Anyone need a syllabus? Anyone need to sign roster? Syllabus as is: Tues. Oct. 26: Landscapes Thurs. Oct. 28: Spill-over and review Tues. Nov. 2: Exam 2 Thurs. Nov. 4: Earth Beneath the Oceans Proposed change to syllabus: Tues. Oct. 26: Spill-over and review Thurs. Oct. 28: Exam 2 Tues. Nov. 2: Landscapes (go vote!) Thurs. Nov. 4: Earth Beneath the Oceans Details
“What is GEOLOGY?” Rocks? Yeah, but ….
The constant formation and reformation of Earth (plate tectonics) Geology includes ….
Processes that shape the surface of Earth (rivers, coastlines, hillslopes, glaciers)
Environmental Issues (groundwater, nuclear waste, pollution,What happened to Lake Jackson?, global warming, river restoration) Outstanding Florida Water Body, Lake Jackson (Tallahassee), is known nationally as a premiere bass fishing lake.
...just like chemistry and physics! Geology is a science... However, geologists face the special challenge of not being able to do experiments like physicists and chemists do.
So what do geolgists have? Scientific principle: The natural world is sensible and is governed by immutable rules.
How do you figure out these“immutable rules”? The Scientific Method.
The Scientific Method 1) Make an observation about the sensible world. 2) Develop an explanation (hypothesis) that predicts the outcome of other observations or experiments.
3a) Make new experiments. The Scientific Method (cont.) 3b) Make new observations.
The scientific method (cont.) return to step 2 return to step 3 4) Do the results match the predictions of the hypothesis ? Reject the hypothesis no yes
Fig. 1.1 The Scientific Method
An hypothesis is an explanation initially offered for a set of observations. When a hypothesis withstands many tests it may be called a theory. A theory for which it seems there to be no sensible reasons to challenge is called a law. Hypothesis - Theory - Law
In reality, no scientist actually follows the scientific method like a flow chart. Bursts of progress, banging your head against the wall, finding out after a month of experiments that something just won’t work. Oh, if it were only that easy.
Since geologists are interested in systems that are very big (hundreds of kilometers) and that have evolved over long periods of time (millions of years), they cannot always conduct controlled experiments. They must observe the results of nature’s experiments that are already complete. Oh, if it were only that easy, Part II.
The big difference between geology and other sciences: TIME. (Geologically speaking, not much happens in a human lifetime!) Rates of geologic processes: µm/year to cm/year Big earthquakes may displace the ground several meters in a few seconds, but they occur only every 500 years or so. TIME
The rates of geologic processes are almost always slower than the rates of human effects on the environment. TIME
The official SI unit of time is the second, but it would be very inconvenient to use this unit in geology; even the year is too small in most cases. Therefore, geologists use millions of years as the standard unit of time: 10 Ma = 10 million years ago 10 m.y. = an interval of time lasting 10 million years TIME
Uniformitarianism Principle of uniformitariansim: The geologic processes that we see in action today have worked in much the same way through geologic time. “The present is the key to the past.”
This does not imply that all geological processes happen slowly! This does also not imply that the only significant geological phenomena are the ones that we see today! Some events occur very infrequently (not within a human lifetime) but regularly. Uniformitariansim