Tephra
Videos
Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size, or emplacement mechanism.
Volcanic tephra at Brown Bluff, Antarctica (2016)
Tephra horizons in south-central Iceland: The thick and light-coloured layer at the centre of the photo is rhyolitic tephra from Hekla.
Molten lava fountain at Kilauea volcano on Hawaii, with black cloud of associated tephra
Rocks from the Bishop tuff, uncompressed with pumice on left; compressed with fiamme on right
Pyroclastic flow
Videos
A pyroclastic flow, more broadly known as a pyroclastic density current, is a fast-moving current of hot gas and volcanic matter that flows along the ground away from a volcano. Pyroclastic currents t
Tephra
…China, a large volcanic eruption in the early Cretaceous caused the fossilization of an entire ecosystem known as the Jehol Biota when powerful pyroclastic flows inundated the area. The deposits include many perfectly preserved fossils of dinosaurs, birds, mammals, reptiles, fish, frogs, plants, and insects…
Pyroclastic flows sweep down the flanks of Mayon Volcano, Philippines, in 2018
Building remnant in Francisco Leon destroyed by pyroclastic surges and flows during eruption of El Chichon volcano in Mexico in 1982. Reinforcement rods in the concrete were bent in the direction of the flow.
A scientist examines pumice blocks at the edge of a pyroclastic flow deposit from Mount St. Helens