A mountainis an elevated portion of the Earth’s crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher than a hill, typically rising at least 300 metres (980 ft) above the surrounding land.

Mountains are formed through tectonic forces, erosion, or volcanism, which act on time scales of up to tens of millions of years. Once mountain building ceases, mountains are slowly leveled through the action of weathering, through slumping and other forms of mass wasting, as well as through erosion by rivers and glaciers. 

The highest mountain on Earth is Mount Everest in the Himalayas of Asia, whose summit is 8,850 m (29,035 ft) above mean sea level. The highest known mountain on any planet in the Solar System is Olympus Mons on Mars at 21,171 m (69,459 ft).

The Quran has referred to mountains as “pegs” –  defined as a small pointed piece of wood or metal that attach to the ropes of a tent and push into the ground in order to hold the tent in place”. Mountains can have a underground component as large or larger than their visible parts and that submerge part is referred as peg in Quran. The “peg” can provide functional sturdiness to the mountain and allows them to rise above ground without marked instability. Geologist and Geomorphologist conformed that the mountains extend down in the lithosphere several time deeper than the elevation exposed above the surface. Just like mountains most part of the peg or picket is usually hidden in rock or soil to hold something
on the ground therefore the term peg or picket seem to be literally and scientifically more correct description for downward extended part of the mountain than the term root (Amy, 2013; El-Naggar, 1992 ). The height of Mount Everest is approximately 09 km (8845m or 29,029 feet) above sea level, has a root deeper than 125 km. Besides the plate tectonics theory and mountains having deep roots/pegs was introduced only in the latter half of the nineteenth century or the beginning of the 20th century (Oreskes, 2003). The Quran clearly mentions this phenomenon over 1400 years ago!

The second important fact stated is role of mountains as stabilizer. The Quran states

“And He has affixed into the earth mountains standing firm, lest it should shake with you, and rivers and roads, that you may guide yourselves” (Quran 16:15)

According to Ma et al. (2007) San Gabriel Mountains of California help protect Los Angeles from shaking during Earthquake.  They showed a specific example studying the effect of the San Gabriel Mountains, which are bounded by the Mojave segment of the San Andreas fault on the north and by the Los Angeles Basin on the south. By simulating a M_w 7.5 earthquake on the Mojave segment of the San Andreas fault, they show that the 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.

 Similar results have been reported by Shiann et al. (2009). They studied the relationship and influence of source location, depth and the rupture process on topographic effects in the Taipei basin and the central mountain range (CMR) of Northern Taiwan. The study reveals that the central mountain range substantially disperses the surface waves and, therefore, reduces ground shaking in the Taipei basin.

These studies reveal that the geographic topography (the arrangement of the natural and artificial physical features of an area) with mountain ranges can help insulate and protect the inter mountain basins from seismic ground shaking. The Quran mentions this fact over 1400 years ago!