Without a specific map or set of changes to reference, it is difficult to accurately identify the cause of any changes to the map of Canada. However, there are many factors that can contribute to changes in maps over time, including:
1. Natural events: Natural disasters such as floods, fires, and earthquakes can alter the physical landscape of an area and change the way it appears on a map.
2. Human activities: Human activities such as urbanization, deforestation, and mining can alter the physical landscape and change the way it appears on a map.
3. Political changes: Changes in political boundaries or the creation of new territories or provinces can alter the way an area appears on a map.
4. Technological advances: Advances in technology, such as satellite imagery and remote sensing, can provide more detailed and accurate maps than were previously available.
5. Map-making errors: Errors in map-making, such as inaccurate measurements or misinterpretation of data, can lead to changes in maps over time.
These are just a few examples of the many factors that can contribute to changes in maps over time.