USA: MBARI’s Seafloor-Mapping Robot D. Allan B. Yields Host of New Geologic Discoveries

MBARI's mapping AUV underwater

MBARI’s seafloor mapping robot has had a busy year. It documented a huge lava flow from a three-month-old volcanic eruption off the Oregon coast; it charted mysterious three-kilometer-wide scour marks on the seafloor off Northern California; and it unearthed data that challenge existing theories about one of the largest offshore faults in Central California. MBARI researchers will describe these achievements, and others, in 10 different presentations at this week’s meeting of the American Geophysical Union in San Francisco.

Technically speaking, this yellow, torpedo-like robot is known as an autonomous underwater vehicle (AUV). It is programmed at the surface, then released to fly within 50 meters (165 feet) of the seafloor, using sonar to map ocean-bottom features as little as 15 centimeters (five inches) tall. MBARI’s mapping AUV, the D. Allan B., carries three different types of sonar, which simultaneously provide information on seafloor depth, bottom texture, and sub-bottom features such as layers of buried sediment.

Last summer the mapping AUV helped make geologic history. In July and August 2011, two research teams from MBARI and Oregon State University (OSU) were using remotely operated vehicles (ROVs) to study Axial Seamount, an active volcano about 270 kilometers (170 miles) off the Oregon coast. The OSU team discovered that several instruments, placed on the seafloor during previous expeditions, had disappeared. Similarly, the MBARI team couldn’t figure out why the seafloor looked very different from previous dives. After comparing notes, they realized that a recent volcanic eruption had covered large areas of the seafloor with up to three meters of fresh lava.

MBARI’s marine operations crew scrambled to deploy the D. Allan B. In two days, the AUV had created a new bathymetric map that depicted the 10-million-square-meter flow with an astonishing one meter of horizontal resolution and 20 centimeters (eight inches) of vertical resolution. The map showed not only the exact boundaries of the new flow, but also lava pillars, individual lava pillows, and other small flow features.

By painstakingly comparing the new map with an older map created by the mapping AUV, the MBARI team was able to get a precise estimate of the amount of lava released during the recent eruption. They also discovered that the new eruption reoccupied many of the same fissures and followed a flow pattern that basically mimicked the existing flows—information that would have been impossible to gather through ROV dives or sonar surveys using surface ships. Needless to say, the new map also made it much easier for scientists to navigate and find geologic features of interest during subsequent ROV dives.

In addition to creating the world’s most detailed map of an underwater lava flow, the D. Allan B. provided data that led to a number of other exciting geologic discoveries:

The AUV mapped the supposed trace of the San Gregorio fault in Monterey Bay. But the resulting sonar profiles failed to show obvious signs that the fault cut through young seafloor sediments. This suggests that this section of the fault is either improperly located on existing maps, or is not as active as previously believed.

The AUV mapped a large underwater landslide in Monterey Canyon known as Tubeworm Slump. The sonar data showed that Tubeworm Slump formed during several small slope failures rather than one large event. Previous research suggested that if Tubeworm Slump had failed in one event, it would have generated a large enough tsunami to threaten the entire Monterey Bay region.

The AUV mapped 60-meter-high underwater mounds near Eel Canyon, off Northern California. These mounds are likely to be the sources of 1,400 meter-high plumes of natural gas that were detected by previous shipboard studies.

Mapping AUV images revealed two giant scour marks on the seafloor in Eel Canyon, off Northern California. The larger of these seafloor gouges is about 100 meters deep and over three kilometers wide. Geologists are still trying to figure out what kind of undersea flow eroded the shoreward edges of these scours but filled in their seaward margins.

Subsea World News Staff , December 06, 2011;  Image: MBARI

Share this article

Follow Subsea World News


<< Feb 2016 >>
1 2 3 4 5 6 7
8 9 10 11 12 13 14
15 16 17 18 19 20 21
22 23 24 25 26 27 28
29 1 2 3 4 5 6

FPSO Europe Congress


Pursuing Cost-Optimization & Project Excellence across Europe’s FPSO Value Chain!

Launched to great success in 2015, the FPSO Europe Congress is set to return on 24-25 February 2016 in London for yet another exciting gathering of Europe’s leading oil operators, FPSO contractors, EPCs, shipyards and solution providers to discuss the most topical and critical FPSO developments in the North Sea, Latin America, Brazil and West Africa market.


Why Attend the 2nd Annual FPSO Europe Congress?

  • Discover how FPSO leaders are embracing the new realities of a low oil price environment – what are the strategies to adopt in pursuit of viable economical FPSO projects?
  • Brainstorm with industry experts on innovative FPSO engineering, construction and technology breakthroughs leading to significant CAPEX and OPEX savings
  • Review, refine and optimize your existing FPSO operations – how can we enhance oil recovery and extend FPSO asset lifetime?
  • Learn from FPSO experts on the ins-and-outs of delivering successful FSPO projects in North Sea, West Africa, Latin America and Brazil – how can we comply with local content and form effective native partnerships?
  • Engage and form sustainable partnerships with European-based oil companies and FPSO contractors that are leading offshore E&P and FPSO projects in the region


2016 FPSO Distinguished Speakers Include:

  • Curtis Lohr, Stones Project Manager, Shell
  • David Hartell, Senior Development Manager, Premier Oil
  • Terry Hughes, Project Director, Tullow Oil
  • Sid Sircar, Facilities Delivery Manager – Catcher Development, Premier Oil
  • Michael Wyllie, Group Technology Director, SBM Offshore
  • Chris Brett, President, Teekay Offshore
  • Puneet Sharma, Vice President, MODEC
  • Eirik Barclay, CEO, Yinson Production


The FPSO Europe Congress 2016 is proud to bring you an updated program offering fresh perspectives, creative solutions and critical market intelligence fundamental to FPSO business sustainability as we discuss just HOW and WHAT you can do in pursuit of a viable, efficient and safe FPSO strategy.

For more information please visit the website at or email


read more >

Topsides Platforms & Hulls

Topsides, Platforms & Hulls Conference & Exhibition is the offshore industry’s only event dedicated to the topsides, platforms and hulls…

read more >

The 16th North Sea Decommissioning Conference

The 2016-programme has been composed to shed light on the effect of the current low oil-price environment on the decommissioning market…

read more >

Substructures for UK Offshore Wind

Design, construction and installation

Optimising offshore substructures is one of the key challenges for reducing LCOE. Foundation designers have produced a variety of different solutions: monopiles, GBS, jackets, suction buckets and floating foundations. Looking at U.K. projects – different soils, water depths,fabrication timelines and installation challengescreate many questions for the industry to solve. We’re entering uncharted territory; projects arelarger, farther and more complex than ever completed.

Now is the time to have a close look at lessons learnt and define the room for improvement for the U.K. wind industry.

More Info

read more >