If you switch between the Recent and Trending tabs, you'll notice that the dots on the map change:
On the Recent map, you can see incidents that occurred within the current map area, sorted by recency. The larger dots represent incidents that are considered active.
If you want to only see incidents that are nearby your current location, tap the "Recenter" button in the bottom right corner of the map. As you navigate the map, the list contents will change automatically to reflect your current map bounds.
On the Trending map, you can navigate the map in the same way to find the biggest incidents & stories that occurred in the last month. The larger dots represent incidents at the top of the Trending list.