Starting in March 2020, safety measures to dampen the transmission of COVID-19 impacted field instruction related to geoscience education. While the COVID-19 pandemic forced geoscience educators to design alternatives to in-person field instruction, this demand for remote instruction also highlighted the shortcomings of the traditional geoscience curriculum to include students who, for a multitude of reasons, have difficulties accessing traditional field-based coursework (e.g., Wolfe and Riggs, 2017; Carabajal et al., 2017). The need for educational experiences that incorporate fundamentals traditionally taught in field-based courses will remain after the pandemic. Such educational experiences might be deployed for the purpose of inclusion or for skill development in data collection and analysis as an alternative or precursor to traditional field courses.

Historically, the emergence of geoscience in Europe and North America was closely tied to objective descriptions of outcrops and discussion of the observations in the field (e.g., Hallam, 1990). The practice dates from at least the time of James Hutton in the late 1780s (e.g., Gould, 1982), and the tradition continues in modern field conferences (e.g., Evenson et al., 2000) and field trips associated with professional geoscience assemblies (e.g., Lageson et al., 1999). Contemporary geology education recapitulates this process, with bachelor degrees commonly culminating in a required capstone field course (Whitmeyer et al., 2009).

In the Department of Earth and Space Sciences at the University of Washington (UW), capstone field instruction includes components of objective rock description at outcrops and the measurement of bedding orientation and other structural data for the purpose of mapping, constructing cross-sectional interpretations from maps, and interpreting a geologic history from the observed data. A course typically taken in the first year of the major also includes these components in a staged, fictional scenario with hand samples in the classroom. Remote learning mandates related to the COVID-19 pandemic precluded field or classroom instruction, and we sought alternative approaches that could address at least some of the original learning goals of these exercises.

We designed video-game-style exercises to provide a three-dimensional, first-person perspective, virtual field experience accessible via standard internet browsers. Here, we present two examples of virtual field experiences that we implemented during the COVID-19 pandemic for remote instruction in (1) the department's capstone field course as part of a module on folding and (2) an introductory geology course as a substitute for the usual in-classroom rock identification and map-making final laboratory project. Each virtual field experience incorporates a terrain model that was generated through different means, namely a structure-from-motion (SfM) model made from drone-captured photographs for the capstone course and a fictional terrain model designed in 3D modeling software for the first-year geology course. Here, we report on pandemic-related emergency replacements for field exercises, with a prototype game to provide proof of concept for our approach.

We aimed to make an experience in which students could explore outcrops and terrains in a first-person perspective without limitations on where they could collect data. We designed the virtual field experiences in Unity (Unity Technologies, 2020), a cross-platform game engine with which we imported our geologic terrain models into a 3D environment and wrote scripts to govern how the users (in this case, the geoscience students) can interact with the outcrops and terrain. The cross-platform nature of Unity allowed us to choose how to package the virtual field experience for student access. We chose WebGL, a JavaScript application programming interface (API) for rendering interactive 3D graphics within web browsers, as being the ideal platform for sharing the virtual field experiences. By building the exercises for the web, anyone with a computer and an internet connection can be granted access, no special equipment (e.g., headset, glasses, or joystick) is needed, and no extra steps for downloading an operating-system-specific application are required.

Here, we report on the some of the functions within our virtual field exercises, but we intend to publish a detailed report on how we developed our virtual field experience interface in Unity. We have made our workflow and the Unity-based software package for generating a video-game-style virtual field experience publicly available, so that anyone with a 3D model can design their own virtual field experience and leverage the tools we developed for education and/or research. (See the code availability statement at the end of this paper.)

The user interface for our course-related virtual field experiences simulates some classic geology tools with novel visualization abilities, including a distance-measuring tool that permits linear measurements between multiple points in 3D space and prints the distances along user-generated line segments. Toggling the map view grants an orthogonal aerial view of the terrain and shows the user's position. The video game setting also permits tools that are not typically available to geologists, such as a jetpack that allows users to fly over the terrain and enables the interrogation of outcrops that would typically be at difficult or unsafe locations at which to collect data (Fig. 1a). The user can control movement in all directions, with their computer keyboard arrow keys, and change perspective, using their mouse or track pad. While in jetpack mode, the user can also change elevation.

