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August 16, 2012 Minutes

 

CIET Conference Calls

 

Agenda

  1. Oceanus delay and schedule for remaining 2012 deployment cruises
  2. 2013 schedule
  3. CIET meeting in October
  4. Misc. Issues

Minutes

Participants:   Bob, Richard, Susan, Doug, Emilie, Rick, Jeff, John, Martin Rapa, Dean, Will

Oceanus delay and schedule

Oceanus will remain in shipyard longer than expected.  Available to load for leg 4, Tuesday the 21st, sail on the 22nd of August at the earliest.

William revised timelines again and legs 4 and 5 are doable, just barely, if surveying is included.  To save time, we discussed options of not surveying and not following to the bottom.  The priority is as follows:

  1. Deploy, track to bottom and survey
  2. Deploy, track to bottom, do not survey
  3. Deploy, do not track or survey. 

Because instruments are new and early anchor releases have occurred, it is strongly preferred that we track the instrument to the seafloor.  Thus options 1 and 2 are acceptable.  Option 3 is not advised.  On leg 4, for example, we could save 1.5 days by not surveying, but tracking instruments to the seafloor.

Given the squeeze on time we also need to prioritize our site deployments; more on that below.

If all goes exceedingly well, all OBSs can be deployed and surveyed.  However, that leaves no contingency time.  To build contingency, it was decided that the earlier deployments should choose option 2 above.  I.e., it is best to use the early part of the cruise to build up contingency in the event of either weather or instrument problems.

Will:  Are we sure that we can offload and unload in 24 hours?  Offloading for WHOI gear will not consume much time.  Martin Rapa estimates 17 or 18 crane picks in a few hours.  Very good.  
 
Action Item:  Talk to Demian about after hours issues for crane operator available.  Can they hang on and do more work.  If port call is one day, gets us a day of contingency.
 

2013 Schedule

The 2013 schedule is under development. Scheduling needs to consider time for OBS refurbishment.  Current estimates are:

  • SIO:  4 weeks
  • WHOI:  6 weeks
  • LDEO:  TBD

SIO/WHOI have pickup cruises in fall for Nabelek that we need to consider when building the schedule.  LDEO will likely use Atlantis for ROV work.

Action Item: Toomey to develop an estimate of cruise durations for 2013

Data Quality and Availability

Action Item:  Toomey to ping on IICs for dates when data available.

Shallow water instruments: There are reports that these stations are noisier and that biofouling is particularly severe above 100 m water depth.  Encrusted and corrosion.  Martin Rapa reported on= instrument out for a year, was at 55 m. Real mess, barnacles.  Sacrificial anodes of 5 years, corrosion off of anchor.

Question came up of how to make decisions about deployment sites given noisy data and biofouling.  Something to be discussed as we move forward, particularly as we learn more about current data and plan for 2013 deployments.

Noted that  quite a few TRMS had the seismometer fail and that data return rate was not great. Not sure yet what caused the instrument failure.  For stations that did not fail, what do the horizontals look like?
 
Action Item:  Need to start cataloging data quality and availability.  Central topic at CIET meeting in October.

CIET Meeting

Action Item: Toomey to finalize dates, most likely in early October.

Miscellaneous Topics

Data Delivery to DMC

  • Why does it take so long to make the data available?  Part of the reason is personnel availability.  
  • How much time does it take to do all of this if personnel are available?  Less than one month, depending on whether or not there is a leap second. SIO got it on their server, making adjustments of leap second.  Data is being looked at, not sure when it will be up at DMC.

 Site prioritization for 2012

Need to prioritize sites for for upcoming deployment cruises.  It looks like OBS performance for the year 1 Focused Array was poor.  We want to consider that when prioritizing sites for year 2 and ensure that the Focused Array off of the MTJ is fully deployed.

Emilie and Will sent out priorities for leg 4.  Need to get input frome the rest of CIET.
Is the  4 year reference array sacrosanct?  Some discussion that it should be preserved?
Leg 6 order of deployment is not fixed.  In the event of problems, which is more important, aperture or spacing?
Jeff’s concern is that 3 or 4 might be missing at start of leg 6.  Can readjust spacing to maintain aperture, but others might say spacing is more important than aperture.   Data recovery for the TRMS. One third returned no data from the seismometers, but did return data from APGs.  1/3 did not record seismic data; what was cause of problems?
 
Action Item: Prioritize sites for legs 4, 5 and 6 and keep an eye on the completion of the FA at MTJ

Miscellaneous Topics

Marine Mammals

William spent a good part of summer writing ONR planning letter to record high freq. at a small number of sites.  Will be submitting in a week or two.  Try and deploy an EW line in year 3 and 4 of the instruments.  Could be part of TRM, otherwise a separate deployment side by side. Would the navy provide ship time?  Likely that it would
 

Shallow water instruments

Susan will talk with Katy (fisheries) at 1 pm Pacific time, ask about 3 sites in shallow water off coast of Oregon for our cruise.  Few locations for leg 5.