Welcome to Map Pedometer. Google is likely using SRTM data for the elevation information. According to Nasa's website, the radar does not "see" through thick vegetation canopies. So, the elevation reading is likely due to tall trees in that area. Also, due to the resolution of the elevation data locations that Google provides, it is likely that some of the elevation points are measurements from locations slightly off your path. If you create a path on a steep hill (or next to a cliff), you could get measurements that are from locations close by, but happen to be at a significantly different elevation than your path.
If you haven't already noticed, you can move your mouse over the elevation graph and it will highlight the location of the elevation point. Also, clicking on the elevation graph will pan the map to the location for the elevation point. In your particular route, clicking on the 1.1 mile point on the elevation graph shows an area with a lot of trees.
stevechapal wrote:I mapped my first running route of about 3.5 miles in my north Tampa neighborhood. The elevation chart seems accurate except at about the 1.1 mile point, where it shows a sharp 20 foot elevation gain from 40 feet to 60 feet gain and then back down, all within about a 0.1 mile distance. The course is basically flat all the way around and there is nothing noticeable at the 1.1 mile mark. Any idea what would cause that spike?