Our Unity-based stereonet tool (written in C# programming language) is a novel way to collect data from surfaces and instantly have the data printed to a stereonet within the user's view. When the stereonet tool is activated, the user can click on surfaces within the virtual field experience and take the following three different types of measurements: (1) planes (Fig. 1b and c), for which the user generates polygons on the surface, (2) poles to planes (Fig. 1d), for which the user clicks once on the surface and generates a flag normal to the surface, and (3) lineations (Fig. 1e), for which the user clicks twice to generate a line on the surface. For each measurement, the data are not only plotted to the stereonet, but the numeric values (strike and dip; trend and plunge) are printed on the screen (e.g., Fig. 1a). The pole component has two extra features, where pole-style measurements also print the elevation at the measured point, and once several poles are collected, the user can initiate a stereonet pi plot (e.g., Marshak and Mitra 1988, p. 157) which indicates an approximate trend and plunge of a fold axis (Fig. 1a) and updates as more measurements are taken. Data acquired with these tools can be exported for use in StraboSpot (Walker et al., 2019), Stereonet (Cardozo and Allmendinger, 2013) and other plotting and analysis software.

As part of the remote instruction for our department's capstone summer field geology course, we devised a module on fold geometry that included a virtual field trip. The creation of the virtual field experience leveraged an existing SfM-derived terrain model of folded sedimentary rocks. The assignment related to this virtual field experience revolved around the special opportunities to study folds at this site in the field, while also providing the opportunity to collect data from locations at the field site that are not accessible on foot.

The Bear Valley Strip Mine (Shamokin, Pennsylvania) is a popular destination for structural geology field trips due to its excellent, three-dimensional, exposure of an excavated sandstone fold train, of which the central anticline is named the Whaleback (Fig. 1a; Nickelsen, 1979; Levine and Eggleston, 1992). Visitors can walk along the crests of two anticlines, or next to the 200 m long fold limbs, which feature fossils, concretions, joints, and decimeter-scale secondary faults. Because the Whaleback is 30 m high (from trough to crest), with steeply dipping/overturned limbs, most of the sandstone surface is inaccessible to direct measurement in the field. To study the geometry of the Whaleback for a research project, drone-acquired photographs of the strip mine were used with SfM photogrammetry to make a 3D point cloud of the surface in Agisoft PhotoScan Professional (2018). We edited the point cloud by removing as much vegetation as possible to preserve only the exposed sandstone surface and sediment cover. Within the PhotoScan workflow, a polygonal mesh was generated from the point cloud, along with an associated texture, which contains the color information for the mesh. Because the photogrammetry utilized real-world coordinates, the polygonal mesh (subsequently referred to as a model) is scaled to real coordinates (Universal Transverse Mercator (UTM) and elevation) and dimensions (meters). This model forms the basis of the virtual field experience; our virtual geology tools (compass and stereonet, ruler, map, and jetpack) provide the mechanism for the students to explore the virtual field site and collect data. In addition to the 3D model, we also produced an orthorectified aerial image of the site to use as a base map (Fig. 2c).

