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Issue 67
Pink Salmon Returns at Solomon Gulch Hatchery
Users often combine Golden Software products to produce their final project. In the summer of 2007, a study was conducted by Dr. Richard Crawford of the Prince William Sound Science Center (PWSSC) in conjunction with the Valdez Fisheries Development Association to develop a tool to enhance the evaluation of fish abundance with their commercial-grade echo sounders. The goal was to maximize the harvesting of brood stock at the Solomon Gulch Hatchery. For their analysis, PWSSC used a combination of Surfer, Voxler, and Grapher to complete the study of Enhancing in-house assessment of pink salmon returns at Solomon Gulch Hatchery in Alaska. See the full report for additional information.
Prince William Science Center, located in Cordova, Alaska.
As Richard describes, “We explored the use of three-dimensional modeling for studying fish distribution and behavior at the Solomon Gulch Hatchery in Prince William Sound by combining traditional fisheries acoustics techniques with the novel use of Geographic Information System (GIS) modeling and graphical visualization. The goal was to gather information to help optimize escapement for brood stock while maximizing the opportunity for harvesting the surplus for cost recovery and the open fishery. Golden Software products Surfer, Voxler and Grapher were perfect for the task.”
Isosurfaces were created in Voxler to display the
volume visualization for the schools of fish. This allows the true
shape of the fish schools to be displayed.
A Voxler image reflecting the fish
distribution along a bathymetric feature.
A 3D surface in Surfer, displaying the study area showing
the East and West schools of fish concentrated along the
shelf break (light and dark blue patches).
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Surfer contour and base map overlays showing the main bodies of fish
at the West School (left) and East School (right).
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A Grapher bar chart and line graphs display a
modeled distribution of the schools of fish.
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Issue 67
Geophysics for Geothermal Exploration
The Dewhurst Group is a global geophysical exploration company that specializes exclusively on site selection for geothermal exploration and geothermal power development. The Dewhurst Group consists of a team of geologists, engineers, and geophysicists that integrate geophysics, geologic mapping, and geochemistry to pinpoint geothermal sources for electric power generation. The group relies heavily on both broadband magnetotelluric (BMT) and low frequency magnetotelluric (LMT) instrumentation. MT instruments are designed and built in collaboration with the Russian Academy of Sciences and Vega Geophysics. Typically, the instruments are capable of acquiring resistivity values from a few meters in depth to many kilometers. With the LMT equipment it is often possible to gather data at depths as far down as the Mohorovicic discontinuity, the boundary between the Earth’s crust and mantle. Information at such depths can be helpful in understanding the tectonics that might drive a shallower geothermal source and related “plumbing” system.
Figure 1. Field work at the Pueblo of Jemez. Dewhurst Group incorporated Members of the Pueblo within the field teams.
With well over 100 years of collective experience among principals, The Dewhurst Group has participated in projects all over the world. These include an exploration study for the State of Montana in order to assess the viability of developing the first geothermal power plant for the state, geothermal exploration in the Basin and Range province of the Mojave desert, and an innovative project near Jemez, NM. The Jemez project was part of a Department of Energy grant and the work was in collaboration with TBA Power, Inc. and the Pueblo of Jemez. Of more local interest perhaps, the company has just completed exploration work near Buena Vista and Salida, CO for Mt. Princeton Geothermal, LLC. These resistivity imaging surveys are perhaps the first to be conducted in Colorado, exclusively for geothermal exploration.
According to the company’s founder, Warren T. Dewhurst, Ph.D, P.E., Golden Software products have played a key role in the company's work from the very beginning. While a graduate student at the Colorado School of Mines, he used the first iteration of Golden Software products.
Figure 2. Conceptual cartoon of how MT data are gathered in the field at stations along profiles.
Case Study in Jemez, NM
The Dewhurst Group employed a four-phased exploration approach at Jemez, NM. The first phase used geo-electric strike and dimensionality analysis to design and test the survey location. During Phase 2 the data was collected at over 150 stations throughout the survey area, approximately 37 km2. Once all of the pertinent information was gathered, the group analyzed and modeled the results.
The Dewhurst Group utilized Golden Software’s MapViewer, Grapher, Surfer, Didger and Voxler throughout the project. During the analysis and interpretive phase, Voxler was used to generate 3-D renderings all 1-D, 2-D and 3-D inversion results. The various models were compared and integrated to generate a resistivity imaging model of Earth’s subsurface at the Pueblo. The final imaging model, shown below, was interpreted and provided to the client. Theiso-surfaces within the image depict different resistivity zones.
Figure 3. 3-D image of subsurface resistivity at the Pueblo of Jemez. Red shows areas of low resistivity, often associated with geothermally altered cap rock or a concentration of geothermal brine. Target area shown at a depth of 1800m and “X” marks the spot to drill.
The Dewhurst Group credits the visualization tools available within Voxler for helping locate an optimal drilling depth and target location. Notably, the resistivity results generated by their data and displayed with Voxler were later confirmed by further exploration that included a subsequent seismic survey.
