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The Tanana River and Big Delta airborne magnetic and radiometric geophysical survey covers parts of the Big Delta, Charley River, Circle, Eagle, Fairbanks, Kantishna River, Livengood, Mount Hayes, and Tanacross quadrangles near Fairbanks and Delta Junction, Alaska (fig. 1). Magnetic and radiometric data were collected with a fixed-wing aircraft from May 14 to August 4, 2022, by MPX Geophysics LTD. The survey contains six individual blocks. A total of 97,386 line kilometers were collected. The six blocks total 33,095 km2; they cover 32,944 km2 due to overlap. The magnetometer was mounted to a rear-facing fixed boom ("tail stinger"). The radiometric crystals were located in the cabin of the aircraft. The Tanana, Chena, Healy, Eisen, and North Pole blocks were flown with a line spacing of 400 meters (m). Mean ground clearances were: Tanana, 188 m; Chena, 352 m; Healy, 295 m; Eisen, 430 m; North Pole, 180 m. The Eisen Infill block was flown with a line spacing of 200 m and a mean ground clearance of 422 m. [ABSTRACT FROM AUTHOR]

The White Mountains airborne magnetic and radiometric geophysical survey covers parts of the Livengood, Circle, and Fairbanks quadrangles 25 kilometers north of Fairbanks, Alaska (fig. 1). Magnetic and radiometric data were collected with a fixed-wing aircraft June 30 to August 22, 2021 by MPX Geophysics LTD. A total of 36,933 line kilometers were collected covering 13,423 square kilometers. The magnetometer was mounted to a rear-facing fixed boom ("tail stinger"). The radiometric crystals were located in the cabin of the aircraft. The White Mountains survey was flown with a line spacing of 400 meters (m) and a mean ground clearance of 270 m. [ABSTRACT FROM AUTHOR]

The Eagle airborne magnetic and radiometric geophysical survey covers parts of the Charley River, Eagle, and Tanacross quadrangles near Eagle, Alaska (fig. 1). Magnetic and radiometric data were collected with a fixed-wing aircraft May 24 to June 27, 2021 by MPX Geophysics LTD. A total of 26,926 line kilometers were collected covering 9,731 square kilometers. The magnetometer was mounted to a rear-facing fixed boom ("tail stinger"). The radiometric crystals were located in the cabin of the aircraft. The Eagle survey was flown with a line spacing of 400 meters (m) and a mean ground clearance of 330 m. [ABSTRACT FROM AUTHOR]

The mission of the Alaska Division of Geological & Geophysical Surveys (DGGS) is to determine the potential of Alaskan land for production of metals, minerals, fuels, and geothermal resources, the locations and supplies of groundwater and construction materials, and the potential geologic hazards to buildings, roads, bridges, and other installations and structures. To help fulfill this mission, DGGS geologists and scientists distribute public information through the creation of a wide variety of maps, digital data, and written reports. Maps play a crucial role in supporting DGGS' mission by helping geologists and scientists understand, interpret, and visualize Alaska's diverse geologic resources. Unfortunately, the overall look and feel of DGGS produced small-format maps are often inconsistent, particularly how map marginalia are included or excluded, placed, and designed. Such inconsistencies have the potential to create confusion for the user, leading to difficulties in orienting the map, measuring distances, identifying map symbols, or learning about the topic and important production information about the map. In addition, the overall appearance of some of the marginalia elements used on past DGGS maps do not conform to what is considered good cartographic design. The variation in map marginalia elements also contributes to the lack of cartographic consistency and continuity in the look and feel of the division's maps. The purpose of this Report of Investigation is to establish recommended designs for map marginalia and present guidelines for their inclusion, design, and placement. An extensive literature review was performed to compile and document accepted cartographic conventions for marginalia inclusion, design, and placement. A qualitative survey was developed and administered to gather user reactions to, and opinions about, DGGS marginalia elements. Results of the literature review and qualitative survey supported the establishment of recommended designs for map marginalia and guidelines for their inclusion and placement with the purpose of greatly increasing the consistency of DGGS smallformat maps and helping map makers critically think about the purpose, role, and considerations of each element on a map. These guidelines will offer DGGS map makers the flexibility to more easily and consistently create a variety of small-format maps that are recognizable as well-designed, professional, organizational products that have a consistent appearance, while supporting the DGGS' mission and meeting the needs of the map's intended users. [ABSTRACT FROM AUTHOR]

