physics

ShakeMap

ShakeMap is a physics 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 ShakeMap rather than just read about it. In short: ShakeMap is a product of the U.S. Geological Survey (USGS) to map the shaking of earthquakes.

Key takeaways

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

Reference excerpt

ShakeMap is a product of the U.S. Geological Survey (USGS) to map the shaking of earthquakes. According to the USGS, "ShakeMaps provide near-real-time maps of ground motion and shaking intensity following significant earthquakes. These maps are used by federal, state, and local organizations, both public and private, for post-earthquake response and recovery, public and scientific information, as well as for preparedness exercises and disaster planning." The system's development was led largely by USGS seismologist David J. Wald with others. ShakeMap's goal is to "go beyond magnitude and epicenter" to depict the variations in the distribution of shaking intensity. Here, "shaking intensity" is used informally, as in "how intense was the shaking?" ShakeMap is now an open-source software program employed to automatically produce a suite of maps and products that portray the geographical extent and severity of potentially damaging shaking following an earthquake. It is routinely used to provide post-earthquake situational awareness for emergency management and response and for damage and loss estimation. ShakeMap is also the primary shaking hazard input for many other downstream USGS earthquake products, including ShakeCast's assessments of critical facilities, PAGER's societal losses, and estimates of ground failure.

References

Illustrations

Worked examples

Example 1 — a first encounter with ShakeMap

Start with the simplest possible case. Write down what ShakeMap claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, 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 ShakeMap 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 ShakeMap 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 ShakeMap

In research: ShakeMap appears in physics 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 ShakeMap 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: ShakeMap is common in secondary-school and first-year university syllabi. It links to neighbouring topics Disaster management tools, Geophysics stubs, Maps, so understanding it makes those chapters shorter.
In everyday life: Look for ShakeMap 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 ShakeMap in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what ShakeMap 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 ShakeMap out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is ShakeMap in simple terms?

ShakeMap is a product of the U.S. Geological Survey (USGS) to map the shaking of earthquakes.

Why does ShakeMap matter?

Because it connects several physics 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 ShakeMap?

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 ShakeMap.