{"id":497010,"date":"2026-06-13T01:41:10","date_gmt":"2026-06-13T01:41:10","guid":{"rendered":"https:\/\/www.newsbeep.com\/ie\/497010\/"},"modified":"2026-06-13T01:41:10","modified_gmt":"2026-06-13T01:41:10","slug":"earths-largest-waterfall-is-hidden-underwater-in-the-denmark-strait-between-iceland-and-greenland-where-dense-cold-water-plunges-about-3500-meters-down-the-seafloor-far-exceeding-any-waterfall-on","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ie\/497010\/","title":{"rendered":"Earth’s largest waterfall is hidden underwater in the Denmark Strait between Iceland and Greenland, where dense cold water plunges about 3,500 meters down the seafloor, far exceeding any waterfall on land in drop height and volume"},"content":{"rendered":"

The tallest waterfall on Earth sits unseen on the seafloor between Iceland and Greenland, with no spray and no audible roar, and the water that pours over it moves not through air but through more water. The Denmark Strait cataract<\/a>, as oceanographers call it, drops about 11,500 feet, down a slope on the ocean floor. That is more than three times the height of Angel Falls in Venezuela, the tallest waterfall on land.<\/p>\n

The mechanism turns on density, and it ends up shaping the circulation of the entire Atlantic.<\/p>\n

What makes a waterfall, and why an underwater one counts<\/p>\n

A waterfall on land works because gravity pulls water down a cliff faster than the riverbed below can carry it away. Underwater, the same logic holds, but the trigger is not a cliff of rock. It is a difference in density between two bodies of water that resist mixing.<\/p>\n

Cold water is heavier than warm water. In the Denmark Strait, frigid water from the Nordic Seas meets warmer water from the Irminger Sea, and because the cold mass is denser, it slides underneath and spills down the sloping seabed. The result behaves like a waterfall, even though there is no visible drop and nothing crashes. Mike Clare<\/a>, who leads marine geosystems work at the National Oceanography Centre in Southampton, puts the geometry plainly: \u201cIf we visualize it, it looks like a relatively low-gradient slope.\u201d There is no sheer wall, just a long, deep incline that the dense water creeps over.<\/p>\n

The descent is so gradual that little appears to be happening at all. Clare notes<\/a> that \u201cif you were down there, you probably wouldn\u2019t notice a whole heap going on.\u201d The cataract moves at roughly 1.6 feet per second<\/a>, about half a metre per second \u2014 far slower than the dramatic plunge of water over Niagara Falls. The drama is in the volume and the depth, not the speed.<\/p>\n

How the Denmark Strait cataract forms<\/p>\n

The surface gives no sign of what\u2019s happening below. Anna Sanchez Vidal<\/a>, a marine science professor at the University of Barcelona who led a 2023 expedition to the strait, described the contrast: \u201cAt the surface, you have typical sunny Arctic conditions.\u201d Everything that makes this the largest waterfall on the planet is happening hundreds of metres below.<\/p>\n

Not all of the cold water takes the plunge. North of the cataract, only the bottom 660 feet<\/a> of the roughly 1,300-foot-deep water column is cold and dense enough to cascade down the slope, forming a dense layer around 200 metres thick. The upper half mixes with surface water heading north instead.<\/p>\n

The slope itself was carved long ago. Glaciers shaped it<\/a> during the last ice age, between roughly 17,500 and 11,500 years ago, leaving behind the topography the overflow now follows.<\/p>\n

Scale that defies comparison<\/p>\n

The numbers are what make the cataract hard to picture against anything on land. Angel Falls drops 3,212 feet<\/a>, roughly 980 metres. The Denmark Strait drop is more than three times that. Even the portion, before the cold water reaches the deep pool spanning the rest of the slope, runs to around 2,000 metres<\/a>, still roughly double Angel Falls.<\/p>\n

The flow rate is the second huge thing. The overflow is estimated to move about 3.5 million cubic metres of water per second<\/a> across the sill. The cataract is also extraordinarily broad, running roughly 300 miles (480km) wide.<\/a><\/p>\n

Why it matters beyond the record books<\/p>\n

The cataract is not simply a curiosity of superlatives. It is one of the engines of the Atlantic\u2019s deep circulation, the slow conveyor that carries heat and dense water around the globe. The cold, dense water that pours over the slope feeds the lower limb of the Atlantic Meridional Overturning Circulation<\/a>, the global conveyor belt that moves heat, oxygen, and nutrients around the planet.<\/p>\n","protected":false},"excerpt":{"rendered":"The tallest waterfall on Earth sits unseen on the seafloor between Iceland and Greenland, with no spray and…\n","protected":false},"author":2,"featured_media":497011,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[61,60,82],"class_list":["post-497010","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-ie","tag-ireland","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/497010","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/comments?post=497010"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/497010\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media\/497011"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media?parent=497010"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/categories?post=497010"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/tags?post=497010"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}