Seafloor sediment flows (turbidity currents) are among the volumetrically most important yet least documented sediment transport processes on Earth. A scarcity of direct observations means that basic characteristics, such as whether flows are entirely dilute or driven by a dense basal layer, remain equivocal. Here we present the most detailed direct observations yet from oceanic turbidity currents. These powerful events in Monterey Canyon have frontal speeds of up to 7.2 m s −1 , and carry heavy (800 kg) objects at speeds of ≥4 m s −1 . We infer they consist of fast and dense near-bed layers, caused by remobilization of the seafloor, overlain by dilute clouds that outrun the dense layer. Seabed remobilization probably results from disturbance and liquefaction of loose-packed canyon-floor sand. Surprisingly, not all flows correlate with major perturbations such as storms, floods or earthquakes. We therefore provide a new view of sediment transport through submarine canyons into the deep-sea.

MBARI has been conducting remotely operated vehicle (ROV)-based video surveys of the upper 1000 meters of the water column in Monterey Bay, California for over 23 years. These surveys have produced a unique midwater time-series data set that has enabled MBARI scientists to observe changes in mesopelagic animal distribution and community structure in Monterey Bay over that time period. These changes can generally be associated with both short and long term changes in water mass structure, including some now being associated with climate change. This historical data set is becoming even more important as we begin to observe the effects of climate change on community structure and ecology in the midwater environment and try to predict the impact of future change. However, this data set comes at a high cost in ROV and support ship time required to conduct the surveys. In order to sustain these surveys into the future, a more cost effective approach is required. In an effort to reduce cost, improve methodology and develop a system that has the potential to be exported to other institutions, MBARI has developed a high definition video module to be deployed on its Dorado class autonomous underwater vehicle (AUV). This paper explores the challenges of this development, the chosen solutions, and presents early data derived from our initial inter-comparisons of video collected concurrently with MBARI's ROV and midwater imaging AUV.

MBARI biological oceanographers make increasing use of mobile autonomous sensor platforms to observe dynamic phenomena, and require near real-time data in order to focus resources on rapidly evolving areas of interest. We have implemented a Wave Glider-based payload called Hot Spot that creates a disruption-tolerant communications network between shore and at-sea autonomous platforms. The Hot Spot uses multiple radio and acoustic modems and software to implement a store-and-forward network; the system reliably transfers data between the at-sea Wave Glider Hot Spot, Autonomous Underwater Vehicles (AUV's), benthic instrument packages, and computers on shore. Hot Spot achieves this reliability in an environment where communication links are often unpredictably disrupted. Onboard Hot Spot applications use these capabilities to acoustically determine the location of multiple underwater targets, and can autonomously direct the Wave Glider to follow a moving underwater object. We describe deployments during which Hot Spot quickly transferred science and engineering data between multiple vehicles and shore, and where the Wave Glider used its Hot Spot acoustic tracking application to autonomously follow a moving submerged AUV as part of a large biochemical science campaign.

The 2009 Marine Advanced Technology Education (MATE) remotely operated vehicle (ROV) competition focuses on a submarine rescue training exercise. There are four tasks outlined for the Ranger class, each providing its own challenge. Our ROV was designed to carry out these tasks with precision and agility.The team spent numerous hours planning, building, and field testing our ROV. We had to be prepared to combat technical problems and overcome the challenge of differing opinions. Because of the diversity of the tasks, Suijin had to be very well designed. This required the creation of a rigid frame, useful end effectors, and a versatile propulsion system; a form of buoyancy, effective sensors, and proper wiring were also necessary. There were many ideas to consider and obstacles to overcome, but finally, we completed our masterpiece.Heritage Robotics is very pleased to present the following technical report, which communicates the details of Suijin , an ROV created by students from Heritage Collegiate, Lethbridge, Newfoundland, Canada. This document includes detailed descriptions and diagrams of Suijin ’s components, possible future improvements, trouble shooting techniques, the lessons we learned, the challenges we faced, information on the Submersible LR5, reflections, a thorough budget, and acknowledgments of all those who helped along the way.

The Monterey Ocean Observing System (MOOS) moored observatory hosts tens of instruments on multiple networked nodes distributed over the sea surface, water column, and seafloor. Commands and data are exchanged between instrument nodes over high-speed copper and fiber-optic links at 10 Megabits per second using TCP-IP protocols. Science and engineering instruments on each node acquire and log data at various rates; the current deployment of five instrument nodes logs tens of Megabytes of data per day. Approximately 5 Megabytes per day of telemetry is required to provide a subset of science data and system status information. The surface node periodically establishes a PPP connection to shore using the Globalstar satellite system, providing a link for remote system control, maintenance, and telemetry retrieval. Telemetry retrieval is particularly challenging, given the capacity and cost of the 7800 bits per second communications link The challenge is compounded by limited satellite availability, wave-driven motion of the surface buoy antenna, and occasional outages of hardwired network connections between nodes. To address these issues, we have developed software strategies to manage the low-bandwidth satellite link in a highly efficient manner. Elements of our telemetry retrieval strategy include use of data summarization algorithms, PPP compression, multi-threaded utilization of the satellite link, optimized data packet size to reduce protocol overhead, and assertive reconnection of prematurely disconnected satellite links. We discuss the efficiency and trade-offs of various approaches, as well as overall observed improvements in telemetry rates. Our current implementation is capable of retrieving at least 10 Megabytes of telemetry per day, and we discuss further improvements which could substantially increase that rate.

