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earth science

Lightning injury

Lightning injury 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 Lightning injury rather than just read about it. In short: Lightning injuries occur when someone is struck by lightning. Initial symptoms may include heart asystole and respiratory arrest.

Lightning injury — main illustration
Lightning injury — illustration

Key takeaways

  • Lightning injury 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 Lightning injury to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Lightning injury from memory before moving on to harder problems.

Reference excerpt

Lightning injuries occur when someone is struck by lightning. Initial symptoms may include heart asystole and respiratory arrest. While the asystole may spontaneously resolve fairly rapidly, the respiratory arrest is typically more prolonged. Other symptoms may include burns and blunt injuries. Of those who survive, about 75% have ongoing health problems as a result, such as cataracts and hearing loss. If death occurs it is typically from either an abnormal heart rhythm or respiratory failure. Lightning injuries are divided into direct strikes, side splash, contact injury, and ground current. Ground current occurs when the lightning strikes nearby and travels to the person through the ground. Side splash makes up about a third of cases and occurs when lightning strikes nearby and jumps through the air to the person. Contact injury occurs when the person is touching the object that is hit. Direct strikes make up about 5% of injuries. The mechanism of the injuries may include electrical injury, burns from heat, and mechanical trauma. Diagnosis is typically based on history of the injury and examination. Prevention includes avoiding being outdoors during a thunderstorm, and sheltering in a fully enclosed structure (such a closed building or metal car). If being outdoors is unavoidable, bringing the feet and knees together is recommended (if possible, while crouching low in the 'lightning position'— crouched low, hands over ears, feet touching if possible) so as to provide only one point of contact with the ground. When indoors the use of devices connected to electrical outlets and contact with water is not recommended. Among those who appear in cardiac arrest and have no central pulse, cardiopulmonary resuscitation (CPR) should be started. In those who have a central pulse but are not breathing artificial ventilation, such as mouth to mouth, is recommended. As of 2019, it has been estimated that lightning injuries worldwide occur 240,000 times a year with 24,000 deaths. Areas with mountainous terrain and moisture-heavy airflow, such as Central Africa, have the highest rates of lightning strikes. Among pregnant women who are hit by lightning, the death of the fetus occurs in about half. In the United States, about 1 in 10,000 people are hit by lightning during their lifetime. Males are affected four times more often than females. The age group most commonly affected is 20 to 45 years old.

Signs and symptoms

Common injuries caused by lightning include: muscle pains, broken bones, cardiac arrest, confusion, hearing loss, seizures, burns, behavioral changes, and ocular cataracts. Loss of consciousness is very common immediately after a strike. Lightning burns result from energy caused by lightning strikes, and are characterized by a unique pattern of skin lesions. These tree-like lesions resemble feathering or ferning, and are also called Lichtenberg figures. The marks are formed when capillaries beneath the skin rupture due to the electrical discharge and they usually appear "within hours" of the strike though they tend to disappear within a few days. They also generally occur on the upper body. The brief duration of the exposure frequently limits the damage to the outer layer of skin. The intense heat generated by a lightning strike can burn tissue, and cause lung damage, and the chest can be damaged by the mechanical force of rapidly expanding heated air. Just as heat can cause expanding air in the lungs, the explosive shock wave created by lightning (the cause of thunder) can cause concussive and hearing damage at extremely close range. Other physical injury can be caused by objects damaged or thrown by the lightning strike. For example, lightning striking a nearby tree may vaporize sap, and the steam explosion often causes bark and wood fragments to be explosively ejected. Lightning strikes can also induce a transient paralysis known as keraunoparalysis. Signs and symptoms of keraunoparalysis include lack of pulse, pallor or cyanosis, and motor and sensory loss in the extremities. However, keraunoparalysis usually resolves within a few hours.

Pathophysiology Although the current flow of a lightning strike occurs only over a short period, the current has an extremely high voltage of some 30 million volts. Lightning is neither a DC or an AC current but best described as a unidirectional massive current impulse of electrons. Lightning strikes are grouped into four categories: direct strikes, side splash, contact injury, and ground current.

Direct strike: lightning directly hits the person Orifice entry: may occur if lightning strike occurs near the head entering eyes, ears and mouth to flow internally Side splash: lightning jumps from the location of primary strike to a nearby person Contact injury: injury that occurs when a person is touching an object on the pathway of lightning Ground current: lightning strikes nearby and the current travels through the ground to the person Lightning injury may occur by these electrical mechanisms or by secondary blunt trauma as a result of the strike.

Diagnosis Diagnosis is typically based on history of the injury and examination.

Prevention

… excerpt ends here. Continue reading the full article.

Illustrations

Lightning injury illustration
Lightning injury: A person who was affected by a nearby lightning strike. Note the slight branching redness traveling up the victim's leg from the effects of the current.
A person who was affected by a nearby lightning strike. Note the slight branching redness traveling up the victim's leg from the effects of the current.

Worked examples

Example 1 — a first encounter with Lightning injury

Start with the simplest possible case. Write down what Lightning injury 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 Lightning injury 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 Lightning injury 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 Lightning injury

In research
Lightning injury 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 Lightning injury 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
Lightning injury is common in secondary-school and first-year university syllabi. It links to neighbouring topics Injuries from lightning strikes, Lightning, Weather and health, so understanding it makes those chapters shorter.
In everyday life
Look for Lightning injury 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 Lightning injury in 20 minutes

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

Frequently asked questions

What is Lightning injury in simple terms?

Lightning injuries occur when someone is struck by lightning. Initial symptoms may include heart asystole and respiratory arrest.

Why does Lightning injury 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 Lightning injury?

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 Lightning injury.

Tags

  • Injuries from lightning strikes
  • Lightning
  • Weather and health

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