Answering Islam - A Christian-Muslim dialog

Are Mountains “Pegs” Which Prevent the Earth from Shaking?

Andrew Vargo


The Qur’an, in several passages, tells us that Allah placed mountains on the earth so that the earth would not shake:

Sura 16:15 : And He has set up on the earth mountains standing firm, lest it should shake with you; and rivers and roads; that ye may guide yourselves;

Sura 21:31 : And We have set on the earth mountains standing firm, lest it should shake with them, and We have made therein broad highways (between mountains) for them to pass through: that they may receive Guidance.

Sura 31:10 : He created the heavens without any pillars that ye can see; He set on the earth mountains standing firm, lest it should shake with you;

Sura 78:7 : And the mountains as pegs?

Sura 79:32-33 : And the mountains hath He firmly fixed;- For use and convenience to you and your cattle.

Note that only Sura 78:7 refers to mountains as “pegs”. The Qur’an says nothing about mountains having “roots”. However, as we look at several Muslim arguments, Muslim apologists often refer to the “roots” of mountains as “pegs” in an attempt to align the term with the Qur’an. Muslims see this as a “miracle” since Muhammad could not have known that mountains had “roots” – so Muhammad’s reference to mountain roots (in spite of the fact that the Qur’an uses the term pegs and not roots) could only come from Allah. However, the existence of the roots of mountains was known in ancient times. Here are three verses from the Bible:

Job 28:9 : People assault the flinty rock with their hands and lay bare the roots of the mountains.

Psalm 18:7 : The earth trembled and quaked, and the foundations of the mountains shook; they trembled because he was angry.

Jonah 2:6 : To the roots of the mountains I sank down; the earth beneath barred me in forever. But you, LORD my God, brought my life up from the pit.

It is semantically incorrect to equate “roots” with “pegs” because “roots” are not the same as “pegs”. Roots are the result of natural processes. In the case of mountains, the “roots” are created by the collision, and subduction, of continental plates. “Pegs” are made by humans and are driven into the ground by humans. It should also be mentioned that not all mountains, such as volcanoes, have roots.

Some might read these passages as poetry; others might read it as an allegory. Others might read these passages and conclude that people in those days believed that the earth was flat and saw mountains serving a similar purpose as paperweights, holding the earth still. However, there are some Muslims who see these verses as “proof” that the Qur’an is miraculous because it discusses scientific concepts unknown to people in the ancient world. In fact, if you query Google for the terms mountains pegs miracle there are more than 3000 hits!

George Sale (cited by Wherry) tells us:

"The Muhammadans suppose that the earth, when first created, was smooth and equal, and thereby liable to a circular motion as well as the celestial orbs; and that the angels asking who could be able to stand on so tottering a frame, God fixed it the next morning by throwing the mountains on it."

The Tafsir al-Jalalayn says:

and the mountains pegs?, with which the earth is tied down like tents are tied down with pegs (the interrogative is meant as an affirmative).

Problems: Facts and Logic

The most obvious problem, with the idea that mountains prevent the earth from shaking, is that there are earthquakes each and every day on planet earth. Anyone can go on the United States Geological Survey site Latest Earthquakes in the World - Past 7 days to see where Magnitude 4.5, and above, earthquakes have occurred. Please go to this site and notice where the past week’s earthquakes have taken place: western North and South America, the Aleutian Islands, the Pacific “Ring of Fire”, and the Himalayas – all are regions with large mountains! Also, take a look at the Latest Earthquakes in the USA - Last 7 days and notice where these take place - in the Rocky and Cascade Mountains in the west and in the Appalachian Mountains of the east!

Mountains are created and formed by the movement and collision of tectonic plates and by volcanic forces – not by Allah placing them on the surface of the planet. Tectonic plates collide, creating mountains such as the Himalayas and the heat generated from one plate sub-ducting (or sliding) under another plate creates volcanoes such as the Cascade Mountains. These areas, as can be plainly seen in the USGS map, are where earthquakes occur.

In addition to these factual errors, the Qur’an is simply not logical when it refers to mountains as “pegs”. A peg is used to fix, or anchor, something – such as a tent – to the ground. So, if mountains are “pegs”, as the Qur’an says, exactly to what do mountains “peg” the earth? Do they “peg” the earth to itself? That would be absurd!

However, no argument appears to be absurd when it supports the Qur’an. One Muslim apologist tells us:

Mountains do hold the tectonic plates together and also do function as buffer against earthquakes! There’s plenty of research confirming this, don't let these pseudo-scientists tell you otherwise. The problem is, although mountains do all this, they are in the first place created by the movement of the tectonic plates and earthquakes. Therefor people naturally assume that since they are created by it, they cannot afterwards negate the effect. But that assumption is wrong. While it is true that Allah subhana wa ta'ala creates mountains trough tectonic movement and earthquakes; once that those mountains are big enough they do counter the effect. In that sense the analogy with the apple is also very deceiving. The two are hardly comparable. The presence of mountains, especially the older and bigger ones has a huge effect in buffering earthquakes.

This is incorrect because it confuses cause and effect. Mountains are created by the collision of tectonic plates – a process that does not stabilize the earth, but is the cause of earthquakes. In other words, the mountain is the effect of the collision of tectonic plates and plate movement slows because one plate impacts the other and the formation of mountains has nothing to do with this.

