2010 Projects
A
Peltier freeze-shoe sampler to recover aquifer sand and groundwater
Lex van Geen, Ben Bostick - Geochemistry Division Chris
Manning - Manning Applied Technology, Troy, Idaho with Stefan Mrozewski and
Dave Goldberg - Borehole Group
A key reason
that biogeochemical processes regulating the composition of groundwater are
poorly understood is that current sample recovery technologies do not provide
geoscientists with pristine groundwater in contact with its host aquifer sands.
The goal of this Observatory Technical and Innovation Center (OTIC) proposal is
to address this shortcoming through the development of a novel sampling tool.
The proposed tool will be deployable from a variety of platforms and will
collect aquifer sand and groundwater simultaneously by freezing the bottom of a
core tube. A few freeze-shoe devices have previously been constructed and
deployed by other groups with some success. The innovation that we propose is
to use an array of Peltier coolers, rather than liquid CO2 or N2, to freeze a
plug at the bottom of the coring tube. Preliminary calculations suggest
freezing could be achieved within a few minutes, while providing much better
control of the entire process. The first prototype will be constructed by modifying
an existing commercial coring device that already has been used extensively for
sediment sampling in Bangladesh and Vietnam. Patenting the proposed
modifications and licensing to manufacturers is a distinct possibility given
the demand for better sand recovery around the world.
Custom
Leaf Cuvette For Simultaneous Measurements of the Thermal Tolerance of Photosynthesis and Respiration
Kevin Griffin
I propose to build a custom gas exchange/cuvette system to
simultaneously determine the
thermal tolerance of photosynthesis and respiration of plants under
controlled conditions of a
constant vapor pressure deficit and a constant rate of temperature change. The proposed system will combine commercially available
instruments in a unique way
allowing for the first time the simultaneous quantification of both respiration (from CO2 flux) and
photosynthetic thermal tolerance (from chlorophyll fluorescence) over the entire physiologically relevant temperature
range (-Â10 - +50 °C).
Once developed the system will be used to survey the temperature
tolerance of various terrestrial
plants from many ecosystems (globally) in order to more fully understand the physiology controlling the global
carbon cycle.
Development of Recording CO2-CH4-O2-pH-Salinity Sensor System for Field
and Borehole Measurements in Aquifer Studies
Taro Takahashi and David Goldberg
Sequestration of CO2 recovered from industrial
fossil fuel usages is considered to be one of the viable solutions for reducing
emissions of this greenhouse gas into the atmosphere. Of various sequestration
schemes, disposal of liquid CO2 into geological formations is a realistic option. It has
been practiced in locations like Sleipner gas field in Norway, and is being
tested in deep aquifers such as Mt. Simon Sandstones in the Illinois Basin and
Columbia River Basalt near Wallula, WA. One of the major environmental concerns
for such geological sequestration is leakage of the stored CO2 back into upper layers and
eventually into potable aquifers. Acidification of potable waters resulting
from CO2 addition
may cause a release of undesirable metals and compounds from aquifer rocks into
drinking waters. For this reason, EPA has recently issued a RFP for early
detection of upward migration of CO2 from sequestration strata below into potable aquifers
above. In response, we have submitted a proposal to EPA (Goldberg et al.,
ÒIntegrated Design, Modeling, and Monitoring of Geologic Sequestration of
anthropogenic Carbon Dioxide to Safeguard Sources of Drinking Water
DiagnosticÓ, $900,000 for three years). In this proposal, we proposed to
collect water samples in bottles in irregular frequencies (daily or weekly) and
measure in our laboratories the concentrations of dissolved CO2, CH4, and O2 gases and pH in the stored samples.
This operation is not only labor intensive, but also samples may be altered
during storage. Furthermore, the anticipated data lack high-frequency
variability information including amplitudes of variability, and an analysis of
such coarse time- resolution data might yield an erroneous time-trend. We,
therefore, considered that an automatic recording sensor system for the
continuous measurements of these dissolved gases and pH would allow us to
document not only short-time, but also weekly and seasonal variation of them,
and help to clearly define the evolution of an aquifer system. Such a system,
when developed, would put us in a highly competitive position in future
research projects including near- and far-field observations for the dispersion
of CO2 within
an aquifer system as well as across geologic formations. This proposal is to
request support for initial development of a field operation system for the gas
species dissolved in water.
2009 Projects
A robust control system for autonomous vehicles
Nick Frearson
The goal of this project is to define and
develop a robust navigation and control system for airborne autonomous vehicles
that will be fault tolerant. This technology will be used to support sensor
development and deployment of geophysical sensors on similar and other
platforms.
