International District to ASHES

Sunday, August 15, 2010
Tube Worms in Diffuse Flow
Summit of Diffusely Venting Chimney

Summit of diffusely venting chimney in the International District.

Much of yesterday was spent conducting detailed photomosaic imaging of the International District Hydrothermal Field. Using the Insite Pacific high-definition camera, the Enlighten '10 team viewed spectacular imagery of colorful, extremely dense, and diverse biological communities supported by nutrient-rich, warm hydrothermal fluids. Organisms within the diffuse flow sites included vibrant lavender-blue cilliates waving in the upwelling fluids set against a backdrop of luxuriant bushes of tubeworms with red plumes sprouting from white chitin tubes. There were also iridescent brown-red palm worms and white limpets.

We conducted vertical, highly detailed imaging of the 8 major chimneys in the area, spending significant time at the 14- to 18-m  black smoker chimney called El Guapo, the handsome one. This structure is venting black smoker fluids at temperatures of 339°C and hosts numerous beehive chimneys at its summit where clear jets of fluid egress from multiple orifices. The jets rapidly turn black from precipitation of fine-grained sulfide minerals.

There are numerous extinct channels and fluids have found other new conduits from which to vent. The chimney is a complex structure with multiple overhanging ledges, or flanges, that once hosted pools of hydrothermal fluids and diffuse flow. El Guapo is a candidate for follow-on drilling efforts to take internal temperature measurements of the chimney and to sample the extremophile microorganisms that thrive within its hot internal walls.

We also visited the chimneys Castle, Flat-top, Top Gun, Diva, Escargot, and Hermosa. Many of these structures hosted abundant areas of diffuse flow and were covered in biological communities. The Jason pilots, Jimmy V, Tito, and Scott, used the vehicle to conduct skilled pirouettes around the chimneys for high-level overviews of the edifices. Of note was the chimney Castle, which appeared to be rotating in the blackness of the deep ocean waters with none of its base in sight. 

Following completion of the first site survey of the International District, a reconnaissance survey was completed of the cable route and site for the Primary Node3B on the eastern flank of Axial. Currently Jason is conducting a bathymetric survey to the west, across the caldera valley floor, and ending in the ASHES Hydrothermal Field later today.