SUNDAY, 02.08.09

1003: Lee Frey To Ted Waitt
Mr. Waitt,

Related to the proposed survey of the Lau eruption site, we have prepared a brief two-page summary of what we feel we would be capable of achieving if we diverted to the site. We are certain that the scientific community would desire a more comprehensive study, but this is what we feel would be reasonable given the situation. Follow-on work would be possible in the future, of course. Regarding time, the diversion would mean a two to three day loss of survey time at the Howland site on Leg 1. Regarding funding, we believe there may be financial support available from several agencies on existing programs including NSF, CORE, NOAA OE, R2K, etc. So, it would be worthwhile to inquire with Woods Hole Oceanographic Institution (WHOI) to see if there could be some contribution to offset the daily costs associated with the Lau survey. Please review the attached summary. We look forward to your response.

Regards,
Lee Frey

Lau Eruption Site Survey
Initial Best Effort Survey from Onboard Technical Staff
Proposed to T. Waitt (WID)

Descriptive:
Active underwater volcanic activity has recently been discovered along the North Lau Spreading Center (NLSC). The discovery has prompted an announcement to the oceanographic community to search for available resources and time to further investigate the site.

The R/V Seward Johnson is currently (08 Feb) in port in Pago Pago, American Samoa. The ship is equipped with two REMUS 6000 autonomous vehicles being prepared to support other survey activities in the region. The ship is currently scheduled to depart port on 09 Feb to support these activities. The NLSC site is a one-day steam from Pago Pago. This document is provided to outline a scenario that would enable the R/V Seward Johnson and its onboard technical staff to perform a timely and meaningful survey of the area.

Proposed Survey:
A limited survey of the NLSC area will be performed with the two AUV’s in their current survey configuration.

Figure 1: Proposed 2km x 6km survey area. (Initial image provided by of R. Embley - NOAA via Resing, J. et al)

It is proposed to survey a 2 x 6 kilometer area centered over the axis of the ridge between the Maka and Tafu mounds. The vehicle will be equipped with a dual (non-simultaneous) 75/410 kHz side scan sonar unit, SBE CT sensor and a Wetlabs backscatter sensor. The vehicle is also equipped with an electronic still camera. The capability to image using the camera system will be limited to areas of benign bathymetry. The survey of this area will be performed at 250 meter track line separation, 600 meter sonar range and 60 meters of vehicle altitude. This box may be expanded and/or the survey resolution adjusted in order to meet vehicle operational obligations.

The survey plan proposed was derived from onboard staff as a starting point. Factors taken into account are the vehicle capabilities and meshing the survey objectives with current onboard technical objectives pertaining to the vehicles, time and funds. The area picked was based on our opinion that it was an area of high interest from a science point of view.

The NLSC bathymetry represents that which is typical in certain areas of the Pacific.

Schedule:
The survey mission would be performed as part of the initial vehicle systems check. Minimum operational tasks will include a CTD cast, deployment of long baseline transponders and two vehicle sorties. The completion of these two surveys and review of the data sets will determine moving on to the next phase of the current vehicle work.

Based on current in-port preparations, the following schedule is proposed:
09 Feb Monday. 1800 RVSJ Departs Pago Pago
10 Feb Tuesday. 1800 RVSJ Arrives NLSC Site
1800 - 2000 CTD Cast
2000 - 2300 Deployment and Survey of Transponders
11 Feb Weds. 0000-2400 Vehicle Survey Time. Three Vehicle Sorties
12 Feb Thurs. 0000-0200 Recover Gear at NLSC Site. Underway. Impact to current schedule reflects up to a three-day loss of survey time from ship’s current objectives.

Additional Capabilities:
Additional survey capabilities exist within the vehicle and shipboard systems. These capabilities include high resolution vehicle multibeam systems and shipboard CTD system. Use of these sensors requires expanded vehicle configuration efforts or additional shipboard time on site that would need to be discussed.

Cost Discussions:
The further timely investigation of this site is of great interest to the scientific community. Response funding for efforts like this is available through consortium offices housed at research institutions. This proposed effort will need to be reviewed by them to make sure it is in concert with their needs.

A specific point of contact to solicit these funds (assurance of their availability) is actively being sought. An individual who can attest to the availability of these funds and provide guidance is the WHOI Director of Research.

1117: To Ted Waitt, Lau Eruption Site Survey
Earlier this morning, Dave Gallo asked me where we were with this work. I told him we’d get back to him, but I leave that to you or Dominique Rissolo, depending on what you think about this. Also, I’m sure Dom is right in his message of last night about checking with the scientists who are interested.

The biologist is getting his net ready to try and take biologic samples when the girls (AUVs) are down, too. I’d say the crew feels pretty confident that it’s a good piece of work and gives us the chance to see how the pencil beam avoidance is doing. Also, as I mentioned yesterday, Steve Dabagian thinks the chances of damage are slim at 60 to 70 meters altitude (although there’s certainly some risk, I don’t know much about that stuff but an underwater pyroclastic blowout couldn’t be good on them; like flying a plane over Mount St. Helens during an eruption I would think). There’s also a negative cost to our overall mission time-wise, but not having any idea on the funding that might come our way from this, I don’t know what the cost/benefit analysis is on it. It’s your call.

Right now, the latest is that we get our boxes at midnight. If that happens and the testing of the machines dockside goes okay (need the bottles for it), we’ll be ready for an on-time 9 a.m. departure tomorrow. Delay in boxes or problems with testing will push us back the amount of time they take up in resolution.

One Last Test

Testing a vehicle after the long voyage to American Samoa

1717: To Ted Waitt, Don’t Mean To Pester You
But sometime in the next 18 hours, we are going to need to know what you think about the Tau site. We were unable to get any numbers on any of the local WWII planes, so we’ll just look for a nice flat bottom nearby to test if not on that other site. Cheers.

1731: Response From Ted Waitt
I’d say we proceed as planned unless we secure funding. We will consider between Legs 1 and 2, or after 2, as a possibility. We’re already behind schedule and over budget for our primary mission and we haven’t started yet.

2057: Slight Delay
We have been informed by our agent that although our mission critical boxes are on the island, the earliest we will be able to get them from customs is 8 a.m. tomorrow morning. We are going to need eight to 10 hours dockside after receiving them for testing. This will necessitate a delay of our departure until tomorrow afternoon or evening.