A
Proposal for Developing Inexpensive, Easily Hidden Seismometers
Roger Buck and Scott Nooner
There are areas of the world where there is a
pressing need to collect seismic data, but where any above ground instruments
are subject to vandalism or theft. Thus, there is a need to build seismometers
that could be buried and operate for long periods on batteries. Since we expect
that some of these instruments may be found and stolen we would like to keep
the instruments inexpensive. Small size will also reduce costs of transport and
make them easier to hide. The decrease in cost and size of solid-state memory,
efficiency of electronics and batteries may make it possible to build such
instruments for a few thousand dollars each.
2008 Projects
A
High-Speed Self-Contained Video Camera System for Optical Plume Velocimetry
Timothy J. Crone (http://www.fluidcontinuity.org/
)
Hydrothermal flow within
the mid-ocean ridge system is the primary mechanism by which new crust cools
and it facilitates large chemical fluxes between the seafloor and the ocean
(Elderfield and Schultz, 1996). These flows strongly influence the physical
properties of the lithosphere, the chemistry of the ocean, and the geology of
the crust. Hydrothermal flow also delivers the energy required to support large
and diverse ecosystems living at and below the seafloor, and in this way serves
as a critical link between the geophysical, chemical, and biological components
of mid-ocean ridge systems (Kelley et al., 2002).
Despite the
importance of hydrothermal flow, little is known about its magnitude or its
spatial and temporal variability. Flow measurements in these systems are extremely
difficult because the fluids can be very hot (> 350◦C), are highly
acidic (pH < 2), and are saturated with metals and min- erals which
precipitate as the fluids mix with cold seawater. These factors make long-term
invasive flow measurement in hot hydrothermal vents, called Òblack smokersÓ,
essentially impossible.
A solution to this problem is the development of
non-invasive flow measurement techniques, whereby flow rates can be ascertained
without making physical contact with the flow. One promis- ing new technique in
this class is based on video image analysis. Called Optical Plume Velocimetry
(OPV), it relies on the establishment of a time-averaged optical flow field
from an image sequence showing the plume of a black smoker vent. This technique
has been shown to work well on lab- oratory flows using standard digital video
sequences (Crone et al., In Press). The next step is to implement the OPV
technique within a stand-alone camera system, which can collect vent imagery
and process the video to obtain flow rates in real time. We propose to design
and build such a cam- era that can be tested on laboratory flows. We will then
leverage this prototype design to obtain the NSF funding required to build
several OPV cameras and deploy them in a mid-ocean ridge setting.
2007 Projects
Satellite
Telemetry for ShakeNet Strong-Motion
Sensor Networks
Colin P.
Stark, David Gassier, Tarik Hussein, Andrew Barclay
Collaborating engineer: Alberto Behar (JPL/NASA)
We are designing a prototype satellite telemetry interface
for the ShakeNet project as a means of building LDEO institutional expertise in
the use of satellite communications to scientific instrumentation. ShakeNet is
an Earth Institute (CCI) funded pilot program to design and deploy low-cost
networks of smart strong-motion sensors in impoverished, highly populated
regions at great seismic risk. Its
aims are to enable the rapid assessment of shaking and damage following a
destructive earthquake, to promote awareness of earthquake risk, and to provide
vital data on attenuation, site effects, and infrastructural
vulnerability. Since landline and
cellular networks will inevitably be compromised or overloaded in a damaging
earthquake, satellite communications will be needed for emergency-mode
communication between the sensors and a remote server. Our key aims are therefore: (1) to
understand the constraints and possibilities offered by low-cost satellite
telemetry, and (2) to develop a prototype interface system that integrates
off-the-shelf sensors, microcontrollers and satellite transponders into an
adaptable tool for use both in the ShakeNet project and in future LDEO field
projects.
Ice Thickness
Spar
Doug Martinson (dgm@ldeo.columbia.edu),
Xiaojun Yuan
We are proposing to build an affordable (<$6 k)
functioning prototype of an ice thickness-measuring spar (ITS). The ITS will be
a thick-walled PVC pipe, with thermistors located every 5-8 cm epoxied into
small holes in the side of the spar. The spar is designed to be deployed in
open ocean and frozen into the ice pack when it forms, operate for a minimum of
1 yr transmitting back the temperature profile via iridium (or, ideally, using
ShakeNet being developed by Stark et al. in another OTIC project). The spar,
can be any length, but the prototype will be designed for the nominal Antarctic
seasonal sea ice cover, requiring a spar that can accommodate 1.5 m of sea
ice/sea water and a 0.7 m snow cover. Buoyancy requirements are simple and show
that we can easily accommodate enough batteries to allow more than 1 year of
continuous operation. Experience during our ANZFLUX project in the Weddell
gyre, using T-profiles through the ice and snow with similar non-transmitting
PVC tubes show that the conversion from T to ice thickness is easy and precise,
even allowing good estimation of the ice and snow conductivity and heat flux.
