Department of Earth Science |Northeastern Illinois University

INTRODUCTION TO EARTH SCIENCE
ESCI 121

Section 06
Fall 2009

Review for Exam #4 (December 15, 2009)                                                                                                         Dr. Sanders

For the exam, you should be able to do the following:

EARTHQUAKE MAPS AND GEOTECTONICS

w  Using the earthquake maps the class produced, arrange them in meaningful groups based on the patterns of earthquake epicenters and based on the patterns of focal depths you observe in each.  The worksheet appears at this link.

TOPOGRAPHIC MAPS

w   List and explain the components that are common to all well-made maps:

title            key or legend    coordinate system
scale        north arrow

w   Using the scale on a topographic map, find the distance between two points.

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Define these terms:

topography           topographic map           contour line        contour interval

w   Using the green globs of "playdough", sculpt a model of a hill, scribe contour lines into your sculpture, and based on your model, sketch a topographic map of the area.

w   Using a topographic map, find the elevation of a point.

w   Determine the direction a stream flows based on a topographic map.

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Using a topographic map, determine the difference between steep and gentle slopes.

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Using a USGS topographic map, identify these landforms/features:

○  hill                               ○  valley                                   ○  closed depression (basin)
○  stream                        ○  intermittent stream            ○  lake

w   Using the scale on a topographic map, find the distance between two points.

w   Use a topographic map to estimate the latitude and longitude of a point.

w   Explain what is meant by "7.5-minute quadrangle".

 Using the topographic quadrangles provided, find at least one place that illustrates each of the following features.  Label and place a sticky note on one map or the other, to indicate the location of each feature.  It is necessary to find each feature only once. * a gentle slope   * a steep slope   * a closed depression   * a round hill top   * a ridge (elongated hilltop)   * a lake * a benchmark * a stream; find two places where contour lines cross the same stream and put sticky notes on the map to show both places.  Tell what direction the stream is flowing. * a “Gaging Station” along a stream      * a forested or undeveloped area (how can you tell?) * an urban area (how can you tell?)

w   Delineate a watershed based on a topographic map.

w   Review:  Using topographic maps, determine the difference between steep and gentle slopes, find the elevation of a point, find the distance between two points, determine the direction a stream flows, identify a hill, a  valley, a closed depression (basin), a stream, an intermittent stream, and a lake.

w   Explain the terms meander, oxbow, and floodplain.

Complete the following three activities at your own pace.  A handout with these activities appears here.

 ACTIVITY ONE:  Sketch a profile illustrating a floodplain.  Explain how a floodplain would appear on a topographic map.  Using topographic quadrangles from two groups (named below), identify any floodplains you can see, and also point out meanders, and oxbows. Map Group 1:  Clinton Illinois-Iowa; Menominee Illinois-Iowa; and Blackhawk, Illinois, identify any floodplains you can see. Map Group 2:  Atkinson, Illinois; and Geneseo, Illinois.
 ACTIVITY TWO:  On the Galena, Illinois quadrangle, find the word “RAWLINS” in the middle of the map.  Between the W and the L in RAWLINS flows an intermittent stream.  Using tracing paper, outline the watershed (drainage basin) for this stream.  Follow this strategy: 1) Place the tracing paper over the stream area and mark on the paper a few landmarks that appear on the map.  When the paper slides around, you’ll be able to re-orient it using these landmarks.2) Using blue pencil, trace the course of several streams that occur in the area, including the one we are working on.3) Find the highest land between the streams and our stream of interest.  Draw a very light line following the general location of this high area.4) Now, get more precise:  Locate the very highest places between the streams.  Ask yourself, “If rain fell to the land surface here and started flowing downhill, which way would it flow?”  If it goes in a direction that makes it end up in our stream of interest, it is part of that watershed!  Draw the exact line showing the boundary of the watershed.
 ACTIVITY THREE:  The Stream Table  Preparation: Smooth the surface of the sand in the stream table.  Make it reach the level of the metal plate on the upstream side, and gradually decrease until it ends at the tape mark on the side of the table.  The surface should be perfectly smooth and even, like a perfect ramp.  Experiment A: Turn the water on by flipping the switch.  Adjust the discharge by turning the valve until there is a small but continuous flow.  This flow will create a stream.  Carefully observe the stream for the next 5-10 minutes.  It will change continuously during that time, and your job is to observe what happens.  w   How does the stream channel form?  What shape does it take?  Does the shape change over time?w   Where does erosion occur?  Where does deposition occur?  Does this change over time?  If so, how?w   What feature forms where the stream meets the ocean?  Sketch it.  Place a toothpick near the main channel in this area.  Watch it for a few minutes.  What happens?  If you build your house on a feature like this, what is likely to happen to it? Experiment B: Shut the water off, and smooth the sand again.  Carve a deep, meandering channel for the stream.  Then, turn the water back on.  Watch one meander for a few minutes.  Where does erosion occur?  Deposition?  Which side has steeper banks?

