Question: Is there any deeper canyon on earth than the Grand Canyon?
About the article "Grand Canyon", section "Geography".

Candidate passages:
Zhemchug Canyon is a giant underwater canyon located in the middle of the Bering Sea.
This submarine canyon is the largest canyon in the ocean.
The canyon has a vertical relief of 2600 metres dropping from the shallow shelf the Bering Sea to the depths of the Aleutian Basin.
Zhemchug Canyon is deeper than the Grand Canyon.
Zhemchug Canyon has two main branches, each larger than typical continental margin canyons such as the Monterey Canyon.
What makes the Zhemchug Canyon the largest canyon in the world is not only its great depth, but its large cross-sectional area.
Zhemchug Canyon is the largest submarine canyon in the world, based on drainage area (11,350 km2) and volume (5800 km3). 
Many stretches of the Fraser are named in their own right, starting with the Little Canyon between Yale and Spuzzum, which is officially the lowest reach of the Fraser Canyon (although in regional terms Hope, farther south, is considered a canyon town and to be the southern outlet of the canyon because the highway became more difficult from that point; the river is navigable to Yale).
Between the Spuzzum and Boston Bar was known in the gold rush as the Big Canyon or Black Canyon; there are several named subcanyons of the Big Canyon, most famously Hells Gate Canyon (in some descriptions the Black Canyon is below Hell's Gate).
Above the Big Canyon there are the Lillooet Canyon, Fountain Canyon, Glen Fraser Canyon, Moran Canyon, High Bar Canyon, French Bar Canyon and more all the way up to Soda Creek Canyon near Quesnel.
Upstream from there the river flows in wider country, but in the Robson Valley between Prince George and Tête Jaune Cache, the river enters the Grand Canyon of the Fraser.
The Black Canyon was the site of a shantytown of the same name, much of which was on catwalks on the ramparts of its dark-rock cliffs.
Nearly all tributaries of the Fraser have canyons of varying scale; the few exceptions include the Pitt and the Chilliwack in the Lower Fraser Valley.
The Thompson Canyon, from Lytton to Ashcroft, is a sequence of large canyons of its own, some of them also named, although most British Columbians and travellers think of it as part of the Fraser Canyon.
Other important canyons on tributaries include Coquihalla Canyon, the Bridge River Canyon, Seton Canyon and adjacent Cayoosh Canyon, Pavilion Canyon, Vermilion Canyon (Slok Creek) and Churn Creek Canyon.
The Chilcotin River also has several subcanyons, as does the Chilko River, notably Lava Canyon and another Black Canyon. 
Greenland's Grand Canyon or Grand Canyon of Greenland is a tentative name for the canyon of record length discovered underneath the Greenland ice sheet as reported in the journal "Science" on 30 August 2013 (submitted 29 April 2013), by scientists from the University of Bristol, University of Calgary, and University of Urbino, who described it as a mega-canyon.
Ice-penetrating radar data collected during NASA's Operation IceBridge showed a huge subglacial canyon running from the central region of the island northward into the Arctic Ocean, to the fjord of the Petermann Glacier.
The canyon is likely to have influenced basal water flow from the ice sheet interior to the margin.
Jonathan Bamber, a geographer at University of Bristol, stated, "The distinctive V-shaped walls and flat bottom suggests water carved the buried valley, not ice.
"The canyon is more than long, up to deep and wide, making it the longest canyon discovered on the Earth to date.
There are, however, many canyons—including Arizona's Grand Canyon and Xizang's Yarlung Tsangpo Grand Canyon, previously the world's longest—which are deeper.
The canyon predates ice sheet inception and has influenced basal hydrology in Greenland over past glacial cycles.
It is estimated to be at least four million years old, possibly millions of years older.
The mega-canyon has relevance today because it “extends from almost the center of the island and ends beneath the Peterman Glacier found in northern Greenland.
The researchers believe the canyon plays an important role in transporting sub-glacial melt water from the interior of Greenland to the edge of the ice sheet into the ocean.
Evidence suggests that before the presence of the ice sheet, as much as 4 million years ago, water flowed in the canyon from the interior to the coast and was a major river system.
So the mega-canyon is a channel for water to travel from Greenland’s interior to the sea.
A large portion of this data was collected from 2009 through 2012 by NASA's Operation Ice Bridge, an airborne science campaign that studies polar ice.
One of Ice Bridge’s scientific instruments, the Multichannel Coherent Radar Depth Sounder, operated by the Center for the Remote Sensing of Ice Sheets at the University of Kansas, can see through vast layers of ice to measure its thickness and the shape of bedrock below.
