R.V. Atlantis

The last post discussed the underlying features of plate tectonics – mountain ranges, using magnetic fields to determine the ages of rocks, and the discovery of vast underwater “tears” in the earth’s crust – and the subsequent race to explore these underwater rifts in detail.  This post goes on board the Woods Hole Oceanographic Institution’s (WHOI) research vessel Atlantis for a first-hand glimpse at the tools and toys of a modern-day oceanographer exploring these tears in the earth.   It’s interesting to consider the science of oceanography as a sister calling to astronomy.  In fact, I’m told that the NASA Administrator at the time of the shuttle program was a former WHOI leader, and in fact named the shuttles after existing deep-sea oceanographic vessels – thus Atlantis the ship came before Atlantis the shuttle, and Discovery, and so on.

You can see the large crane-like device on the back, this is used to lower and raise the various instruments and submersibles into and out of the water.  The ship has a full-time crew, and the scientific teams rotate on an off.  It´s funded by the U.S. National Science Foundation.  You can also see the white dome, which contains all manner of radio equipment. The ship has internet access, and is able to stay connected to the "real" world.  Alongside, you can see a small boat, to get on and off Atlantis requires climbing a rope ladder from the small boat up to the main deck.  It´s best to be sober when you do this.  It´s about a 25 foot climb, and the ladder sways in the swells.


Below is the punch line to the whole story:  It´s a picture of the ocean floor around the Galapagos.  At the bottom right of the picture, you´ll see the islands -- they have small circles of gradated colors signifying depth.  The lines are the tracks of the ship Atlantis, you can see it has made a few tripos before to the Galapagos Spreading Plate, which is that jagged line on the upper left and center of the screen.  This trip, they plan to go to the bottom of the ocean and explore in minute detail the actual "tear" in the earth at two locations:  one on the western edge, and one closer to the eastern edge.  Since the adjoining plates are moving northeast (the upper Cocos Plate) and  eastward (the lower Nazco Plate), the new earth is newest on the western side, and is a bit older on the eastern side.The Cocos plate is slipping underneath Central America; the Nazcoi Plate is sliding underneath the Andes Mountains.  No rush -- a few centimeters a year, but it adds up.

The second picture, above, shows more detail:  you can see the black lines of the zipper-like movement of the ship as it moves back and forth over the rift.  The colors signify depth.  These are the lines of the Atlantis.  Below, I show pictures of the three submersibles that fill in the blanks between these lines.  Alvin, the manned submersible.  SENTRY, the unmanned autonomous vehicle.  The Towed Camera (no sexy name for this utilitarian piece of equipment).  Together, these three examine the micro-details of this ruft -- at resolutions of a few meters and less.

Here´s a picture of the main research vessel on Atlantis:  Alvin.  Alvin is a storied craft, having been one of the first manned deep-sea research vessels ever built.  Dr. Bob Ballard, then of Woods Hole, is considered its father, and he went on to some fame when he used Alvin to discover the R.M.S. Titanic, among other ships. Ballard-Alvin-Titanic You can see the storage shed for Alvin, and the railroad tracks used to move it to the back of the shipo, where it is lifted by the aforementioned crane and lowered gently into the water.  Alvin is driven by a specialized pilot (there are three on board Atlantis), and can also transport two scientists.  You´ll see that the scientists are limited to looking and not touching while on board.  To the right of the manned vessel Alvin, and under the canopy tent, is the yellow unmanned submersible SENTRY.  This is the vessel built by friend Dana and his colleagues.  They trade-off, these two submersibles.  Alvin spends its days underwater, taking picture and picking up samples with its remotely-controlled "hands" and returns for service and recharging at night.  SENTRY spends the nights underwater, without any tether to the surface, and, on its own, explores the bottom before surfacing for battery recharging during the daylight hours.

Here´s a closer picture of Alvin´s "hand" -- covered with a glove to protect the hand from damage, and, because the hand is steel, to protect human heads from damage.  The hands are controlled via a joystick inside the vessel.  In the old days, the joints were controlled by switches, and the pilot can still use a switch to conserve power.  The joints in the arm and hand are the same as a human´s -- it´s a robotic arm.  A skilled pilot can pick up very fragile bits of the bottom and place them into a bag for closer examination on the surface.  An unskilled pilot can crush precious specimens.  There are no unskilled Alvin pilots.

Of course, all work and no play makes for a tedious journey.  Here´s one of several large work rooms for the scientific crew.  Note the ping-pong table.  That´s my sister-in-law Guita in the stylish hat, talking with Dana.  There are several such rooms on board for working, and if you didn´t know you were on a boat, they look just like a lab at a university or a conference room at a high-tech company.  The ship also boasts a video room, a library, and other creature comforts. 



We had a chance to go inside Alvin.  Here´s a  picture of me and Dana inside.  It´s pretty cramped but comfortable enough .  Dana´s face reveals his passion for his work.  Imagine getting to play with grown-up tinker toys and making boats that descend miles under the ocean!  Below, there´s a picture taken down the entrance hatch, with Stephen clearly visible, and Guita´s eyes barely visible on the lower right.  The knees belong to Dave, one of the pilots.  Dave was in the Navy on a sub, and after he got out, he cold-called Woods Hole asking for a job.,  Now he´s one of a tiny handful of Alvin pilots!  It pays to ask!

