We have known for a long time about the existence of deep ocean vents, but they are difficult to find. Recently, one of these treasures was discovered in the waters off Ecuador: it is called Sendero del Cangrejo, a miniature version of Yellowstone.
Western Galápagos Area of Lava Spread
This mysterious world lies beneath the sea in an area called the western Galápagos lava spread, a series of underwater mountains where tectonic plates slowly move apart. Here, lava emerges from the earth’s mantle to create new oceanic crust in a process that formed the Galápagos Islands and smaller underwater features like hydrothermal vents. These vents pump hot, mineral-rich water into the ocean in massive plumes and can offer clues about the origin of life on Earth. Studying hydrothermal vents on Earth may provide a gateway to discovering life, or at least its components, on other planets.
Discovery of Sendero del Cangrejo
Modern Sendero del Cangrejo features a series of hydrothermal vents that extend for nearly two football fields. It hosts hot springs and vibrant chimneys that support a variety of creatures, ranging from giant tube worms resembling pasta to white mountain-dwelling galatheid crabs.
Crab Guide
The crabs, also known as dwarf crabs, helped guide researchers to Sendero del Cangrejo. Ecuadorian observers chose the site’s name, which translates to “Crab Trail,” in honor of them.
“It felt like the dwarf crabs were leading us like breadcrumbs, as if we were Hansel and Gretel, to the actual vent site,” said Hayley Drennon, a senior research assistant at Columbia University’s Lamont-Doherty Earth Observatory, who participated in the mission.
Searching for Hydrothermal Vents
The combined American-Ecuadorian research team set out aboard the Falkor research vessel of the Ocean Institute in mid-August in search of new hydrothermal vents. They conducted some mapping and sampling on their way to their target site, about 300 miles off the west coast of the Galápagos Islands.
The team used “tow-yo” technology to collect and transmit real-time data to the ship’s crew. “We lowered sensors attached to a long cable to the seabed, then pulled the cable up and down like a yo-yo,” explained Roxanne Penart, an associate professor at the University of Rhode Island and the chief scientist for the mission. “This process allowed us to monitor changes in temperature, water clarity, and chemical composition to help us identify potential hydrothermal vent locations.”
Sampling Under Harsh Conditions
The Atlantic Institute’s ROV SuBastian is designed to withstand the high pressure, high acidity, extreme heat, and intense cold found near hydrothermal vents. SuBastian is equipped with lights and cameras to assist the pilot on the surface in maneuvering it. Its titanium arms are strong and corrosion-resistant. However, collecting samples remains challenging.
Rocks and organisms in the deep sea have adapted to conditions we consider extreme. Thus, for them, the surface environment is a harsh environment. Transporting them to a drastically different environment requires quick and precise handling and proper storage in insulated containers that maintain cold temperatures until they reach the surface, preserving the integrity of the samples. Some containers, known as gas-tight samples, remove gas samples and store liquid samples under the pressures found on the seabed. These samples retain dissolved gases while being brought to the surface, allowing scientists to study the elements and different molecules in the vent gases. These components may carry clues about the activities taking place beneath the seabed.
Exploring the Crab-Dense Area
When they reached a seemingly promising area, they deployed the remote-operated vehicle SuBastian for a better look. Less than 24 hours later, the team began to see more and more galatheid crabs, which they followed until they found the vents.
They were
Crabs are useful guides where the fluids of the vents are clear, unlike the “black smokers” which create easily visible columns. SuBastian explored the area for about 43 continuous hours in the longest robot dive to date.
The Real Discovery Process
The real discovery process took decades. Researchers have known for nearly 20 years that the area was home to hydrothermal activity thanks to chemical signals measured in 2005. About a decade later, teams went out again and collected animal samples. Now, thanks to a recent Atlantic Institute mission, they have the most comprehensive dataset ever for this site. This includes chemical, geological, and biological data, as well as the first high-temperature water samples.
“It’s not uncommon for the actual discovery to take decades,” said Jill McDermott, an associate professor at Lehigh University and a co-scientist on the mission. “The ocean is a big place, and the locations are very remote, so it takes a lot of time and plans to get to them.” The team will continue their research onshore to help us understand how oceanic hydrothermal vents affect our planet.
Born from Hell?
