His depth on arrival: 35,756 feet (10,898 meters)—a figure unattainable anywhere else in the ocean.
Reaching bottom, the National Geographic explorer and filmmaker typed out welcome words for the cheering support crew waiting at the surface: “All systems OK.”
Hovering in what he’s called a vertical torpedo, Cameron is likely collecting data, specimens, and imagery unthinkable in 1960, when the only other explorers to reach Challenger Deep returned after seeing little more than the silt stirred up by their bathyscaphe.
After as long as six hours in the trench, Cameron—best known for creating fictional worlds on film (Avatar, Titanic, The Abyss)—is to jettison steel weights attached to the sub and shoot back to the surface. (See pictures of Cameron’s sub.)
Meanwhile, the expedition’s scientific support team awaits his return aboard the research ships Mermaid Sapphire and Barakuda, 7 miles (11 kilometers) up.
Cameron pioneered the use of syntactic foam as a structural material. What are the benefits of making the sub’s structure double as the flotation system?
Syntactic foam is an epoxy matrix containing glass microspheres that are hollow. It’s been the standard of deep-ocean construction for about the last 20 years. It had always been used as passive flotation. We thought it was silly to build a vehicle out of negatively buoyant substances, like aluminum or steel, and then have to add all this flotation to get it neutrally buoyant so it could operate at the bottom of the ocean.
We had to make syntactic foam stronger, and we had to make it a more uniform, more consistent material.
Costs $8 million
It’s going to be in the zone of $8 million. I spent two and a half million dollars building the ROVs that we used to explore the inside of the Titanic and the Bismarck, and then we took them to the hydrothermal vents in 2003, and then we took them to the Titanic again in 2005. Those things eventually paid for themselves twice over, so there’s no reason to assume that I can’t make money with this vehicle as well, or at least pay for it.
Why dive to the Mariana Trench?
Two of the deepest places in the world’s oceans exist in the Mariana Trench system. But also of interest are the Kermadec Trench and the Tonga Trench, which has possibly the second deepest spot in the world’s oceans—close to 36,000 feet. So there are a number of targets around the Southwestern Pacific that need to be explored. And there are other deep trenches in the world as well. They’re the last great frontier for exploration on this planet.
The Kermadec Trench is one of Earth’s deepest oceanic trenches, reaching a depth of 10,047 metres (32,963 ft). Formed by the subduction of the Pacific Plate under the Indo-Australian Plate, it runs over a thousand kilometres parallel with and to the east of the Kermadec Ridge and island arc, from near the northeastern tip of New Zealand’s North Island to the trench’s junction with the Louisville seamount chain northeast of Monowai Seamount. The Tonga Trench marks the continuation of subduction beyond this point. Subduction south of the Kermadec Trench is marked by the shallower Hikurangi Trench.
Trench Ocean Depth Mariana Trench Pacific Ocean 11,033 m (36,198 ft) Tonga Trench Pacific Ocean 10,882 m (35,702 ft) Kuril–Kamchatka Trench Pacific Ocean 10,542 m (34,587 ft) Philippine Trench Pacific Ocean 10,540 m (34,580 ft) Kermadec Trench Pacific Ocean 10,047 m (32,963 ft) Izu-Bonin Trench Pacific Ocean 9,780 m (32,090 ft) Japan Trench Pacific Ocean 9,000 m (30,000 ft) Puerto Rico Trench Atlantic Ocean 8,800 m (28,900 ft) Peru-Chile Trench Pacific Ocean 8,065 m (26,460 ft)
The Mariana Trench or Marianas Trench is the deepest part of the world’s oceans. It is located in the western Pacific Ocean, to the east of the Mariana Islands. The trench is about 2,550 kilometres (1,580 mi) long but has a mean width of only 69 kilometres (43 mi). It reaches a maximum-known depth of about 10.91 kilometres (6.78 mi) (35,800 ft) at the Challenger Deep, a small slot-shaped valley in its floor, at its southern end, although some unrepeated measurements place the deepest portion at 11.03 kilometres (6.85 mi)
First off, here are the average depths of the earth’s oceans; the Arctic Ocean is 1,038 meters (3,407 feet) deep, the Indian Ocean is 3,872 meters (12,740 feet) deep, the Atlantic Ocean is 3,872 meters (12,254 feet) deep and the Pacific Ocean is 4,188 meters (13,740 feet) deep.
The deepest point in each of the earth’s oceans are as follows; the Arctic Ocean’s Eurasian Basin at 5,450 meters (17,881 feet) deep, the Indian Ocean’s Java Trench at 7,725 meters (25,344 feet) deep, the Atlantic Ocean’s Puerto Rico Trench at 8,648 meters (28,374 feet) deep and the Pacific Ocean’s Mariana Trench at 11,033 meters (36,201 feet) deep.
