"The Alaska Division of Geological & Geophysical Surveys completed surficial-geologic mapping, lidar data evaluations, and paleoseismic trenching investigations along the Minto Flats seismic zone (Minto fault), the Northern Foothills thrust and associated backthrust faults, and the Stampede–Little Panguingue Creek, Healy Creek, Healy, Park Road, Denali, and Castle Mountain faults. Additionally, aerial reconnaissance and lidar assessment were completed along the Tozitna, Kaltag Extension, and Victoria Creek faults. The purpose of these investigations was to summarize the relative tectonic activity for each structure of concern, evaluate fault rupture parameters, and delineate the locations of possible fault crossings of the proposed pipeline route"-- Summary and conclusions.

Helicopter and ground reconnaissance surveys were conducted in the Yukon River area in the northwestern Livengood Quadrangle to assess the locations and relative activity of tectonic faults that could pose hazards to the Dalton Highway and proposed future infrastructure developments. Previously identified faults were evaluated, including the Victoria Creek fault (southern, middle, and northern strands), the Kaltag Extension fault, and the Tozitna fault. Several unnamed faults and the Hess Creek and Ray River lineaments were also investigated. The results indicate that none of the faults and lineaments investigated are expressed in Holocene deposits and none exhibit tectonic geomorphic features that indicate Quaternary deformation. High rates of geomorphic processes, low rates of tectonic deformation, and thick vegetative cover may inhibit the recognition of tectonic geomorphology. Future investigations using high-resolution topographic datasets would provide an opportunity to validate the conclusions.

Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 179. This multidisciplinary monograph provides the first modern integrative summary focused on the most spectacular active tectonic systems in North America. Encompassing seismology, tectonics, geology, and geodesy, it includes papers that summarize the state of knowledge, including background material for those unfamiliar with the region; address global hypotheses using data from Alaska; and test important global hypotheses using data from this region. It is organized around four major themes: subduction and great earthquakes at the Aleutian Arc, the transition from strike slip to accretion and subduction of the Yakutat microplate, the Denali fault and related structures and their role in accommodating permanent deformation of the overriding plate, and regional integration and large-scale models and the use of data from Alaska to address important global questions and hypotheses. The book's publication near the beginning of the National Science Foundation's EarthScope project makes it especially timely because Alaska is perhaps the least understood area within the EarthScope footprint, and interest in the region can be expected to rise with time as more EarthScope data become available.

Reports on a Alaska Division of Geological & Geophysical Surveys multi-year geologic project which was focused on a corridor along the Alaska Highway between Delta Junction and the Canada border. This project provided information, including active fault hazards, is relevant to a proposed Alaska-Canada natural gas pipeline and other future development in the corridor.

I have identified evidence for potentially active northeast-striking faults in the greater Fairbanks area and have developed a model for their evolution that defines the character of faults and timing of structural events. Seismicity, topographic data, and geological and geophysical maps show that potentially active faults correspond with previously mapped bedrock faults, topographic lows, and magnetic anomalies. Seismicity indicates that faults in Interior Alaska have low to moderate tectonic activity; geomorphic and structural analyses of mapped faults indicate they are dominantly left-lateral strike-slip, but have smaller normal or reverse components. The normal component of slip increases to the west toward the Nenana basin based on tilted fault block geometries observed in seismicity. Deformed Pliocene to Quaternary strata, placer deposits presumably related to tectonic-induced stream capture events, and geomorphic anomalies such as valley and basin asymmetry, barbed drainages, and changes in river morphology all suggest Pliocene-Quaternary tectonic activity along northeast-striking left-lateral faults. Northeast-striking faults have been at least episodically active since the late Cretaceous. Northeast-striking fault-hosted gold deposits related to ~90 Ma intrusions suggest that fault parallel extension fractures or tension veins formed at ~90 Ma during a period of northwest-southeast extension. Thermochronological data are consistent with exhumation at ~56-42 Ma, possibly resulting from dextral shearing between the Denali and Tintina faults. Northeast-striking faults were reactivated as normal faults along pre-existing extensional trends. Thermochronological data suggest that strike-slip displacement on the Tintina fault significantly decreased at ~42 Ma. However, dip-slip motion continued along northeast-striking faults after 42 Ma as a result of contraction related to northward plate convergence. Drainage restorations, high-levels of background seismicity, and focal mechanisms support the hypothesis that at ~6 Ma, significant left-lateral motion occurred along northeast-striking faults and has continued to the present.