Planning a Marine Geodesy Experiment
Spahr Webb
Lamont Doherty Earth Observatory
Columbia University
The experiment requires deploying instruments at sea?
How do I get ship time?
You apply for ship time as part of a NSF proposal by attaching a “Ship time and Marine Equipment request form” (SME) at the end of the proposal.
You generate the SME by completing the form at the Marine Facilities Planning website: https://mfp.us/ (go to “research planning”)
You need a separate SME for each “leg” of the experiment- that is separate SMEs for a deployment leg, and a recovery leg. Also any ship time you might need for waveglider deployments/recoveries
You can not plan a project longer than 5 years by NSF guidelines- but once funded it may be possible to request no-cost extensions. (This may be changing).
How much ship time do I need to do the project?
Start by picking start and end ports for the cruise- how do you pick that?
Mostly, you need to pick ports near your planned work area.
Note projects a long way from the US, particularly in the Indian Ocean may be very difficult to get funded, and take a long time to get to sea, because ships are rarely in the area (and long transits are expensive!)
Picking ports is something where you should talk to ship operators and colleagues who are experienced.
Next figure out the total transit distance for the project- how many nautical miles to the first site from the start port, then between sites and finally back to the end port.
A good rule of thumb is to assume 10knots (10 nautical miles per hour). Divide distance by 10 to get total transit time in hours. (Ships can be as fast as 14kts- but weather can slow you down, and smaller ships tend to be slower).
How much ship time do I need to do the project?
You then need to figure how much time it will take to do each site.
Here you need to discuss things with the providers of the equipment- A GNSS-A deployment typically takes one day per site if you deploy three benchmarks, and do a CTD.
A simple pressure sensor deployment might be a few hours. You may need to wait for the instrument to fall to the seafloor. (40m/min).
Add up transit time in days, plus the time for each site to do the work.
The MSE will automatically add a port day at the beginning for loading of the ship, and a day at the end for unloading. For planning travel for science personnel, you can only move onto the ship during the loading port day and move off the ship after the unloading.
How much ship time do I need to do the project?
You should likely add a ”weather day” or two for possible slow downs due to high seas, or equipment failures. It is always hard to know how much to add-you don’t want to make things too expensive in ship time. Ship is order $50K+/day
Which ship do I ask for on the SME form?
Mostly you can just check “intermediate vessel” for regional GNSS-A work.
If you need an ROV, you need a “large vessel”.
Some ships are typically in one area- you can pick a particular ship on the form if it seems obvious, but the ship schedulers will figure out which ship to use.
What equipment do I need to request for the ship on the the SME?
If you need an ROV (Jason) to place or move instruments on the seafloor- you request it on the SME. Definitely discuss your plans with the deep submergence group before submitting a proposal:https://www2.whoi.edu/site/deepsubmergencelab/
You will need a fairly large scientific research party to adequately staff the Jason van during operations. It would best to work with an experienced scientist on any Jason project. Sign up for a Jason leg as a volunteer!
NSF asks that you submit a proposal that requires a ROV 18 months before the planned use.
For use of intermediate and regional class vessels, they recommend you submit your proposal at least 12 months ahead.
Other concerns
Weather matters. It is very hard to work in the far North or far South (roaring forties, screaming fifties!). You need a large ship.
You can only work in Alaska or Cascadia in the summer months (May=Sept).
It takes longer to do work in rough weather and ships travel more slowly.
You can not deploy a ROV in very rough weather.
I recommend “tropical geodesy”
Working in the EEZ of another country requires permission from that country (usually routinely given but not always). You will likely need to share data and have a foreign collaborator.
Ships Equipment:
Most marine geodesy operations mostly just require a crane and/or an ”A-frame” which is standard on all ships.
If you want a profile of sound speed for GNSS-A analysis you need to request a CTD, and plan for the time it will take to deploy the CTD.
Most ships have a multbeam- a sonar seafloor mapping system. You will often need this to accurately place seafloor instruments and avoid nasty topography for GNSS-A sites . Also systems such as FETCH transponders may be depth limited (3000m).
In regions with strong currents, a “ADCP” acoustic doppler current profiler may be useful to look for strong surface currents, which may cause your instruments to be drift substantially from the deployment locations on the way to the seafloor.
Two new ROVs are being constructed!
Good Luck! Questions?