrounding the earth able

to maintain life• Provides air to breathe, while protecting us from

the Sun’s intense heat and harmful radiation.• Without the atmosphere our planet may be lifeless

and resemble the surface of the moon.• Half of mass lies below 5.6 kilometers (3.5 miles)

• Compare to a radius of earth ~6400 km (4000 miles)

Earth's “Spheres"Earth's “Spheres"Biosphere

• Extends from the ocean floor upward into the atmosphere.

• Consists of parts of the hydrosphere, atmosphere and geosphere

• Includes all life • Organisms don’t just adapt to their

environment, countless interactions have allowed organisms to maintain and alter their environment.

Earth's “Spheres"Earth's “Spheres"

Geosphere• Extends from the surface to the center of the

planet (depth of 6400 km)• Largest of the four spheres• Based on compositional differences, it consists of:

• Dense core• Less dense mantle• Crust (very thin, light outer skin of the Earth)• Crust is not uniformly thick, but ranges from very thin

under the oceans to thickest where mountains are located.

Earth’s layered structureEarth’s layered structure

Earth system science Earth system science

Earth is a dynamic body with many separate but highly interacting parts or spheres

Earth system science studies Earth as a system composed of numerous parts, or subsystems

System - any size group of interacting parts that form a complex whole

Earth system science Earth system science

System • Closed systems are self-contained (e.g. an

automobile cooling system) • Open systems - both energy and matter

flow into and out of the system (e.g. a river system)

Earth system science Earth system science

Feedback mechanisms • Negative-feedback mechanisms resist change and

stabilize the system (human sweating – cooling phenomena)

• Positive-feedback mechanisms enhance the system (you somewhat like art and take an art class; get more enthusiastic about it, take it as major; find much satisfaction and a job, make a living out of it)

Earth as a system • Consists of a nearly endless array of subsystems (e.g.

hydrologic cycle, rock cycle)

Earth system cyclesEarth system cycles

Figure 1.17

Earth system science Earth system science

Earth as a system • Sources of energy

• Sun – drives external processes such as weather, ocean circulation and erosional processes

• Earth’s interior – drives internal processes including volcanoes, earthquakes and mountain building

• Humans are part of the Earth system • Parts of the system are connected

• Change in one part can produce change in one or all other parts

• Complex, nonlinear, hard to predict