Google Earth was launched in 2005 (Google 2005) and to date over 1 billion people across the globe have downloaded it (Google 2011). As well as providing detailed satellite and aerial imagery, the platform provides the user with a web-based geographical information systems (GIS) tool, while allowing the import of external data sources in a Keyhole Markup Language (KML) format, an Extensible Markup Language (XML) based script, that aids the user in managing three-dimensional geospatial data in the software (Stefanakis and Patroumpas 2008). Google Earth also allows the user to integrate a number of interactive features such as 3D buildings, place markers, image overlays and virtual tours. This functionality provides a powerful tool that can be used to display and disseminate information and data. Within the application itself, Google Earth provides base mapping in the form of high-resolution satellite imagery from multiple time periods. There are also ten primary data layers for users to use and explore including: Borders and Labels; Places; Photos; Roads; 3D Buildings; Ocean; Weather; Gallery; and Global Awareness.
Google Earth first entered use in archaeology as a prospection tool, when it provided imagery for sites where remotely sensed data was missing or hard to access (Beck 2006; Myers 2010; National Geographic 2006; New Scientist 2011; Sadr and Rodie 2012; Scollar and Palmer 2008; Ullmann and Gorokhovich 2006; YouTube 2014). In recent years, the most common use of Google Earth in archaeology is rapidly becoming one of dissemination. A variety of projects have started to post layers containing basic information on cognate groups of archaeological sites. Examples include those created by the Archaeological Institute of America for the United States and Canada; the Atlas of Rural Settlement in England GIS; and the Defence of Britain Archive (Council for British Archaeology 2006).
The potential for Google Earth in archaeology was recognised early on by Ur (2006), who noted the strength of the new software lay at its interface with students and the interested public, and its use within the classroom. Since this time, continual improvements and updates have seen a rise in the possibilities of it as a data dissemination and engagement tool for archaeology. With an ability to reach mass audiences, it has been noted how Google Earth crosses several key thresholds in communicating archaeological information, taking it beyond the realm of conventional spatial data and geographic information systems, and engaging more complex dimensions of human perception and aesthetic preference (Beck 2006; Sheppard and Cizek 2009; Ullmann and Gorokhovich 2006). A particular strength was the ability to provide a way of visualising and interpreting landscape and archaeological sites by contributing to an appreciation of the wider geographical context (Beck 2006).
Google itself has been keen to encourage data dissemination via Google Earth, and created the Google Faculty Research Awards program, which aims to 'identify and support world-class, full-time faculty pursuing research in areas of mutual interest' (Google 2014). A suite of grants have resulted in a variety of science-based projects being created for Google Earth that primarily seek to disseminate information about a specific subject, while providing a spatial context within the virtual globe. The Google Earth Gallery and Google Earth Outreach pages provide repositories for users to download and engage with these data.
Within the Google Earth Gallery there are over 150 projects within the 'Culture and Society' and 'Historical' categories. The majority are focused on cartographic and geographic information, and those that link directly to archaeological sites are rare. Situated within the Outreach pages, a notable exception is the Global Heritage Fund, with interactive layers that can be opened within Google Earth to display text-based information, images and polygons of heritage sites and monuments found in the Americas, Asia and Pacific, Europe, Middle East and Africa. There are also a few sites that are hosted outside of Google. Examples include the Archaeology of Lower Egypt projects, and the reconstruction of proto-historic Maori land use in the Banks Peninsula, New Zealand.
Download the Seeing Beneath Stonehenge KMZ (view using Google Earth)
The ever-increasing quantities of primary digital data being collected directly by archaeologists in the field, coupled with the desire to further communicate and engage about discoveries with the public, suggest that Google Earth is perhaps now more than ever an exciting medium that the archaeological community could engage with more fully. This view is explored using a case study based on the creation of Seeing Beneath Stonehenge, a project funded by a Google Research Award and focused on disseminating the results of the Stonehenge Riverside Project (Parker Pearson 2012).