Hazards key words Flashcards
anomaly
something that is different from what is expected; an outlier in some data
composite cones
volcanoes resulting from alternating types of eruption in which first ash and then lava are ejected. (Mount Etna is an example of this)#
conservative boundary (transform boundary)
two plates sliding past each other
divergent boundary
when two tectonic plates move away from eachother
ductile
easily bent or structured: ductile rocks can change shape without breaking
fissure vent
a fissure is a long narrow opening of fracture line, in a fissure eruption two plates move apart and lava may be ejected through fissures rather than via a central vent
mid - oceanic ridge
a continuous range of undersea volcanic mountains formed as a result of plate tectonic processes
mountain belt
a linear mountain range formed by a combination of tectonic processes including faulting and folding
phreatomagmatic
volcanic eruptions caused by the interaction between magma and water
plate tectonics
earths most outermost layer is broken into a dozen or more large and some small plates that are moving relative to one another
pyroclastic flow
a fast moving avalanche-like mixture of how volcanic rocks, ash and gases that can travel up to 150km per hour
shield volcano
a volcanic cone with long gentle sides, make up of many layers of lava from repeated flows (an example is Mauna Loa on Hawaii)
slab pull
at a subduction boundary one plate is denser and heavier than the other the denser heavier plate begins to subduct beneath the plate that is less dense, the sinking of the plate is called slab pull
subduction
as an oceanic plate moves towards a continental plate it sinks beneath the continental plate because it is heavier forming deep sea trenches and island arcs with volcanoes
tectonic plates
large - scale features of earths surface, they are hug rigid blocks generally composed of both continental and oceanic lithosphere
