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WHOI Funding
and Awards --> Cecil H.
and Ida M. Green Technology Innovation Awards --> 2003
Abstracts
Abstracts of 2003 Cecil H. and
Ida M. Green Technology Innovation Awards
A
Three-dimensional
Tracking of Tagged Whales in Real Time via a Free-Floating
Hydrophone Buoy Array
Mark Baumgartner, Peter Wiebe
Biology Department
and
Lee Freitag
Applied Ocean Physics & Engineering Department
The foraging behavior of top marine predators is difficult to observe because it nearly always occurs below the sea surface. The advent of archival tags that are attached to animals and record depth-of-dive information has allowed investigations of one-dimensional (1D) diving behavior. When combined with oceanographic sampling, these observations of diving behavior can be put into an appropriate environmental context to reveal novel insights about foraging ecology. However, foraging behavior is not 1D, it is three-dimensional (3D). To understand how marine predators locate and exploit discrete prey patches, we must be able to observe their 3D movements. Furthermore, we must do this in real time so that we can adaptively sample prey distribution and the physical environment to characterize the oceanographic factors that influence foraging behavior. Recent advances in tagging technology has begun the transition from 1D to 3D observations, however the resulting instrumentation cannot separate motions of the tagged animal from that of the ocean and it cannot provide 3D location data in real-time. We propose to develop a system with which marine predators can be tracked unambiguously in 3D and in real time. The system consists of a free-floating array of GPS-linked hydrophone buoys that will allow the position of an animal equipped with an acoustic transmitter to be determined based on acoustic time-of-arrival information. The time-of-arrival data will be relayed from the buoys to a mother ship immediately upon receipt of each acoustic pulse from the transmitter (nominally received once per second) so that a position can be determined continuously in real time. A Green Technology Innovation Award is being sought to develop the core technology of this system. We hope to obtain additional support from the Northeast Consortium Project Development Fund to build an operational system to be deployed in our upcoming research on North Atlantic right whales in the spring of 2004.
Development
of an in-situ Iron Electrode
Katrina Edwards and Daniel R. Rogers
Marine Chemistry & Geochemistry Department
Among
the principal goals in the geobiological sciences
(geomicrobiology, biogeochemistry, others) is the
development and implementation of in-situ methods
that allow direct quantification and characterization
of the physical and chemical environment inhabited
by microorganisms. Owing to the size of microbes
(~micron) and their corresponding microenvironments
(often sub-millimeter), and the transient nature
of their occurrence, empirical parameterization of
their chemical microhabitats is decidedly non-trivial.
One of the foremost technologies that has been developed
and applied towards in-situ chemical measurements
at the micro-scale is the microelectrode. Microelectrodes
for the measurement of oxygen, pH, nitrous oxide,
and sulfide are now used routinely and are readily
available from commercial vendors. However, though
the technology exists for microelectrode measurements
of many other chemical species (iron [Fe], manganese
[Mn], hydrogen, iodine, thiols, thiosulfate, trithionate,
copper, zinc, cadmium, lead), commercial products
for many of these ions are not available. Consequently,
microelectrodes for measurements of chemical species,
other than those for which commercial microelectrodes
are available, have to date only been developed and
used in a few laboratories.
We propose to develop a microelectrode for the measurement
of Fe and Mn in the environment. Our interest in Fe
and Mn stems from our ongoing and growing number of
projects that relate to Fe cycling in coastal and in
the deep ocean environments. We anticipate, however,
that interest in this technology would be quite widespread
here at WHOI, and that scientists from a number of
departments would benefit from its development.
Mechanical
Design for an Autonomous Expendable Instrument
System (AXIS)
David M. Fratantoni
Physical Oceanography Department
and
Keith von der Heydt
Applied Ocean Physics & Engineering Department
Expendable
probes used to measure temperature and salinity
are often employed by oceanographers for intensive
studies of rings, eddies, and fronts in the ocean. In
addition, research and commercial vessels routinely
deploy these probes as part of a global observing
network that provides data critical to our understanding
of the oceans and their role in climate variability.
We propose to undertake the initial design and
development of an integrated autonomous system
to streamline the collection and dissemination
of these crucial measurements.
Developing
a Highly Accurate Moored Dissolved Oxygen Sensor
William J. Jenkins and Fred L. Sayles
Marine Chemistry & Geochemistry Department
Time-series
measurements are an important tool for quantifying
and characterizing biogeochemical processes in the
ocean. Such measurements will form an important element
in the future global observing system. The fundamental
challenge ahead, however, is to increase the frequency
of observations down to scales that are relevant
to biogeochemical processes, and to extend coverage
to areas where access is difficult on traditional
ship platforms. One particularly promising area of
research involves the deployment of autonomous, moorable
sensors that can monitor biogeochemical properties
with sub-hourly resolution over monthly to annual
time-scales. Dissolved oxygen is a biogeochemically
important gas, as it is affected by a variety of
processes (air-sea exchange, bubble trapping, biological
production, respiration, and oxidation). Sensors
have been developed that exhibit reasonably good
short-term precision and relatively rapid response,
but frequent calibration is required. These techniques
are based on an electrode technology that is susceptible
to systematic shifts in performance due to qualitative
changes in membrane and reagent characteristics.
