ERSC- Sept. 13th, 2011
An Introduction to Your Planet
December 1968- first man vessel to escape earth and go around the dark side of the
Earth is a planet that is small and self-contained.
Earth has four spheres:
-Geosphere (ground, earth)
Earth as a system:
Earth’s four spheres are linked as a system through their interactions. Characterized by
-Vary on spatial scales from fractions of a millimeter to thousands of kilometers.
-Have time scales that range from milliseconds to billions of years.
The earth system is powered by the Sun that drives external processes in the:
atmosphere, hydrosphere, and earth’s surface. The Earth system is also powered by the
Earth’s interior: heat remaining from Earth’s formation, and heat that is continuously
generated by radioactive decay, power the internal processes that produce volcanoes,
earthquakes and mountains.
What is the Environment?
-Best defined as “all that surrounds us with which we interact”.
-This can be pretty far-reaching (eg. Mars rovers, Voyager, etc).
What is Geology?
-From the Greek term Geo (earth) and logos (discourse). Discussing the earth.
-The science that pursues an understanding of planet Earth.
-Geology is very multidisciplinary. It draws from physics, chemistry and biology - an
Earth Systems Science approach.
-But what is science?
The nature of Scientific Ideas: -Science is a system of knowledge that is based on general “truths” or facts as they are
known at the time.
-Scientists use observations (to gather the facts) and deduction to offer explanations of
-Deductive reasoning: to draw conclusions regarding phenomena based on all that is
-Earth Science (Geology): focuses on natural phenomena that are related to the Earth.
Developing & Expressing such Explanations of Natural Phenomena
-Speculation: simply opinion or guess.
-Hypothesis: a logically derived explanation that is based on a body of knowledge;
everything known about what is being explained.
-It remains tentative (possibly wrong) until further evidence and rigorous testing proves it
Given more than one hypothesis for a given phenomenon the simplest hypothesis is
-Theory: a very well verified and communicated explanation that explains all of the data.
-Law: Theories become Laws (eg. The Law of Gravity) when they re shown to be
absolutely correct for the conditions to which they apply.
Science is a process of continuous refinement and testing of such
The Science of Geology:
Geology is the science that pursues an understanding of planet Earth.
-Physical geology - examines the materials composing Earth and seeks to understand
the many processes that operate beneath and upon its surface
-Historical geology - seeks an understanding of the origin of Earth and its development
The Science of Geology:
A Canadian Profile
-Sir William Edmond Logan has been called Canada’s #1 scientist in history
-He was the first director of the GSC and was active in the outdoor pursuits of geology
-Helped with extracting minerals in Canada. Herodotos (500 BC): recognized that the Nile River deposited sediment during flood
(i.e., the land surface was modified by natural processes).
Aristotle (384-322 BC): recognized that fossils in rocks resembled many living
organisms; concluded that fossils were once-living animals. Implies that rocks formed
since there was life on Earth.
Theophrastus (374-287 BC): wrote the first book on the minerals that make up rocks.
A Brief History of Geology:
St. Thomas Aquinas (1225-1274): explained all geological phenomena in terms of the
Landscape on Earth today was formed during creation