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 moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or un ...

drops formed when airborne particles of molten material fuse into tearlike drops of

volcanic glass Volcanic glass is the amorphous solid, amorphous (uncrystallized) product of rapidly cooling magma. Like all types of glass, it is a state of matter intermediate between the closely packed, highly ordered array of a crystal and the highly disorde ...

. 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.

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 un ...

. 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, the

viscosity The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water. Viscosity quantifies the inte ...

(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 Several types of volcanic eruptions—during which lava, tephra (ash, lapilli, volcanic bombs and volcanic blocks), and assorted gases are expelled from a volcanic vent or fissure—have been distinguished by volcanologists. These are often ...

. 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 up ...

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, macro ...

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 is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural sa ...

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 a rupture in the Crust (geology), crust of a Planet#Planetary-mass objects, planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and volcanic gas, gases to escape from a magma chamber below the surface. On Ear ...

s. This is important in the management of

natural hazards A natural hazard is a natural phenomenon that might have a negative effect on humans and other animals, or the environment. Natural hazard events can be classified into two broad categories: geophysical and biological. An example of the distincti ...

References

External links

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

Formation

Scientific importance

See also

References

External links