Once inside, the hatch is closed, and the three-person crew breathes from a slow trickle of oxygen streamiung out from a tank onboard. The carbon dioxide is scrubbed out of the air using dry chemicals, so the resulting air, while a bit rich in CO2, is usable for many hours. It´s a tall vessel -- maybe 15 feet high, and you need to climb down a ladder to get into the pressurized cabin. 


















Here´s SENTRY, Dana´s baby.  He´s explaining to Stephen and Guita its design.  It was built to be simple, reliable, easy-to-transport, and cheap.  It fulfills all these criteria to a tee, and it now has 4-5 sister craft on other research ships.  Alvin takes an entire ship to support its infrastructure (remember the railroad tracks?!), SENTRY takes a small container that´s easily moved around the world. 

Engineering is often the art of the possible, and Dana is describing one of the many challenges they had to overcome in building SENTRY:  how to provide both bouyancy (so it can come back up after a dive) and submersibility (how to get it down to the bottom).  It turns out that this is not an easy problem to solve, and the craft is covered in a special mix of microscopic glass balls -- encased in that yellow material -- as part of the buoyancy-structural stability solution. 

A few weeks earlier, an older version of SENTRY named ABE suffered a catastrphic failure off the coast of Chile (unrelated to the recent earthquake).  Dana was on board that research ship at the time, and was forced to accept and mourn the loss of ABE.  A subsequent New York Times obituary for ABE may be the first such obit run for an inanimate object.  Dana took the loss wello, pointing out that one of the risks of putting vehicles deep underwater is the possibility of failure ABE´s NYT Obituary


Underneath SENTRY lie the instruments -- several magnetometers (remember the need to measure the magnetic fields of rocks?) as well as other detection and location-determining devices.  The orange rudder on the front is just that.  SENTRY can hover, rise, fall, and drive forward without
human intervention.  It´s all by itself on the bottom, and can track the sea bottom at a pre-defined height, moving up and down across the sea floor.  Dana´s colleague James is part of the team that wrote the control software for SENTRY -- software which allows the vessel to correct for ocean currents.  In fact, one of the now-many hydrothermal vents discovered on the bottom of the ocean (where very hot water is ejected from beneath the ocean floor) was discovered by SENTRY when Dana and team noticed it jumping up unexpectedly as it crossed a strange underwater feature.  The hot water was rising, and throwing SENTRY (briefly) upward and off course. Taking a closer look, the SENTRY team discovered a hole in the earth´s crust, deep underwater, where superheated water was shooting out into the cooler ocean.



The yellow shell in the second picture is used to cover the vessel underwater and to create a more streamlined shape.  It sits inside the container that houses SENTRY in its world travels --. a container just like the ones you see on trucks on the highway.  Simple.  Easy.  Usable.  The more I talked with Dana and the team, the more I appreciated the scientific value of simplicity.  Building a $10 million submersible that needs a $100 million ship to carry it first-class is helpful perhaps, but nothing like a $2 million vehicle that can travel coach class.

The third and last large research apparatus on Atlantis is the towed camera.  Here, a colleague of Dana´s, Allison, is explaining how this gets lowered over the back of the ship and is towed at varying depths, taking strobe-lit photographs very few seconds or so.  It´s basically a rectangular grid of steel, with very sophisticated gear bolted on, with a cable running back to the ship.  The trick is operating it. Together, the data gathered from Alvin, SENTRY, and the towed cam can be combined to create detailed pictures and understandings of the sea floor, and, on this expeditiopn, of the Galapagos Spreading Plates.  In so doing, we can understand more about the geologic forces that drive the drifting of the continental plates, and color in the storyline of plate tectonics.


I mentioned the underwater thermal vents before.  These are rather new discoveries, and in their most dramtic, these deepwater vents (which occur far below the depth which light pentrates) are accompanied by life forms that, uniquely, do not rely on solar-based photosynthesis for their energy. These new life forms are just beginning to be understood by scientists.  As these vents spew out from the bottom, the water is extremely rich in dissolved minerals.  Like stalactites and stalagmites in caverns, these minerals precipitate out of the water and form fabulous undersea formations.  Here´s one of the more dramatic of these formations, a formation mapper entirely by SENTRY.  If you look closely at the 4th name on the listing at the middle left of the poster, you´ll see Dana credited for his seminal work.  You can also see the flume of ejecting water behind the towers.

We had a great time visiting Atlantis and catching up with Dana.  We were also blessed to meet with many of his colleagues, including (Little) Dave, Marshall, Bruce, Allison, and others.  A big thanks to the Captain and crew, and we´ll close with a picture of the ship´s departure plate:  with all of the crew and scientists, no excuses for missing the departure time!  Atlantis left on schedule, and is presently atop the Gapalapgos Spreading Plate, filling its data coffers with new information on how our earth continues to grow and shift beneath the seas ... filling in a storyline that began when certain school children and iconoclastic scientists took a look at the continents, and asked: "Doesn´t it look like South America could fit puzzle-like into Africa?

Sometimes, it´s the obvious that´s hard to see.