To Do: Migrate
Alaska hosts a wide range of archaeological site types, contexts, and research questions—ranging from Pleistocene hunters to historic mining. Search areas in the state are dauntingly vast, but with great potential for new discoveries. Efficient approaches to explore and identify past contexts are thus important. In spite of this, the value of geophysics as an aid to efficient research has only seen minimal use in Alaska. Ironically, the application of geophysical methods in Alaskan archaeology goes back to at least 1960, making it among the earliest test regions in North America for archaeological geophysics (Urban 2012; Urban 2016). Archaeologists J. Louis Giddings and Douglas D. Anderson made these first attempts with the use of electrical and magnetic methods on archaeological sites in northwest Alaska. During these surveys, frozen organic-rich sediments limited the usefulness of resistivity data and magnetic surveys were hindered by rapid diurnal fluctuations and magnetic disturbances in the Earth’s field at these high latitudes. Though recent attempts have met with much greater success, Arctic and sub-Arctic environments still pose special challenges to archaeo-geophysical investigations. These include a range of cryogenic disturbances that generate anomalies that can be mistaken for archaeological features, sites that are often remote or otherwise difficult to access, and the typical magnetic disturbances that occur at high latitudes. At the same time, geophysical methods offer great potential for site discovery and reconnaissance of known or suspected sites, and may also greatly extend the viable field season for archaeological research at these high latitudes. Geophysical methods also offer cultural resource managers in Alaska, home to vast swaths of public lands, a powerful set of tools for site assessment and monitoring in a rapidly changing environment (Urban et al. 2016b; Holt et al. 2016).
Example of magnetometer survey in Noatak National Preserve. NPS photo, J. Rasic. The system is being used with a single sensor on “search mode” to pinpoint an already detected magnetic anomaly for excavation.
A funding award from the National Center for Preservation Technology and Training facilitated the incorporation of geophysical survey methods into a number of ongoing archaeological field investigations and cultural resource management projects in Alaska. The funding provided supplementary support that tied many otherwise unrelated projects together by addressing broader methodological themes, consolidating travel and equipment, sharing personnel, and synthesizing results into more comprehensive findings. Participating projects were also funded by the National Park Service (through CESU agreements with Cornell University or direct resource management funds) and the National Science Foundation through new or existing grants that overlapped with the research period covered by the NCPTT funding. Originally designed to focus specifically on sites in the Alaskan Arctic, the field investigations expanded to include sites throughout the entire state as the broader project developed and specific needs emerged. The notion of having a single set of gear and field team moving among projects to provide technical support was based on the idea of efficiency and cost-effectiveness through resource sharing among many projects. In some instances the geophysical team, as outlined in the initial application, supported site dating in tandem with geophysical mapping. The latter was particularly true in cases where hearths or camp fires were located with geophysical methods and subsequently excavated.