BP continued testing the latest cap on its blown rig Friday, increasing scans of the seafloor for leaks. The oil stopped spewing from the well Thursday, but scientists are monitoring the pressure in the wellhead—if it doesn’t rise to a certain high level and then stay constant, it could mean there are new leaks forming. If those leaks are discovered on the seabed, the cap’s valves will be opened and vessels on the surface will resume sucking up some of the oil. On Friday, pressure rose quickly to 6,700 pounds per square inch—a good sign—before slowing down, worrying federal officials who then asked the oil company to monitor the cap more closely. BP will take more seismic readings of the seabed, and a ship will scan for methane bubbles in the water, which would indicate that BP’s problems are back. The slower rise in pressure could be the result of months of leaking, lowering pressure on the oil reservoir.