North American Impact Events throughout History – A Map Animation

By: Nicole Slattery. Geovis Project Assignment @RyersonGeo, SA8905, Fall 2018

For my Geovisualization assignment, I wanted to create an animated map of impact crater events in North America throughout history. I decided to use ArcGIS Pro in order to do this because of the nature of the data. The Earth Impact Database maintained by the Planetary and Space Science Centre (PSSC) in New Brunswick, has achieved the 190 confirmed impact craters from around the world. The impacts have occurred anywhere from 1850 million years ago to 600 000 years ago. Usually, when creating an animated map throughout time, the map software requires a date. The impacts did not occur within the span of the Gregorian calendar used today; therefore, this software cannot map this data. However, ArcGIS Pro includes a tool “Animate through a range” which allows for this data to be animated sequentially without a date.

2D Map of Impact Craters in North America

In order to utilize ArcGIS Pro’s animation through a range tool, the data points of impact craters were geocoded and added to a new map. The points were displayed by proportional symbols of their diameter on the earth in km. Therefore, the map displays the distribution of impact craters across North America by their diameter. The locations were symbolized as well, in a gradient colours brown to black, in order for the points to appear to have depth. The 2D map can be viewed above. The basemap of the map was added from the basemap gallery under the Map tab in ArcGIS Pro. The World Imagery basemap was selected; this layer presents high resolution satellite and aerial imagery of the world. Another interesting feature of ArcGIS Pro is that any 2D map can be converted to a 3D scene for data visualization. Under the View tab, the Convert button was selected. Within this drop-down menu, the option To a Global Scene was selected. This converted the map into a 3D globe.


Converting the 2D map into a Global Scene     
Global Scene 3D Map

Under Properties of the scene layer impact points, the range setting was enabled for the “Age” attribute of the layer. The age attribute describes when the impact occurred in MYA (millions of years ago). The range was set between 1850 and 0 MYA, as this is the full range of the data in the layer. A range slider was added to the side of the scene. By dragging the slider, the points animatedly appear and disappear depending on their ages.


Enabling Range on the “Age” Attribute of the Impacts
Range Slider (display at 1315 MYA)

In order to start an animation, the Add button was selected in the View tab. This created and opened an Animation tab within ArcGIS Pro. In order to start the video, the Range of visible data was selected as 1850-1850. This way only the oldest impact crater is displayed. The scene was zoomed out for the first shot of the animation. By setting the Append Time to 5 seconds and selecting Append, the first clip of animation was created. This clip was 5 seconds. In order to display the progression of impacts occurring, the slider was dragged closer throughout time. By increasing Append time to 15 seconds and selecting Append, the animation clip was created. The animation clip is range aware therefore it will progress through the range slider up to where the slider was dragged throughout this append time. This process was repeated until the whole range was animated.

Range set at 1850-1850 in order to start animation
Append Animation to Video
Animation Timeline for video editing

After the range of ages of the impacts was animated, a camera path was animated in order to create an interesting visual. By zooming and changing the view of the map and using the append animation clip, a visualization of the satellite imagery of the impact craters was created. For example, the Sudbury crater was zoomed in upon and animated. Then, a paragraph of facts about the Sudbury crater was overlaid using the Overlay option in the Animation Tab. As well, a scale was overlaid using the same tool. This was done for three other craters and was added to the animation video.

Add overlay graphics to the video
Overlay with details about the impact

Finally, the animation was exported as a MP4 file in order to easily share the file.

The Final Video seen above was uploaded to YouTube.