The data collection will be conducted through the USGS Earth Mapping Resources Initiative (Earth MRI), a partnership between the USGS and state geological surveys that is revolutionizing our understanding of the nation’s geology and critical mineral resources, which are vital to the U.S. economy, national security and energy technology.  

“Earth MRI is collecting an unprecedented volume of foundational data, comprising multiple types of data across the nation with extensive focus on areas with potential for critical minerals,” said David Applegate, USGS director.

The airborne survey focus will cover a geologic region around the Kuskokwim River corridor, one of the state’s largest and most actively explored mineral belts. The entire region of interest spans approximately 40,000 square miles, roughly the size of Kentucky. The area is known to host a diverse variety of minerals such as antimony, which is primarily used in lead-acid batteries and flame retardants, zinc, which is used to galvanize steel, and tin and tungsten, which are primarily used in steel alloys and wear-resistant coverings, respectively.

The sheer size of Alaska, coupled with its wild terrain and severe weather, have left much of the Last Frontier underexplored for critical mineral potential. While previous geophysical surveys have offered scientists clues to the region’s prospectivity, officials say they were “postage-stamp size” areas compared to the vast coverage generated through Earth MRI. 

“Earth MRI allows us to fly the whole area at once and see a full regional perspective of how the mineral system works at the scale it operates,” said Evan Twelker, a mineral resources geologist at the Alaska Division of Geological and Geophysical Surveys (DGGS). “To see such a large mineral system across its full footprint is truly special.” 

Doug Kreiner, the Associate Center Director for geology at the USGS Alaska Science Center in Anchorage, Alaska, noted how Earth MRI has accelerated the data collection process. 

“An alternative technique for obtaining these measurements is walking the ground with a back-mounted sensor, which would presumably take decades or longer to collect the same amount of data,” said Kreiner. 

Following the survey, scientists will be able to see more than just the mineral belt in a new light. The survey’s foundational data will also inform scientists about the region’s tectonic history and fault structure, expanding on what’s known about potential natural hazards such as earthquakes. 

“This region is heavily covered by forest, so the geophysical surveys will allow us to ‘see’ the geology in a way it hasn’t been seen before. This is a seismically active area, so understanding the young faults and neo-tectonics will give us new insight into the potential hazards,” said Twelker. 

The airborne geophysical surveys will collect a combination of magnetic and radiometric data. These data can be used to map rocks from just beneath vegetation and shallow sediment cover down to thousands of feet underground. Magnetic data can be used to identify faults, lava flows, other geologic features and mineral deposits with distinct magnetic properties. Radiometric data indicate the relative amounts of potassium, uranium and thorium in shallow rocks and soil.  

Scientists use this information to help map rocks that may contain mineral deposits, faults that may rupture during an earthquake, areas that may be prone to increased radon and areas likely to contain groundwater or energy resources.

The initial airborne geophysical survey may be followed by additional investments, including new geologic maps, geochemical sampling, and other techniques to better understand the region’s geologic framework.

The geophysical survey design abuts two other survey footprints covering the Kuskokwim region, from which data are still being processed. 

In addition to this funding, the Alaska DGGS has invested an additional \$1.6 million to support bedrock geologic mapping, bringing the total investments in mapping Alaska to \$5.6 million.

Since 2021, the Bipartisan Infrastructure Law has advanced scientific innovation through a \$320 million investment for the USGS to better map the Nation’s mineral resources, both still in the ground and in mine wastes, and to preserve historical geologic data and samples. Through the end of fiscal year 2024, more than \$198 million has been obligated for Earth MRI initiatives, propelling efforts to make “once-in-a-generation” advancements in the nation’s geologic and geophysical data collections and mapping.