The police are now monitoring criminal/gang/drug 'activity' in the area.
There has been an increase in the city's (level of) economic 'activity'.
The instruments are used to detect volcanic 'activity' on the island.
(..) - What do you mean? - We're to patrol the Neutral Zone. In case the Romulans decide to take advantage of the situation. There has been no unusual activity along the Romulan border. Does Starfleet feel we need more shakedown time? We're ready! The Enterprise E is the most advanced ship in the fleet. (..)1996 Star Trek: First Contact