The Monterey Bay Aquarium Research Institute (MBARI) in support of the MBARI Ocean Observation System (MOOS) Science Experiment 2006 (MSE06) has established a benthic cabled observatory. The goal of MSB 06 is to study deep seafloor processes within and adjacent to the outer Monterey Bay Submarine Canyon. At the study site near Shepard Meander, a Benthic Instrument Node (BIN) and a McLane Vertical Profiler have been deployed in the axial channel of the canyon at depths of 3,450 meters. On the adjacent flank, outside the canyon another BIN has been deployed at a depth of 3,000 meters. These interdisciplinary BINs and profiler will be interconnected with a fiber optic/power cable using the ROV Tiburon. This will establish a network that can measure currents, suspended sediments concentrations, salinity, and temperature at these sites. The BINS and profiler will be cabled to a MOOS mooring. A satellite link from the mooring to shore will be used to monitor system function as well as deep sea conditions during the experiment. The ROV based cable deployments will consist of 3.5 kilometers between the lower and upper BINs, 2.5 kilometers between the upper BIN and the MOOS mooring and 200 meters between the profiler and lower BIN. Borrowing from the cable laying tool sled technology developed for the ROV Ventana (Bird 2002), this effort will integrate the knowledge gleaned from the Canyon Dynamics experience to the ROV Tiburon and MSE06. Some of the challenges involved in this project include weight constraints, power requirements, cable management, navigation, and electro/mechanical controls. In the future this technology will actively support the (Monterey Accessible Research System (MARS), and ORION/OOI. This presentation will deal specifically with the cable laying tool sled developed for the ROV Tiburon, cable packs, and infrastructure created to accomplish these tasks. Elements include the cable laying tool sled, BIN platforms, interconnects, profiler, mooring bottom expression, and cable handling equipment. Design elements includes; integration with the ROV Tiburon, meet operational weight constraints, the ability to (pick up, drop, and reacquire the cable spool), support the vehicle's Kraft Raptor manipulator, monitor cable payout speed and distance and a variable ballast system controlled by the amount of cable deployed. The operational procedure is, launch the vehicle at a BIN platform site with up to 4.5 km of cable on the spool. The vehicle will dive to the BIN, perform the interconnect, and establish a Doppler Velocity Log (DVL) bottom lock and enter coordinates of the location. Using the navigational program ArcNav, the vehicle will proceed along pre-mapped way points. The vehicle will follow the contours 1 to 2 meters off the bottom maintaining visually both the bottom and the cable as it is deployed. The maximum deploy speed will be .5 knot (.9 km) per hour. Deploying approximately 10% more cable length versus distance traveled will avoid tensioning the cable and forming spans. This will be accomplished using a graphic user interface that displays the amount of cable deployed versus the actual distance traveled across the bottom. Pay out speeds will be adjusted manually to match the speed of the vehicle. Upon reaching the BIN, the cable spool will be dropped, as an anchor, holding the excess cable. Using the manipulator, the connector will be removed from a dock within the cable spool body. A 20 meter service loop of cable on the exterior of the cable spool will allow the vehicle to maneuver to the BIN and perform the interconnect. In early July 2006 a successful cable lay of 2,800 meters, between the MOOS mooring and the shelf BIN was performed. In early October the remaining cable lays are scheduled

This paper presents results of numerical modeling of an oceanographic mooring system and makes comparisons to loads measured on a deployed test mooring near Monterey Bay, California. The numerical modeling solves the non-linear equations of motion of the cable in the time-domain. The deployed system is instrumented to monitor environmental loading and the resulting tensions in the mooring cable below the buoy and above the anchor Comparison of the numerical results to the measured results is useful to refine the accuracy of the model, allowing its use in determining fatigue life of the system and for designing similar systems to be deployed in new locations. This study is part of a project to develop and improve mooring systems for oceanographic use that include an electro-optical-mechanical mooring cable that delivers power and data communication to a network of sea-floor instrumentation. The modeling and test results highlight the engineering challenges associated with designing these systems for long lifetimes.

Buoy based seafloor observatories require lightweight synthetic strength member electro-optical anchor cables to be feasible. Typically these cables have maximum elongations of around 0.6% before damage occurs to the copper and optical elements and therefore provide minimal compliance to absorb wave and current forces acting on the surface buoy and cable. A stretchy mechanical system known as a snubber has been developed at WHOI for absorbing wave energy and protecting the buoy electro-optical cable from excessive strain. Results are presented from field trials of three different ocean mooring designs that all use snubber hoses as a key design element.

One of the key capabilities envisioned of MOOS (MBARI Ocean Observing System) is to provide both power and communications to oceanographic instrumentation in the benthic environment. With many technical elements, such as low-power instrument control 'nodes' and EOM (electro optical mechanical) cabling being proven at sea, the need to manage TCP/IP communications over a fiber optic link to the benthic environment became apparent. This requirement led to the construction of a custom network switch with fiber optic capability named Medusa. Medusa provides the foundation for MOOS undersea networks with managed L2 TCP/IP packet switching including fault tolerance and enhanced diagnostic capabilities for gauging the health of the undersea network. This paper describes the overall requirements, design, software capabilities, and features of the Medusa platform

There has been considerable discussion and planning in the oceanographic community toward the installation of long-term seafloor sites for scientific observation in the deep ocean. The Monterey Bay Aquarium Research Institute (MBARI) has designed a portable mooring system for deep ocean deployment that provides data and power connections to both seafloor and ocean surface instruments. The surface mooring collects solar and wind energy for powering instruments and transmits data to shore-side researchers using a satellite communications modem. A specialty anchor cable connects the surface mooring to a network of benthic instrumentation, providing the required data and power transfer. Design details and results of laboratory and field testing of the completed portions of the observatory system are described