Modeling Intraplate Earthquakes with Booby Trap

Description

Intraplate earthquakes have long intrigued both students and educators. Classroom exploration of United State seismicity and hazards maps inevitably generates numerous questions from the learners regarding the New Madrid Seismic Zone (NMSZ). Unfortunately, many earth science teachers are not prepared to exploit this interest by discussing the ongoing debate regarding the seismic hazard in the region. Instead, they are likely to respond to such questions by stating only that these issues are not well understood. Such a response is likely the result of two factors; 1) many teachers lack adequate knowledge of the current understanding of intraplate seismic zones and 2) teachers lack adequate instruction tools to convey such content to students. To empower teachers, this article summarizes ideas about the mechanisms of intraplate seismic zones and maps this to a physical model useful for exploring this phenomena and the debate surrounding it.

Audience

Grades 5 to 12

Time

~ 45 Minutes

Objective

The goal of this instruction is to encourage students’ development of a mental model for intraplate seismic zones that include the following elements;

  • Elastic rebound theory describes individual faults’ behavior and appears to adequately describe temporal and spatial patterns of seismicity across plate boundary regions.
  • Intraplate seismic zones
    1. are more complex than plate boundaries and the elastic rebound theory applied to any individual fault appears inadequate to explain temporal and spatial patterns of seismicity,
    2. may distribute stress and thus earthquakes across all the faults within the zone in a complex pattern that varies temporally.
    3. transfer stress within the system, following an earthquake, in a way that is difficult to predict
  • It is unclear whether past locations of earthquakes are predictors of future events in intraplate seismic zones.

Description

The full description of the use of this model is contained in the following article

Hubenthal, M., Stein, S., Taber, J. (2011) A Big Squeeze: Examining and Modeling Causes of Intraplate Earthquakes in the Earth Science Classroom. The Earth Scientist, 27(1), 33-39.

Instructional Sequence

Learning Cycle Description Resources

Prerequisite Instruction

 Introduce and explore elastic rebound theory as a mechanism for earthquakes
Open Have students play Booby TrapTM as class under flexcam or in small groups The Booby TrapTM game is available online for ~ $15
Prior Knowledge

a) Introduce intraplate seismic zones by exploring and describing the following with your students

  • US Hazard Map
  • Description of 1811-1812 events
  • Paleoseismic record of historical earthquakes in NMSZ
  • Current seismicity in NMSZ
b) Ask students to predict a mechanism for large earthquakes in this region and what they thing the current pattern of seismicity suggests for the future?
Explore/Explain a)Introduce GPS data across the NMSZ and compare to student predictions.

b)Explore study of the North China Seismic Zone

c)Reintroduce the Booby TrapTM as a model with explicit mapping between target and analogy.

d)Lead guided discovery of Booby TrapTM using questions above.
Reflect Journal-write on their conception of the relationship between elastic rebound theory and intrapate earthquakes.
Apply Assign Is the Midwest’s NMSZ a Serious Threat for student reading. Discuss in small groups.

Additional readings for teachers or students