Another theory is that the mantle flows neither in cells nor large plumes but rather as a series of channels just below the Earth's crust, which then provide basal friction to the lithosphere. Source: Internet
A portion of the core's thermal energy is transported toward the crust by mantle plumes ; a form of convection consisting of upwellings of higher-temperature rock. Source: Internet
A hot, less-dense lower boundary layer sends plumes of hot material upwards, and likewise, cold material from the top moves downwards. Source: Internet
Black plumes of smoke were pictured billowing from between the historic building's towers while raging flames were seen inside. Source: Internet
Amateur video showed thick plumes of black smoke rising over Mitiga Airbase Saturday after Haftar’s forces targeted it with dozens of Grad rockets. Source: Internet
Also, significant thermal anomalies have been reported and gas-steam plumes extended roughly convert to the north-east from the volcano on 3 March. Source: Internet