2 August 2000

Western Flyer completes MBARI's first expedition 
to Juan de Fuca Ridge

The research vessel Western Flyer and remotely operated vehicle Tiburon recently completed a 12-day geological and geochemical expedition to the southern portion of the Cleft segment of the Juan de Fuca ridge, some 300 km (~200 miles) from Newport, Oregon. Tiburon also dove at Axial Caldera. 

Special geological sampling equipment was integrated on Tiburon for the first time, including a drillsled for coring vertical rock faces, wax cores for basalt glass sampling, and geocompass and magnetometer instruments. A total of 137 geological samples and approximately 700 biological samples were collected by Tiburon. The above photo shows a sample of hydrothermal vent tubeworms in Tiburon's manipulator arm. 

The volcanically active Juan de Fuca Ridge is known for its dynamic geology and awe-inspiring hydrothermal vents. New ocean crust is being formed at this mid-ocean ridge. This expedition was MBARI's first to this region. The image on the left shows a high temperature hydrothermal vent. The black "smoke" emerging from the vent is composed of minerals precipitating out of solution as the hot water (more than 300 C) cools upon contact with the cold seawater. 

The mission's chief scientist, MBARI geologist Debra Stakes, was joined by Michael Perfit of the University of Florida (basalt geochemistry) and Maurice Tivey of the Woods Hole Oceanographic Institution (magnetics). MBARI Postdoctoral Fellow Thomas Chapin managed the instrument deployment/recovery dive at Axial Caldera. Other members of the shipboard scientific party were all from MBARI. These included Karen Salamy who was responsible for the Tiburon drillsled and for the archival of all geological samples. Tony Ramirez was responsible for navigation and post-dive data. Greg Moretti (summer intern) was responsible for sample photography and daily cruise reports for the web. Josh Plant worked with Chapin to prepare the instruments and analyze fluids from Axial Caldera. Robby Young was the shipboard biologist who collected both vent and non-vent specimens. Perfit supervised the night wax coring program with assistance from Stakes, Chapin, Plant, Salamy, Ramirez and Moretti.

Gazeebo_07_40_20_28.jpg (80449 bytes) Use_01_59_37_24.jpg (90121 bytes) Drainback_00_18_13_17.jpg (81166 bytes)
A drainback supported by lava columns. Drainbacks are geologic formations that form when lava recedes after a flow. This lava pillar is also a drainback feature. Lava pillars are formed around vents that ejected gases when active.  This geological feature is called a "skylight," a window for researchers into a lava tube system.

Contact: Debbie Meyer (831) 775-1807, pressroom@mbari.org