Over a week ago, Thaler tagged in my a Tweet.

O’ how I coveted my neighbor’s Life magazine.  In case you cannot tell that is February 15, 1960 issue featuring Picard, Walsh, and the Trieste on the cover.  The two men in the Trieste reached a record maximum depth of about 10,911 metres (35,797 ft), in the deepest known part of the Earth’s oceans, the Challenger Deep, in the Mariana Trench.  This Life issue was published just weeks after this record dive (January 23, 1960).

I am in awe that Thaler parted with such a momento and gifted it to me.

The post An Unexpected Surprise in My Mail first appeared on Deep Sea News.

In trying to explain to friends, colleagues and Twitter followers during recent days what James Cameron may have seen out that softball-sized window of the Deep Challenger submersible last Sunday, I’ve struggled to convey effectively just how hostile the deep sea environment can really be.  It just looks so plain, serene and (in Cameron’s words) desolate.  I have one skeptical friend who objected to my statement that, relative to the Marianas Trench “space is easy”.  Of course space is not entirely easy.  Getting there is the hardest part, and once you’re there, cosmic rays, weightlessness and those nasty bitey little micrometeoroids can play havoc with even the most well-prepared astronaut and his/her spacecraft.

But there is one property where my throwaway holds true and that is pressure.  You see, inside a space capsule the pressure is 1 atmosphere, the same as on land at mean sea level on earth, while the pressure outside the capsule is close to zero: the vacuum of space.  That’s a pressure difference of 1 atmosphere.  When Deep Challenger descended to the earth’s deepest point, however, it passed that difference at just 10 meters (30ft) below the surface!  Indeed, you can experience and survive this difference quite easily for short periods, so that scene in Total Recall where Arnie and Rachel Ticotin’s eyes are bugging out of their heads on the Martian surface? Yeah, not so much.  At the bottom of the Marianas Trench, however, the weight of seven miles of water overhead means that the ambient pressure is about 1,100 atmospheres.  That’s a different of 1,099 ATM between Mr. Cameron and the outside of that 40-inch sphere he’s jammed into.

What does that mean though?  1,100 ATM is just an abstract number.  OK.  Well, in Cameron’s own words, it’s so great that the steel sphere in which he travels to the bottom actually shrinks measurably during descent.  One analogy the Deep Sea Challenge team uses (and I quoted yesterday) is that 1,100 ATM is equivalent to inverting the Eiffel Tower and resting its point on your big toe. Ouch. Now imagine another Eiffel Tower for every square inch of your body.  A second way to think about it is that 1,100 ATM is about the same as the peak pressure that occurs in the chamber of a handgun for a fraction of a second after the bullet fires.  Unlike the gun, however, the pressure in Challenger Deep is sustained and pervasive.  It’s like living in a moment frozen in time, inside an explosion.  If the sub had rivets to pop (which it doesn’t), they would literally become bullets inside the sphere.  1,100 ATM is also a little less than the pressure in a commercial water cutter that uses a high pressure jet of liquid to cut patterns out of steel.  It would certainly be enough that after that imaginary rivet popped, the ensuing water jet would slice soft human tissue like butter.  Of course, not for very long, because the weakness in the vessel would likely result in catastrophic implosion and instantaneous death for the unfortunate occupant.  Outside an appropriately strong metal sphere, the human body would be compressed to a fraction of its volume at the surface as every last void space collapses and the tissues themselves condense under the massive load.  I don’t know what the final effect would be, but I’m imagining something like an extra large meat-lovers pizza…

OK, I think we’ve established that the pressure down there is really high and that generally speaking it’s not especially good for one’s health.  It couldn’t get worse could it?  Well…  There are other differences at massive pressures that any organism that wants to live down there has to cope with.  Here’s just three:

One important difference concerns cell membranes, those phospholipid bilayers that surround every cell in the body.  Cell membranes are “semi-permeable”, which means that some things pass through them and some things don’t.  It turns out that the permeability of membranes is very sensitive to pressure, so something as fundamental as keeping water or important molecules inside (or outside) cells becomes harder to manage at hadal pressures.  The cells of organisms may shrink like raisins or swell and burst, or simply leak important chemicals in or out, none of which is A Good Thing.

