Terrestrial Gas Hydrate Characterization in Alaska North Slope: Exploring New Ideas and Research Directions

Research on gas hydrates, especially on on-shore gas hydrates, is still limited. Though extensive gas hydrate deposits exist beneath the Alaska North Slope (ANS) infrastructure, the exact location, extent, nature, and stability of these accumulations and their feasibility for serving as alternate energy resource are not fully understood.

ANS is a remote, harsh and logistically difficult terrain to work in. Consequently, it is not feasible or economic to use only field-based techniques for gas hydrate characterization in ANS. The Bureau of Land Management, the US Geological Survey and the University of Alaska Fairbanks have been working together since 2004 on alternative methods to evaluate and predict gas hydrate occurrences. Our approach includes mapping zones of hydrocarbon enrichment, and permafrost related landscape elements such as pingos, using remote sensing techniques and limited field work. We hypothesize that these features may be related to hydrocarbon rich fluid migration to the surface along open subsurface fault systems.

Research results show that while shallow gas geochemistry, hydrocarbon microseepages, and gases trapped in frozen lake ice all indicate that hydrocarbon rich fluids are reaching the surface, our original hypothesis that these anomalies are directly related to mapped subsurface open fault systems is too simple to capture the complexity of the real world processes. Recommendations for further research in gas hydrate characterization include using airborne hyperspectral data to collect a more robust dataset around known surface hydrocarbon seepages to further evaluate the linkage between these seeps and surficial landforms; collating and analyzing existing 3-D seismic data and stratigraphic data to further our understanding of the distribution of leaky faults and gas hydrate accumulations. Integration of all these data sets will lead to more robust modeling of the connection between surface seeps and landforms, gas hydrate occurrences and potential migration pathways.