Upside Down Lakes Discovered

Upside Down Lakes Discovered

On 23 July 2005, University of Washington oceanographer Deborah Kelley and Rhode Island University professor Robert Ballard led an expedition into the depths of the Atlantic Ocean, discovering enormous underwater structures dubbed the Lost City.

The expedition was rooted in a 2000 study by Kelley who led a team on a National Science Foundation expedition into the unexplored depths of the Atlantic. Utilizing both a manned submersible and underwater cameras, the team began investigating an area known as the Atlantic fracture zone—a fault in the mid-Atlantic ocean floor.

During this expedition, the team watched as a mass of strange, bone-like spires came into view out of the darkness. The images that were relayed were similar to other hydrothermal vents that Kelley had analysed previously but, as the team discovered, were of a different chemistry and grew from much older rock formations.

Upon the release of Kelley’s findings, these structures, akin to huge underwater skyscrapers, were given the collective nickname of the Lost City, in reference to both the research vessel Atlantis and the mythical realm mentioned in Plato’s dialogues.

In 2005 Kelley embarked upon another expedition to the area, this time accompanied by Ballard—best known for heading the team that discovered the wreckage of the RMS Titanic in 1985.

The huge carbonite chimneys discovered at the Lost City, the largest of which measure approximately 55 metres (180 feet) in height, are situated 640 metres (2100 feet) below sea level on a hydrothermal field now known as the Atlantis Massif. The vents exude methane and hydrogen into the surrounding water but, unlike so called “black smoker” vents that were first discovered in 1977, these produce no significant amounts of carbon dioxide, hydrogen sulfide, or metals.

Having poured over chemical data, scientists have also estimated that the vents have been thermally active for around 30,000 years, making them older than the earliest known black smoker vents by two orders of magnitude.

PH levels analysed at the Lost City vents were found to be alkaline on an equivalent scale to a cleaning product such as Drano, unlike the black smoker vents whose output is highly acidic. The mineral rich water that the Lost City vents exude supports a variety of life forms and bacteria, including small crabs, sponges, and coral.

Kelley and Ballard’s ten-day expedition to the Lost City was organised and partly funded by the Institute of Exploration. Using the Institute’s state-of-the-art technology, live video feeds were relayed to shore-based oceanographers over 8,046 kilometres (5,000 miles) away in real time, one of the first occasions such systems were deployed.

The Lost City is also significant in that it provides scientists and geologists with a working ecosystem from which to obtain data about life processes. According to some, conditions present in the Lost City are comparable with those that could have accounted for the beginning of life on Earth.

Credit: Image courtesy of IFE, URI-IAO, UW, Lost City science party, and NOAA.
Caption: Some say conditions in the Lost City are comparable with those that could have accounted for the beginning of life on Earth.