Images compiled from amateur aircraft-tracking stations illustrate the gradual clearing of traffic in UK airspace following the spread of a volcanic ash cloud from Iceland.
The aircraft-tracking data has been compiled from automatic dependent surveillance-broadcast (ADS-B) transmissions, and similar sources, which can be detected and interpreted with inexpensive equipment and plotted on dedicated Internet sites.
Data from around 06:30 today shows a virtual absence of aircraft in the northern UK as a result of restrictions on air traffic.
UK air navigation service NATS has closed the country's airspace until at least 06:00 on 16 April in order to avoid risk to high-altitude flights.
"The cloud of volcanic ash is now spread across the UK and continuing to travel south," it states.
Nordic and Irish airspace has also been heavily affected by the ash cloud.
Image compilation: Flightradar24 and Planeplotter (credit: John Locker)