Woods Hole Oceanographic Institution

Cruise Planning Synopsis

view revisions

AR23-02 Transit magnetometer


RV Neil Armstrong

Cruise Party

Mark Behn: Chief Scientist, Principal Investigator
Woods Hole Oceanographic Institution Clark 260B, MS#22 Woods Hole, Ma. USA 02543
+1 508 289 3637

Jean-Arthur Olive: Principal Investigator
Lamont Doherty Earth Observatory 61 Route 9W P.O. BOX 1000 Palisades, NY USA 10964-8000
+1 845 365 8648

Departure: Oct 2, 2017

Ponta Delgada, Azores

Arrival: Oct 12, 2017

Woods Hole, MA

Operations Area

Azores to Woods Hole
Lat/Lon: 36° 0.0′ N / 34° 0.0′ W
Depth Range: 1200 / 5500
Will the vessel be operating within 200 NM of a foreign country? No
Are visas or special travel documents required? no

Science Objectives

Fault generated abyssal hills are a primary morphologic feature of the ocean floor.  Abyssal hills are created at the ridge axis and their formation is controlled by a combination of the rheologic properties of the lithosphere and magmatic processes in the crust.  Ambient pressure in the Earth’s mantle caused by fluctuations in sea level can drive changes in melt production along the global mid-ocean ridge system.  Several recent studies have proposed that these sea level-induced melting variations are expressed in abyssal hill fabric (e.g., their size and spacing)—and thus that seafloor bathymetry acts as a recorder of past sea level variability.  However, the mechanism by which variations in melt production generate changes in abyssal hill morphology remains unclear. In particular, the mechanically-controlled spacing of abyssal hills is very similar to the spacing that would be predicted from orbitally-controlled sea level changes making it difficult to determine a cause-and-effect relationship.

To investigate the relationships between faulting, magmatism, and sea level change we are conducting a 10-day research cruise on board the RV Neil Armstrong from the Azores to Woods Hole.  The cruise will collect underway geophysical data (bathymetry, gravity, magnetics) to characterize variations in crustal thickness and lithospheric properties along a flow line that extends from the Mid-Atlantic Ridge to the US East Coast margin.  The cruise is being conducted as part of a graduate student seminar within the MIT/WHOI Joint Program in Oceanography and will be led by the students taking the course.  Processing of the data collected during the cruise will be performed by the students during the remainder of the fall semester. 


Science Activities

Collect underway geophysical data: multi-beam bathymetry, gravity, magnetics, sub-bottom profile.   A list of preliminary waypoints is uploaded below.  These are the same as originally discussed in May when proposing the extra day for the transit.

Additional Info

Pre-cruise Planning Meeting: Teleconference/Visit WHOI
Meeting Notes: I can do either. If we want to involve Jean-Arthur we would probably need to do a telecon.
Media personnel on board: Writer
There is a possibility of a write from Time, but I don't know if this will actually pan out.


Supporting documentation:



Funding Agency: WHOI
Grant or contract number: No number; just extra ship day
Funding Agency: NSF
Grant or contract number: OCE-14-58201

Scientific Instrumentation for R/V Armstrong

Shipboard Equipment

Bathymetry System 12 kHz
Bathymetry System 3.5 kHz
EM122 (12 kHz) Multibeam Echosounder
Towed Magnetometer
Shipboard Equipment Notes: We'd like to run the gravimeter, magnetometer, EM122 and the Knudsen 3620 subbottom profiler.  I'm not sure the difference between the EM122 and the 12 kHz Bathymetry system listed here.  Also, are there any problems running the EM122 and Knudsen simultaneously?

Shipboard Communication

Basic Internet access via HiSeasNet

Critical CTD Sensors

Storage Notes:


Will you be using Long Base Line (LBL) navigation? no
How many nets? null
How many tansponders? null
Will you be using Ultra-short baseline (USBL) navigation?no


Navigation Notes:
Winch Notes:
Winch Notes:

Standard Oceanographic Cables

Slip ring required? no
Non-standard wire required? no
Traction winch required? no

Specialized Deck Equipment

Mooring Deployment/Recovery Equipment Required: no Type: 
Cruise Specific Science Winch Required: no Type: 
Nets Required: no Type: 

Over the Side Equipment

Will you be bringing any equipment (winches, blocks, etc.) that lowers instruments over the side? yes
Details: The only over-the-side equipment will be the towed magnetometer.

Special Requirements

Elecrical Power: no Identify 
Equipment Handling: no Identify: 
Inter/intraship Communications: no Identify: 
Science Stowage: no Identify: 
Water: no Identify: 

Additional Cruise Items/Activities

Explosive Devices:no
Portable Air Compressors:no
Flammable Gases:no
Small Boat Operations:no
SCUBA Diving Operations:no

Hazardous Material

Will hazardous material be utilized?no
Describe deployment method and quantity:

Radioactive Material


Additional Information

Is night time work anticipated on this cruise?no
Specialized tech support (Seabeam, coring, other):
Other required equipment and special needs:
Load equipment at WHOI before Armstrong departure on Sept 11th

Checklist & Notes


U.S. Customs Form: yes
Diplomatic Clearance: no
Date Submitted:
Date Approved:
Agent Information:
Must fill out 4455 cutom forms 5 days before departure on 9/11 for any gear loaded onto the ship.
Isotope Use Approval: no
Isotope Notes:
SCUBA Diving: no


SSSG Tech: