ALBERT

Anmerkung: CONTENTS Preface Abstract Chapter I. Introduction to problem 1. Previous attempts at blasting frozen ground 2. Necessity for fundamental approach 3. Terminology 4. Description, objectives, and scope of the Keweenaw Tests 5. Selection of explosives 6. Classification and properties of commercial explosives 7. Characteristics of explosives in the Keweenaw Tests 8. Comparison of Atlas, Hercules, and Du Pont nitroglycerine-base explosives Chapter II. Test program Section I. Field tests 1. General 2. Test site 3. Field test procedure a. Site preparation b. Instrumentation c. Snow removal d. Determining depth of frozen ground e. Soil sampling and coring f. Layout of the test site g. Spacing of blast holes h. Blast-hole drilling i. Blasting procedure j. Field analysis and crater surveys k. Data-sheet computations l. Photography Section II. Laboratory tests 1. Soil handling and storage 2. Soil classification tests a. Specimen preparation b. Test procedure c. Test results 3. Tests to determine stress-strain relationship a. General b. Specimen preparation for unconfined compression tests c. Test procedure d. Results e. Observations Chapter III. Analysis of blast tests Section I. Mechanics of crater formation in frozen Keweenaw silt 1. Introduction 2. Shock phenomena 3. Expansion of the gas bubble 4. Rupture of surface and conversion of pressure head to velocity head Section II. Blast Test A - Relationships of explosive, radius of crater, volume of crater, and depth of crater 1. Introduction 2. Description 3. Results and analysis 4. Summary of observations Section Ill. Blast Test B - Energy utilization in blasting 1. Introduction 2. Description 3. Results and analysis 4. Summary of observation Section IV. Blast Test C - The frozen-ground interface 1. Introduction 2. Relation of frozen-ground interface to scaling laws 3. Relation between the ratio of chamber volume to crater volume and the volume-utilization factor 4. Increase in volum.e-utilization factor for charges placed below the frozen layer 5. Position of the gas bubble relative to the frozen-ground interface 6. Igloo-type foxhole construction Section V. Blast Test D - Foxhole construction 1. Introduction 2. Application of shaped charges to foxhole construction 3. Application of hand-auget drilling to foxhole construction 4. Conclusions Section VI. Blast Test E - Temperature effect 1. Introduction 2. Description 3. Results and analysis 4. Summary of observations Section VII. Blast Test F - Effect of charge shape 1. Introduction 2. Description 3. Conclusions Chapter IV. Summary of objectives; conclusions and recommendations Section I. Summary of objectives 1. Introduction 2. Objective 1: Most efficientt type of explosive for blasts in frozen ground 3. Objective 2: Fundamental relation between weight of explosive and depth of charge 4. Objective 3: Proper position of charge relative to the frozen-ground interface 5. Objective 4: Feasibility of fracturing the frozen layer by placing a charge in the underlying unfrozen material 6. Objective 5: Effect of diameter of the borehole and shape of charge on results of blasting Section II. Conclusions and recommendations 1. Feasibility of using explosives for constructing foxholes in frozen ground 2. Methods of placing the charge 3. Mechanics of crater formation 4. The crater equation 5. Future instrumentation 6. Classification of explosives 7. Correlation of blast data Appendix: Data sheets, Experiments 1-13

Anmerkung: Contents I. Introduction, by H. Bader II. Excavation of trenches and tunnels, by R.W. Waterhouse III. Excavation of deep pit, by J.K. Landauer IV. Trench covering, framing, and instrumentation, by R.W. Waterhouse V. The snow house, by R.W. Waterhouse VI. Load measurements in the N-S trench, by R.W. Waterhouse VII. Deformation measurements, by J.K. Landauer VIII. Distance changes on the ice cap, by B.L. Hansen and H. Bader IX. Annual accumulation, by H. Bader X. Snow density and snow load in deep pit, by J.K. Landauer XI. Air permeability of snow from deep pit, by J.A. Bender XII. Viscosity of snow from deep pit, by J.K. Landauer XIII. Crushing strength of snow from deep pit, by T.R. Butkovich XIV. Shear strength of snow from deep pit, by T.R. Butkovich XV. Tensiel strength of snow from deep pit, by T.R. Butkovich XVI. Angle of internal friction of snow from deep pit, by T.R. Butkovich XVII. Snow temperatures, by J.K. Landauer

