Campeche Knolls facts for kids

The Campeche Knolls are a group of interesting underwater hills in the southern Gulf of Mexico. They are formed from huge salt deposits that have pushed up through the seafloor. Imagine giant salt domes rising from the deep! These knolls are found southeast of another area called the Sigsbee Knolls. They are bordered by the Campeche Bank to the east, the Bay of Campeche to the south, and a flat, deep area called the Veracruz Tongue to the west.

Scientists believe these salt deposits formed a very long time ago, during the Late Jurassic period. This was when the Gulf of Mexico was first forming. Pictures taken by a special sonar device during the R/V Sonne research trip in 2004 show these knolls as long, distinct hills. They are usually about 3 by 6 miles (5 by 10 km) in size. Some of them rise as high as 1,475 to 2,625 feet (450 to 800 m) from the seafloor.

What are the Campeche Knolls?

The Campeche Knolls are covered by very thick layers of sediment, which are like layers of mud, sand, and rock. These layers can be 3 to 6 miles (5 to 10 km) thick! These thick sediments are important because they contain the remains of ancient plants and animals. Over millions of years, these remains turned into valuable resources like oil and natural gas.

Why are they important?

The Campeche Knolls are a very rich area for finding oil and gas. Studies show that the salt moving around deep underground helps oil and gas escape towards the surface. This makes the Campeche Knolls a key region for energy exploration.

Discovering Gas Hydrates

Scientists have known about the possibility of finding gas hydrates in the Campeche Knolls since the 1970s. Gas hydrates are like ice, but instead of just water, they also contain natural gas trapped inside. They look like white, icy crystals.

Early Discoveries (DSDP Site 88)

During a research trip called Leg 10 of the Deep Sea Drilling Program (DSDP), scientists drilled at a spot called Site 88. They wanted to prove that a high bump on their maps was actually a salt dome. As they drilled, they found a lot of gas in the core samples they brought up. These samples had high levels of natural gases, including H2S.

When the cores were brought onto the ship, they released huge amounts of gas. It was so much gas that they had to drill small holes in the core liners to stop the samples from breaking apart! The gas also took a very long time to escape, over two hours. These strange results made the researchers think that gas hydrates were present. Gas hydrates can hold a lot of gas in a small amount of water, which would explain the large gas volumes and long release times.

The Chapapote Knoll Discovery

In 2004, during the R/V Sonne SO174 research trip, scientists used special remote sensing tools. These tools helped them find oil, gas, and even asphalt (like tar) leaking out on top of one of the knolls. This knoll is in the northern part of the Campeche Knolls. They named it Chapapote, which is an Aztec word for "tar." It's located about 1.8 miles (3,000 m) deep underwater.

Chapapote has large areas covered in hardened asphalt. One of these asphalt flows is at least 49 feet (15 m) across! Scientists also found thin layers of gas hydrate in the sediment samples from Chapapote. The gas in these hydrates was found to be "thermogenic," meaning it came from deep underground, formed by heat and pressure.

More Research at Chapapote

In 2006, another research ship, the METEOR Cruise No. 67 (MC67/2b), returned to Chapapote. They found more hydrates there. One core sample contained a large piece of pure, white gas hydrate stuck in asphalt. When they brought this core up, a lot of gas bubbles rose to the sea surface. Scientists believe the hydrate formed inside the asphalt after the asphalt was deposited.

Life in the Deep Sea

The Chapapote knoll is not just about oil and gas; it's also home to a diverse community of living things. Despite the deep, dark, and cold conditions, many amazing organisms thrive there. These include:

• Tubeworms: Long, colorful worms that live in tubes attached to the seafloor.
• Bacterial mats: Layers of tiny bacteria that can use chemicals from the seeps for energy.
• Chemosynthetic mussels: Mussels that get their energy from chemicals, not sunlight, like most life on Earth.

These creatures have adapted to live in this unique environment, using the chemicals leaking from the seafloor as their food source.

Why are Campeche Knolls Important?

The Campeche Knolls are a very important place for studying gas hydrates. The Chapapote asphalt volcano, located within the knolls, is where the deepest known gas hydrate was found on the seafloor. It was found at a depth of 1.8 miles (3,000 m) and was embedded in asphalt. This discovery helped scientists learn more about how gas hydrates form and exist in such deep environments. The Campeche Knolls are also the only place in the southern Gulf of Mexico where gas hydrate has been found.