The Icy Cape airborne magnetic geophysical survey covers parts of Icy Cape, Alaska, which is located on the coast of the Gulf of Alaska near Icy Bay. Data were acquired by helicopter between August 20th and August 22nd, 2016, by Precision GeoSurveys Inc. The survey helicopter was equipped with a Scintrex cesium vapor CS-3 magnetometer, spectrometer, data acquisition system, magnetic compensation system, pilot guidance unit (PGU), and GPS navigation system. A Garmin VIRB XE video camera integrated with a GPS antenna was used to record the flight path video. In addition, two GEM GSM-19T magnetometer base stations with integrated GPS time synchronization were used to record diurnal magnetic variations. The survey area consists of four contiguous blocks covering an irregular area of 42.5 km by 19.1 km with 173 survey lines and 16 tie lines. The four blocks are centered 130 km northwest of Yakutat, Alaska, and cover a total of 520.8 square km. A total of 846.2 line-km were collected. [ABSTRACT FROM AUTHOR]

The Shaw Creek and Shawnee Peak airborne magnetic and radiometric geophysical survey covers parts of the Big Delta and Eagle quadrangles northeast of Delta Junction, Alaska (fig. 1). Magnetic and radiometric data were collected with a helicopter July 4-25, 2020 by MPX Geophysics LTD. A total of 10,100 line kilometers were collected over approximately 2,600 square kilometers. The magnetometer was mounted to a forward-facing fixed boom ("stinger"). The radiometric crystals were located in the cabin of the helicopter. Data were collected in eight named blocks. Mertie Mountains, Shaw Creek, and Volkmar River have a line spacing of 400 meters (m) and a mean ground clearance of 130 m. Stoneboy has a line spacing of 200 m and a mean ground clearance of 80 m. Eagle, Echo, Healy, and LMS-X have a line spacing of 100 m and a mean ground clearance of 80 m. [ABSTRACT FROM AUTHOR]

The Holitna airborne magnetic geophysical survey covers the Holitna basin, located in the Sleetemute and Lime Hills quadrangles surrounding the town of Stony River in southwest Alaska. Magnetic data were collected September 8th to October 7th 1997. A total of 13,658 line kilometers were collected covering 9,229.1 square kilometers. Line spacing was 800 meters (m). Data were collected using a fixed wing aircraft with a mean ground clearance of 90 m. PURPOSE These data were collected to assist the state in assessing the hydrocarbon potential of the Holitna basin area. The aeromagnetic data was intended to be interpreted and integrated with available geoscience data. SURVEY OVERVIEW DESCRIPTION This document provides an overview of the survey and includes text and figures of select primary and derivative products of this survey. A table of digital data packages available for download is provided to assist users in data selection. For reference, a catalog of the available maps is presented in reduced resolution. Please consult the metadata, project report, and digital data packages for more information and data. [ABSTRACT FROM AUTHOR]

The airborne magnetic geophysical survey of the Bethel Basin, Alaska is located in the Bethel, Baird Inlet, Russian Mission, and Marshall quadrangles near the town of Bethel in southwest Alaska. Magnetic data were collected during October 1996 by Sanders Geophysics Ltd. and August 1994 by GEONEX Aero Service and its subsidiaries. A total of 20,915 line kilometers were collected covering 14,953 square kilometers. Line spacing was 800 meters (m). Data were collected using a fixed-wing aircraft with a median ground clearance of 90 m. [ABSTRACT FROM AUTHOR]

