08 December 2003                                      FOR IMMEDIATE RELEASE

MBARI research highlights
AGU 2003 Fall Meeting

SAN FRANCISCO—Researchers from the Monterey Bay Aquarium Research Institute (MBARI) will present a dozen talks and posters at the American Geophysical Union 2003 Fall Meeting in San Francisco. Some of these cover geological studies in the Gulf of California, Mexico; the Hawaiian Islands; and the Santa Barbara Channel. Others focus on technological tools, such as a computerized system that can pick out sightings of deep-sea animals from hours of underwater video. A few of these topics are highlighted below. A complete list of MBARI-authored abstracts is also available.

Explosive volcanism in the deep sea
Geologists have long known that volcanic eruptions continued intermittently after the main island-forming eruptions on the Hawaiian islands. These "late-stage" eruptions formed landmarks such as Diamond Head and Punchbowl. Clague, et al. show that late-stage eruptions also occurred beneath the sea, hundreds of kilometers away from the main islands. They describe undersea surveys of the resulting lava flows, which cover an area comparable to all the present Hawaiian islands combined. Davis and Clague present surprising evidence that most of these eruptions were explosive, even though they occurred down to depths of 4,200 meters. This contradicts the commonly held belief that explosive submarine eruptions are an indicator of shallow water.

D.A. Clague, et al., Submarine rejuvenated-stage lavas offshore Molokai, Oahu, Kauai, and Niihau, Hawaii. Mon AM, 0805, MCC 3006, V11B-01.

A.S. Davis, D.A. Clague, Pyroclastic fragmentation of alkalic lava in abyssal depths at the North Arch Volcanic Field, Hawaii (poster). Tues PM, 1330, MCC Level 1, V22C-0592.

Finding jellies in marine snow
MBARI's two remotely operated vehicles typically record more than 1300 hours of deep-sea video annually. This video forms a vital part of MBARI's scientific record. After each dive, MBARI biologists review the footage and identify the discernable animals and other objects of interest, recording the results in a searchable database. This process requires a great deal of time and expertise. Edgington, et al. have been developing a computer hardware and software system to spot, identify, and track these organisms in a more automated way and eventually in real-time at sea. This is particularly difficult because many marine animals, such as jellies, are small and translucent. In addition, the computer must ignore ubiquitous organisms such as krill, as well as small, translucent particles of marine snow. The researchers describe in a poster how well their computer system compares with human experts in its ability to pick out animals of interest.

D.R. Edgington, et al., Detection of visual events in underwater video using a neuromorphic salience-based attention system (poster). Mon AM 8:30, MCC Level 2, H11F-0912.

Dating underwater landslides
High-resolution bathymetric data has revealed many large submarine landslides in the seafloor off the California coast. Some of these landslides could have generated devastating tsunamis. However, because of lack of field data, geologists have found it difficult to determine how long ago these slides occurred. Greene, et al. describe a method for using sediment thickness to analyze the failure history of a complex submarine landslide near Santa Barbara, which covers about 130 square kilometers of sea floor. Barry and Whaling discuss the challenges and possibilities of using biological communities, like deep-sea clam fields, to date such slides. 

H. Greene, et al., Dating one slide event of the complex compound Goleta submarine landslide, Santa Barbara Basin, California, USA. Wed AM 08:30, MCC 3000, OS31A-03.

J.P. Barry, P.J. Whaling, Use of vesicomyid clams as proxies for ageing submarine landslide events. Wed AM 09:30, MCC 3000, OS31A-07.

Rocks that grow overnight
Geologists typically study Earth processes that take place over hundreds, thousands, or even millions of years. But in the Guaymas Basin last Spring, researchers chronicled the dynamics of a hydrothermal vent field where chimney structures grew as fast as one meter in 24 hours. Deep-sea scientists from MBARI, Woods Hole Oceanographic Institution, and the U.S. Geological Survey teamed to study this active area during an expedition in March 2003 using MBARI’s research vessel Western Flyer. Their intensive effort relied on remotely operated vehicle Tiburon to measure and monitor the geology, chemistry, and microbiology of the vents in unprecedented detail. Early results are presented in posters by D.S. Stakes, et al. and M. K. Tivey, et al. in the session "Recent advances in understanding submarine environments and the future of submergence research and facilities."

M.K. Tivey, et al., Use of thermocouple arrays to investigate the environment within actively forming chimney deposits, Guaymas Basin (poster). Wed PM 1330, MCC Level 1, OS32A-0233.

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Still images related to these research presentations can be found at:
http://www.mbari.org/news/news_releases/2003/nr06-agu-images.html

Media Contact: 
Debbie Meyer, AGU Press Room Dec. 8-12 (415) 348-4440
or at MBARI ( 831) 775-1807, pressroom@mbari.org