Vocabulary Chapter 9 Flashcards
a lava flow with a rubbly surface
a’a’
Tiny solid particals or liquid droplets that remain suspended in the atmosphere for a long time.
aerosol
A volcano that has erupted in the past few centuries and will likely erupt again.
active volcano
Tiny glass shards formed when a fine spray of exploded lava freezes instantly upon contact witht the atmosphere.
ash
Large angular pyroclastic fragments consisting of volcanic rock, broken up during the eruption
block
A large circular depression with steep walls and a fairly flat floor, formed after an eruption as the center of the volcano collapses into the drained magma chamber below.
caldera
A subaerial volcano consisting off a cone-shaped pile of tephra whose slope approches the angle of repose for tephra.
cinder cone
A type of fracturing that yield roughly hexagonal columns of basalt; they can form when a dike, sill, or lave flow cools.
columnar jointing
A cricular depression at the top of a volcanic mound.
crater
A volcano that has not erupted for hundreds to thousands of years but does have the potential to erupt again in the future.
dormant volcano
An eruption that yields mostly lava, not ash.
effusive eruption
The character of a particular volcano eruption.
eruptive style
Violent volcanic eruption that produce clouds andavalanches of pyroclasic debris
explosive eruption
A volcano that was active in the past but has now shut off entirely and will not react in the future
extinct volcano
A conduit in a magma chamber in the shape of a long crack through which magma rises and erupts at the surface
fissure
Vast sheets of basalt that spread out over the land; may form at a continental rift and where lava is hot and has low viscosity
flood basalt
Solidified pyroclastic flows
ignimbrite
Formed when volcanic ash and debris mix with water either in rivers or from melting snow and ice on the volcano’s flank
lahar
Pryoclastic Partical(s) 2mm-marbel size
lapilli
The empty space left when a lava tunnel drains
lava tube
A space below ground filled with magma
magma chamber
A lava flow with a surface texture of smooth, glassy, ropelike ridges
pahoehoe
Glass encursted basalt blobs that form on the sea floor and cool very quickly
pillow lava
Fragmented material that sprayed out that sprayed out of a volcano that landed on the ground or seafloor in solid form
pyroclastic debris
A fast moving avalanch that occurs when hot volcanic ash and degris mix with air and flow down the side of a volcano.
pyroclastic flow
A subarial volcano with a broad, gentle dome, formed either from low-viscosity basaltic lava or from large pyroclastic sheets
shield volcano
A large coneshaped subarieal volcano consisting of layers of lava and tephra
stratovolcano
A pyroclastic igneous rock composed of volcanic ash and fragmented pumice, formed when accumulations of the debris cement together
tuff