Anmerkung: Table of Contents: List of contributors. - Cryosphere Science: Series Preface. - Preface. - Acknowledgments. - About the companion website. - 1 Remote sensing and the cryosphere. - 1.1 Introduction. - 1.2 Remote sensing. - 1.2.1 The electromagnetic spectrum and blackbody radiation. - 1.2.2 Passive systems. - 1.2.3 Active systems. - 1.3 The cryosphere. - References. - 2 Electromagnetic properties of components of the cryosphere. - 2.1 Electromagnetic properties of snow. - 2.1.1 Visible/near-infrared and thermal infrared. - 2.1.2 Microwave region. - 2.2 Electromagnetic properties of sea ice. - 2.2.1 Visible/near-infrared and thermal infrared. - 2.2.2 Microwave region. - 2.3 Electromagnetic properties of freshwater ice. - 2.4 Electromagnetic properties of glaciers and ice sheets. - 2.4.1 Visible/near-infrared and thermal infrared. - 2.4.2 Microwave region. - 2.5 Electromagnetic properties of frozen soil. - 2.5.1 Visible/near-infrared and thermal infrared. - 2.5.2 Microwave region. - References. - Acronyms. - Websites cited. - 3 Remote sensing of snow extent. - 3.1 lntroduction. - 3.2 Visible/near-infrared snow products. - 3.2.1 The normalized difference snow index (NDSI). - 3.3 Passive microwave products. - 3.4 Blended VNIR/PM products. - 3.5 Satellite snow extent as input to hydrological models. - 3.6 Concluding remarks. - Acknowledgments. - References. - Acronyms. - Websites cited. - 4 Remote sensing of snow albedo, grain size, and pollution from space. - 4.1 Introduction. - 4.2 Forward modeling. - 4.3 Local optical properties of a snow layer. - 4.4 Inverse problem. - 4.5 Pitfalls of retrievals. - 4.6 Conclusions. - Acknowledgments. - References. - Acronyms. - Websites cited. - 5 Remote sensing of snow depth and snow water equivalent. - 5.1 Introduction. - 5.2 Photogrammetry. - 5.3 LiDAR. - 5.4 Gamma radiation. - 5.5 Gravity data. - 5.6 Passive microwave data. - 5.7 Active microwave data. - 5.8 Conclusions. - References. - Acronyms. - Websites cited. - 6 Remote sensing of melting snow and ice. - 6.1 Introduction. - 6.2 General considerations on optical/thermal and microwave sensors and techniques for remote sensing of melting. - 6.2.1 Optical and thermal sensors. - 6.2.2 Microwave sensors. - 6.2.3 Electromagnetic properties of dry and wet snow. - 6.3 Remote sensing of melting over land. - 6.4 Remote sensing of melting over Greenland. - 6.4.1 Thermal infrared sensors. - 6.4.2 Microwave sensors. - 6.5 Remote sensing of melting over Antarctica. - 6.6 Conclusions. - References. - Acronyms. - 7 Remote sensing of glaciers. - 7.1 Introduction. - 7.2 Fundamentals. - 7.3 Satellite instruments for glacier research. - 7.4 Methods. - 7.4.1 Image classification for glacier mapping. - 7.4.2 Mapping debris-covered glaciers. - 7.4.3 Glacier mapping with SAR data. - 7.4.4 Assessing glacier changes. - 7.4.5 Area and length changes. - 7.4.6 Volumetrie glacier changes. - 7.4.7 Glacier velocity. - 7.5 Glaciers of the Greenland ice sheet. - 7.5.1 Surface elevation. - 7.5.2 Glacier extent. - 7.5.3 Glacier dynamics. - 7.6 Summary. - References. - Acronyms. - Websites cited. - 8 Remote sensing of accumulation over the Greenland and Antarctic ice sheets. - 8.1 Introduction to accumulation. - 8.2 Spaceborne methods for determining accumulation over ice sheets. - 8.2.1 Microwave remote sensing. - 8.2.2 Other remote sensing techniques and combined methods. - 8.3 Airborne and ground-based measurements of accumulation. - 8.3.1 Ground-based. - 8.3.2 Airborne. - 8.4 Modeling of accumulation. - 8.5 The future for remote sensing of accumulation. - 8.6 Conclusions. - References. - Acronyms. - Website cited. - 9 Remote sensing of ice thickness and surface velocity. - 9.1 Introduction. - 9.1.1 Electrical properties of glacial ice. - 9.2 Radar principles. - 9.2.1 Radar sounder. - 9.2.2 Radar equation. - 9.3 Pulse compression. - 9.4 Antennas. - 9.5 Example results. - 9.6 SAR and array processing. - 9.7 SAR Interferometry. - 9. 7.1 Introduction. - 9.7.2 Basic theory. - 9.7.3 Practical considerations of InSAR systems. - 9.7.4 Application of InSAR to Cryosphere remote sensing. - 9.8 Conclusions. - References. - Acronyms. - 10 Gravimetry measurements from space. - 10.1 Introduction. - 10.2 Observing the Earth's gravity field with inter-satellite ranging. - 10.3 Surface mass variability from GRACE. - 10.4 Results. - 10.5 Conclusions. - References. - Acronyms. - 11 Remote sensing of sea ice. - 11.1 Introduction. - 11.2 Sea ice concentration and extent. - 11.2.1 Passive microwave radiometers. - 11.2.2 Active microwave - scatterometry and radar. - 11.2.3 Visible and infrared. - 11.2.4 Operational sea ice analyses. - 11.3 Sea ice drift. - 11.4 Sea ice thickness and age, and snow depth. - 11.4.1 Altimetric thickness estimates. - 11.4.2 Radiometric thickness estimates. - 11.4.3 Sea ice age estimates as a proxy for ice thickness. - 11.5 Sea ice melt onset and freeze-up, albedo, melt pond fraction and surface temperature. - 11.5.1 