What's Shaking in Greenland?

This lab is designed to be used in an intro geoscience level course for either majors or non-majors.

Before undertaking this activity, students should understand the basic causes of earthquakes (e.g. Elastic Rebound Theory). They should receive basic instruction on glaciers and glacial processes.

The activity is designed as a stand alone exercise to follow an introduction to earthquake basics. It could also be used in an intro course that is focused on climate change and/or glaciology to give an example of climate effects on the earth system.

Students will be able to:
1. Identify major features of a continental glacier system in satellite imagery and explain how the system operates.
2. Describe icequake occurrence in Greenland and demonstrate how their increasing frequency exemplifies the concept of Earth as a system, connecting climate change, glacial melting, and seismic activity.

Students analyze data to infer the causes of ice quakes and then must use systems thinking to connect ice quakes with climate change.

Students are expected to work in groups to complete the activity.

In this lab, students attempt to answer the question "What causes icequakes in Greenland?" To accomplish this, students use Google Earth to examine both the spatial distribution of the icequakes, as well as the physical features of the glacier in regions where icequakes occur. Next, students examine the temporal distribution of the icequakes and compare this evidence to monthly and annual mean air temperatures in Greenland. Finally, students synthesize the evidence they have collected to create a multi-paragraph explanation of how icequakes in Greenland exemplify the concept of "Earth as a system."

This IRIS (Incorporated Research Institutions for Seismology) activity is part of a collection of activities based on questions that identify promising research directions on the frontiers of seismology as outlined in the Seismological Grand Challenges in Understanding Earth's Dynamic System. The collection has been developed to engage students in the analysis of real data and to bring examples of frontier research topics into the undergraduate classroom. Further information about the activity including links to related resources is available on the IRIS website at http://www.iris.edu/hq/inclass/lesson/whats_shaking_in_greenland .

Instructor guide: "What's Shaking in Greenland?" (Microsoft Word 2007 (.docx) 135kB Jun15 17)
Student worksheet KEY: "What's Shaking in Greenland?" (Microsoft Word 2007 (.docx) 1.2MB Jun15 17)
Student worksheet: "What's Shaking in Greenland?" (Microsoft Word 2007 (.docx) 1.2MB Jun15 17)

Icequakes 1993-2010 (KMLFile 81kB Jun1 17)

Greenland air temperature data (Microsoft Word 2007 (.docx) 89kB Jun1 17)

1) Following a lecture on glaciers and glacial processes, assign students to work in pairs to complete the lab worksheet
2) Once students have completed the lab, the following quotation can be assigned as homework or a class discussion.

Research into icequakes is new and there are many unknowns regarding how and why they occur. Extend this lab with a reflection and class discussion of the conclusions that scientists Meredith Nettles and Göran Ekström from Columbia University write about in an article from 2010 in the journal Annual Reviews in Earth and Planetary Sciences:

"The retreat and advance patterns of glacier termini provide a general explanation for the variability in glacial-earthquake frequency on seasonal and interannual timescales...To explain these variations, better knowledge of the physical controls on calving-front advance and retreat, and on calving style, is required... Sea-ice conditions and variations in water temperature and currents in the fjord system correlate with interannual advance and retreat patterns, but seasonal conditions are poorly known... A better understanding of interactions among ice, ocean, and atmospheric conditions is needed to clarify the mechanisms controlling the timing of large-scale calving events."

An activity key is provided which can be used to assess whether students have met the goals of the activity, as is a rubric for the final assignment.

Grand Challenge #4 – How do processes in the ocean and atmosphere interact with the solid Earth?
http://www.iris.edu/hq/files/programs/education_and_outreach/CCLI/Glacial_EQ/Ocean_Atmosphere_Interact.pdf

Glaciers and ice loss animation: https://www.youtube.com/watch?v=FVm3rZZs49s

References:
Lay, T., Aster, R. C., Forsyth, D. W. and the Seismological Grand Challenges Writing Group (2009). Seismological Grand Challenges in Understanding Earth's Dynamic System, http://www.iris.edu/hq/lrsps/seis_plan_final.pdf.

Nettles, M. and G. Ekström, G. (2010). Glacial earthquakes in Greenland and Antarctica, Annual Reviews of Earth and Planetary Science, 38, 467–491, doi: 10.1146/annurev-earth-040809-152414, 2010.

Sampson, V. and Grooms, J. (2010). Generate an argument: An instructional model. The Science Teacher, 77(5), 33-37.

Tsai, V. C. and Ekstrom, G. (2007). Analysis of Glacial Earthquakes. 
Journal of Geophysical Research, 112, F03S22.

Veitch, S. A. and Nettles, M. (2012). Spatial and temporal variations in Greenland glacial-earthquake activity, 1993–2010. Journal of Geophysical Research, 117, F04007.