Our task this module involved experimenting with two sets of sequential data in ArcMap as seen in the screenshots above. The first map depicts the most populous cities in the U.S. from 1790 to 2000. By including a column in the city layer attribute table for year, we can enable the use of ArcMap's time functions in the layer's properties. From here, the field, format, interval, and other options are set to display time as required. Finally, using the Time Slider window, we can cycle through each year and the symbology for that year's city populations. This can be captured in a video for playback outside ArcMap. The second map, depicting the eruptions of volcanoes, went through a similar process. In this case, the option to 'Display data cumulatively' was engaged, keeping the symbols for each eruption on the map as new ones are added. This allows the patterns of eruptions along fault lines to form as each eruption is symbolized through time.
Like most tools available in ArcMap and in GIS in general, creating videos of data symbolized through time may be helpful or irrelevant. In the cases above, there is too much temporal data to display simultaneously, thus creating a video or interactive interface to depict the data over time makes sense. Doing so may reveal patterns more directly than a series of static maps. As in most cases, the usefulness of these tools depends on the data, the audience, and the intention of the cartographer.