The Stikine geophysical survey is located in southeast Alaska near the city of Wrangell, about 175 kilometers south of Juneau, Alaska. Frequency domain electromagnetic and magnetic data were collected with the DIGHEMV system from March to May 1997. A total of 8,097 line kilometers were collected covering 2,870.1 square kilometers. Line spacing was 400 meters (m). Data were collected approximately 30 m above the ground cover or tree canopy from a helicopter-towed sensor platform ("bird") on a 30-m-long line. The large trees and steep terrain resulted in an average ground clearance of 150 m. [ABSTRACT FROM AUTHOR]

The Southern NPRA electromagnetic and magnetic airborne geophysical survey is located in northwest Alaska in the southern National Petroleum Reserve-Alaska, about 320 kilometers south of the City of Utqiaġvik. Frequency domain electromagnetic and magnetic data were collected with the DIGHEMV system from July to August 2005. A total of 11,115 line kilometers were collected covering 3,947.9 square kilometers. Line spacing was 400 meters (m) and 200 m over the Drenchwater area. Data were collected with an average ground clearance of 35 m from a helicopter towed sensor platform ("bird") on a 30-m-long line. [ABSTRACT FROM AUTHOR]

This geophysical survey is located in southeast Alaska in the Ketchikan area, about 350 kilometers south of Juneau, Alaska. Frequency domain electromagnetic and magnetic data were collected with the DIGHEMV system in May 1992. A total of 679 line kilometers were collected covering 133.6 square kilometers. Line spacing was 200 meters (m). Data were collected approximately 30 m above the ground cover or tree canopy from a helicopter-towed sensor platform ("bird") on a 30-m-long line. The large trees and steep terrain resulted in an average ground clearance of 150 m. [ABSTRACT FROM AUTHOR]

Field investigations in the Parks Highway, Minto Flats, and Dalton Highway infrastructure corridors were conducted by the Alaska Division of Geological & Geophysical Surveys (DGGS) to support engineering-geologic decisions related to the planning, routing, and construction of future infrastructure development. Airphoto and lidar hillshade interpretations, helicopter surveys, and ground reconnaissance surveys were conducted in the ~700-mi-long by ~1-mi-wide corridor between Cook Inlet and Prudhoe Bay to develop information about landscape geomorphology and evaluate potential geologic hazards. The corridor crosses diverse terrain, several major mountain ranges, and 12 physiographic provinces. We identified a wide variety of geologic hazards along the corridor that are a product of local geomorphic conditions. This report documents our Quaternary geologic observations from the 2011, 2012, and 2013 field seasons and includes maps identifying specific geologic hazards in the infrastructure corridor. The methodology employed during this investigation, specifically concerning the evaluation of a long, relatively narrow swath across variable terrain, can be applied to other infrastructure corridor studies in Alaska and elsewhere. [ABSTRACT FROM AUTHOR]

Field investigations in the Parks Highway, Minto Flats, and Dalton Highway infrastructure corridors were conducted by the Alaska Division of Geological & Geophysical Surveys (DGGS) to support engineering-geologic decisions related to the planning, routing, and construction of future infrastructure development. Airphoto and lidar hillshade interpretations, helicopter surveys, and ground reconnaissance surveys were conducted in the ~700-mi-long by ~1-mi-wide corridor between Cook Inlet and Prudhoe Bay to develop information about landscape geomorphology and evaluate potential geologic hazards. The corridor crosses diverse terrain, several major mountain ranges, and 12 physiographic provinces. We identified a wide variety of geologic hazards along the corridor that are a product of local geomorphic conditions. This report documents our Quaternary geologic observations from the 2011, 2012, and 2013 field seasons and includes maps identifying specific geologic hazards in the infrastructure corridor. The methodology employed during this investigation, specifically concerning the evaluation of a long, relatively narrow swath across variable terrain, can be applied to other infrastructure corridor studies in Alaska and elsewhere. [ABSTRACT FROM AUTHOR]