Standard off-the-shelf parts will make this affordable, with the hopes that
after successful testing of the prototype even supplements to our existing
Antarctic grants will allow purchase of many spars allowing good coverage of
ice thickness in regions we are currently studying in detail (for DGM this is
within a dense grid of ocean stations along the mid-western margin of the
Antarctic Peninsula; for XY, the target area is in the Pacific center of the
ADP to complement mooring observations). Our dream is to have these
continuously sampling throughout the pack ice, and low-cost is the key to this.
2006
Projects
The Lamont Rapid
Deployment Ocean-Bottom System
Andrew
Barclay, Patrick Jonke, James Gaherty, Spahr Webb
The
proposed Lamont Rapid Deployment Ocean Bottom System (LRDOBS) is a seafloor
delivery/recovery and datalogger system that is lightweight, inexpensive, and
easy to operate. Although the
LRDOBS has potential use for general time-series measurements (e.g.,
seismometers and hydrophones; pressure, current and flow meters; magnetometers;
temperature and chemistry probes; acoustic profilers; and optical
backscatter/transmissometer sensors), it meets an immediate and well-defined
need in active-source seismology.
The seafloor seismometers that are used for marine seismic refraction/tomography
experiments and that also provide crucial seismic velocity information for
reflection surveys are typically designed for broader applications and are
unnecessarily large, complicated and expensive. With fixed capabilities that are matched to the requirements
of active-source seismology (e.g., a single hydrophone recording continuously
for one month at a fixed sample rate), the LRDOBS will be a low-cost, reliable,
and low-maintenance instrument that can be stored on board ship and efficiently
used at sea. Automated
pre-deployment programming, battery recharging, and data download are necessary
to minimize the time and personnel required for LRDOBS operation. OTIC funding will be used to develop a
prototype instrument for demonstration and testing. Many of the prototypeÕs components will be off-the-shelf;
design and construction will focus on the datalogger for which the critical
challenge is to minimize cost, size, weight and power consumption for 1-2
months of single-channel, 24-bit recording.
A
portable universal water sampler for dissolved gases
Martin Stute (martins@ldeo.columbia.edu) Brice Loose (brice@ldeo.columbia.edu)
Concentrations and isotope ratios of gases dissolved in
surface and ground waters give us important clues about fluid flow and
transport dynamics (e.g. CFCs, SF6, SF5CF3, 3He), past climate conditions (e.g.
noble gases, N2), and biogeochemical processes (e.g. CO2, H2, H2S, CH4, N2).
We are proposing to build a suitcase size, portable,
user-friendly, self-contained sampler that will separate dissolved gases based
on an in-line equilibrator with a fast semi-permeable membrane (Polypropylene,
manufactured by Liqui-Cel¨, www.liqui-cel.com). We expect that the new system
will yield reliable uncontaminated samples for all (or at least most) gases of
interest.
At the heart of the system is a ÔcontactorÕ manufactured by
Liqui-Cel¨, which consists of thousands of 300mm diameter polypropylene
hydrophobic membranes that act as barrier for water, but are permeable for all
gases. Gases being pumped in a closed circuit through the fibers equilibrate
with passing water on the other side of the membrane. The characteristic
equilibration time in the fibers is of the order of seconds (Liqui-Cel, 2006)
and depending on the volume of the attached sample containers, the entire gas
phase is expected to equilibrate over a period of minutes to tens of minutes.
Partial pressures of the individual compounds in the gas phase depend on the
temperature of the membrane and the (known) solubility of the gases in water.
In order to determine the concentrations of dissolved gases in water from the
mixing ratios in the gas phases, a precise temperature and total gas pressure
measurement is required, and the whole system needs to be stabilized at the
water temperature by placement into an thermally insulated box. The sampler
will also require a small 12V battery to run the membrane pump and various
gauges.
If successful, this universal sampler might revolutionize
how environmental gas samples are collected and will benefit a wide range of
current and proposed projects being conducted at Lamont.