The Congo River is the second-longest river in Africa (the Nile River being the longest). It is also the second-largest in the world by discharge volume, with an average of 1,400,000 cubic ft/s (41,000 m³/s). The river is famous for two things – one of which is, obviously, the topic of this article.
First, the Congo River shelters the highest number of unique species of flora and fauna worldwide – that’s more than just impressive! Then, to top this off, so to speak, the river is also the deepest recorded ever.
The Congo River can reach depths of around 720 ft (219.5 m) across the 2,922 mi (4,700 km) that it travels. As in the case of lakes and seas, the depth of the river varies and is influenced by the area, elevation, discharge, water speed, level, or riverbed erosion, among many others.
However, this information is only the beginning, as many more things can be said about the deepest recorded river in the world; let’s find out more about it!
What is the average depth of the Congo River?
The Congo River has a maximum depth of 720 ft (219.5 m). However, the average depth of the river is 32.8 to 262.4 ft (10 to 80 m), according to the research paper that analyzed the river’s depth at various points. The maximum depth mentioned is considered abnormal, with most parts of the river having a normal depth.
The Congo River is the deepest major river in the world, both at its lowest point and on average – making it even more impressive. Compared to the Nile, which has an average depth of 26.2 to 36 ft (8 to 11 m), the Congo River is still deeper than usual. The Amazon has an average depth of 66 to 164 ft (20 to 50 m), and its deepest point stands at 330 ft (100 m) below the surface.
What part of the Congo River is deepest?
The deepest parts of the Congo River can be found between Malebo Pool and Pioka. This section is located in the Lower Congo part of the river. It has been subject to intense measurements, especially in 2009. Then, it was believed that the Lower Congo River was the deepest in the world – now, that is no longer an assumption but the truth.
Pool Malebo can make for a great holiday in Africa. Located in Brazzaville, it is where the Congo River meets a fragmented island, Ile M’Bamou, and splits in two. Then, the sections meet again, forming two spectacular river banks for Brazzaville. There’s a beach and different trails that can be explored here.
While Malebo Pool looks calm and can sometimes be explored by boat, the same cannot be said of the previous and upcoming sections of the Congo River. These feature dangerous rapids and deep underwater gorges.
How is the Congo River so deep?
This is where things get exciting and a bit complicated!
The channel formed by the Congo River resembles a mountain stream with a steep slope (hence a rapid water flow) and a significant discharge volume. It is believed that what once was a short mountain river eroded the stretch before Malebo Pool. The main result was the formation of the Lower Congo part of the river, which now hosts the river’s deepest part, mainly due to the increased levels of erosion.
Some compare it to the Grand Canyon – in both aspect and formation. The differences are that the Congo River is much smaller in-depth and full of water.
However, speaking of erosion, it is essential to highlight why the Congo River has an immense erosion power compared to other similar rivers, such as the Amazon. After all, every area featuring flowing water is susceptible to erosion – but not all areas have such impressive depths as the Congo River.
The Congo River drops 656 ft (200 m) in altitude when reaching sea level in its final 62.1 mi (100 km). When it’s 186 mi (300 km) from the ocean, the river’s series of gorges starts, making it drop 12 ft (3.6 m) every mile. The deepest portion of the river and its erosion power are attributed to the river’s height profile and water volume.
In comparison, the Amazon River drops 656 feet (200 m) in altitude to sea level over 3,107 mi (5,000 km). The sudden drop of the Congo River provides the significant water volume of the river (1,400,000 cubic ft/s (41,000 m3/s)) with enough erosion power to carve the now-deepest stretch of the river.
What’s at the bottom of the Congo River?
The bottom of the Congo River features a grinding landscape – currents running both down- and upstream that strip fauna and sediments off massive rocky towers. The landscape creates conditions suitable for the formation of water pockets that isolate fish populations. As a result, the evolution of new species is favored.
The deepest part of the Congo River is often compared with the ocean’s twilight zone. Its depth is too much even for light to penetrate. As such, you can be sure that, besides the grinding landscape, interesting species of fish dwell down there.
One of these species is the mondelli bureau, dubbed the strange, blind fish. How did scientists find out about these fish? They sometimes get caught up in the currents surrounding the water pockets mentioned above. The currents grab the mondelli bureau and propel them towards the surface at incredible speeds. The fish reach the surface dead, with their swim bladders destroyed. Five other fish species in the Lower Congo part of the river are similar to the mondelli bureau. They have evolved with elongated forms, lost their scale pigment, and shrunk their eyes during the evolutionary process.
The environment and life at the bottom of the deepest parts of the Congo River are influenced not only by its depth but also by its incredibly powerful currents.
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