We piloted this virtual field experience in July 2020, with 31 undergraduate geology students enrolled in the University of Washington's remote field course, in a day-long workshop. Following a refresher on stereonets and fold geometry, the students received access to the Whaleback WebGL-based virtual field experience which was hosted on a department server. The assignment had the following four components: first, to familiarize them with the game controls, we asked the students to explore the strip mine by walking or flying through it, to screen-capture an interesting geologic feature, and to write an associated objective description. Many students noted the anticline and syncline on the mine's eastern wall (Fig. 2a; the syncline is apparent in the background of Fig. 1a); however, one student wrote an interesting geological description of some automobile tires that are remnants of trash within the mine. To help students to understand the geologic compass function and practice the transition from a 3D field perspective to 2D map, the students took strike and dip measurements of the surface of the Whaleback and plotted strike and dip symbols on the orthorectified aerial image. Once they were fully introduced to the game, we asked the students to investigate the along-trend variability of the Whaleback anticline. Students used the pole tool to create transects across the fold in four different areas that they selected (e.g., orange flags plotted in Fig. 1a). They then produced annotated aerial images, with four stereonets to show how the trend and plunge of the fold axis varies longitudinally (Fig. 2b and c). From their data, students were able to observe that the Whaleback is doubly plunging rather than purely cylindrical. The fourth exercise required constructing a profile of the fold train and interpolating the synclines that presumably connect the three exposed anticlines. In order to make this profile, students used the pole tool to measure elevation on the surface and the distance-measuring tool to constrain horizontal distance a long a transect perpendicular to the fold and then plotted the values, interpolating below the sedimentary cover.

Implementation of the exercise was straightforward. Regarding the WebGL performance on the students' machines, no computing or model-rendering problems were reported. Although students were not discouraged from working in groups, the students primarily worked alone for these exercises.

The virtual experience we created is open-ended, as there are no specific checkpoints or pieces of information that the user is required to collect; rather, the user chooses what data to collect and where to make those observations. Because of the flexibility of this virtual field experience, other instructors can design exercises appropriate to their courses and students. In addition to the exercises we piloted, students could make a structure contour map of the top of the Whaleback sandstone using the elevation tool, compare the arc length to wavelength of the fold, examine mesoscale structures on the larger fold, compare the pi diagram (poles to bedding) to beta diagram (intersecting great circles) to direct measurements of the fold hinge line for the representation of the fold axis, compare axes and shapes of different folds (Whaleback vs. northern anticlines), and compare folds in different stratigraphic horizons (Whaleback vs. syncline above); there are undoubtedly other possibilities. In short, the open structure of the virtual field experience gives instructors similar opportunities to what they have in the field to adapt to the needs of their students.

At the time of the pilot exercise, we gave the students an optional, open-ended opportunity to provide feedback about the game: (“If you have any comments regarding improvements to the interface in the Whaleback part of the game, please let me know in the space below!”) Although the prompt requested feedback regarding improvements to the game interface, we also received comments related to the student learning experience. Note that, although responses to this question were optional, it was included as part of a graded assignment, and this may have affected how students responded. Out of 31 students, 14 students (48 %) noted that the virtual experience was aesthetically pleasing and/or fun. Examples of these statements are as follows: “I thought it was great! It's a really cool way to visualize an area we are not able to visit”, and “This is a lovely game! I absolutely enjoyed it and it really helped with the immersion. It was super enjoyable!” On the other hand, one student reported being “scared by the walking sounds because it's the same sound bite a lot of pixel horror games use”. Positive remarks about the interface were made by 11 students (35 %). Examples of these are as follows: “I really liked the interface; I thought it was very user-friendly and intuitive to use”, “I think that the games works very well and is pretty intuitive”, and “I really liked the map mode button which created a standardized view of the map; it made it easy to orient myself and compare my map view to the instructions.” An additional eight students (26 %) offered only suggested improvements to the interface. Examples of these include the following: “I think an F1, instructions command that provides the full scope of the program would be helpful!”, and “Add an ability to click/highlight a previous point so that we can see what the strike and dip values were. This way, we don't have to go back and redo it to find out what the values were.” Finally, six students (19 %) volunteered that their education was enhanced by the virtual field experience. Examples of these comments include the following: “The stereonet tool is really cool! Stereonets in mineralogy were so confusing – this illustrates how they work spatially so well”, and “I am 100 % a visual learner… So what you are doing is right up my alley, and genuinely allowed me to learn more about structural geology, on a conceptual level, than any of my other previous classes.”

