Science Probe I Technology Activities

Chapter 12

Internet

1. Sea floor spreading is a force behind much of the tectonic plate movement and has been the subject of research recently. Conduct an Internet search for current research on sea floor spreading. Obtain information that will answer the following questions:

a.How much higher is the mid-ocean ridge than the neighboring ocean floor? b.How much volcanic activity is there along the ridges?
c.How has the activity along the ridges affected ocean water temperatures? d.How has the activity along the ridges affected the living organisms in the region?

It might also be helpful to correspond through e-mail or talk in a web discussion site with a geologist to get your answers. Prepare a presentation using maps, sketches, computer graphics, or other multimedia to inform your classmates about sea floor spreading. Below are some web sites to get you started:

Pacific Ocean Sea Floor Spreading
http://library.advanced.org/15931/rof/seaspr.html

United States Geological Survey Homepage
http://geology.usgs.gov/index.shtml

Oceanography Resources on the Internet (NOAA)
http://www.esdim.noaa.gov/ocean_page.html

Application Software

Activity 12C – Locate an Internet site that provides information about ocean trenches. Use this information to locate the trenches on your map and color them. Conduct a search for information about any connections between the trenches, mountain ranges, earthquakes, and volcanoes. Be prepared to discuss with the class how this information verifies or disproves your hypothesis.

Activity 12F – After completing the discussion questions in this activity, conduct an Internet search for information about the intersection of the Juan de Fuca, Pacific, and North American plates. Obtain answers to the following questions:

a.How much movement has there been in the past 10,000 years?
b.How far under the North American plate does the subduction zone go?
c.How much earthquake activity has there been along this subduction zone in the past 500 years?
d.Why is the Juan de Fuca plate descending beneath the North American plate?
e.What visible surface features are the result of this subduction process?

Prepare a presentation using maps, sketches, computer graphics, or other multimedia to inform your classmates about this subduction zone.

Probeware

Activity 12E – Use magnetic field sensors connected to either a computer or calculator to make the magnetic field measurements. Move the sensors in a circle around the bar magnet, as directed in this activity, recording the field strength and direction in at least six locations around the bar magnet. The application software provided with the sensors will record the values for you. Rotate the bar magnet 90° clockwise and repeat. Use the graphing function of your interfacing application software to plot the magnetic field strength and direction. Print the data and graph, and secure them in your SCIENCE PROBE Logbook where you will answer the discussion questions.