The R/V Marcus G. Langseth is equipped with numerous survey instruments to enhance scientific studies of the seafloor and beyond. The science equipment is summarized below, additional science equipment may be utilized during a specific cruise to complete the mission objectives. For cruise participants, please notify the technical staff before bringing additional equipment aboard.
The sonars equipment on vessel include the Kongsberg EM122 12 kHz multibeam echo sounder and the Knudsen 3260 3.5 kHz Sub-bottom Profiler are operated continuously throughout every cruise. Staff on board Langseth are proficient in basic operation of these systems, but are not sonar experts.
The EM122 multibeam echosounder (MBES) is normally run with standard options enabled and automatic parameter adjustments enabled where possible. This configuration should provide good coverage (swath width), but may not provide optimal coverage under all conditions. These settings will not provide the best data quality. Specifically, reducing swath width is often required to attain the best data quality and density. Consult with the technical staff or other authorities if there are specific requirements for your cruise.
Bathymetry data will be acquired (recorded) using a Kongsberg EM-122. The EM122 sound velocity profile (SVP) will be processed from the Expendable Bathythermograph (XBT) data and uploaded to the EM122 system by the technical staff. The updates will occur at the discretion of the technical staff or at PI request, up to once per day, coincident with XBT deployment.
Should more frequent updates than once per day be required, the science party must supply the necessary probes. They must also supply approx. 30 minutes of personnel time to perform the processing, per profile. Training in processing and uploading the profile to the multibeam will be provided by technical staff.
The Knudsen 3.5 Hz Sub-bottom Profiler (SBP) is normally run synchronized with the EM122 MBES. This sometimes results in a reduction in the Knudsen sampling rate, but minimizes interference with the EM122. PI's who wish to run the Knudsen without synchronizing to the EM122 must discuss this with the Chief Science Officer. If the multibeam is not in use, the Knudsen will be run in internal sync. Knudsen data is recorded in SEG-Y, KEA, and KEB formats.
Magnetics and Gravity
The Langseth carries two Geometrics 882 magnetometers – one being a spare unit. Langseth policy is to deploy the magnetometer only in the work area. The magnetometer is not deployed during transits to and from the work area. The magnetometer must be recovered at less than 3 knots. The magnetometer will not be deployed during OBS recovery or deployment operations.
The Langseth is equipped with a Bell Aerospace BGM-3 gravimeter. Gravity data will be handled by the R2R data archive group at LDEO. Photo to the left of the gravimeter.
The Langseth carries Sippican T-5 and T-7 Expendable Bathythermograph (XBT) probes, suitable for general oceanography and sound velocity use in the multibeam processing. Langseth deploys one probe daily when possible. Science party assistance (one person, ~20 minutes daily) is required for routine probe launch. Multiple people can be trained on probe launch operations. If no science party members are available to assist with deployments, deployments may be reduced as necessary. Due to space and cost considerations, Langseth does not routinely carry probes in excess of these requirements. PI's who require additional probes or probes of a different type must discuss their needs with OMO before the cruise. PI's who have a specific deployment plan should work with shipboard technical staff during the cruise. The standard cut-off limit for XBT probes will be used unless a specific request is made by the PIs (Probe T-5 to 1850 m and Probe T-7 to 700 m). Other Mk21 probes, e.g. XCTD’s and XSV’s, may be deployed using the Mk21 system. The LDEO technical staff does not provide these probes.
The Langseth carries a Sea-Bird Electronics SBE19 Conductivity, Temperature, Depth (CTD) system. This instrument does not have a water sampling system.
(Image CTD deployment)
The Langseth does not have a permanent coring setup, however the capability is available from Oregon State University (OSU). In 2012, the Langseth had a successful coring cruise, MGL1208, with th
e coring team from OSU.
The navigation equipment on the vessel is as follows:
• Furuno FE700 echosounder
• Furuno DS50 doppler speedlog
• C-Nav 3050 DGPS
• C-Nav 2000 DGPS
• SImrad GC80 gyrocompass
• Sperry Mark 37 gyrocompass
• POS/MV Integrated Nav System
• Seapath Integrated Nav System
• Spectrum Instruments TM-4 Event Logger
These systems are provided to support seismic operations and the multibeam system. There are no user-configurable options. These systems are operated by the crew and technical staff, and are turned on or secured as necessary. They are normally operated, unless equipment or permit requirements dictate otherwise. All of these instruments output serial data and are logged using the Lamont Data System.
The navigation processing will be performed by the technical staff using the Concept Sprint Navigation Processing System.
Data format: UKOOA P294 (final P190)
Data medium: Electronic
Langseth has an RM-Young Weather Station installed for wind speed/direction, air temp/humidity, and barometric pressure.
The following meteorological and hydrographical instruments are on the Langseth and are routinely operated:
- LDEO PCO2 (Image on right)
- SBE-45 TSG
- Applied Microsystems MicroSV
- Sea-bird Electronics SBE38 Temperature Sensor
Set-up and operation of client-provided instrumentation is the responsibility of the Chief Scientist. The technical staff can assist with serial data feeds and network access. Please inform the OMO office and technical staff before bringing new instrumentation to the vessel.