Plate Tectonics and Materials of the Earth is a first-year geology course at the University of Washington that introduces rock identification and geologic structures. The course traditionally culminates with an in-classroom mapping exercise for which rock specimens are arranged around the lab room and for which students produce a map, cross section, and geologic history. By creating a fictional (but realistic) mapping exercise, we can adjust the complexity appropriate to introductory students and create scenarios that draw on important concepts from the 10-week course. This type of classroom-based mapping exercise also has the advantage of being accessible to many students (e.g., Cooke et al., 1997). During remote instruction for winter 2021, we aimed to simulate this exercise within a virtual field experience. We produced a fictional field site, generally inspired by the geology of the northwestern Washington state (USA). We designed the map to include only a handful of different rock types, with elements that represent accreted oceanic crust, folded terrestrial sedimentary rocks, arc volcanism, and simple geologic structures with clear cross-cutting relationships.

The topography and lithology featured in the cartoon-style virtual field experience (Fig. 3a and b) were constructed in 3D from a simple map and an associated cross section, including a topographic profile based on the relative resistance to the weathering of each rock type. The terrain model, outcrop surfaces, and various other game elements (e.g., trees, campfire, rock hammer, etc.) were designed in Blender (Blender Foundation and Community, 2020), a free and open-source 3D computer graphics software. To make a hillshade-style base map of the terrain (virtual lidar), we rigged artificial lights in Blender to highlight the topography of the terrain and then exported a grayscale image of the shaded aerial view (Fig. 3c). Model outcrops began as cubes in Blender and were subsequently beveled to have varying bedding geometries. The 35 outcrops were positioned throughout the terrain and geographically oriented; thus, if students identified the outcrop lithology and took the strike-and-dip of bedding, they would be able to make the desired geologic map for the final project.

Identifying rocks at outcrops in the remote environment poses obvious problems of not being able to perform the standard battery of tests on a physical specimen. To simulate examining rocks at outcrops, each outcrop had an adjacent rock hammer icon (Fig. 3a and b), which opened an on-screen canvas with information about an outcrop. These informational canvases included photographs (of real outcrops of the rock type, hand samples, and/or petrographic microscope images) and brief descriptions of characteristics that could not be conveyed from the photos alone.

The cartoon-style virtual field experience was hosted at https://itch.io (last access: 29 May 2021; itch.io, 2021), a website for hosting, selling, and downloading video games. Since the virtual field experience is WebGL based, students could explore the terrain in their internet browsers without having to permanently download files. The itch.io site allows for user paywalls and/or for password protection of games. We password-protected the virtual field experience and provided a link and password within the assignment instructions. Students connected to the game via their own computers (with various processor speeds and operating systems) and home internet connections (with various data rates). If the students' computers and/or internet connections could not support the game, the course instructors were prepared to share their screens while using the virtual field experience as students directed the game play; however, no issues of access were reported. Therefore, we assume that student computer systems that could successfully run common videoconference software (a requirement to participate in the class) were also sufficient for accessing the virtual field exercise. It is important to note that some remote learning situations in primary and secondary schools limit the types of websites students can visit; therefore, it may be important to consider such conditions, depending on the intended audience of a particular virtual field experience.

To complete the virtual fieldwork of mapping, students worked in preassigned groups via videoconference and, much like in-person student fieldwork, divided and alternated tasks. In video breakout rooms, one student shared their screen while moving through the terrain, measuring bedding orientations at outcrops and activating the informational canvases. Other students used the shaded terrain map to guide the main player, similar to how students use terrain maps during field mapping exercises. Other participants updated the group's shared spreadsheet to record the bedding measurements and include objective descriptions, based on the informational canvases, for future discussions on rock identifications. With the orientation and lithologic data collected from the virtual field experience, students successfully generated geologic maps and subsequently drafted cross sections and interpreted a geologic history for the fictional field site. Furthermore, students reported this assignment to be a highlight of the online course, and several students mentioned showing the game to friends or family outside of class. These anecdotal reports of increased student engagement are corroborated by analytics that record the number of browser plays between the time the assignment start date and due date; that number was 3–5 times greater than the minimum number required for student groups to complete the assignments. In other words, students visited the virtual field experience, on their own, for fun.