The current “best design” sensors are stable only
to 1-2% over monthly time-scales. Such shifts degrade
the quality and reliability of these time series
results.
We
propose to develop a new oxygen sensor that could
be stable to ~0.1% over many months. The design will
be based on a technology developed by Pro-Oceanus
using ultra-stable pressure transducers manufactured
by ParoScientific. Whereas their existing design
exhibits a response time of ~15 hours, we plan on
using a pumped reductant system that could reduce
this time to less than an hour. Our proposal is to
develop and evaluate this technology in the laboratory,
build a moorable package, and then “sea truth” the
sensor at the WHOI dock by comparing it to a combined
GTD/pN2/SeaBird O2 electrode sensor combination.
A
New Fast-Response Thermometer
Raymond Schmitt
Physical Oceanography Department
and
Robert Petitt
Applied Ocean Physics & Engineering Department
In
order to sense the centimeter-scale temperature gradients
of importance to ocean mixing, it is necessary to
have thermometers with very quick temporal response.
However, response times are lengthened by the necessity
for heat to diffuse through the fluid boundary layer
surrounding a moving probe and the solid elements
of the probe itself. Faster movement through the
water can thin the boundary layer, so the intrinsic
response time of the probe material is normally the
more limiting factor. Most temperature microstructure
measurements are presently made by using small glass-coated
thermistors with response times that are inconveniently
long. In addition, the thermistors are very delicate
and have proven to be susceptible to development
of microcracks when cycled to high pressure, as is
done on the High Resolution Profiler. Probes capable
of faster response could be used to make microstructure
measurements from higher-speed towed vehicles like
Seasoar, a capability which would be very valuable
for understanding the mixing processes affecting
upper ocean temperature, climate, and the relationships
between biota and turbulence. Here we propose to
develop a new type of fast temperature sensor that
uses a short length of thin wire as the sensing element,
protected from the seawater with a thin coating of
diamond. The very low resistance of this sensor will
be measured with special 4-terminal electronic circuitry
designed by Neil Brown.
Development
of LA ICPMS Techniques for Quantitative Analysis
of Fluid Inclusions
Nobu Shimizu
Geology & Geophysics Department
and
Lary Ball
Marine Chemistry & Geochemistry Department
This is a joint effort by N. Shimizu (G&G) and Lary Ball (MC&G) aiming at developing techniques
for quantitative chemical analysis of fluid inclusions in quartz with the laser
ablation ICP MS instrumentation at WHOI.
In
order to advance quantitative understanding of magma
genesis in the convergent plate margins, it is essential
to determine elemental fluxes from subducting slab
to the mantle wedge via hydrous fluids. Fluid compositions
evolve as subduction proceeds and are, at the moment,
poorly understood. The LA ICPMS techniques to be
developed here will become an essential part of an
experimental project for studying geochemical evolution
of hydrous slab-derived fluids as a function of pressure
and temperature along a spectrum of P-T trajectories
that subducting lithosphere could take.
Development of a Durable Carbon Nanotube Foil for Electron Stripping in Accelerator Mass Spectrometry (AMS)
Enid Sichel and Karl von Reden
Geology & Geophysics Department
AMS is by far the most
sensitive isotope ratio measurement technique available
to research. Rare or radioactive isotopes (like 14C)
can be detected at levels of 1 in 1,000,000,000,000,000
atoms in a sample of less than one milligram of the
element. The ability to reduce the required sample
size even more is of great importance to the ocean
sciences community. Many types of samples are severely
limited in the amount of carbon available for collection
(e.g., ocean sediments in regions of low biological
activity, specific organic compounds in fossils of
marine organisms). It becomes essential to minimize
all identifiable sources of measurement contamination.
One of the key procedural steps in AMS is the conversion
of negative carbon ion beams (extracted from a sample)
to the positive charge state in the terminal of a tandem
accelerator. This process involves grazing collisions
of the accelerated negative ions with atoms of a medium
introduced into the high vacuum, leaving the ions stripped
of several electrons. In most AMS systems, the stripping
medium is argon gas at low pressure. This has the disadvantage
of raising the gas pressure in the remainder of the
system, thereby reducing the beam transmission and
mass resolution of the spectrometer. Thin, solid-state
stripper foils have long been used in tandem accelerators
as well but have had a different set of problems: under
ion beam bombardment they tend to either disintegrate
prematurely or slowly thicken, leading to the complete
loss or serious degradation of the positive ion beam
after a few days of exposure.
