WHOI Funding and Awards --> Cecil H. and Ida M. Green Technology Innovation Awards --> 2006 Abstracts

Abstracts of 2006 Cecil H. and Ida M. Green Technology Innovation Awards

Matchbox: A Miniature In-Situ Methane Detector Using Novel Mass Spectrometer Components
Richard Camilli

Methane concentrations are important for understanding a number of compelling scientific problems such as air-sea greenhouse gas cycling, anaerobic respiration processes in sediments, groundwater fluxes, and marine pollution monitoring. Accurate in-situ measurement is difficult or impossible with commercially available instruments in real-world environments. This is because commercially available instruments rely on sensing modalities that are unable to decouple methane concentration from variability in temperature, pressure, DO, and contributions from higher-chain hydrocarbons. We propose to develop a low cost, miniaturized, methane sensor that overcomes the limitations of commercially available methane sensors. Our design will use elements of mass spectrometry, have a form factor approximately the size of a flashlight and be deployable for extended time periods underwater or in air.

Low-Power, Portable PIV System for Deep Sea Flow Measurement
Norm Farr, Mark Grosenbaugh and Alexandra Techet

We proposed to develop a compact, portable, deep-sea Particle Imaging Velocimetry (PIV) system, capable of high temporal and spatial flow field measurements in a two-dimensional plane. The goal is to design and construct a low-power system which can be diver-deployed or fixed on an ROV, AUV or ocean observatory. In situ measurements of flow fields in the deep ocean have widely been limited to point measurement techniques. Conversely, PIV provides instantaneous, two-dimensional planar velocity fields, which can then be used to determine vorticity, divergence, strain, and turbulent fluxes in the flow field. Such a technique is highly applicable to the study of oceanographic flows including hydrothermal vents, oceanic boundary layers, and the flow around freely swimming animals. To fully model the dynamics of these flows we need to be able to resolve key whole-field spatial and temporal scales of the flow in a non-intrusive and relatively inexpensive fashion.

A Non-Invasive Medium-Term Tag to Study Habitat Use and Fine Scale Movements of Marine Mammals and Turtles
Mark Johnson, Tom Hurst and Michael Moore

Regulatory bodies charged with the conservation of marine endangered species must choose management strategies that best protect critical populations without unduly burdening industries such as fishing or shipping that operate in the same areas. This task is made more difficult by a lack of information about the movement patterns and habitat use of many at-risk species. Although long-duration satellite tags and short-term multi-sensor tags have provided a great deal of insight into, respectively, the migratory movements and the fine-scale foraging behavior of some whales, large data holes exist that cannot be addressed effectively with currently-available tools. To address this need, we propose to design a medium-time-scale miniature tagging device capable of acquiring both precise locations and high-resolution movement information over intervals of a week or longer. The tag will combine accelerometers and depth sensors with a fast GPS sensor able to acquire an accurate position within the short surfacing period of many marine mammals. To overcome the slow acquisition time of standard GPS receivers, we will use a novel off-line data processing approach that yields positions from surfacing times as short as 0.1 s. As invasive attachment methods are unsuitable for use on some endangered whales, we will pursue a suction cup attachment. An existing short-term suction cup tag, the DTAG, pioneered at WHOI, occasionally remains attached to whales for up to 3 days. The proposed new tag will be substantially smaller and should therefore experience less drag and a lower risk of being dislodged by impacts with other animals. We will also study the process of suction cup detachment using carcasses of stranded dolphins which will be kept at WHOI's new Marine Research Facility. This realistic test setup will enable us to explore the potential of different cup materials and surface treatments to increase attachment duration.

Direct Spectroscopic Assessment of Rhodopsin in Marine Microbial Assemblages
Samuel Laney and Rob Olson

Rhodopsin is a pigment used for vision in many organisms, but certain microbes also use it to obtain energy for metabolism from the ambient light field. The widespread occurrence in seawater of microbial genes for rhodopsin has generated considerable speculation regarding a second, more primitive form of phototrophy in the ocean. Very little is known about microbial rhodopsin in marine systems: where it is found, how its distributions vary seasonally or with depth, or how many different types of rhodopsin exist. The goal of this project is to develop a transient absorption spectrophotometer to measure the optical properties of rhodopsin directly in marine microbial samples. This instrument will be a valuable tool for exploring this potentially important mode of light harvesting, by providing spectroscopic information about the presence of rhodopsin and its optical characteristics, in living cells collected from different marine environments.