The implementation of interactive virtual field experiences in the two courses successfully addressed the immediate need by substituting engaging online lessons for field and classroom exercises that were precluded by pandemic-related restrictions. Considering the stress and exhaustion that many students experienced as a result of the global pandemic, the students submitted work that conveyed comprehension of the intended educational goals. We also demonstrated that our structural geology query interface in Unity is successful for both structure-from-motion-generated models of actual field sites and custom-designed 3D models of fictional geology. For the college courses, students did not report access issues with regard to where the virtual field experiences were hosted or how their personal computers and internet connections performed. That is, the games functioned well for more than 130 individual users across the globe with an array of hardware, connection speeds, and browsers. With this contribution, we establish that these virtual field experiences are functional and accessible to many students, and that students understand how to operate the tools and can make interpretations from the information they collect.

In response to the 2020 pandemic, the National Association of Geoscience Teachers and the International Association for Geoscience Diversity led a collaboration of more than 300 geoscience educators in developing a framework for designing remote/virtual field experiences to meet the same learning outcomes as in-person exercises (Atchison et al., 2020). The exercises that we implemented within each virtual field experience address many of the highlighted learning outcomes (Table 1). Importantly, however, is that the open-ended nature of these simulations, and especially the Whaleback, enables other geoscience educators to design assignments tailored to different educational goals. We have made the Whaleback virtual field experience available to anyone at https://www.virtualfieldgeology.com/ (last access: 9 June 2022; Needle, 2021); at the time of writing this paper, hundreds of individuals have played the game, including temporal clusters that suggest many instructors have designed their own field trips to this virtual site.

These virtual field experiences have a utility beyond the emergency transition to remote learning. Such simulations can continue to enable students to investigate 3D outcrops without the physical, geographic, and financial limitations often associated with field-based instruction. For example, the Whaleback anticline is more than 4300 km from Seattle (an impractical field trip), but we will continue to visit it virtually, post-pandemic, via the game interface. We also see a role for these games in blended learning (see Bond and Cawood, 2021; this issue) and scientific visualization more broadly. In the virtual field experience, it is possible to observe and collect data from areas of the Bear Valley Strip Mine that are inaccessible on foot; thus, the Whaleback game can augment in-person educational field trips to the site. Because the game is built on a high-resolution, georeferenced terrain model, it could be used for research collaboration. Furthermore, the Whaleback is on private land, and public/educational access is evolving. The immersive virtual field experience we have created can help to preserve a record of this geoheritage site (Geyer and Bolles, 1979), should access be further restricted.

Benefits also persist for the virtual field experiences in fictional sites even after a full return to the classroom. While there are obvious advantages in using the laboratory-based version of a fictional mapping exercise with real hand specimens for petrologic description, the video-game-based exercise offers the independent collection of structural data and more information in the terrain. Our success in building a fictional mapping exercise suggests that geoscience educators need only imagination and bit of 3D modeling skills to design unlimited virtual geologic settings and structural histories for their students to map. It is, thus, possible to create idealized geology to permit students to discover foundational concepts. For example, imagine a unit on fold geometry in which students visit and measure bedding orientations on folds in the full range of shapes and attitudes and can instantly compare stereonets from each one. In these open-ended, fictional settings, it is also possible to deliberately manipulate how much uncertainty the students encounter.

The modular nature of the Unity game engine and our structural geology query tools means that it is relatively simple to build new virtual field experiences on other outcrop models. We intend to share the template and modules to enable others in the geoscience community to generate virtual field experiences using our interface and their own terrain models. Future work includes creating instructions and workshop for this process, so that anyone with a 3D model can produce a field simulation without significant programming effort or experience. We see field simulations, like the two we describe here, as an emerging opportunity to provide the exploration of geologically interesting features without the typical limitations of field-based geology. Upon re-establishing many of our traditional practices as geologists (post-pandemic), we envision broader adoption of video-game-based field experiences as one way to include more people in our geologic conversations.