Geophysical Mapping: Problem Details 20 of 39 Problem Name: Ice thickness Problem Type: Natural Hazards Assigned Methods: + Borehole imaging, Structure logging Borehole Methods + DC geoelectrics - Sounding Electrical Methods + Electrical and induction logging Borehole Methods + Ground penetrating radar (surface-based) Electromagnetic Methods + Nuclear logging Borehole Methods + Shallow reflection seismics Seismic Techniques + Standard refraction seismics Seismic Techniques + Very-high resolution reflection seismics Seismic Techniques 0 Acoustic logging Borehole Methods 0 Geoelectrics - Tomography (surface based) Electrical Methods 0 Land gravity Gravity 0 Refraction seismic tomography (surface-based) Seismic Techniques 0 Seismic surface waves methods Seismic Techniques 0 Time-domain electromagnetics - Profiling Electromagnetic Methods 0 Time-domain electromagnetics - Sounding Electromagnetic Methods    '+' = Technique applicable; '0' = Application possible/limited use