science

Pressure ridge (lava)

Pressure ridge (lava) is a 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 Pressure ridge (lava) rather than just read about it. In short: In volcanology, a pressure ridge or a tumulus (plural: tumuli), and rarely referred to as a schollendome, is sometimes created in an active lava flow. Formation Formation occurs when the outer edges and surfaces of the lava flow begin to harden.

Key takeaways

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

Reference excerpt

In volcanology, a pressure ridge or a tumulus (plural: tumuli), and rarely referred to as a schollendome, is sometimes created in an active lava flow.

Formation Formation occurs when the outer edges and surfaces of the lava flow begin to harden. If the advancing lava underneath becomes restricted it may push up on the hardened crust, tilting it outward. Inflation also takes place and is a process where the plastic layer of lava underneath expands as it cools and small crystals form. The result is a raised mound of hardened lava rock, usually a relatively narrow but long ridge. Tension cracks form on the surface of pressure ridges and run along the axis of elongated ridges, and at both edges of broader ridges, sometimes referred to as pressure plateaus. Along the edges of a pressure ridge, if the tension crack is large enough it will create a liftup cave. Other caves can form inside pressure ridges in which conditions arose for the ridge to form and but the lava that created the internal pressure quickly drained leaving an inflationary cave. Pressure ridges may reach heights of 15 meters or more and lengths range more than 500 meters but most are less than 100 meters.

Pressure plateaus Similar to pressure ridges, pressure plateaus are uplifted areas of a ponded lava flow. Instead of narrow and elongated, pressure plateaus are generally wide and long with an amorphous shape. They are formed when the volume of lava funneled by a lava tube exceeds the capacity of the flow front to expand.

See also Pressure ridge (seismic), in a fault zone

References

Further reading Walker, George P L (1991). "Structure, and origin by injection of lava under surface crust, of tumuli, 'lava rises', 'lava-rise pits', and 'lava-inflation clefts' in Hawaii". Bulletin of Volcanology. 53 (7): 546–58. doi:10.1007/BF00298155. S2CID 53544868. Rossi, M.J; Gudmundsson, A (1996). "The morphology and formation of flow-lobe tumuli on Icelandic shield volcanoes". Journal of Volcanology and Geothermal Research. 72 (3–4): 291–308. doi:10.1016/0377-0273(96)00014-5. Glaze, L. S (2005). "Statistical distribution of tumuli on pahoehoe flow surfaces: Analysis of examples in Hawaii and Iceland and potential applications to lava flows on Mars". Journal of Geophysical Research. 110 (B8): B08202. doi:10.1029/2004JB003564. Appelgate, Bruce; Embley, Robert W (1992). "Submarine tumuli and inflated tube-fed lava flows on Axial Volcano, Juan de Fuca Ridge". Bulletin of Volcanology. 54 (6): 447–58. doi:10.1007/BF00301391. S2CID 128822196.

Illustrations

Worked examples

Example 1 — a first encounter with Pressure ridge (lava)

Start with the simplest possible case. Write down what Pressure ridge (lava) claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In 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 Pressure ridge (lava) 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 Pressure ridge (lava) 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 Pressure ridge (lava)

In research: Pressure ridge (lava) appears in 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 Pressure ridge (lava) 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: Pressure ridge (lava) is common in secondary-school and first-year university syllabi. It links to neighbouring topics Lava caves, Lava flows, so understanding it makes those chapters shorter.
In everyday life: Look for Pressure ridge (lava) 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.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Pressure ridge (lava)” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Pressure ridge (lava) in 20 minutes

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

Frequently asked questions

What is Pressure ridge (lava) in simple terms?

In volcanology, a pressure ridge or a tumulus (plural: tumuli), and rarely referred to as a schollendome, is sometimes created in an active lava flow. Formation Formation occurs when the outer edges and surfaces of the lava flow begin to harden.

Why does Pressure ridge (lava) matter?

Because it connects several 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 Pressure ridge (lava)?

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 Pressure ridge (lava).