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Logbook: September 22, 2004

45° 56.02' N, 130° 0.81' W

image of RAS intake funnel
2004 RAS fluid intake funnel in place at Virgin Vent. Visible are the excavation tool, HOBO and temperature sensor (T1) at the base of tripod (counter-clockwise from lower left). New RAS is in the background.
 

Dive R854 was largely devoted to recovering the 2003 RAS (Remote Access Sampler) and replacing it with 2004 RAS. The new RAS is essentially the same as last year's model but has an additional sensor for Eh (a redox measurement of electron movement). The new RAS had been dropped to the seafloor the previous day from the Thompson and ROPOS had to move it into its final position. The 2003 RAS first had to be nudged to the surface by the ROV as it had been caught on a thin line when given its release signal. After placing the new RAS, ROPOS then positioned the intake funnel and temperature probe over the vent where the anhydrite chimney had formed the prior year. The anhydrite chimney had been knocked over on yesterday's dive when recovering the old RAS and after only a day, more anhydrite deposits were being formed.

The remainder of the dive was devoted to recovering and deploying long-term temperature sensors, and collecting digital images of several vents (Mushroom, Hell, and Phoenix). One HOBO (high temperature probe) instrument was placed at Virgin, another recovered at Marshmallow and a suction sample of blue microbial mat was made at Phoenix vent.

 

 

 

Sep/Oct 2004
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Click on day to view other logbook entries. <- Back | Forward->

 

Today's photos
click for larger view
image of biology at Phoenix vent
Biological community...
image of Hell vent
Hell Vent at ASHES...

 

 
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