While the growing abundance of remote sensing platforms has dramatically improved the ability to measure the Earth’s surface, research into the subsurface remains hindered by data scarcity. Borehole and well data, where available, represent invaluable but spatially limited windows into geologic and hydrogeologic conditions, and it can be difficult to assess variability between these points.
Obtaining timely, accurate information on streamflow in Alaska’s rivers is difficult because gaging stations are sparse, with many located in remote inaccessible areas. Even for established gages, the maintenance and periodic measurements required to operate a gage are logistically challenging and can place personnel at risk, particularly during high flows.
The goal of the 3D Elevation Program (3DEP) is to complete acquisition of nationwide lidar (Interferometric Synthetic Aperture Radar (IfSAR) in Alaska) in 8 years to provide the first-ever national baseline of consistent high-resolution elevation data—both bare earth and 3D point clouds—collected in a timeframe of less than a decade.
This project focuses on the illegal artisanal and small-scale mining (ASM) of small and low-grade mineral and gemstone deposits. Project scientists employ field mapping, geomorphological techniques, and remote sensing to map, monitor, and evaluate mineral deposits and ASM activities in conflict zones and during complex emergencies.
The USGS presently operates 102 streamgaging stations distributed throughout Alaska. As many of these stations are quite remote, considerable effort is needed to collect periodic measurements and maintain gages. Thus, developing remote sensing methods for measuring streamflow in this vast, largely inaccessible State is valuable for many reasons.
The potential for gravitational and explosion-driven collapse is one of the greatest hazards of lava dome eruptions. Topographic modeling of active lava domes is useful for detecting changes that may influence collapse or explosive activity. It also provides constraints on the volume of potentially collapsible material, a key parameter of effective hazard assessment.
The NPS, Arctic Inventory and Monitoring Network (ARCN) is using 35-mm aerial photography to monitor the growth of permafrost thaw slumps in the five national parks of northern Alaska. These slumps can grow for a decade or longer and shed large amounts of sediment into nearby rivers and lakes. ARCN scientists have obtained overlapping, oblique and vertical, digital aerial photographs of 15 slumps taken from a helicopter or fixed-wing aircraft in a 4 to 7 year span between 2008 and 2016.
The USGS Cascades Volcano Observatory utilizes oblique and vertical aerial photography to monitor topographic changes at Mount St. Helens volcano.
The Hawaiian Volcano Observatory continues to rely heavily on satellite and airborne remote sensing data for monitoring and research of Kilauea Volcano’s ongoing summit and East Rift Zone eruptions.
Groundwater research is often hindered by the scarcity of information about the subsurface, leading to uncertainty in groundwater model predictions and resource management decisions. Borehole and well data, where available, represent invaluable but spatially limited windows into the hydrogeologic conditions at depth, and it can be difficult to assess how conditions change between these points. To fill in the gaps, the USGS has been using airborne electromagnetic (AEM) methods as part of a number of groundwater-resource and related studies. AEM data can be used to develop spatially compre