Skip to main content

June 23, 2011

CIET Conference Calls

Agenda

  1. Approval of Revised Deployment Plan
  2. Update on Mapping
  3. Update on Instrument Readiness
  4. Ship time requests for 2012
  5. CIET Meeting, Seattle
  6. Review action items from previous call: June 9, 2011

Minutes

Participants : Emilie Hooft, Susan Schwartz, Doug Toomey, Maya Tolstoy, Anne Trehu, William Wilcock, Richard Carlson

Approval of Revised Deployment Plan

The deployment plan has been approved by AASC.

Action Item 1: Notify community of change in deployment plan

Status of Bathymetry

William Wilcock reviewed the status of bathymetry data. No sites west of Gorda were covered due to heavy seas. Ship headed north to avoid system, hoping to return south. No luck. Once ship returns to port the figures/web site will be updated.

NOAA/PMEL has additional data that is not yet in NGDC and GeoMapApp. This data is being transmitted to NGDC.

Action Item 2: Review recently collected bathymetric data.

Update on Instrument Readiness

Andrew Barclay (LDEO) provided the following update via email on June 21, 2011

We did some testing of the trawl-resistant OBSs in Long Island Sound on June 15 and 16, and we expect to be able to supply instruments with working seismometers in time for the July deployment:
1. We may not have time to prepare all 20 TRMs. We plan to assemble and test them in sets of five.
2. We have successfully collected seismometer data, but we have not yet successfully collected absolute pressure gauge (APG) or hydrophone data. The APG didn't work properly on the seafloor, and the hydrophones have not yet been delivered.
3. There is still a risk from late delivery of or problems with critical components, but this risk is becoming increasingly controllable.
June 15-16 test cruise
We deployed a TRM in 40' water three times, with one overnight deployment. During the first deployment, the TRM dropped several feet onto the deck, but the sensor, leveling system and datalogger survived. The seismic data look OK, although suitably noisy for the water depths and currents. The APG worked in the lab, but not on the seafloor, and we think the problem was using 9V cells instead of the standard lithium battery pack. We further refined our deck-handling, although we've not yet handled the TRM in anything other than calm seas.
Year-long corrosion test
We recovered an early TRM prototype that had been sitting in Long Island Sound for a year. The low levels of corrosion and biology were reassuring, although it is probably very site-dependent.
TRM 2012 recoveries
We have 3 recovery options: popup release; LDEO 300m ROV; and a larger >=1000 m ROV such as Jason or Ropos. We have 15 popup release systems that can be used in water depths of 200 m or shallower, and can be fitted to ~14 of the 20 Year 1 sites. The LDEO ROV can go to 300 m, which makes it an option for 15 of the 20 sites. A larger ROV is definitely needed for 5 of the 20 sites.
Popup buoys have a spotty track record and we don't know how well they will perform. We need more experience with the LDEO ROV before we can predict how well that will work. Both Jason and Ropos have been retrieving an increasing number of heavy seafloor packages, and from talking to the Jason group, recovering the TRMs should be doable, except possibly for the shallowest (<100 m) sites. In the worst-case scenario, a large ROV may be required to recover all of the TRMS.

We reviewed this email on during the call. In addition to the above we discussed the following:

  • Assembly is moving forward. Leveling parts are coming from Germany
  • Pressure cases from SIO are behind, but likely to arrive in time
  • Painting of frames is lagging, but expected to be complete.
  • Currently aiming for 10 instruments for the first leg.
  • Found a fast option (4 days) for shipping to Newport. Ship on 15 (or 14) June. Arrive on 18th. Expect team to arrive in port early for additional OBS preparation.
  • May consider leaving port a day or so later, if possible.

Ship Time Requests for 2012

A ship time request (STR) has been submitted to UNOLS for future CIET expeditions. Ample information was provided and feedback from Jon Alberts (UNOLS) was positive.

A copy of the STR is provided: str_102970.pdf

CIET Meeting, Seattle Sept. 13-14, 2011

The meeting has been scheduled!

Review of Previous Action Items

Action Item (Remains Active): Initiate a discussion on issues related to Wecoma scheduling and possible recovery of a subset of LDEO instruments in 2011 (Tolstoy, moderator)

Notes:

  • Maya will continue to moderate a wiki page that lays out the possible options. The general questions is whether the 10 days of Wecoma time can be split and some of the days used later in the summer for recovering and checking a couple of instruments.

Action Item (Remains Active): Follow up on ships of opportunity (Wilcock/Tolstoy)

Action Item (Remains Active: Determine OBSIP space needs in Newport (Collins)