2015 JIRP Student Project: GPS Surveys on the Juneau Icefield
Faculty experts: Scott McGee, Surveyors, Shad O’Neel, Allen Pope.
Overview: The primary purpose of the GPS survey project is to measure the surface velocities
and surface elevations of the glaciers on the Juneau Icefield. The GPS project also provides
GPS support for other JIRP research projects, as needed. Collected GPS measurements are
evaluated against previous years’ GPS records to determine spatial and temporal changes in
the morphology and behavior of the Juneau Icefield’s glaciers.
Level 1 students will learn the basics of GPS and will participate in collecting GPS survey
data. They will learn how to set up a differential GPS system and will operate a rover GPS to
collect data on one or several standard survey profiles. Level 1 students’ involvement will be
limited to the summer field season and they are not expected to perform advanced analysis of
GPS data nor compile a student report related to their GPS work.
Level 2 students will be exposed to the same aspects as Level 1 students. In addition, Level 2
students will form the core GPS team, which entails going out on GPS surveys daily
throughout the summer field season. Level 2 students will learn and perform detailed
analysis and presentation of GPS data. It is expected that Level 2 students will compile a
group report of their summer GPS field work, to be turned in near the end of the fall
semester.
GPS Projects: Following are GPS projects that will be conducted during JIRP 2015:
A. Surface Velocity. Transverse profiles on the Taku Glacier system will be surveyed
multiple times in order to determine surface velocity and direction of movement
(Levels 1 and 2). Results will then be compared with data collected in previous years
to determine if, and where, changes in the flow regime have occurred (Level 2).
B. Surface Elevation. Transverse and longitudinal profiles on the Lemon Creek Glacier
and the Taku Glacier system will be surveyed in order to determine surface elevation
(Levels 1 and 2). Results will be compared with data collected in previous years to
determine if, and where, changes in the surface elevation and gradient of the glaciers
have occurred (Level 2).
C. Strain Rates. Profile 4 on the Taku Glacier is comprised of two parallel lines with the
survey points offset so as to form a series of triangles across the width of the glacier.
Multiple surveys of this profile will be performed (Levels 1 and 2), allowing the
computation of strain rates. Results will be compared to strain rates from previous
years in order to discern possible changes in the flow regime of the main trunk of the
Taku Glacier (Level 2).
Timeline and Logistics: GPS surveys will commence during the last half of the Camp 17
occupation and will continue for the following six weeks. During this time, the survey team
will be in the field every day, spending 6 to 8 hours performing GPS surveys. Surveys on the
Lemon Creek Glacier are conducted via ski. Due to the large geographic extent of the profiles
on the Taku Glacier system, those surveys will be done via snowmobile. Faculty experts will
supervise the field work, with students operating the GPS system and recording data. Data
will be processed in camp, with basic results being used for the student project presentations
in Atlin and Juneau at the end of the field season. In-depth data processing and presentation
(Level 2) will take place as part of the student’s group project report, due near the end of the
fall semester.
References (numbered by priority, i.e. study #1 first, #10 last):
1. Annual JIRP GPS Survey Reports, Crevassezone.org, http://crevassezone.org/reports-GPS.htm
2. JIRP Survey Overview, Crevassezone.org, http://crevassezone.org/tutorials/JIRP-Survey-
Overview.pdf and http://crevassezone.org/tutorials/JIRP-Survey-Overview.pptx
3. Calculating Glacier Movement Vectors, Crevassezone.org,
http://crevassezone.org/tutorials/Glacier-Movement-Vectors.pdf
4. Basics of the Global Positioning System, Trimble, Inc., http://www.trimble.com/gps_tutorial/
5. Global Positioning System, Wikipedia.org, http://en.wikipedia.org/wiki/Global_Positioning_System
6. Application of GPS in Glaciology, by Matt King, Encyclopedia of Snow, Ice, and Glaciers (V.P.
Singh, P. Singh, U.K. Haritashya, editors). http://crevassezone.org/tutorials/Application-of-GPS-
in-Glaciology.pdf
7. Glacier Monitoring Techniques, Ronald D. Karpilo, Jr., Department of Geosciences, Colorado
State University, http://www.nature.nps.gov/geology/monitoring/files/geomon-06.pdf
8. Response of Glacier Basal Motion to Transient Water Storage, by Timothy Bartholomaus,
Robert Anderson, Suzanne Anderson. Nature Geoscience, Vol. 1, Jan. 2008.
http://www.nature.com/ngeo/journal/v1/n1/full/ngeo.2007.52.html and
http://crevassezone.org/tutorials/Glacier-Basal-Motion.pdf
9. Direct Observations of Evolving Subglacial Drainage Beneath the Greenland Ice Sheet, by
Lauren C. Andrews, Ginny A. Catania, Matthew J. Hoffman, Jason D. Gulley, Martin P. Lüthi, Claudia
Ryser, Robert L. Hawley & Thomas A. Neumann. Nature 514, 80–83 (October 2, 2014).
http://www.nature.com/nature/journal/v514/n7520/full/nature13796.html
10. The Terrestrial Reference Frame and the Dynamic Earth, EOS, Vol. 82, No. 25, June 19, 2001,
pp. 273-284. http://crevassezone.org/tutorials/ITRF.pdf