For more information about the Dewhurst Group, please visit their website.
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Issue 67
Netherlands Company Uses Surfer to Search for Drowning Victim
November 20, 2011-Four recreational divers went looking for known wreckages at the bottom of De Nieuwe Meer in Amsterdam, Netherlands, a ~30 m deep lake with strong bottom currents.
The group split into two pairs and set out on their adventure. Around 11:30 AM the only woman diver reported looking back for her partner, a 55 year old man from Amstelveen, but all she could see was a cloud of sediment. He never surfaced.
Rescuers operating the sidescan SONAR. Picture from AT5
The fire department was called and they immediately sent out divers to locate the man. Because of dense fog, the search was called off for the day. The next day, National Police Agency divers and specially trained cadaver dogs along with AT (equivalent of American SWAT) with sidescan SONAR joined the retrieval mission. The water was cold enough and the diver had been down there long enough that he was assumed dead. On the third day of the search, the Dutch Navy brought in autonomous underwater vehicles (AUV’s), but they still couldn’t locate the body. On November 25 the site was opened to anyone from the public wishing to participate in the investigation.
It was at this point in the story that Henk de Vries and Metaldec Survey BV enter the picture. Metaldec uses Golden Software products Didger, Voxler, and Surfer, for a wide variety of projects, including pro-bono work with off-duty members of the Amsterdam police department. They had previously helped the department set protocols for forensic drowning scenes, and they were known to volunteer frequently to help the police.
So, on December 10th Mr. de Vries and his team, at the request of off-duty National Police Agency members, got to work. The divers had taken depth recordings every 30 seconds, so Mr. de Vries used Surfer 10 to create a 3D depth map of the lake, from which the divers identified the approximate location where they’d lost track of their comrade. In this refined area, Metaldec set up their sidescan SONAR equipment and collected their own bathymetry data.
3D Surface Map of De Nieuwe Meer created with Surfer 10
As Mr. de Vries overlaid his bathymetry data on a Google Earth image of the lake, he made a surprising and concerning discovery. The pipeline running through the middle of the lake, which sucked up water to cool servers in a local hospital, did not cross the entire lake as everyone had assumed, but stopped at an inlet near the center of the lake. No previous divers had ever mentioned this, but they were all in danger of being sucked into the pipe, so all diving was immediately halted. Interestingly, this inlet area was near where the dogs and the other divers believed the man disappeared. The lake was dredged to no avail. On January 6, 2012 the search was called off permanently, as no body had been found.
Metaldec’s SONAR images overlain on Google Earth image of De Nieuwe Meer
Now, more than 5 months later, the body is still missing. Some think the body was sucked into the pipe, though it’s more likely the diver got stuck under the pipe or inside of one of the ship wreckages nearby. Regardless, through the selfless acts of Metaldec and Henk de Vries, the lives of numerous divers were saved with the discovery of the dangerous inlet pipe. As for the missing diver, Mr. de Vries holds out hope that he will be recovered one day.
For more information, visit:
AT5, 23 Nov 2011, “Duiker Nieuwe Meer nog steeds spoorloos.”
Franke, Ronald, Hulpdiensten Online, 21 Nov 2011, “Zoekactie naar vermiste duiker in Nieuwe Meer gestaakt.”
RTV-NH: Radio+TV Noord-Holland, 6 Jan 2012, “Zoekactie duiker Nieuwe Meer gestaakt.”
AT5, 21 Nov 2011, “Politie zoekt naar lichaam duiker." |
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Issue 67
Welcome to the Sondermülldeponie Kölliken (SMDK): the Kölliken Hazardous Waste Landfill
Rainer Albert is an experienced Surfer user and recently discovered the versatility of Voxler. Below outlines his contribution to the modeling of the Kölliken hazardous waste landfill using 3D visualizations from both Surfer and Voxler.
The landfill consists of a wide range of organic and inorganic wastes from the industry, commerce and public sectors. Over a 7 year span 475,000 tons of hazardous wastes were deposited in the landfill. The site’s restoration process started in 1985 and the site is currently being excavated and remediated under the large hall (as pictured above) in order to be fully restored by 2016.
Rainer uses Surfer to display the topography of the site along with the 3D rendering of buildings. The image below shows a 3D surface map with an overlaid contour map, post map and image. The building in the forefront is the Swalba and House Matter Hall.
Topography at the end of 2011; Modeling done by ARGE Phoenix using Surfer 10.
Voxler is used to display the waste type and waste concentration from data collected between the surface and bottom layers. The distances between the surface and bottom can span up to 17 meters apart. In the below Voxler image, the transparent surface layer is overlaid with contour lines to display the landfill’s terrain while also displaying the chemical types and concentrations below.
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This image, created in Voxler 3, details the Kölliken hazardous waste landfill’s terrain along with chemical types and concentrations.
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The concentration of manganese in the site from a bird’s eye view. For the full views, click here.
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For more information, visit the Surfer and Voxler webpages. And for more information on Rainer Albert’s interesting project, visit SMDK. |
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