w   Review:  Sketch a profile illustrating a floodplain, and explain how a floodplain would appear on a topographic map.  (The quadrangles we used were Clinton Illinois-Iowa, Menominee Illinois-Iowa, Blackhawk Illinois, Atkinson Illinois, and Geneseo Illinois.)

w   Review:  Delineate a watershed boundary (divide) on the Galena Illinois quadrangle.

w   Review:  Using the stream table, demonstrate how erosion, transport, and deposition of sediments occur, and how a stream channel, floodplain, and delta form.

WEATHER

w   Explain what humidity is and tell how humidity measurements are expressed.

w   Explain what an air mass is.

w   Describe continental polar (cP), maritime tropical (mT), continental Arctic, (cA), and other air masses that affect the continental United States.  (See http://okfirst.mesonet.org/train/meteorology/AirMasses.html and http://www.qc.ec.gc.ca/meteo/Documentation/Masse_e.html .)

w   Explain what a front is.

w   Using the worksheet attached here, study and interpret the weather maps we have been collecting for the past month.  Today, the focus is on air mass temperature, fronts, and precipitation.

w   Explain how  temperature and moisture content of an air mass affect its density.

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Complete the data collection and analysis of the "Weather Tracking Day 1" worksheet, and compare your CONCLUSIONS with the rest of the class.

w   List the steps that lead to the formation of a cloud.

w   Explain the terms condensation and condensation nuclei as they relate to cloud formation.

w   Describe the characteristics of cirrus, cumulus, and stratus clouds.

w  Tell what cumulonimbus and nimbostratus clouds have that ordinary cumulus and stratus clouds don't.

w   Explain the processes that lead to orographic, convective, and frontal precipitation, and sketch a diagram illustrating each one.

w   Make a sketch of a warm front and use it to explain why precipitation is associated with these fronts.

w   Make a sketch of a cold front and use it to explain why precipitation is associated with these fronts.

w   Explain the meaning of air pressure / barometric pressure

w   Move on to "Weather Tracking Day 2", using the map linked here.  Here, the focus is on high and low pressure systems and how they relate to fronts and precipitation.

Here's a cool weather site for anyone, but especially for you pre-service teachers!

w   Explain why as warm, moist air rises it may form clouds that yield precipitation.

w   Explain why precipitation is associated with warm fronts and with cold fronts.

w   Describe the characteristics of stationary fronts and occluded fronts.  Here are a few websites explaining fronts:  From the University of Illinois  From the Oklahoma Climatological Survey    From Eduplace.com

w   Tell what makes the wind blow, and how winds are named (e.g. "west wind", "north wind", and so on).

w   Tell what kind of weather generally accompanies highs and lows.

w   Describe the rotation and vertical motion of winds about a HIGH pressure center and a LOW pressure center.

w   Using a slip of paper with a circle to represent a HIGH or a LOW, draw arrows on the circles to indicate direction of the rotation.  Trace the circles on tracing paper, and place the tracing paper over weather maps to illustrate rotation of the HIGH and LOW systems.

Describe how the winds change in Chicago under the following situations:

 __ A HIGH approaches Chicago, passes directly over it, and then moves on. __ A LOW approaches Chicago, passes directly over it, and then moves on. __ A HIGH passes to the north of Chicago. __ A LOW passes to the north of Chicago. __ A HIGH passes to the south of Chicago.    __ A LOW passes to the south of Chicago.

w   Given a weather observation, what can you reasonably conclude?  See the attached worksheet!

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Putting together all the data trends we have observed, particularly regarding air masses, fronts, highs,  lows, and winds, forecast the weather.

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Practice forecasting using today's (Tuesday, Dec. 8) weather map from the Chicago Tribune (it's a big 2 MB file--patience, please!)

w   Practice forecasting using today's (Thursday, Dec. 10) weather map from the Chicago Tribune.

Department of Earth Science | Northeastern Illinois University

Copyright 2009 Laura L. Sanders.  Last updated December 10, 2009.