Arctic Field Projects



Project Title: Collaborative Research: In Situ Borehole Measurements To Partition The Velocity Of The Greenland Ice Sheet Into Ice Deformation And Basal Sliding Components (Award# 1203418)

PI: Harper, Joel T (Joel@mso.umt.edu)
Phone: (406) 243.5867 
Institute/Department: U of Montana, Department of Geosciences 
IPY Project?
Funding Agency: US\Federal\NSF\GEO\OPP\ARC\ANS
Program Manager: Dr. Marc Stieglitz (mstiegli@nsf.gov )
Discipline(s): | Cryosphere |

Project Web Site(s):
NSF_Award_Info: http://www.nsf.gov/awardsearch/showAward.do?AwardN...
Data: https://arcticdata.io/

Science Summary:
Sliding of an ice mass along its basal boundary is a fundamental component of motion where bed conditions are wet. Estimates of basal sliding generally result from an inverse analysis of observed surface motion using a model assuming Glen's generalized constitutive law for isotropic ice. Evidence suggests that this law does not adequately represent ice deformation, due to a variety of issues including ice thermal variations, preferred fabric, and chemical impurities in the ice. The PIs will use an innovative experimental design to improve our understanding of the ice deformation and sliding. A grid of 9 boreholes, each approximately 750 m in depth and extending to the bed, will be drilled through the Greenland Ice Sheet and instrumented with more than 675 sensors to observe ice temperature, ice deformation, and basal sliding. Analysis of the resulting data set will yield the full 3D velocity field and full stress and strain rate tensors for a 420x106 m3 block of ice. The results will be used to assess and improve the constitutive law and will provide a data set for testing inversion methodologies. The Greenland and Antarctic Ice Sheets contain enough water to cause massive inundation of heavily populated coastal regions and associated infrastructure, if they were to degrade significantly through melting or delivery of icebergs to the coastal ocean. Our ability to predict future sea level rise is hampered by an inability to accurately model glacier dynamics that connect these ice sheets to the ocean. This project will provide data sets and consequent insight into processes that will lead to improved models of glacier dynamics.

Logistics Summary:
This collaboration between Harper (1203418, U of MT, Lead) and Humphrey (1203451, U of WY) continues work begun under NSF grant 0909495, and centers on a detailed study of ice deformation in Western Greenland near Pt 660 and Kangerlussuaq. Researchers will drill and instrument a grid of 9 boreholes, each ~750 m and extending to the bed. Sensors will be installed in the boreholes for measuring ice temperature, deformation and basal sliding, and will make other supporting measurements such as surface velocity and basal water pressure. From 2014 through 2017, a field team of ~8 will spend time each summer on the ice sheet east of Kangerlussuaq. In July 2014, a team of five will travel by commercial air to Kangerlussuaq to prepare for the field work. Activities will include staging fuel, camp supplies, and science equipment/gear at Point 660 near the edge of the ice sheet. When all cargo is positioned and the remainder of the team arrives via ANG in Kanger and positions at Point 660, a helicopter ferried from Nuuk will shuttle all researchers and the camp to the field site. Drilling and instrument installation will continue until early August, when the team will be taken out via helicopter. After storing project gear in Kangerlussuaq, they will depart Greenland via commercial air. In late September, four team members will return to Greenland via commercial air from Copenhagen. They will fly by helicopter to their field study site, GL-14-S1 and spend 5-6 hours downloading data and reconfiguring instruments for over-winter operations. When this work is completed, the researchers will depart, again via commercial air. 2015 features plans for three deployments. In late April, four team members will return to Greenland via commercial air from Copenhagen. They will fly by helicopter to their field study site, GL-14-S1, and spend 5-6 hours downloading data and checking their instruments prior to summer season. When this work is completed, the researchers will depart via commercial air. At the end of June, five researchers will travel via the 109th Air Guard, and three will fly on a commercial flight, to Kangerlussuaq to prepare for their upcoming field work. When all cargo is positioned at Pt 660, the team of eight will also camp there prior to the arrival of a Bell 212 helicopter ferried from Ilulissat, which will shuttle all researchers and the camp gear to the field site. Drilling and instrument installation will continue until the end of July, when the team will be taken out via helicopter to Pt 660, and shuttled back to Kangerlussuaq again. After completing shipping preparations and storing project gear in Kangerlussuaq, the researchers will depart Greenland via the 109th Air Guard. Finally, in late September, four researchers will return to Greenland via commercial air from Copenhagen. They will fly by helicopter to their field study site and spend 5-6 hours downloading data and reconfiguring instruments for over-winter operations. When this work is completed, the researchers will depart, again via commercial air. In 2016 the team will make two deployments. In late April, four team members will travel to Greenland via an ANG 109th Air Guard flight. They will fly by Sikorsky helicopter to their field study site, GL-14-S1, and spend 5-6 hours downloading data and checking their instruments to ensure readiness for the summer melt season. When this work is completed, the researchers will depart via commercial air. In mid-August, a team of six will assemble in Kangerlussuaq, five travelling via the 109th, and one travelling via commercial air. The researchers will spend a day or so in Kangerlussuaq, using the NSF-leased warehouse spaces to prepare for their field work. They will put in to their field site by helicopter and will depart Greenland the same way that they arrived. Under NSF Supplement #1660567, six researchers will return to the GL-14-S1 field site in 2017 for their final year of field work traveling via Commercial Air and Air National Guard. An NPR reporter will join the team in the field, traveling via Commercial Air. The team will remove all of the instruments, including the UNAVCO equipment, at the end of the visit.

In 2014-2016, CPS will provide Air National Guard (ANG) coordination for passengers and cargo between NY and Kangerlussuaq, KISS user days, rental truck (HiLux), helicopter charters, access to warehouse space, over-winter container storage, fuel, camp gear and equipment allocations, communication & safety gear. UNAVCO will provide GPS equipment. All other logistics will be organized by the researchers and paid through the grant. In 2017, CPS will provide Air National Guard coordination for passengers and cargo between NY and Kangerlussuaq, assistance with obtaining the gate key (for access to Pt. 660), camp gear and equipment allocations, assistance with lodging and truck rentals, and safety/comms gear. UNAVCO will provide GPS equipment. All other logistics will be organized by the researchers and paid through the grant to include commercial air travel to and from Greenland, helicopter support, truck rental, lodging and meals.
SeasonField SiteDate InDate Out#People
2014Greenland - GL-14-S107 / 05 / 2014 08 / 06 / 20148
2014Greenland - Kangerlussuaq07 / 05 / 2014 09 / 26 / 20148
2014Greenland - Point 66007 / 05 / 2014 08 / 06 / 20148
2015Greenland - GL-14-S104 / 22 / 2015 07 / 23 / 20158
2015Greenland - Kangerlussuaq04 / 21 / 2015 07 / 27 / 20158
2015Greenland - Point 66007 / 01 / 2015 07 / 24 / 20158
2016Greenland - GL-14-S104 / 20 / 2016 08 / 17 / 20166
2016Greenland - Kangerlussuaq04 / 19 / 2016 08 / 20 / 20166
2016Greenland - Point 66004 / 21 / 2016 08 / 18 / 20166
2017Greenland - GL-14-S107 / 21 / 2017 07 / 25 / 20177
2017Greenland - Kangerlussuaq07 / 18 / 2017 07 / 28 / 20177
 


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