EG - Vocab - Plate margins

Activity

Processes - sedimentation, reversals of Earth's magnetic field
Concepts
relationship between vertical position of sedimentary rock layers and time
layers of sedimentary rock as records of Earth history
magnetization of rocks relationship of paleomagnetic anomalies of oceanic crust and geologic time seafloor spreading

Useful demonstrations
1. Stratigraphic column Set up sand flow into a column at a rate of 2 cm / minute for a minute. Drop a plastic marker - trilobite Increase flow rate to 4 cm /minute for a minute. Drop a marker - dinosaur. Decreate flow rate to 2 cm a minute for two minute. Drop a marker - plastic polar bear. Teacher shows how setup works Discuss: Where the older sediment Absolute vs. relative time Absolute time at each marker Teacher controls mystery flow Students provide change in sediment color and markers Thickness as a function of sedimentatio rate and duration Draw diagram on paper Teams trade and interpret time Interpret time scale on right-side 2. Magnetization of seafloor Definition of anomaly Lock in record Sideways Bishop Tuff Dating tool - fingerprint unique wherever you find it

Determination of seafloor spreading rates
Measurement ...
Math application - rates, distance and time
Applied experience
Student must estimate distance and develop a feel for adequate precision given a particular problem a. Distances between known landmarks can be used to estimate distance b. For advanced students, an opportunity to point out that a fixed distance scale can't be applied to a flat map because of distortion
Exposes students to imperfect data - the magnetic stripes are not perfectly straight
Activity reinforces and refines
Understanding of seafloor spreading
Highlights the ongoing nature of the seafloor spreading process and associated hazards Links modern hazard with key process, and importance of multidimensional data Highlights role of science in society problem Simplified activity for students who have trouble reading maps

Advanced activity Stu Like a recipe - you get a sense when you can substitute and when you have to measure better Questions for thought
1. Does a single tectonic plate such as the North American plate exhibit just one kind of plate margin or not?
2. Do you live within 200 miles of a plate margin?
3. What kind of plate margin is near San Diego?
4. What kind of geologic hazards occur? What doesn't? Ev
5. Should people who live in higher risk areas pay more? High risk sports more ?



	Activity Back Home Determining seafloor spreading rates using seafloor paleomagnetic anomaly map Purpose and summary Materials Prerequisites Processes - sedimentation, reversals of Earth's magnetic field Concepts relationship between vertical position of sedimentary rock layers and time layers of sedimentary rock as records of Earth history magnetization of rocks relationship of paleomagnetic anomalies of oceanic crust and geologic time seafloor spreading Useful demonstrations 1. Stratigraphic column Set up sand flow into a column at a rate of 2 cm / minute for a minute. Drop a plastic marker - trilobite Increase flow rate to 4 cm /minute for a minute. Drop a marker - dinosaur. Decreate flow rate to 2 cm a minute for two minute. Drop a marker - plastic polar bear. Teacher shows how setup works Discuss: Where the older sediment Absolute vs. relative time Absolute time at each marker Teacher controls mystery flow Students provide change in sediment color and markers Thickness as a function of sedimentatio rate and duration Draw diagram on paper Teams trade and interpret time Interpret time scale on right-side 2. Magnetization of seafloor Definition of anomaly Lock in record Sideways Bishop Tuff Dating tool - fingerprint unique wherever you find it Determination of seafloor spreading rates Measurement ... Math application - rates, distance and time Applied experience Student must estimate distance and develop a feel for adequate precision given a particular problem a. Distances between known landmarks can be used to estimate distance b. For advanced students, an opportunity to point out that a fixed distance scale can't be applied to a flat map because of distortion Exposes students to imperfect data - the magnetic stripes are not perfectly straight Activity reinforces and refines Understanding of seafloor spreading Highlights the ongoing nature of the seafloor spreading process and associated hazards Links modern hazard with key process, and importance of multidimensional data Highlights role of science in society problem Simplified activity for students who have trouble reading maps Advanced activity Stu Like a recipe - you get a sense when you can substitute and when you have to measure better Questions for thought Does a single tectonic plate such as the North American plate exhibit just one kind of plate margin or not? Do you live within 200 miles of a plate margin? What kind of plate margin is near San Diego? What kind of geologic hazards occur? What doesn't? Ev Should people who live in higher risk areas pay more? High risk sports more ?