Earth Science 101 Instructor : Pete Kozich Introduction to Earth Science Chapter 1

Earth 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 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” 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

Oceanography 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.

Meteorology 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  Environment Surrounds and influences organisms or “small” entities Physical environment encompasses water, air, soil, and rock

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  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  Environmental problems Human-induced and accentuated Urban air pollution Acid rain Ozone depletion Global warming (probable) Natural hazards Earthquakes Landslides

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  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  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 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"  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"  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"  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"  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 structure Earth’s layered structure

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  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  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 cycles Figure 1.17

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