Long-Range Plume Detector for AUVs
Rob Reves-Sohn

The circulation of seawater through young oceanic crust is a fundamental process for inter-disciplinary studies in marine geology, chemistry, and biology, with direct relevance to diverse topics such as global heat flow, the accretion and alteration of new crust, habitat for the subsurface biosphere, the formation of metalliferous ore deposits, and perhaps even the origin of life on Earth. Scientific studies of hydrothermal processes have always been limited by the relatively inaccessible position of vent fields on the deep seafloor, and this problem is particularly acute when it comes to the task of finding “new” fields. For more than 25 years, scientists have utilized the grossly inefficient “tow-yo” method of dragging CTD packages through the water column in the hopes of detecting anomalies associated with hydrothermal discharge. Recently, however, autonomous underwater vehicles (AUVs), have begun to revolutionize the vent finding process. The superior speed and positioning capabilities of AUVs have allowed scientists to rapidly generate comprehensive maps of venting activity at the scale of a single ridge segment (10s of km) for the first time, and the imaging capabilities of AUVs allow scientists to inspect a vent field prior to diving for sample collection – key technological advances with large scientific payoffs.

Laser Ablation Accelerator Mass Spectrometry
Brad Rosenheim and Simon Thorrold

The NOSAMS group at WHOI is currently pioneering the field of 14C accelerator mass spectrometry (AMS) with the construction of a CO2 gas-accepting continuous flow AMS (CFAMS) system, a significant advance in the measurement of 14C. The CFAMS system will allow several new advances in both the types of samples measured and, subsequently, the types of scientific questions addressed. This proposal outlines a two-part interfacing experiment that will establish protocol for the development of a laser ablation device for CFAMS. The use of a laser for radiocarbon measurement will enable ultra high spatial resolution sampling of a variety of materials with minimal sample handling by producing CO2 in situ, directly from the sample substrate (coral, otolith, sclerosponge, hardwood, etc). Our goals in this proposal are to 1) measure the efficiency of CO2 production from a laser ablation system already in use at WHOI, 2) use these data to develop a coupling protocol with the CFAMS system and 3) interface the two systems for in situ radiocarbon measurement of laser samples. This experiment will enable us to leverage funding for a dedicated laser sampling system that will offer significant improvements over the current system which is optimized for ICP-MS analysis.

An Osmotic Engine for Ocean Vehicle Propulsion
Ray Schmitt and Don Peters

Significant contrasts in salinity exist in the world oceans which, in principle, could be exploited to provide energy or even freshwater (Levenspiel and de Nevers, 1974). Energy can be extracted from the vertical salinity contrasts, because the salinity distribution is far from an equilibrium state in the gravity field. That is, at equilibrium the salinity distribution in the ocean would be decidedly bottom heavy, with the gradient in chemical potential balancing the gravitational potential. Thus, even an ocean with uniform salinity could be tapped for energy. We note that the situation is even more favorable than these chemists considered, with many regions of the mid-low latitude ocean having top-heavy distributions of salinity that provide energy for double-diffusive salt fingers. As with "Ocean Thermal Energy Conversion" (OTEC), little effort has been made to exploit such broadly distributed oceanic energy sources, because the energy needs of civilization are land based and the technical challenges of large-scale at-sea heat exchangers and membranes are not trivial. Here we propose a vehicle propulsion system suitable for floats, gliders or moored profilers that is analogous to the thermal powered "Slocum" glider, in the sense that it exploits a broadly distributed energy source to power the motion of the vehicle in the salinity gradient, rather than pumping water to localize the salinity gradient. This proposal would fund the development of a demonstration model and support scientist input to a patent filing. The osmotic engine could prove useful for a large variety of autonomous ocean vehicles, and will help to focus attention on this renewable energy source.

Seismic Reflection Profiling at the Seafloor using ABE
Steve Swift and Dana Yoerger

High resolution imaging of sub-seafloor structure is essential to solving many questions about the nature and dynamics of geological, hydrothermal, and geochemical systems in ocean crust and sedimentary sequences. Many of the most interesting areas of investigation, such as mid-ocean ridges, fracture zones, subduction zone trenches, and continental slopes, have steep or rough seafloor, which diffract sound and require extensive processing of conventional multi-channel seismic systems producing loss of spatial and vertical resolution. These systems fail to image near-vertical faults along which flow the fluids that are key to understanding the geochemical evolution of ocean crust. By moving the receiver onto an AUV close to the seafloor, we preserve source frequencies >100 Hz, reduce signal loss due to spreading, and reduce trace spacing from 6-20 m to 2-2.5 m. Green funding will be used to implement a deep-hydrophone system on ABE and to test it in deep water. We will then seek NSF funding to use the new system to demonstrate the system’s utility by producing the first images of lithologic structure in shallow ocean crust. The system then becomes a facility for all users of ABE, Sentry, or other suitable vehicles. Future developments include 3D mapping using multiple vehicles and applications to industry mapping of complex oil-bearing structures.

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