Daily Objectives

MEASURING EARTHQUAKES

In your groups, do the following:

n Review: Using the data posted by the class last time on the wiki page, create three graphs and answer three questions about them.

Graph 1: Show the travel time of the P waves from the Central Italy earthquake. (This graph should look something like the graph from the Indian Ocean tsunami earthquake of Dec 26, 2004--but just for the P waves.) Question: how does this graph compare to the Indian Ocean graph?

Graph 2: Show the travel time of the S waves from the Central Italy earthquake. (This graph should look something like the graph from the Indian Ocean tsunami earthquake of Dec 26, 2004--but just for the S waves.) Question: how does this graph compare to the Indian Ocean graph?

Graph 3: Show the distance to the Central Italy earthquake episode on the horizontal axis ("X" axis), and velocity of the P wave on the vertical axis ("Y" axis). Question: is there a relationship between velocity of the earthquake wave and how fast the wave travels? If so, describe and explain it.

TOPOGRAPHIC MAPS and STREAMS

n Explain the meaning of the following terms:

stream canal meander oxbow (lake) floodplain
watershed drainage basin divide stream hydrograph discharge

n Explain why not all streams have well-developed floodplains.

n Using the map of Major Watersheds of Illinois, determine what watersheds (more than one!) a particular Illinois town falls within.

n Find the following features on the topographic maps provided:

• two different well-developed stream floodplains: one should be the Mississippi River, and one should be another stream. Measure their floodplain widths in miles.

• a meandering stream

• a channelized stream (or canal)

• a gaging station

• an oxbow and/or oxbow lake

• a stream that appears not to have a well-developed floodplain

• on the Clinton Illinois-Iowa map, find evidence of a former channel of the Mississippi River, now dry.

• a divide between two watersheds. HINT: Look for two good-sized streams, and then look for the topographically high area between them. The Galena, Illinois map is a good one for this!

• the divide between the Lake Michigan and Mississippi River watersheds. It appears on the River Forest Quadrangle. It's not marked, so you'll have to use your knowledge of topographic maps to find the high area separating these two major bodies of water--Lake Michigan to the east, and the Des Plaines River/Illinois River/Mississippi River to the west.

Find stream records for last fall's flooding. Follow the instructions that appear here.

Department of Earth Science | Northeastern Illinois University