Melt onset and freeze-up. - 11.5.2 Sea ice albedo and melt pond fraction. - 11.5.3 Sea ice surface temperature. - 11.6 Summary, challenges and the road ahead. - References. - Acronyms. - Website cited. - 12 Remote sensing of lake and river ice. - 12.1 Introduction. - 12.2 Remote sensing of lake ice. - 12.2.1 Ice concentration, extent and phenology. - 12.2.2 Ice types. - 12.2.3 Ice thickness and snow on ice. - 12.2.4 Snow/ice surface temperature. - 12.2.5 Floating and grounded ice: the special case of shallow Arctic/sub-Arctic lakes. - 12.3 Remote sensing of river ice. - 12.3.1 Ice extent and phenology. - 12.3.2 lce types, ice jams and flooded areas. - 12.3.3 Ice thickness. - 12.3.4 Surface flow velocities. - 12.3.5 Incorporating SAR-derived ice information into a GIS-based system in support of river-flow modeling and flood forecasting. - 12.4 Conclusions and outlook. - Acknowledgments. - References. - Acronyms. - Websites cited. - 13 Remote sensing of permafrost and frozen ground. - 13.1 Permafrost - an essential climate variable of the "Global Climate Observing System". - 13.2 Mountain permafrost. - 13.2.1 Remote sensing of surface features and permafrost landforms. - 13.2.2 Generation of digital elevation models. - 13.2.3 Terrain elevation change and displacement. - 13.3 Lowland permafrost - identification and mapping of surface features. - 13.3.1 Land cover and vegetation. - 13.3.2 Permafrost landforms. - 13.3.3 Landforms and processes indicating permafrost degradation. - 13.4 Lowland permafrost - remote sensing of physical variables related to the thermal permafrost state. - 13.4.1 Land surface temperature through thermal remote sensing. - 13.4.2 Freeze-thaw state of the surface soil through microwave remote sensing. - 13.4.3 Permafrost mapping with airborne electromagnetic surveys. - 13.4.4 Regional surface deformation through radar interferometry. - 13.4.5 A gravimetric signal of permafrost thaw?. - 13.5 Outlook - remote sensing data and permafrost models. - References. - Acronyms. - 14 Field measurements for remote sensing of the cryosphere. - 14.1 Introduction. - 14.2 Physical properties of interest. - 14.2.1 Surface properties. - 14.2.2 Sub-surface properties. - 14.3 Standard techniques for direct measurements of physical properties. - 14.3.1 Topography. - 14.3.2 Snow depth. - 14.3.3 Snow water equivalent and density. - 14.3.4 Temperature. - 14.3.5 Stratigraphy. - 14.3.6 Sea ice depth and ice thickness. - 14.4 New techniques for high spatial resolution measurements. - 14.4.1 Topography. - 14.4.2 Surface properties. - 14.4.3 Sub-surface properties. - 14.5 Simulating airborne and spaceborne observations from the ground. - 14.5.1 Active microwave. - 14.5.2 Passive microwave. - 14.6 Sampling strategies for remote sensing field campaigns: concepts and examples. - 14.6.1 Ice sheet campaigns. - 14.6.2 Seasonal snow campaigns. - 14.6.3 Sea ice campaigns. - 14.7 Conclusions. - References. - Acronyms. - Websites cited. - 15 Remote sensing missions and the cryosphere. - 15.1 In

Anmerkung: Contents: 1. Introduction. - (1) The purposes of the long-term plan report. - (2) The background and particulars of this report. - (3) Contents of this report. - 2.Changes in the Arctic environment to date and in the near future. - 3. History of Arctic environmental research. - 4. Abstracts of all themes. - (1) Elucidation of abrupt environmental change in the Arctic associated with the on-going global warming. - Theme 1: Arctic amplification of global warming. - Theme 2: Mechanisms and influence of sea ice decline. - Theme 3: Biogeochemical cycles and ecosystem changes. - Theme 4: Ice sheet, glaciers, permafrost, snowfall, snow cover and hydrological cycle. - Theme 5: Interactions between the Arctic and the entire earth. - Theme 6: Predicting future environmental conditions of the Arctic based on paleoenvironmental records. - Theme 7: Effects of the Arctic environment on human society. - (2) Elucidation of environmental change concerning biodiversity. - Theme 8: Effects on terrestrial ecosystems and biodiversity. - Theme 9: Influence on marine ecosystem and biodiversity. - (3) Broad and important subjects on the Arctic environment. - Theme 10: Geospace environment. - Theme 11: Interaction of surface environment change with solid earth. - Theme 12: Basic understanding on formation and transition process of permafrost. - (4) Development of methods enabling breakthroughs in environmental research. - Theme A: Sustainable seamless monitoring. - Theme B: Earth system-modeling for inter-disciplinary research. - Theme C: Data assimilation to connect monitoring and modeling. - 5. Improvement of research foundation. - Authors and reviewers.