earth science

Michoud fault

Michoud fault 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 Michoud fault rather than just read about it. In short: The Michoud fault is a geological fault that runs through eastern New Orleans. The Michoud fault is the subject of extensive scientific inquiry into why Louisiana is losing vast tracts of land.

Key takeaways

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

Reference excerpt

The Michoud fault is a geological fault that runs through eastern New Orleans. The Michoud fault is the subject of extensive scientific inquiry into why Louisiana is losing vast tracts of land. Subsurface mapping identified the Michoud fault, on the basis of well cutoffs and seismic surveys. Sedimentary growth implies that movement along the Michoud fault has been intermittent since Oligocene time (Bebout and Gutierrez, 1983). A cross section in McBride (1998) shows a high-angle normal fault that was correlated by Dokka (2006) with the Michoud fault. This fault merges with a low-angle detachment fault at –7 km deep that developed along the top of a slightly south-dipping zone of weak salt and shale. These structures are considered to be related to a regional south-vergent extensional-contractional complex described by Peel et al. (1995; Fig. 1). Movement of the complex and thus on the Michaud fault reflects gravitational instabilities and down-dip motion during times of high sedimentation (Peel et al., 1995). The Michoud fault belongs to a class of geologic structures known as growth faults (Mauduit, T., Brun, J. P. 1998). Growth faults are common geologic structures of regions undergoing high sedimentation rates, such as river deltas and passive margins. They often develop where weak rock layers (detachments) such as salt, anhydrite, or shale underlie regions of rapid sedimentation. These weak zones allow the growing mass of material above them to slide downhill, either continuously or episodically. These downslope movements will be correspondingly experienced in the headwall region (such as that occupied by the Michoud fault) either as slow (barely perceptible) or rapid (catastrophic) subsidence. Growth faults are also sometimes called "listric faults", implying that the fault is a concave-upward surface that transforms nearly vertical displacements at the surface into nearly horizontal ones at depth. The Michoud fault is not unexpected or unusual as a geologic feature of the Mississippi River Delta. Holocene faulting and tilting is widely recognized in many world deltas, such as the Nile, the Ganges-Brahmaputra, the Yangtze, the Po River, and the Rhine.

References Bebout, D.G., and Gutiérrez, D.R., 1983, Regional cross sections, Louisiana Gulf Coast: Baton Rouge, Louisiana Geological Survey Folio Series 6, 10 p. Dokka R.K., 2006. Modern-day tectonic subsidence in coastal Louisiana. Geology vol. 34, p. 281-284.[1] Hickey, M., and Sabate, R., eds.,1972, Tectonic map of Gulf coast region, U.S.A.: Tulsa, Oklahoma, Gulf Coast Association of Geological Societies and American Association of Petroleum Geologists, Scale 1:1,000,000 Peel, F.J., Travis, C.J., and Hossack, J.R., 1995, Genetic structural provinces and salt tectonics of the Cenozoic offshore U.S. Gulf of Mexico: A preliminary analysis, in Jackson, M.P.A., et al., eds., Salt tectonics: A global perspective: American Association of Petroleum Geologists Memoir 65, p. 153–175. Törnqvist, T.E., Bick, S.J., van der Borg, K., and de Jong, A.F.M., 2006. How stable is the Mississippi Delta? Geology vol. 34, p. 697-700.[2] Mauduit, T., Brun, J. P. 1998. Growth fault/rollover systems: Birth, growth, and decay. J. Geophys. Res. Vol. 103, No. B8, p. 18,119-18,136.

References

External links Fault Motion Animation Tectonic control of subsidence and southward displacement of southeast Louisiana with respect to stable North America Baton Rouge - Denham Springs Fault System, Lake Pontchartrain

Illustrations

Worked examples

Example 1 — a first encounter with Michoud fault

Start with the simplest possible case. Write down what Michoud fault 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 Michoud fault 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 Michoud fault 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 Michoud fault

In research: Michoud fault 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 Michoud fault 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: Michoud fault is common in secondary-school and first-year university syllabi. It links to neighbouring topics Geographic areas of seismological interest, Geology of Louisiana, Seismic faults of the United States, so understanding it makes those chapters shorter.
In everyday life: Look for Michoud fault 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 Michoud fault in 20 minutes

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

Frequently asked questions

What is Michoud fault in simple terms?

The Michoud fault is a geological fault that runs through eastern New Orleans. The Michoud fault is the subject of extensive scientific inquiry into why Louisiana is losing vast tracts of land.

Why does Michoud fault 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 Michoud fault?

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 Michoud fault.