V
Valley Glacier: A valley glacier is a glacier that is enclosed by the
walls of a mountain valley and flows down these walls.
Valley Glacier: see Glacier.
Valley: An area of lowland with slopes either side. A river flows along
the lowest part.
Varve: A varve is a sediment bed, made up of a series of sediment
layers, that is annually deposited in a still water body near a glacial area.
Vector: In geographical terms, vector is defined as a force that has
both direction and magnitude.
Vegetation: All kinds of plants including shrubs and trees.
Vegetation: a ground cover of bushes and grass on a cliff face helps
prevent cliff erosion; their roots hold and trap (stabilise) soil and prevent
it being lost by mass movement.
Velocity: the speed of the water flow.
Vent: A vent is a pipe like opening in the earth's crust, that directs
the flow of volcanic material. A volcano may have one or more than one vent.
Vent: The opening at the Earth's surface through which volcanic
materials (lava, tephra, and gases) erupt. Vents can be at a volcano's summit
or on its slopes; they can be circular (craters) or linear (fissures).
Vineyard: Where grapes are grown to make wine.
Viscosity: Measure of the fluidity of a substance. Taffy and molasses
are very viscous; water has low viscosity.
Visibility: Visibility is the maximum distance up to which a person can
see under a particular weather condition, without the assistance of any
instrument.
Volcanic avalanche: A large, chaotic mass of soil, rock, and volcanic
debris moving swiftly down the slopes of a volcano. Volcanic avalanches can
also occur without an eruption due to an earthquake; heavy rainfall; or
unstable soil, rock, and volcanic debris.
Volcanic Cone: A volcanic cone is a conical hill formed during a
volcanic eruption made up of lava, tufa and cinders.
Volcanic Plume: Volcanic plume is a mixture of gas, lava and other
particles that is emitted during a volcanic eruption, generated when the magma
is fragmented.
Volcano: A cone-shaped mountain made up from lava and ash.
Volcano: A vent (opening) in the Earth's surface through which magma
erupts; also the landform that is constructed by eruptive material.
Volcano: A volcano is a land form, often a mountain, through which
magma, gases and ashes erupt and flow out.
Voluntary Migration: where people move to another area through choice.
V-shaped Valley: A v-shaped valley is a valley that has a
cross-sectional profile and that is formed by the eroding action of streams.
V-shaped Valley: a deep v-shaped valley is usually found in the upper
course of the river where the water has considerable erosive power.
Vulcanism: Vulcanism, also known as volcanism, is a term used to
describe the study of any kind of volcanic activity.
