Originally presented 27 Oct 2012)
Dr. Heather Savage studies earthquake and fault mechanisms with special interest in earthquake triggering and fault damage zones. Understanding the stress on faults during slips is essential to developing a full mechanical model of faulting during rupture. One way to investigate such stress is to find the total energy dissipated as heat through frictional resistance. One strategy used by Dr. Savage and colleagues involves determining the thermal alteration of organic matter.
In this E2C Workshop, Dr. Savage explains this innovative approach toward gaining insights about earthquakes and faulting, drawing on field work and laboratory simulations. In the afternoon, Dr. Savage will lead a special tour of Lamont’s Rock Mechanics Lab.
Introduction to this Workshop
Introductory presentation:
“What Do We Need to Know and Teach about Earthquakes?” ppt
“What Do We Need to Know and Teach about Earthquakes?” pdf
Cutting-Edge Research
NEWS STORY: “DEAD PLANTS HOLD EARTHQUAKE SECRETS” (1/24/14)
The LDEO Rock Mechanics Lab
http://www.ldeo.columbia.edu/rock-mechanics/projects
Research encompasses many aspects of rock and ice deformation. In the rock mechanics lab, we use various laboratory instruments to study the physical properties of materials that are important to earth and planetary science. Primarily we study natural rocks, but soon we will also be working with ice. We have facilities for coring, sawing, and grinding of experimental samples. We have an adjacent machine shop as well as a central facility for more detailed jobs. We also now have access to a cold room for ice sample preparation and storage.
Here are some of the current projects in the rock mechanics lab:
1. Fault heating: Researchers use biomarkers found in natural faults as a paleothermometer for frictional heating during large events.
2. Frictional stability transition:We try to understand better the transitional mode between slowly creeping faults and large strike slip events, which could lead to better prediction of seismic hazards.
3. Frictional sliding of ice:Investigators study dynamic frictional heating in ice to better explain anamolous heat flux observed in icy satellites and accelerated flow of outlet glaciers, both of which phenomena have been linked to the tidal loading of ice layers.
4. Seismic Attenuation: Using new laboratory measurements of attenuation and dispersion, we work with seismologists to scale lab data to seismic observation and, in doing so, be able to constrain things like temperature and the presence of melt at depth.
One example of our research results:
Polissar, P. J., H. M. Savage, and E. E. Brodsky (2011) Extractable organic material in fault zones as a tool to investigate frictional stress, Earth and Planetary Science Letters PDF
Classroom Resources
The Rock Mechanics Lab has sponsored summer interns in the Research Experiences for Undergraduate programs. Here is one example of the research produced through these activities.
Exploring ‘Slow Earthquakes’ in Laboratory Experiments
Caitlin Dieck1, Heather Savage2
1. School of General Studies, Columbia University, New York, NY, USA, 2. Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA
Over the last decade Earth scientists’ have discovered fault failure that has the ability to fail slowly over the course of days to weeks to months called slow-slip events. Though much work has been done to document slow-slip phenomena worldwide, the underlying mechanics of these slow-slip events or ‘slow earthquakes’ are still not understood. With the aim of learning more, we performed preliminary experiments in a simple lab setting in order to study fault behavior and explore the conditions that might facilitate slow slip on faults. Here we loaded our sample into a biaxial apparatus with a direct shearloading configuration. Starting at 0.1 MPa, we increased pressure at a constant rate while measuring the displacement and stress along the slip surface during experiments. We found that increasing the normal stress created different slip speeds along the fault plane. This as a result allowed us to document a complete frictional stability transition in the lab, and produce slow-slip behavior.
Selected Classroom Investigations
“Earthquakes on the Web” activity
Sample questions about earthquakes
“Locating the Epicenter” suggested by Cheryl Dodes
“Determining the Epicenter and Magnitude of an Earthquake” suggested by Cheryl Dodes
“Earthquakes” created by Greg G. Hofer and others
“New Jersey Earthquakes” by Clare Kennedy and Carol Zepatos
“Assessing Earthquake Risk” by Corey Shalanski
Click for the accompanying Student Worksheet
“Earthquake Simulator” from Bonnie Keller
“Extraterrestrial Volcanoes” by Barbara Stonewall (ppt) (pdf)
IRIS (Incorporated Research Institutions for Seismology) Educational Resources
http://www.iris.edu/edu/resources.htm
Earthscope (Exploring the Structure and Evolution of the North American Continent) Educational Resources
http://www.earthscope.org/
NOVA “Volcano’s Deadly Warning”
http://www.pbs.org/wgbh/nova/volcano/
American Meteorological Society Education Program links:
DataStreme Ocean In the “Geological” section, look at links to current earthquake and volcanic activity, tsunamis, acoustic ocean seismicity, and other sites that might be of interest.
DLESE
One of the best resources to locate useful online resources is DLESE — Digital Library for Earth System Education
http://www.dlese.org
Other Resources for This Topic
Polissar, P.J. et all, 2011, “Extractable organic material in fault zones as a tool to investigate frictional stress.” Earth and Planetary Science Letters.
Integrating Educational Technologies
General suggestions: Integrating Educational Technologies into Your Classrooms
Your assignment: Videos in the Classroom
1) What characteristics make videos effective as a classroom teaching tool?
2) When should videos be used for full-class instruction, and when should they be used for small groups or individual projects?
3) Describe strategies to locate suitable videos for your classes.
and
4) Design a lesson plan that incorporates at least one video .
E2C Follow-up:
You may send your model lesson and other responses to this “assignment” to michael@earth2class.org. If suitable, we will post your work in the E2C lesson plans and/or add them to this section of the Workshop website.
MULTIMEDIA:
NEWS STORY: “DEAD PLANTS HOLD EARTHQUAKE SECRETS” (1/24/14)