Developing a virtual tour of the Whaleback Anticline for mobile devices

We are developing a virtual field trip as an offline, mobile, self-guided, 3D, first-person-perspective tour of the Whaleback Anticline, a popular geology field-trip destination in the fold and thrust belt of central PA. Not only can an interactive virtual field trip educate users remotely, this digital experience can augment a visitor's field trip by conveying updated scientific findings. What are the essential capabilities of a mobile-app-based virtual tour? Because of its popularity and well-exposed geologic structures, the Whaleback site is an ideal case for such a discussion.

The sandstone surface of the Whaleback was excavated by coal mining, revealing a 20-m-high E-W-trending antiformal fold where visitors can walk on the hinge and adjacent to a 100-m span of the fold limbs. The fold contains outcrop-scale structures which record stages of the Alleghenian orogeny. However, accessing key features of the Whaleback requires traversing boulders, fallen trees, and a seasonal pond. Furthermore, the Whaleback is on private land, thus public access is constantly evolving.

We chose the format of a mobile app that users may download prior to visiting the Whaleback to operate our virtual tour offline. With drone-captured photos of the strip mine and structure-from-motion photogrammetry, we built a 3D polygonal mesh and an associated texture with raster color information of the 3D surface. We imported the mesh to Unity3D, an open-source game engine that is ubiquitous in game development. We simulate a first-person-perspective walking tour through the mesh terrain of the strip mine. Upon encountering key features, the user may tap a symbol that changes the game perspective to an ideal vantage point for observing the full extent of the geologic feature. Within the viewing frame, we incorporate supplementary text and images to convey scientific details.

As we continue our study of fold mechanics at Whaleback, we intend to share our research through this medium in tandem with traditional journal publications. Because the Bear Valley Strip Mine borders an off-road-vehicle trail network that hosts 1000+ annual visitors, there is a ready audience beyond geoscientists for this app. We look forward to engaging in a community dialogue about how best to build and effectively implement this developing medium for virtual tours.