In their analysis of the radar data, the team discovered a continuous bedrock canyon that extends from almost the center of the island and ends beneath the Peterman Glacier fjord in northern Greenland.
At certain frequencies, radio waves can travel through the ice and bounce off the bedrock underneath.
The number of times the radio waves took to bounce back helped researchers determine the depth of the canyon.
The longer it took, the deeper the bedrock feature.
"Two things helped lead to this discovery," said Michael Studinger, Ice Bridge project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md.
"It was the enormous amount of data collected by Ice Bridge and the work of combining it with other datasets into a Greenland-wide compilation of all existing data that makes this feature appear in front of our eyes."
The Blyde River Canyon is a significant natural feature of South Africa, located in Mpumalanga, and forming the northern part of the Drakensberg escarpment.
It is in length and is, on average, around deep.
The Blyderivierpoort Dam, when full, is at an altitude of .
The Canyon consists mostly of red sandstone.
The highest point of the canyon, Mariepskop, is above sea level, whilst its lowest point where the river leaves the canyon is slightly less than above sea level.
This means that by some measure the Canyon is deep.
While it is difficult to compare canyons world-wide, Blyde River Canyon is one of the largest canyons on Earth, and it may be the largest 'green canyon' due to its lush subtropical foliage.
It has some of the deepest precipitous cliffs of any canyon on the planet.
It is the second largest canyon in Africa, after the Fish River Canyon, and is known as one of the great wonders of nature on the continent.
Possibly the best view in the whole of the Blyde River Canyon is of the "Three Rondavels", huge, round rocks, thought to be reminiscent of the houses or huts of the indigenous people, known as rondavels.
This canyon is part of the Panorama route.
This route starts at the town Graskop and includes God's Window, the Pinnacle and Bourke's Luck Potholes. 
 Webb Canyon is long and originates at several alpine lakes near the western boundary of Grand Teton National Park.
Moose Creek flows through the canyon and empties into Jackson Lake.
Colter Canyon is long and originates north of Ranger Peak.
Waterfalls Canyon is long.
Several cascades near the head of the canyon descend from an unnamed lake.
Snowshoe Canyon has a north and south fork.
This long canyon lies between Eagles Rest Peak and Rolling Thunder Mountain to the north and Raynolds Peak, Traverse Peak and Bivouac Peak to the south.
Moran Canyon is long and is situated south of Raynolds Peak, Traverse Peak and Bivouac Peak and north of Mount Moran.
The canyon outlet is at Moran Bay on Jackson Lake.
Leigh Canyon is long and lies between Mount Moran to the north and Mount Woodring to the south.
The canyon outlet is at Leigh Lake.
Paintbrush Canyon is long and the canyon outlet is near Leigh Lake.
The popular but very strenuous Paintbrush-Cascade Loop hike traverses through the canyon.
Hanging Canyon is a long canyon which is immediately south of Mount Saint John.
Cascade Canyon is long and splits into the North Cascade and South Cascade canyons from its outlet at Jenny Lake.
The canyon is more than deep in places as the north slopes of Mount Owen and Grand Teton tower above the canyon.
One of the most visited canyons in Grand Teton National Park, Cascade Canyon can be accessed by trail via a loop hike around Jenny Lake or a boat shuttle which provides easier access to Inspiration Point and the nearly cascade known as Hidden Falls.
Schoolroom Glacier is located at the head of the South Cascade Canyon while Lake Solitude lies at the end of the North Cascade Canyon.
Valhalla Canyon extends northward from the northwestern slopes of Grand Teton and ends within Cascade Canyon.
Garnet Canyon is long and is the most commonly used canyon by mountaineers to access the upper slopes of Grand Teton, Middle Teton and other peaks of the Cathedral Group.
The terminal moraine at the outlet of Garnet Canyon impounds Bradley Lake.
Avalanche Canyon is long.
Both Snowdrift Lake and Lake Taminah are within the canyon.
South Teton and Cloudveil Dome are to the north and Mount Wister is to the south of the canyon.
The terminal moraine at the outlet of Avalanche Canyon impounds Taggart Lake.
Death Canyon is a popular hiking destination.
More than long, the canyon provides access from Phelps Lake to the Teton backcountry region.
Open Canyon is long and extends from Mount Hunt to Phelps Lake.
Granite Canyon is the southernmost canyon in Grand Teton National Park.
Granite Canyon is almost long and is flanked to the south by Rendezvous Mountain.