earth science

Pele's tears

Pele's tears is a earth science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Pele's tears rather than just read about it. In short: Pele's tears (closest Hawaiian translation: nā waimaka o Pele) are small pieces of solidified lava 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.

Key takeaways

Pele's tears belongs to earth science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Pele's tears to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Pele's tears from memory before moving on to harder problems.

Reference excerpt

Pele's tears (closest Hawaiian translation: nā waimaka o Pele) are small pieces of solidified lava 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 volcanologists. Pele's tears, like Pele's hair, are named after Pele, the Hawaiian 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 lava is being erupted from a lava fountain. 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 (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 volcanologists 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 includes lava, crystals and gases known as volatiles. At high pressures within the magma chamber, gases are dissolved in the melt and are soluble. As the magma 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 magma chamber. This information can be used to determine the explosive nature of an eruption and help to understand the complex processes occurring within volcanos. This is important in the management of natural hazards.

See also Apache tears Limu o Pele Pele's hair Prince Rupert's drop

References

External links

USGS Photo Glossary: Pele's tears

Illustrations

Worked examples

Example 1 — a first encounter with Pele's tears

Start with the simplest possible case. Write down what Pele's tears claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In earth science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Pele's tears before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Pele's tears ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Pele's tears

In research: Pele's tears appears in earth science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Pele's tears in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Pele's tears is common in secondary-school and first-year university syllabi. It links to neighbouring topics Glass in nature, Volcanology, so understanding it makes those chapters shorter.
In everyday life: Look for Pele's tears outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Pele's tears in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Pele's tears means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Pele's tears out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Pele's tears in simple terms?

Why does Pele's tears matter?

Because it connects several earth science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Pele's tears?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Pele's tears.