The second difference concerns proteins and enzymes.  Proteins are long, complex chains of amino acid molecules that have to fold up like molecular origami in order to work correctly.  You can maybe guess that the folding is different under pressure.  This is especially important for the class of proteins called enzymes, which are catalysts for chemical reactions in the body (they make the reactions occur but do not themselves change in the process).   If enzymes fold incorrectly, then the chemical substrates they work with may no longer fit the enzyme properly and the reaction may cease, or possibly they fit too well and the reaction accelerates out of control.  The majority of biochemical reactions in cells are enzyme-mediated, from energy metabolism to cell division, so the effects of enzyme disruption would be profound.  Pressure can even make molecules more (or less) toxic.  Urea is a good example: it becomes far more toxic as pressure increases.  So deep sea sharks, which like all sharks have a lot of urea in their blood, also have a lot more of the protective chemical TMAO to offset this effect than do their shallow water cousins.

The third difference relates to solubility and this is the biggie for fish in the hadal depths.  This is because at those sorts of pressures, some organic molecules or organic/inorganic complexes, like bones, can quite literally dissolve and go back into solution in the water and this is hypothesized to prevent fish and other animals with hardened body parts from living at those depths (but we shall see if this holds true!). This process is called, rather confusingly, “remineralization” and it affects the rest of the food web too.  The marine snow of animal feces and dead bodies and mucus and other dross that gently falls from the sea surface to the depths, for example, can partly or completely dissolve as it falls, leading to a sort of horizon depth above which it is snowing and below which it is not.  In this way remineralization could result in less food making it to the bottom, perhaps contributing to the general sparseness of life.

The old chestnut that “nature abhors a vacuum” might be amended in the deep sea as “nature abhors a vacuum but it is flat-out terrified of 1,100 atmospheres”.  It’s difficult to wrap your head around how staggeringly, mind-bogglingly, literally bone-crushingly intense the pressure is down there, and yet there is still life in those dark, cold, silent, heavy depths.  You can’t help but wonder how they cope and what things we might learn from the biology of pressure-loving life of the hadal zone: the piezophiles.

The post Cool as a sea cucumber: life (and death) at extraordinary deep sea pressures first appeared on Deep Sea News.

We have and everyone else have already covered what is turning out to be the paradoxical blue legacy Bush will leave behind.  But I thought it worth posting this link which is actual text of the presidential proclamation.

The Mariana Volcanic Arc contains objects of scientific interest, including the largest active mud volcanoes on Earth. The Champagne vent, located at the Eifuku submarine volcano, produces almost pure liquid carbon dioxide. This phenomenon has only been observed at one other site in the world. The Sulfur Cauldron, a pool of liquid sulfur, is found at the Daikoku submarine volcano. The only other known location of molten sulfur is on Io, a moon of Jupiter. Unlike other reefs across the Pacific, the northernmost Mariana reefs provide unique volcanic habitats that support marine biological communities requiring basalt. Maug Crater represents one of only a handful of places on Earth where photosynthetic and chemosynthetic communities of life are known to come together.

The waters of the archipelago’s northern islands are among the most biologically diverse in the Western Pacific and include the greatest diversity of seamount and hydrothermal vent life yet discovered. These volcanic islands are ringed by coral ecosystems with very high numbers of apex predators, including large numbers of sharks. They also contain one of the most diverse collections of stony corals in the Western Pacific. The northern islands and shoals in the archipelago have substantially higher large fish biomass, including apex predators, than the southern islands and Guam. The waters of Farallon de Pajaros (also known as Uracas), Maug, and Asuncion support some of the largest biomass of reef fishes in the Mariana Archipelago. These relatively pristine coral reef ecosystems are objects of scientific interest and essential to the long-term study of tropical marine ecosystems.

Thus…

NOW, THEREFORE, I, GEORGE W. BUSH, President of the United States of America, by the authority vested in me by section 2 of the Antiquities Act do proclaim that there are hereby set apart and reserved as the Marianas Trench Marine National Monument (the “monument” or “marine national monument”) for the purpose of protecting the objects identified above, all lands and interests in lands owned or controlled by the Government of the United States within the boundaries described below

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