3: They sort of fire our imagination about exploration,
because there are things that are found in the deep sea.
They've got weird creatures on them. They look strange.
And I think that people can sort of relate to the alien nature of,
of the vents that you see at the bottom,
but they also play a role in chemical cycling in the ocean.
They play a role in the biology and biogeography of the ocean.
And it's very important for us to be able to know where these oases of the deep
are and how they change over time.
4: Scientists have found hundreds of hydrothermal vents since they were first
discovered in 1977.
Today,
there are many questions about the forces that create hydrothermal vents and the
ecosystems that live around them.
I'm Susan Haynes with the NOAA Office of Ocean Exploration and Research.
And I recently spoke with two scientists who studied hydrothermal vents.
Ashton Flinders is a research scientist with the US Geological Survey in Hawaii.
He's explored volcanoes on land and hydrothermal vents at sea.
Hey Ashton, it's good to see you today. Hi.
5: Susan. Thanks for inviting me along.
4: Can you tell us the difference between hydrothermal vents in the ocean and hot
springs or volcanoes on land?
6: Practically the biggest differences associated with them are really just their
accessibility.
You can go pretty much right up to a hot spring in most volcanic environments,
anywhere in the world on land,
but to reach a hydrothermal vent in the deep sea requires a ship,
dozens of people, millions of dollars. And that's just to observe it.
And you're talking a whole another question in terms of,
if you actually want to take a sample of it or measure something in situ in,
in the actual setting.
4: Where do we find hydrothermal vents?
5: We know that these vents form where there's active volcanic processes and these
active volcanic processes typically are associated with tectonic environments.
This is kind of in the full reign from mid-ocean ridges,
which is our type of divergent plate boundary where new oceanic crust is formed.
We also find them at what we call convergent plate boundaries,
so subduction zones.
And then we also find them kind of in the middle of the ocean,
away from these tectonic plates that we're familiar with in places we call
hotspots. So these are areas forming Island, chains hotspot island chains.
So examples, those are like Hawaii, and Galapagos islands.
4: How do they form now?
5: What happens with the hydrothermal vent system is that we have water that's
percolating down through the oceanic crust,
fractures and fissures in that volcanic landscape.
And as it goes down into the shallow oceanic crust,
it gets in contact with that deep heat source.
That's forming that mid-ocean ridge.
So these are the kinds of the magma reservoirs.
It also becomes buoyant because now it's under more pressure and it's hot and
it's being heated up and it's forming geothermal water.
And as it's being heated,
it's dissolving the minerals that formed the rock that formed that oceanic
crust. So it starts rising back up and as it rises back up,
it's eventually comes in contact with cold seawater and that cold seawater,
catalyzes precipitation. So minerals come out of that hydrothermal solution.
And as they're coming out of the hydrothermal solution,
they're deposited on the oceanic floor around them and those form,
those kind of classic chimney structures that we associate with nitrogen.
4: I know there are different types of events and different types of chimneys.
There are black smokers and there are white smokers. What's the difference?
5: A black smoker is a high temperature hydrothermal vent.
So really amazingly hot and the fluids from these vents are usually really
acidic, right? So,
just like kind of acid and these fans contain high concentrations of what we
call metal sulfides. These acidic fluids contain metals like copper,
zinc, lead, and iron.
4: White smokers, um, are significantly different. They're formed by cooler water.
That's anywhere from maybe mid two hundreds to 300 degrees Celsius.
The white smoker fluids are much more alkaline. They're much more basic.
These white smokers are much more enriched in things like silica,
barium, calcium sulfate, calcium carbonate, and it's that,
calcium and, similar minerals that give them their white color.
When you're on an ocean exploration vessel, how do you find these vents?
5: We throw something into the deep ocean. You know,
we're a couple hundred meters above the sea floor and we look for these telltale
signs that we might be in a hydrothermal region.
So we look for heavy metals. We look for increases in temperature.
We look for decreases in the clarity of the water, from, you know,
kind of this black or white smoke that's being formed as these hydrothermal
events are pushing out these fluids,
they're forming essentially a plume of hydrothermal fluids.
That's going up into the ocean,
almost analogous to a plume of smoke in the atmosphere.
And so we can look for those telltale signs of that plume.
4: Diva Amon is a deep sea biologist and scientific associate at the Natural
History Museum of London.
She's explored hydrothermal vent systems in the Pacific and Southern oceans,
as well as the Caribbean sea. Hi diva. We're so glad to have you here today.
7: Hi Susan, my absolute pleasure.
4: Diva, we spoke with Ashton Flinders about the geology of hydrothermal vents.
Can you tell us a little bit about the animals that live there?
7: So the life around these vents is completely amazing and not only is it amazing,
but it's really abundant and diverse. So for instance, in the Atlantic,
the vent communities tend to be dominated by shrimp. In the Pacific,
they tend to be giant tubeworms and in the West Pacific and the Indian ocean,
we have snails dominating. And then in the Southern ocean,
we've got Yeti crabs, really ruling the roost. You know,
most of the animals found at each hydrothermal vents site are much rarer,
about 60% of the species occur only at one vent
site. And so it means that these are some pretty unique places.
4: How do these animals get their energy?
7: And so they use a process called chemosynthesis and the animals don't. In fact,
actually bacteria do.
Bacteria at the base of the food chain down at hydrothermal vent sites.
And these bacteria via a process called chemosynthesis are
able to use chemical energy to reduce sulfides and turn them
into organic compounds, AKA food.
4: Why are these ecosystems so special?
7: They're sites where we can gain new knowledge and understanding at that
intersection of biology and geology, which is really fascinating.
And because of those extreme conditions at hydrothermal vents,
many of the animals of course, are perfectly evolved to cope and thrive,
really.
And so that means they have some really remarkable genetic properties.
And so those genetic properties are increasingly being sought after by the
biotech industry, the medical industry,
and really they can result in cures for diseases.
And I think something that's often underestimated about hydrothermal vents and
the deep ocean in general is that ability to inspire.
It's not just about what we can get from the deep ocean.
It's also about that sense of curiosity and wonder that it has for so
many of us, but importantly,
I think it can teach us a lot of lessons about exploration and about how we
could potentially do that on other planets.
Other planets that have oceans and potentially even have hydrothermal vents.
4: Some scientists believe that hydrothermal vents might exist on the moons of
Saturn and Jupiter. Could they support chemosynthetic life too?
It'll take a while to prove that theory. In the meantime,
we still more to learn about hydrothermal vents here on earth.
NOAA and its partners are exploring hydrothermal vents in several ocean basins.
I wonder what new things we might discover in the years to come!