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Of or relating to the deepest regions of the ocean, below about 6,000 meters (20,000 feet).

[French, from Hadès, Hades, from Greek Haidēs; see weid- in Indo-European roots.]


(Physical Geography) of, relating to, or constituting the zones of the oceans deeper than abyssal: below about 6000 metres (18 000 ft). See also abyssal
[C20: from French, from Hadés Hades]


(ˈheɪd l)

of or pertaining to the biogeographic region of the ocean bottom below the abyssal zone, or from approximately 20,000 ft. (6500 m) to the greatest ocean depths.
[1955–60; Had (es) + -al1]
ThesaurusAntonymsRelated WordsSynonymsLegend:
Adj.1.hadal - relating to the deepest parts of the ocean (below 6000 meters)
References in periodicals archive ?
In their pioneering work on the hadal waters, Mantyla and Reid (2) succeeded in hadal water sampling at ~10000 m depth by applying specially designed free-vehicle instruments for the measurement of hydrographic properties (temperature, salinity, dissolved oxygen, and nutrients) in the Marianas Trench area (11-13[degrees]N, 142-146[degrees]E) of the western Pacific Ocean.
In 2009 Katherine Abu Hadal had her first taste of Yemeni food at a nondescript restaurant in Sana'a.
The hadal zone is the name given to the deepest depths of the ocean, named after hades as the underworld god of Greek mythology.
The HADEEP projects (Universities of Aberdeen, UK, and Tokyo, Japan, and NIWA, New Zealand) have conducted baited camera surveys in five hadal trenches of the Pacific Rim since 2007.
The hadal zone extends from around six kilometers to the deepest seafloor.
They are found throughout the world's oceans in an amazing assortment of habitats: level-bottom muds subtidally on the continental shelf to hadal depths >7,000 m in deep-sea trenches, interstitially in sands, upon isolated seamounts rising from the seafloor at 4,000-m depths, upon octocorals, and from the tropics to polar regions.
13 The hadal zone is a termused for the lowest part of what?
It does not stop until it reaches the bottom of the Hadal Zone, 11 kilometres below the surface.
The hadal zone consists of the deepest ocean trenches.
When asked about the safety of sending people into the hadal zone -- the Hades zone, or depths greater than 6,000 m -- Hawkes replies, "the only sure way to be safe is to be dead.
Since the retirement of the Trieste and the French bathyscaphe Archimede in the early 1960s, no nation has had the capability to dive much below 10,000 feet (6000 meters) into the unexplored hadal zone, located pormarily in the deep canyons winding around the Pacific Rim and into the Indian Ocean and the Caribbean Sea.