Thanks to Brilliant for supporting this episode of SciShow.

Go to Brilliant.org/SciShow to learn how you can take your STEM skills to the next level this year! [♪ INTRO]. If you were to dive about 2000 meters down in the Gulf of California to a place called.

Guaymas Basin, you’d find a strange landscape that looks straight out of a science fiction movie.   All over, you’d see towering volcanic chimneys with hotter-than-boiling water gushing out of them, upside-down mirrors, and brilliantly colored living rocks!  You’ll need a submersible or an underwater robot to get there, and not just anyone can visit.  But the researchers are eager to learn as much as they can about this bizarre sunken habitat, because this otherworldly place can teach us a lot — especially about how life survives in such an extreme environment. The Gulf of California is a narrow body of water located between the Baja California Peninsula and Mexico. Geologically speaking, it’s a pretty new ocean basin.

The Baja Peninsula is actually still in the process of separating from the Mexican mainland. And the water that flows into the Gulf supports a thriving, diverse ecosystem in the shallows, because it brings in lots of nutrients — and those nutrients feed the microscopic plants at the base of the food web.  In fact, there are so many of them that when they die, a lot fall to the seafloor some 3000 meters below. There, they help form a goopy layer of mud that’s several hundred meters thick.

And it’s underneath all that muck that the story of this weird underwater landscape begins.  See, since the peninsula is separating from the mainland, the seafloor is actively spreading apart, creating cracks in the Earth’s crust. Seawater from above travels down through all the mud and into those cracks — until it’s right next to the unbelievably hot magma below.  So, it gets heated up to 300-plus degrees Celsius! This superheated water ends up more like a toxic soup, as thanks to its heat, it pulls chemicals from the rocks it flows past.

It ends up jam-packed with compounds like hydrogen sulfide and methane, and even heavy metals like mercury, arsenic, and lead. As this super hot soup moves back up through the thick layer of mud, these dissolved chemicals react with the dead plankton and other organic matter in the mud to form new compounds. And those harden into rock once they reach the cooler ocean water above.  This ultimately creates massive towers up to 30 meters tall, which continue to spew hotter-than-boiling fluid.

Scientists call these volcanic features hydrothermal vents.  In fact, there’s just so much stuff bubbling out of the seafloor here that many of these vents spread out faster than they spread up, creating edges that stick out a meter or more from either side of the main tower.  While there are other hydrothermal vents around the world, such large ledges have yet to be documented anywhere else — and they're why this one spot in the Gulf of California seems to be the only place that we know of with upside-down mirror pools. The mirror effect is created by pools of scalding hot vent fluid, which get trapped underneath the rock. You see, light actually travels at different speeds depending on what it’s traveling through.

The one physicists usually mean when they say “the speed of light” is its speed in a vacuum; but it’s slower in thicker mediums like water.  And when light hits the boundary between two different mediums, it can change speed or color or even be reflected. This is why you can see the sky reflected in a still pool. In this case, though, there’s just such a huge difference in the temperature and chemical content between the trapped vent water and the surrounding seawater that almost all the light that hits the pool’s surface is reflected, giving it the appearance of a mirror.

Now, the mirror pools themselves are too hot for living things, but life is all around them — that’s what gives the towers their incredible hues.  In particular, microbes thrive here, as they’re able to convert the array of chemicals in the vent water into energy through a process known as chemosynthesis.  Bacteria cover the outside and inside of rocks, literally bringing the geology to life.  And they come in all sorts of vibrant colors, including yellows, oranges, and purples, depending on the chemicals, metals, and temperature of the vent fluid. Some of these colors have never been seen at other vents, so they could be new species of extreme bacteria! And that has researchers asking all kinds of questions about these microbes, like: how can they survive inside the rocks?

What exactly do they use for energy? And how quickly are they processing chemicals into food?  Scientists are especially interested in new species because we already engineer extreme microbes to produce things for us, like plastics, biofuels, and new pharmaceuticals.  So these microbes may be an opportunity to make something we struggle to make on our own, or make things more efficiently. We could also use our understanding of these microbes to develop totally new technologies.  For example, some scientists have suggested harnessing the enzymes they use to break down carbon dioxide to help us remove it from our atmosphere.  And even if they don’t prove commercially useful, the microbes in this amazing environment have already stunned researchers.

They form the basis of an entire deep sea food web, which includes lots of mysterious animals that live nearby.  There’s just so much unexpected life in this extreme environment, and the sheer diversity continues to challenge our perceptions of where — and how — living things can exist. But researchers will have to study all of it as quickly they can, because this underwater world is ephemeral. One large volcanic eruption could obliterate all traces of this extreme ecosystem, including those fabulous mirrors.  Thank you for watching this episode of SciShow!

Before you go, I have a little note from today’s sponsor, Brilliant.  You see, Brilliant offers over 60 fun, interactive STEM courses, all put together by educational experts from places like MIT and Caltech.  So you can have a blast while learning how cryptocurrencies work, or wrapping your brain around the concept of infinity.  And right now, if you head over to Brilliant.org/SciShow, you can get 20% off when you sign up for an annual premium subscription! Which is a pretty sweet deal.  So if that sounds like something you’d be interested in, be sure to head over there and check it out. [♪ OUTRO].