Cendero del Cangrejo may be compared to Yellowstone in some ways, but it’s certainly not a tourist destination. It is completely dark because sunlight cannot reach the deep seabed. The weight of a mile of water presses down from above. The vents are hot and toxic. Some reached 290 degrees Celsius (550 degrees Fahrenheit) – almost hot enough to melt lead.
Before the discovery of the vents in 1977, scientists presumed that such extreme conditions would preclude the possibility of life. However, the pioneering team at the time observed multiple species thriving, including white clams that led them to the vents in the same way that galatheid crabs guide modern researchers to Cendero del Cangrejo. A series of seabed images show a sudden appearance of live white clams that led scientists to discover hydrothermal vents for the first time.
Before the 1977 discovery, no one knew that life could exist in a hostile environment. Now, scientists know that there are microbes called thermophiles that can live only at high temperatures (up to about 120 degrees Celsius or 250 degrees Fahrenheit).
The bacteria surrounding hydrothermal vents do not eat other organisms nor do they produce energy from sunlight like plants. Instead, they generate energy using chemicals like methane or hydrogen sulfide that emanate from the vents. This process is called chemosynthesis and was first characterized by the organisms discovered in these vents. Chemosynthetic bacteria are the backbone of hydrothermal vent ecosystems, serving as a food source for higher organisms.
Life on Earth and Beyond
Some researchers suggest that life on Earth may have originated near hydrothermal vents due to their chemically rich and energy-abundant conditions. Although the proposition remains unproven, the discovery of chemosynthesis has opened our eyes to new places that may be capable of hosting life.
The possibility of chemosynthetic organisms reduces the significance of habitable zones around stars, which describe the orbital distances where surface water can remain liquid on a planet or moon. The habitable zone in our solar system extends from roughly the orbit of Venus to roughly the orbit of Mars.
The “Europa Clipper” mission by NASA is set to launch late next year to determine whether there are places beneath the icy surface of Jupiter’s moon Europa that could support life. It’s much colder there, far from the habitable zone of our solar system, but scientists believe Europa is warmed from within. It is subjected to strong tidal forces from Jupiter’s gravity, which may create hydrothermal activity on the icy ocean floor of the moon.
Hosting
Several other moons in our solar system have subsurface oceans and experience the same tidal heating that could create habitable conditions. By exploring the hydrothermal vents on Earth, scientists can learn more about what to look for in similar environments elsewhere in our solar system.
Sea Vitamin
Although hydrothermal vents are relatively new to science, they are not new to our planet. “These vents have been active since the formation of Earth’s first oceans,” said McDermott. “They have been present in our oceans for as long as they have existed, so for about 3 billion years.”
During this time, they may have altered the chemistry and geology of our planet by recycling chemicals and minerals from the Earth’s crust throughout the ocean.
“All living organisms on Earth need the minerals and elements they obtain from the crust,” said Peter Girguis, a professor at Harvard University who is involved in the mission. “It is no exaggeration to say that all life on Earth is integrally linked to the rocks we live on and the geological processes that occur deep within the planet… It’s the sea vitamin.”
However, the extent of the impact of hydrothermal vents on the planet is still not completely known. In recent years since the first discovery of hydrothermal vents, scientists have found hundreds of them around the world. However, no one knows how many remain unknown; there may be thousands of other vents hiding in the depths. Detailed studies, like those scientists continue to conduct onshore, can help understand how thermal activity affects the ocean.
Instantaneous observations from the team provide a good starting point for further scientific investigation.
“I really expected to find denser animal aggregations in some places,” said Peinert.
McDermott believes this could be related to the composition of vent fluids. “Some vents were obvious – not rich in particles,” she said. “They may be lower in metals, but we are not sure why.” Now, the team will measure levels of various metals in water samples from vent fluids to determine why they are low in metals and whether this has affected the organisms hosted by the vents.
Researchers are learning more about hydrothermal vents every day, but many mysteries remain, such as the potential impact of ocean acidification on the vents. As they seek answers, they are sure they will find more questions and open new avenues for scientific exploration.
Ashley writes about space as a contractor for NASA’s Goddard Space Flight Center during the day and works as a freelance environmental writer. She holds a master’s degree in space studies from the University of North Dakota and is finishing a master’s degree in science writing from Johns Hopkins University. She writes most of her articles while holding one of the
Source: https://arstechnica.com/science/2023/12/otherworldly-mini-yellowstone-found-in-the-deep-sea/
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