We propose to develop a new type of solid-state stripper foil based on carbon nanotube technology.
Imaging the Sub-Bottom from an Autonomous Underwater Vehicle
Maurice Tivey, Brian Tucholke
Geology & Geophysics Department
and
Al Bradley and Lee Freitag
Applied Ocean Physics & Engineering Department
We
propose to build, install, and operate a chirp sub-bottom
sonar system on the autonomous underwater vehicle
ABE (Autonomous Benthic Explorer) in order to image
and document thin sediments (<~60 m) that cover
the ocean crust. Except on near-zero-age crust, sediments
obscure underlying volcanic and igneous basement
that comprises the ocean crust, and they thus prevent
imaging this crust. The sediments do provide, however,
an important history of sedimentation, erosion and
tectonic movement, so they are important geologic
units in their own right. Thus, detecting and imaging
the sedimentary layer is an important component in
seafloor mapping research. Autonomous vehicles provide
superb platforms from which to carry out geophysical
mapping programs, but to date these have been limited
to mapping the shape and visual character of the
seafloor. We seek to add the third dimension of depth
to the autonomous vehicle’s arsenal of sensors
by developing and testing a simple, first generation
chirp sonar for use on ABE. We expect that this will
have three benefits: 1) It will position us to seek
extramural funds for development of a more sophisticated
and capable system, 2) the availability of the system
will greatly enhance the demand for, and use of ABE,
and 3) this development will be adaptable to other
vehicles (e.g., DSL- 120, Jason), thus improving
their capabilities.
MAGnetic
(Induction) Communication System (MAGIC)
Keith von der Heydt and Dan Frye
Applied Ocean Physics & Engineering Department
A commercially-available magnetic communications device has appeared in simple to use, highly-integrated, low-power form. It has been designed for hands-free voice applications over very short ranges of a meter or less to avoid interference from nearby links of the same type. At this time, the link speeds are serial rates of 9600–57600 bits per second and are reliable at ranges of about half a meter. The power requirement however is only about 50mw at the highest speed, and as one might expect, the modulated magnetic field is affected little by the presence of non-ferrous enclosures. The underlying raw data transmission rate is about 200,000 bits per second at a carrier frequency of 10-15 MHz using wound ferrite cores as “antennas” that radiate most of their power in the magnetic rather than the electric field.
Telemetry
of information between sensors, instruments and vehicles
in seawater without benefit of copper or optical
connections is generally considered the domain of
acoustic communication methods. One can think of
numerous applications where a simpler ability to
communicate between submerged devices within a few
meters with no cable connection or external transducer
would be of great benefit. Among the possibilities
might be sensors that could be placed without the
need of physical connection near a subsea observatory
node, make measurements and transfer data to the
observatory network. A docked vehicle would not require
a close tolerance connection to an inductive or optical
coupling. A magazine of data capsules could be more
simply loaded with data from a central controller.
A winched sensor module could download its data to
the subsea winch controller without the need for
slip rings or electrical cable connection Such a
link would be particularly attractive if it required
little power, was simple to use and required no special
housing or orientation.
A Deep Diving Mass Spectrometer for Ocean Exploration of Gas Seeps and Pollution Monitoring
Jean K. Whelan
Marine Chemistry & Geochemistry Department
We propose to build and test an in-situ mass spectrometer suitable for continuous monitoring of methane, gases, and low molecular weight organic compounds including pollutants in the ocean. The instrument will be able to operate to at least several hundred meters water depth and is intended to be a prototype for a future instrument operating at full ocean depth. The scientific motivation for this project is development of a sensitive and versatile instrument for in-situ and continuous monitoring of gases and volatile organic compounds venting from oceanic “cold” seeps associated with methane hydrate deposits. The mass spectrometer will also serve as a tool for exploration for and characterization of methane gas seeps in the ocean floor. These seeps are commonly associated with seafloor gas hydrate deposits, which comprise one of the largest natural gas deposits on the earth. This gas has important influences on the biology, chemistry and geology of the ocean and possibly also on global climate. More and more of these seeps are being found each year, most almost by accident because there is currently no systematic way to explore for the large volumes of gas which typically stream from very localized fractures in the seafloor. Methane seeps are also associated with hydrothermal vent sites and areas of discharge of land-based run-off in the ocean. In-situ mass spectrometry would complement data from our in-situ Raman spectrometer (currently being built with NOAA funding) in characterization of the fluid discharge from all three types of ocean floor vent sites. Alternatively the instrument can be used in shallower waters to unobtrusively monitor a variety of organic compounds in coastal waters impacted by urban runoff, shipping lanes, and point sources of ground water discharge to the ocean.
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