Frazil (pronounced frey-zuhl,
fraz-uhl, fruh-zeel, frey-zil, fraz-il or fruh-zil (regionally variable)).
Ice crystals formed in turbulent water, as in swift
streams or rough seas (moving enough to prevent the formation of a sheet of ice).
1885-1890: A borrowing in US English, from the Canadian
French frasil, frazil & fraisil, from the French fraisil (forge (or coal) cinders), from
the Old French faisil, ultimately
from the Latin fax (torch, firebrand;
fireball, comet; cause of ruin, incitement), from the primitive Indo-European ǵhwehk- (to shine) and cognate
with facētus (elegant, fine;
courteous, polite; witty, jocose, facetious) and the Lithuanian žvakė (candle) and there’s also a
speculative link to the Etruscan word for face (which may also have meant torch). Frazil is a noun and adjective and has been
used as a (non-standard) verb; the noun plural is frazils.
The freezing point of water is 273.15 K (32o F (0o
C)), but it
can be super-cooled to almost 231 K if there are no nuclei for the ice crystals
(ie the water is very pure). Frazil ice
forms in turbulent, very cold water and consists of small discs of ice as small
as 1-4 millimeters in diameter and 1-100 microns in thickness (there can be one
million ice crystals per m3 of water).
As the crystals grow, they will stick to objects in the water, tending
to accumulate on the upstream side of objects and this can cause ice dams to
form and serious flooding can result in unpredictable places because creeks and
other waterways can change directions in response to the movement and
accumulation of frazil ice. Lovely to
watch, frazil ice can pose a problem for hydroelectric power-plants because, in
bulk, it can block turbine intakes or freeze open gates. Fish can also suffer and in oceans, frazil
ice forms around coastlines or ice packs found in open seas and the behavior of
the substance (in this context an aspect of fluid dynamics) has required the
development of protocols by the oil and gas industry for use when working in
arctic regions. For those who struggle
to visualize frazil, it’s something like the slushies sold in convenience
stores.
Available in more than a dozen flavors, Frazil is a
brand-name of the slushie sold by US frozen drinks company Freezing Point.
As the crystals grow, they will stick to objects in the
water, tending to accumulate on the upstream side of objects and this can cause
ice dams to form and serious flooding can result in unpredictable places
because creeks and other waterways can change directions in response to the
movement and accumulation of frazil ice.
Lovely to watch, frazil ice can pose a problem for hydroelectric
power-plants because, in bulk, it can block turbine intakes or freeze open
gates. Fish can also suffer and in
oceans, frazil ice forms around coastlines or ice packs found in open seas and
the behavior of the substance (in this context an aspect of fluid dynamics) has
required the development of protocols by the oil and gas industry for use when
working in arctic regions. The actions
of waves and currents creates a turbulent state which causes the water column
to become super-cooled by the process of heat exchange between air and water,
the temperature dropping below its freezing point. In rivers and creeks, the vertical mixing
induced by the turbulence generates sufficient energy to overcome the crystals'
buoyancy, thus keeping them from floating to the surface while in oceans, the
winds, waves and cold air combine to create a super-cooled layer.
Frazil ice, Yosemite National Park.
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