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 (-­10 -­ +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., Integrated Design, Modeling, and Monitoring of Geologic Sequestration of anthropogenic Carbon Dioxide to Safeguard Sources of Drinking Water Diagnostic, $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 black smokers, 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 prototypes 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 contactor 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.