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Over the past three years, the dams of Chelan County, Washington, its watershed and fish, the electrical grid and the laborers who maintain it, and cleared land with warehouses filled with computers, have all been enrolled as part of the decentralized digital infrastructure of Bitcoin. While popular accounts of the Bitcoin network correctly report the massive scale of energy it consumes and its potential environmental ramifications, in practice, the material geographies of Bitcoin are highly uneven and intertwined with specific infrastructural, ecological, and economic systems. In this article, we examine Bitcoin's impacts on Chelan County, untangling the processes that occur as the distributed, digital infrastructure consumes the very real material resources of one place to produce digital goods used in another. In so doing, we examine not only the material costs of networks like Bitcoin, but also their historical ties to older processes of accumulation.Highlights:• Cryptocurrency miners have flocked to central Washington state, drawn by hydropower's cheap electricity rates.

Spatial decisions increasingly are made by both professional and citizen stakeholders using interactive maps, yet few empirically-derived guidelines exist for designing interactive maps that support complex reasoning and decision making across problem contexts. We address this gap through an online map study with 122 participants with varying expertise. The study required participants to assume two hypothetical scenarios in the North American hazardous waste trade, review geographic information on environmental justice impacts using a different interactive map for each scenario, and arrive at an optimal decision outcome. This study followed a 2 × 2 factorial design, varying interface complexity (the number of supported interaction operators) and decision complexity (the number of decision criteria) as the independent variables and controlling for participant expertise with the hazardous waste trade and other aspects of cartographic design. Our findings indicate that interface complexity, not decision complexity, influenced decision outcomes, with participants arriving at better decisions using the simpler interface. However, expertise was a moderating effect, with experts and non-experts using different interaction strategies to arrive at their decisions. The research contributes to cartography, geovisualization, spatial decision science, urban planning, and visual analytics as well as to scholarship on environmental justice, the geography of hazardous waste, and participatory mapping.

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Problem: Interactive or "slippy" web maps have revolutionized cartography. Slippy maps present a single, coherentlydesigned reference map that can be panned to numerous geographic locations and zoomed across multiple scales. Further, they apply scale-dependent style rules to detailed geographic datasets, with the resulting designs rendered as a large set of interlocking tiles. To account for constraints in data bandwidth, processing, and storage, only those tiles relevant to the user's location and past interactions are served into the web browser or other application, resulting in a seamless, realtime user experience of "a map of everywhere". These slippy tilesets often are used as basemaps for advanced cartographic web and mobile applications, overlaying thematic information and other linework. Arguably, such slippy map mashups are the most common map seen and used today (and perhaps of all time). Yet, most of the cartographic design canon was developed long before slippy maps were possible. Do any of our time-tested design traditions in thematic cartography apply in today's interactive and multiscale mapping context? In this presentation, we discuss preliminary insights from an online map study about the design of interactive and multiscale thematic maps.Background: Our research integrates the cartographic tradition in thematic representation with growing research on interaction design. Thematic maps depict the distribution of one or several geographic phenomena, with the base reference information used as context for interpreting spatial variation in the thematic information [1]. Thematic maps grew in popularity in the 19 th century at the onset of the modern global economy as a method for tracking and controlling materials, labor, and goods [2], and, in today's information-driven society, are created by cartographers for reasons ranging from popular news reporting to exploratory scientific visualization. Thematic maps enable geographic imagination and spatial thinking, often representing abstract or statistical concepts that cannot be observed directly. Common thematic map types include choropleth, dot density, proportional symbol, and isoline, among others [3].Thematic maps can be organized in at least two ways. First, thematic map types differ in the visual variable used to encode the thematic information, or the basic graphic dimension separating variation in the thematic attribute of interest from other reference context [4]. For instance, choropleth maps typically employ the visual variables related to color (particularly color value, sometimes crossing multiple hues or saturations), dot density maps use a combination of arrangement and size, an emergent visual dimension sometimes described as "numerousness" [5], proportional symbol maps use size, and isoline maps use location (creating a new set of geographic linework based on thematic information), and also can include a color ramp between isolines similar to choropleth maps.Second, thematic maps differ in the visual metaphor they evoke in the relatio...