The Magazine for Underwater Professionals

Jan/Feb 2015

INDUSTRY NEWS - SCIENCE & TECHNOLOGY

Scientists examine mysterious asphalt mounds in the deep ocean offshore West Africa

Octopus on an asphalt mound

More than two thousand mounds of asphalt harbouring a wealth of deepwater creatures have been discovered up to two kilometres deep, off the coast of Angola. In a study published in the journal Deep-Sea Research 1, scientists at the National Oceanography Centre (NOC), Southampton, UK, have been examining the images and data captured at the site to build an intriguing picture of the life and geology of this underwater area.

 

The naturally-occurring asphalt mounds are made up of the same substance that covers our roads. They range in size from single football-sized blobs to small hills several hundred metres across. Until now, these features had only been seen in the Gulf of Mexico and off the coast of California. These deep-sea “slow tar volcanoes” are associated with flows of oil from within the sediment and are formed from hydrocarbons migrating around subsurface salt structures.

 

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Researchers have also discovered that the vast array of mounds is home to at least 21 types of deepwater creatures, including large sponges, soft-corals, octopus and fish. Many more common deepwater animals, such as the blobfish and sea cucumbers also live near the mounds. This is a greater number of species than had previously been thought and important information for scientists when predicting biodiversity levels in similar areas of ocean.

 

The distinct mounds of asphalt were discovered by the oil company BP, which was carrying out exploration for oil reserves off Angola. Its initial surveys of the seafloor of these areas of huge oil reserves revealed some unusual surface features, which were subsequently investigated using underwater robots. In the area of seabed investigated, which was around the size of the Isle of Wight (380 square kilometres), a total of 2254 mounds were identified by sidescan sonar, covering a total area of 3.7 square kilometres of seafloor, about the area of a small town.  

 

SENT

BP technical experts subsequently sent the deep-sea images to scientists in Southampton as part of a long-running collaboration between the oil industry and marine scientists at NOC.

 

Lead author of the study, Daniel Jones from NOC, said: “This exciting discovery was a great example of collaboration between oil companies and marine scientists. By working together as a team, we used the industrial data and expertise to get a much better understanding of these important systems, which will be of great value both to the scientists, but also to the BP environmental management teams.”

  • Blobfish
Falcon ROV helps with drifting iceberg research
  • Small experimental unmanned surface craft conducting experiments near an iceberg

Rigs at risk from drifting icebergs can expect an early warning following research by the Memorial University of Newfoundland, Canada.

 

The Autonomous Ocean Systems Laboratory (AOSL) at the university is undertaking a long-term study into modelling the behaviour of icebergs that includes acquiring real-world data that will increase the accuracy of predicting the rate and direction of their drift.

 

They are also finding ways to identify exceptionally deep icebergs that might drag across the seabed in shallow water and damage pipelines.

 

Specially designed autonomous vehicles are being developed for the role. Fitted with ice profiling sonar they will stay with an iceberg for 28 days at a time gathering data on ice thickness and volume – as well as direction and drift.

 

To help evaluate systems planned for use on the unmanned autonomous vehicles, AOSL is using a Saab Seaeye, UK, Falcon ROV as a development platform.

 

BEHAVE

The Falcon is a valuable development tool for helping understand how various payloads will behave when attached to autonomous vehicle systems, according to Neil Riggs, senior project manager at AOSL.

 

“It was recognised at an early stage that in order to be effective in performing R&D for autonomous systems we needed an ROV tool. The acquisition of the Falcon resulted from a careful examination of the available alternatives. It was judged the Falcon suited our needs extremely well. It is a very good R&D support system for us,” he said.

 

The AOSL project has an historical perspective that started with the sinking of the Titanic, which highlighted the need for detailed tracking of icebergs. They are now monitored worldwide by the US National Iceberg Center, and the university’s work will add to this resource by significantly advancing knowledge and safety concerning the predictability of their movement.

  • Lab director Dr Ralf Bachmayer (right) and PhD student Brain Claus preparing the Falcon for an AUV retrieval mission, one of its roles at AOSL
ROPOS ROV recognised for 1800-plus dives
  • ROPOS has conducted more than 1800 dives since 1995, in water depths of up to 5000 metres

The British Columbia, Canada-based ROPOS remotely operated vehicle has been recognised for its contributions to British Columbia’s marine sector with the award of the SS Beaver Medal. The medal, forged from the salvaged remains of the Hudson’s Bay Company’s 19th century steamship Beaver, was awarded by the by Honourable Lieutenant Governor Judith Guichon.

 

Operated by the Canadian Scientific Submersible Facility, the ROPOS (Remotely Operated Platform for Ocean Science) ROV has been a key tool utilised by scientists, researchers and environmental monitoring groups in almost every ocean around the world. The submersible’s capabilities and contributions have brought it widespread recognition as one of the world’s most capable and efficient scientific ROVs, and the SS Beaver Medal for Maritime Excellence recognises in particular the vehicle’s contributions to its home-waters and the marine sector in British Columbia.

 

TASKS

The submersible has had the responsibility of executing challenging tasks such as the retrieval of the bridge systems from the 2006 sinking of the MV Queen of the North, the installation of most of the instruments and extension cables for the NEPTUNE and VENUS offshore observatories, and site surveys for Environment Canada. In addition, the vehicle executes regular scientific missions involving high-definition video surveys, sampling and equipment deployment/retrieval.

 

“It was a privilege and honour to represent the ROPOS ROV receiving this very special award,” said Keith Tamburri, assistant general manager of the Canadian Scientific Submersible Facility. “This award recognises the ROPOS ROV for all the work it’s performed over the years, but without a dedicated and professional team it’s just another ROV. I accepted this award on behalf of all the present and past workers who over its 29-year history has made it into the best science ROV in the world.”

 

Originally built in 1986, the submersible has conducted more than 1800 dives since 1995, in water depths of up to 5000 metres.

  • Keith Tamburri (right) accepts the medal from Lt. Gov. Judith Guichon (middle), alongside Dr Barry Gough (left)

 

 

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