The deepest point of the Mariana Trench is called The Challenger Deep , so named after the British exploration vessel HMS Challenger II, and it is located 210 miles south-west of Guam. This depth was reached in 1960 by the Trieste, a manned submersible owned by the U.S. Navy.
In order to better illustrate the actual depth of the Mariana Trench, consider the following; if Mount Everest, which is the tallest point on earth at 8,850 meters (29,035 feet), were set in the Mariana Trench, there would still be 2,183 meters (7,166 feet) of water left above it.
The Mariana Trench is often used as a North-South passage by submarines as it is part of a long system of trenches that circle the Pacific Ocean, connected with the Japan and Kuril Trenches.
Cameras, 3D and brains
Cameron is building full-ocean-depth-rated 3D cameras right now, and we’ll be testing them in a pressure chamber later this fall. We are going to have cameras inside the sub; we’re going to have cameras outside the sub; we’re taking a huge lighting array. We’ll light up the place. We’ll do the same thing we did at abyssal depths, we’ll just do it at Hadal depths.
I think the lessons, the takeaway, for the lay public are deeper and more meaningful when they see it in 3D. You feel engaged. You feel like you are bearing witness to what’s happening, as opposed to watching, and I think these are subtle differences, but they are very real. And I think it has to do with our brain wiring. There’s neuroscience that now shows the regions of the brain that process parallax. They relate it to other parts of the brain that are doing image analysis . . . and giving you all kinds of depth cues that have nothing to do with parallax. But when you add parallax—or stereoscopy, or stereospis as it’s called medically—into it, all of a sudden it all clicks and it becomes very real.
The Pilot Sphere and the Submarine
Although the DEEPSEA CHALLENGER is as long as a stretch limo, the pilot’s home will be the pilot sphere. With an internal diameter of 43 inches (109 centimeters) and an interior filled with electronics and life-support equipment, the sphere is so small that while inside the pilot’s legs are tightly bent and he can barely move his arms.
Inside the Pilot Sphere
Photograph by Mark Thiessen. During the descent, James Cameron will occupy the pilot sphere. The sphere is held in position with straps. Green cloth covers the sphere
Engineers made the pilot’s chamber spherical because the shape can be both strong and light. They also made the steel 2.5 inches (6.4 centimeters) thick to withstand the crushing pressure of the deep. If they had made the chamber a cylinder, by comparison, the hull would have needed to have been three times as thick to stand up to the pressure. The hull, complete with its hatch and viewport, was tested twice in a pressure chamber at Pennsylvania State University to an equivalent full-ocean-depth pressure of 16,500 pounds per square inch (1,138 bars). It passed both tests. Twenty-two strain gauges attached to the sphere gave data that indicated the sphere could withstand up to 140 percent of the test pressure without buckling.
When designing the sub, James Cameron and Ron Allum kept the sphere’s internal diameter to 43 inches (109 centimeters) because, as the heaviest part of the sub, its weight dramatically impacts the overall size of the vehicle. The heavier the sphere, the more foam would be needed to float the entire structure back to the surface. And the foam itself, capable of withstanding the crushing pressures at full ocean depth, is quite dense. More weight, more foam. More foam … more weight. It adds up quickly and dramatically. To keep the sub small enough to launch and recover from a ship, as opposed to being towed to the site like the Trieste, it was critical to have as small a sphere as possible.
The sub is equipped with two compressed oxygen cylinders, which contain enough O2 to keep the pilot breathing for up to 56 hours—seven times the amount of time he expects to spend diving the Challenger Deep. Cameron trained for the dive by doing exercises to increase his lung capacity and his body’s oxygen efficiency. He’s been running and free diving regularly.
Deep Sea Sub
The pilot is descending almost 36,000 feet, but his ears won’t pop during the journey; the pressure inside the pilot’s sphere stays constant.
The sub’s giant beam of syntactic foam shrinks about 2.5 inches (6.4 centimeters) under the immense water pressure at the ocean’s bottom.
The pilot chamber is a sphere because it is the strongest shape for resisting pressure—if the pilot sat in a cylinder the walls would need to be three times thicker.
If the sub’s 1,100 pounds (500 kilograms) of ballast weights don’t drop when commanded, a back-up galvanic release will corrode in the seawater within a fixed period of time, freeing the sub to rise to the surface.
Small “bladders” inside the oil-filled external battery boxes will take in seawater. The bladders are made from medical drip bags. These “compensation bladders” are a critical part of the deep ocean electronics system, because the oil compresses at depth.
The sub’s batteries are made up of over 1,000 pouch-type lithium ion cells, bigger versions of the batteries hobbyists use for model airplanes.
The sub’s four external cameras are a tenth the size of previous deep ocean HD cameras. The housings were designed by the DEEPSEA CHALLENGE team, and the cameras themselves were created from scratch, from the sensor up.
Illustration courtesy Acheron Project Pty Ltd DEEPSEA CHALLENGER