9 - 5 1 - ERDC/CRREL TR ERDC/CRREL Engineering for Polar Operations, Logistics, and Research (EPOLAR) Remediation of Old South Pole Station Phase I: Ground-Penetrating-Radar Surveys Lynette Barna, Zoe Courville, John Rand, and Allan Delaney July 2015 Cold Regions Research Research Regions Cold Laboratory and Engineering Approved for public release; distribution is unlimited. The U.S. Army Engineer Research and Development Center (ERDC) solves the nation’s toughest engineering and environmental challenges. ERDC develops innovative solutions in civil and military engineering, geospatial sciences, water resources, and environmental sciences for the Army, the Department of Defense, civilian agencies, and our nation’s public good. Find out more at www.erdc.usace.army.mil. To search for other technical reports published by ERDC, visit the ERDC online library at http://acwc.sdp.sirsi.net/client/default. Engineering for Polar Operations, Logistics, ERDC/CRREL TR-15-9 and Research (EPOLAR) July 2015 Remediation of Old South Pole Station Phase I: Ground-Penetrating-Radar Surveys Lynette Barna and Zoe Courville Cold Regions Research and Engineering Laboratory (CRREL) U.S. Army Engineer Research and Development Center (ERDC) 72 Lyme Road Hanover, NH 03755-1290 John Rand Contractor Cornish Flat, NH 03746 Allan Delaney Contractor Alpine, TX 79831 Final Report Approved for public release; distribution is unlimited. Prepared for National Science Foundation, Division of Polar Programs, Antarctic Infrastructure and Logistics Arlington, VA 22230 Under Engineering for Polar Operations, Logistics, and Research (EPOLAR) EP-ANT-11-41, “USAP Operations Engineering Support and Guidance” ERDC/CRREL TR-15-9 ii Abstract Old South Pole Station was built between 1956 and 1957 to support the In- ternational Geophysical Year (IGY). At the time, the buildings composing the main station complex were built on the snow surface, but the increas- ing depth of snow overcame the structures. In an effort to displace the deepening snow and resulting snow loads, wooden structures called “top hats” were built on top of the roofs of the original buildings. These buried buildings and additional top hat structures created dangerous subsurface voids and then further acted to weaken overlying snow layers. Therefore, we conducted ground-penetrating-radar (GPR) surveys at the Old South Pole Station site to identify buried buildings and potential haz- ards. The GPR survey included techniques used in crevasse detection to identify the locations and dimensions of the buildings. GPR located several top hat roofs as shallow as 14 ft below the snow grade with the roofs of the station buildings 30 ft below the surface at the time of the survey. As a re- sult of this study, GPR located nine buildings within the main complex, which were then imploded using blasting. This report describes the meth- ods used to identify the buried buildings and reviews the blasting opera- tions. DISCLAIMER: The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. All product names and trademarks cited are the property of their respective owners. The findings of this report are not to be construed as an official Department of the Army position unless so designated by other authorized documents. DESTROY THIS REPORT WHEN NO LONGER NEEDED. DO NOT RETURN IT TO THE ORIGINATOR. ERDC/CRREL TR-15-9 iii Contents Abstract .......................................................................................................................................................... ii Illustrations ..................................................................................................................................................... v Preface ......................................................................................................................................................... viii Acronyms and Abbreviations ..................................................................................................................... ix Unit Conversion Factors ...............................................................................................................................x Summary ........................................................................................................................................................ xi 1 South Pole Station ................................................................................................................................ 1 1.1 Introduction ..................................................................................................................... 1 1.2 Construction at South Pole ............................................................................................ 3 1.3 Original South Pole Station construction ....................................................................... 5 1.4 Snow maintenance ......................................................................................................... 8 1.5 Problem ......................................................................................................................... 12 1.6 Project objective............................................................................................................ 13 1.7 Technical approach ....................................................................................................... 13 1.8 Project scope................................................................................................................. 14 1.9 Safety ............................................................................................................................. 14 2 Field Testing ......................................................................................................................................... 15 2.1 Ground-penetrating radar equipment.......................................................................... 15 2.2 GPR methodology ......................................................................................................... 18 2.2.1 Establishing the survey grid ................................................................................................... 18 2.2.2 Conducting the GPR survey ................................................................................................... 21 2.3 Density profile with depth............................................................................................. 26 3 Results and Discussion ...................................................................................................................... 27 3.1 Interpretation of GPR profiles ...................................................................................... 27 3.2 Density with depth ........................................................................................................ 33 4 Blasting Operations ............................................................................................................................ 36 4.1 Hot water drilling ........................................................................................................... 37 4.2 Explosives ...................................................................................................................... 40 4.3 Blasting schedule ......................................................................................................... 41 4.4 Blast craters .................................................................................................................. 42 4.5 Seismic plots ................................................................................................................. 47 5 Conclusions .......................................................................................................................................... 51 6 Recommendations .............................................................................................................................. 53 ERDC/CRREL TR-15-9 iv References ................................................................................................................................................... 54 Appendix A: Core Data ............................................................................................................................... 56 Appendix B: Blasting Reports .................................................................................................................. 57 Report Documentation Page ERDC/CRREL TR-15-9 v Illustrations Figures 1 The geographic south pole at the USAP Amundsen-Scott South Pole Station with the Elevated Station, dedicated in 2008, in the background. It is the most modern of the permanent U.S. stations in Antarctica ............................................................... 1 2 A map of Antarctica showing the locations of the U.S. stations Byrd and South Pole, along with international station locations and territorial claims (Central Intelligence Agency 1986) ............................................................................................................. 2 3 Taken in 2000, the photograph shows the existing Dome station in relation to the placement of the compacted snow foundation prepared for the construction of the Elevated Station. The buried Old South Pole Station is outside of this view (approximately 0.75 miles to the left) (modified from