The author also cites a scientific paper which tells us:

"San Gabriel Mountains act as a natural seismic insulator for metropolitan Los Angeles. The topography of the mountains scatters the surface waves generated by the rupture on the San Andreas fault, leading to less-efficient excitation of basin-edge generated waves and natural resonances within the Los Angeles Basin. The effect of the mountains reduces the peak amplitude of ground velocity for some regions in the basin by as much as 50% in the frequency band up to 0.5 Hz. These results suggest that, depending on the relative location of faulting and the nearby large-scale topography, the topography can shield some areas from ground shaking."

The idea that the topography of these mountains reduces the peak amplitude of surface waves, in some places, is interesting. However, these mountains obviously do not prevent earthquakes in the Los Angeles Basin. Since this article discusses the surface topography of mountains, in relation to earthquakes, the mountains do not serve as “pegs”.

The Dishonest Abuse/Misuse of Sources to Support the Qur’an’s “Miracle”

Muslims attempt to rescue their Qur’an from these obvious errors by asserting that mountains are actually “pegs” and proclaim this a miracle! Muslim apologists turn to a number of Geology texts and suspend any pretense of intellectual honesty by removing the author’s text, from the illustrations that they present, and insert their own text. After all, Muslims cannot cite one single Geologist who claims that mountains are “pegs”, or that they prevent earthquakes.

Some Islamic websites (e.g., 1, 2) cite a Geology text book, Earth, by Frank Press. The Muslims cite incorrectly and dishonestly reproduce an image from this text:

Figure 7: Mountains have deep roots under the surface of the ground. (Earth, Press and Siever, p. 413.)

There are two problems with this citation.

First, this image appears on page 429, not page 413 and, as discussed previously, “roots” are not the same as “pegs”. [The Muslims have not specified which edition of this text book they are referring to. I consulted the fourth edition published in 1985.]

The second, and larger, problem is that the Muslims removed the original text from Press’s book and inserted their text under the illustration to fit their agenda. Compare the above text (quoted from a Muslim website) with the image taken from the book that the Muslims claim to cite:

Professor Press used this picture to illustrate the principle of isostasy – that instead of mountains being “pegs” that hold the earth’s surface preventing movement, they, and the rest of the crust, are floating on the mantle.

Here is the text (pages 428-429):

Nowadays seismologist are excited by the finer detail, the variations within the crust, mantle, and core. Consider the lateral variations in crustal thickness in a section extending from continent to ocean, as shown in Figure 17-38; it is one of the most importation recent seismological results. The thickness of the crust varies from about 35 kilometers to 10 kilometers in a section extending for continent to ocean. Under a high mountain the crust thickens to as much as 65 kilometers. If Figure 17-38 suggests to the reader that the continental crust floats on the denser mantle like an iceberg on the ocean, he has made a good observation. Icebergs float because they are less dense than sea water; floatation comes from the large volume of ice that lies below the sea surface. When Archimedes' principle of buoyancy is applied to the floatation of continents and mountains, it becomes the principle of isostasy, ...

Professor Press says absolutely nothing concerning mountains “stabilizing” the earth or preventing earthquakes. Not to be out-done by the facts, one Muslim website proclaims the idea of isostasy as a proof of a “scientific miracle” of the Qur’an, saying:

Actually, the crust of the earth floats on a liquid. This outermost layer of the earth extends 5 km from the surface. The depths of the mountain strata go as far down as 35 km. Thus, the mountains are sort of pegs driven into the earth. Just like the pegs used to stabilize a tent on the ground, so these pegs stabilize the crust of the earth. Mountains are the outcome of collisions between strata of the earth’s crust; the result of the encroachment of a given stratum on another one. These strata that go deeper and deeper enable the crust layers to integrate. [Emphasis ours]

The obvious fallacy here is that mountains are a part of the earth’s crust which also “float” on the mantle along with the rest of the earth’s crust. Pegs cannot hold something firm when they are “floating”! Mountains do not stabilize the earth’s crust through isostacy, it is the crust that stabilizes itself through its own isostacy. Additionally, the collisions between the tectonic plates, of the earth’s crust, that cause earthquakes rather than prevent them.

One of the more bizarre claims made by some Muslim apologists is

By fixing the Earth’s crust they prevent any sliding over the magma layer or amongst the layers themselves. In short, mountains can be compared to nails holding strips of wood together. The fixing effect of mountains is known as isostasy in scientific literature.

Muslims simply cannot decide what isostasy is! Professor Press, whom numerous Muslim websites mentions, says “the crust of the earth floats on a liquid”. So how can mountains play the role of “nails” holding the solid crust to a liquid?

Here are some links to pages that are helpful to learn about isostasy and mountain roots: 1, 2, 3.

Another text, that is abused by Muslim apologists, is Andrae Cailleux’s Anatomy of the Earth. This Muslim website cites this book, once again, dishonestly:

Figure 8: Schematic section. The mountains, like pegs, have deep roots embedded in the ground. (Anatomy of the Earth, Cailleux, p. 220.)

As with Professor Press’ text, the caption has been changed. Note the real caption given by Cailleux:

An image of the complete page is available here.


The notion that mountains prevent the earth from shaking is nonsense that can easily be refuted by simply looking at a map showing where earthquakes occur. There are many Muslim websites which attempt to explain this away, and often produce contradictory arguments. The more serious issue is that Muslims are willing to be dishonest and present counterfeit evidence by copying images out of text books, removing the text describing these images, and then combine the image with a different text to fit their agenda – creating information that the author did not write.

If Muslims believe that Muhammad’s Qur’an is the “truth”, why do they need to lie to prove that it is “true”?

Additional information concerning this topic can be found in these articles/chapters:

For articles on related topics, see the section: Science in the Qur’an