Pele's tears (closest Hawaiian translation: "nā waimaka o Pele") are small pieces of solidified

lava Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a Natural satellite, moon onto its surface. Lava may be erupted at a volcano or through a Fissure vent, fractu ...

drops formed when airborne particles of molten material fuse into tearlike drops of volcanic glass. Pele's tears are jet black in color and are often found on one end of a strand of Pele's hair. Pele's tears is primarily a scientific term used by

volcanologist A volcanologist, or volcano scientist, is a geologist who focuses on understanding the formation and eruptive activity of volcanoes. Volcanologists frequently visit volcanoes, sometimes active ones, to observe and monitor volcanic eruptions, col ...

s. Pele's tears, like Pele's hair, are named after Pele, the Hawaiian fire goddess of

volcanoes A volcano is commonly defined as a vent or fissure in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often fo ...

Formation

The formation of these tears is a complex process depending on a number of different factors as a tiny droplet of

is being erupted from a

lava fountain Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or unde ...

. Whilst it is travelling through the air two things are happening: it is cooling down very rapidly (a process known as quenching) and it is being deformed. The deformation of a droplet depends on the speed at which it is erupted from the volcano, its

surface tension Surface tension is the tendency of liquid surfaces at rest to shrink into the minimum surface area possible. Surface tension (physics), tension is what allows objects with a higher density than water such as razor blades and insects (e.g. Ge ...

, the

viscosity Viscosity is a measure of a fluid's rate-dependent drag (physics), resistance to a change in shape or to movement of its neighboring portions relative to one another. For liquids, it corresponds to the informal concept of ''thickness''; for e ...

(thickness) of the magma and the resistance it experiences as it travels through the air. Pele's tears are also found entangled within fine strands of volcanic glass known as Pele's hair and it was considered that they formed together under similar conditions. Shimozura (1994) investigated this further and found that the velocity of the erupting lava was the main factor in determining whether Pele's tears or Pele's hair were formed. If the velocity of the erupting magma is high then Pele's hair is formed and if the velocity is low the formation of Pele's tears is favoured. Under the microscope very tiny Pele's tears (less than 1 μm) can be found within the cavities of Pele's hair. This would suggest they formed prior to being trapped within the strand and supports a different mechanism for formation. It has been considered that they became trapped during transport in the eruptive plume.

Scientific importance

Pele's tears are interesting to

s because trapped within the glass droplet are bubbles of gas and particles called vesicles. When these are analyzed they can provide a great deal of information about the mechanisms of an eruption. For instance, the shape of a vesicle can provide an indication of the velocity of the eruption. When vesicles form within the lava they are spherical in shape. If the eruption is turbulent the vesicles will deform and become elongated in shape. If the velocity is low they will retain their spherical shape as in the case of Pele's tears. The composition of a

magma chamber A magma chamber is a large pool of liquid rock beneath the surface of the Earth. The molten rock, or magma, in such a chamber is less dense than the surrounding country rock, which produces buoyant forces on the magma that tend to drive it u ...

includes

crystal A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macros ...

s and gases known as volatiles. At high pressures within the

, gases are dissolved in the melt and are soluble. As the

magma Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma (sometimes colloquially but incorrectly referred to as ''lava'') is found beneath the surface of the Earth, and evidence of magmatism has also ...

rises, the pressure decreases and the gases come out of solution. Some of these gases escape and some become trapped in the melt. When the gases trapped within the vesicles of Pele's tears are analyzed they can provide a great deal of information about the chemical composition of the

. This information can be used to determine the explosive nature of an eruption and help to understand the complex processes occurring within

volcano A volcano is commonly defined as a vent or fissure in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most oft ...

s. This is important in the management of

natural hazards A natural disaster is the very harmful impact on a society or community brought by natural phenomenon or hazard. Some examples of natural hazards include avalanches, droughts, earthquakes, floods, heat waves, landslides - including submarin ...

References

External links

USGS Photo Glossary: Pele's tears
{{Hawaiian volcanism Glass in nature Volcanology

Formation

Scientific importance

See also

References

External links