Why those waters do not mix?

Dr. Muzaffer Hussain 🌊

The descriptions of salt and fresh water in the Quran, particularly in Surah Ar-Rahman (Chapter 55, Verses 19-20) and Surah Al-Furqan (Chapter 25, Verse 53), have been subjects of intrigue and reflection within both theological and scientific communities. These verses elucidate the phenomenon of the meeting of two distinct bodies of water—one fresh and sweet, the other salty and bitter—while maintaining a barrier between them that prevents their mixing. This barrier is referred to as "Barzakh" in the Quran.

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The Quran provides descriptions of salt water and fresh water in several verses, highlighting the significance, properties, and divine wisdom behind their creation. Two notable chapters (Surahs) that mention these concepts are Surah Al-Furqan (The Criterion) and Surah Ar-Rahman (The Beneficent).

Surah Ar-Rahman (Chapter 55)

In Surah Ar-Rahman, specifically in verses 19-20, the Quran mentions the meeting of two seas, one sweet and fresh, and the other salty and bitter. It also talks about the existence of a barrier (Barzakh) between them that they do not transgress:

"He released the two seas, meeting [side by side]; Between them is a barrier [so] neither of them transgresses." (Quran 55:19-20)

These verses are often interpreted to refer to the phenomenon where fresh and saltwater meet but do not mix immediately, such as in estuaries or where rivers flow into seas, a concept that has intrigued many for its scientific implications.

Surah Al-Furqan (Chapter 25)

In Surah Al-Furqan, verse 53, the Quran again brings attention to the phenomenon of fresh and saltwater meeting:

"And it is He who has released [simultaneously] the two seas, one fresh and sweet and one salty and bitter, and He placed between them a barrier and prohibiting partition." (Quran 25:53)

This verse emphasizes God's power and wisdom in creating distinct types of water bodies, each serving different purposes in the sustenance of life on Earth.

Significance in the Quran

These references in the Quran are significant for several reasons:

• They serve to illustrate the power, wisdom, and mercy of God in creating and sustaining life.
• They draw attention to the miraculous nature of water as a source of life and its unique properties.
• They encourage reflection and appreciation for the natural world and its carefully maintained balance, urging humans to ponder their relationship with the environment and their stewardship of God's creation.
• The Quran's discussion of fresh and salt water, and the barriers between them, has fascinated both believers and scholars. It highlights the deep engagement with the natural world and its phenomena, inviting readers to reflect on the signs of divine craftsmanship present in the environment around them.

Scientific Perspective 

Halocline: The Barrier Between Fresh and Salt Water

From a scientific viewpoint, the description of the barrier between fresh and saltwater can be understood through the concept of a halocline, which is a form of thermocline or pycnocline where there is a sharp salinity gradient between layers of water. This gradient acts as a barrier that limits the mixing of saline water with fresh water, preserving their unique characteristics over distances.

Estuaries and the Meeting of Waters

Estuaries, where freshwater rivers meet the sea, present a vivid illustration of this phenomenon. In these environments, fresh and saltwater mix to varying degrees, influenced by factors like the volume of river discharge, tidal movements, and the topography of the estuary. However, the mixing is not immediate or complete, often resulting in brackish water—a mixture with salinity levels between those of fresh and salt water.

Oceanographic Features

Oceanographic features such as underwater density currents also demonstrate the Quranic description. For example, the Mediterranean Sea and Atlantic Ocean meet at the Strait of Gibraltar, where denser, saltier Mediterranean water flows into the Atlantic under a layer of fresher Atlantic water. This creates a distinct separation that can persist for considerable distances.

Implications for Understanding and Reflection

The Quranic verses encourage contemplation of the natural world and its phenomena as signs of divine creativity and order. The scientific exploration of the barriers between salt and fresh water aligns with the Quranic invitation to observe and reflect on the intricacies of creation. These verses highlight the meticulous balance and purposeful design inherent in natural systems, serving both spiritual reflection and scientific curiosity.

Conclusion

The Quran's references to the meeting of fresh and salt water, and the existence of a barrier between them, resonate with contemporary scientific understandings of marine and freshwater systems. These verses underscore the marvels of creation and the harmony within natural laws, inviting a deeper appreciation of the world around us through both spiritual and scientific lenses. This convergence of religious text and scientific discovery enriches our understanding of the natural world, offering a multidimensional perspective that spans beyond the mere physical to encompass spiritual significance and reflection.