08/24/2009-Mon (JD236)


Prepping an SIO OBS for deployment

 

Daily Report from Anthony Johnson
082409_V1_DR_MGL.pdf
Second rosette is reloaded and 750 m of damaged line is removed.  The second acoustic package is put in the water.  The end of this day will see the retrieval of the second rosette and the beginning of OBS deployment ops.  

OBS deployments began at 0609Z.  Calm seas and a southerly winds during the night help move the deployments and ship rapidly along the easternmost line.  Deployments are from south to north. WHOI group proceeded quickly up the easternmost line of instruments, deploying sites W1-W10 over a period of 8 hours, finishing just before breakfast.  WHOI group off to the rack following breakfast.

SIO takes over, arrive  site 0820 PDT (1520Z).  Between breakfast and dinner sites S14 (1521Z), S36, S50, S51, S64, S63, S62, S61, S54, S53, S59, S52 (~2400Z).  Twelve instruments in 9 hours, averaging 1.3 hours including transits.  Good progress overall, even though the winds are on the nose and the seas are slightly sloppy.

During the day the winds come up to 20 Kts and the weather deteriorates.  Visibility is down to less than 3 km for much of the day.  Near dinner time the seas lay down and wind calms to <10Kts.  Not a good day for launching airguns if that was our desire.

Teams switch. The WHOI team plus Ernie from SIO take over for the evening shift.  The goal is to deploy along the southwestern corner of the array.  

Endv_OBSdeploy_plan7.pdf

Two deployment teams are set up.  WHOI prefers to be present for all deployments and recoveries of their instruments.  Teams consist of i) Peter Lemmond (WHOI), Dave Dubois (WHOI) and Ernie Aaron (SIO) and ii) Mark Gibaud (SIO) and Phil Thai (SIO). These teams are augmented by Langseth crew members and by graduate students.