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Fall 2013 Colloquia

Thursday, September 12, 2013

Tania Lado-Insua,
Research Scholar at the Graduate School of Oceanography, University of Rhode Island
Title: SCIMPI: A new sub‐seafloor observatory
Host: Dr. Tim Grundl

The Simple Cabled Instrument for Measuring Parameters In-Situ (SCIMPI) is a new ocean observatory instrument designed to study dynamic processes in the sub-seafloor. The first prototype was deployed in Cascadia Margin on May 2013. The deployment Site, U1416, is located close to an active gas hydrate vent field. The first SCIMI comprises nine modules equipped with temperature, pressure and electrical resistivity sensors that take time series measurements of sediments in a drilled borehole. Science applications of SCIMPI include studies of fluid flow, hydrate formation, and seismically induced pore pressure changes. The Arctic Ocean is an area particularly suited for SCIMI deployment.

Thursday, September 19, 2013

Dr. Eungyu Park, Kyungpook National University
Title: A Stochastic Thought on Fluid Flow in Subsurface
Host: Dr. Weon Shik Han

Heterogeneities in subsurface physical properties originate from variations of the composing materials (ie. rocks and soils). The material parcel or category distribution in multidimensional space (generally three-dimensional) is intricate and mutually exclusive. Sound characterizations of these heterogeneities and the associated uncertainties have been the most important issue in many fields of hydrogeology because they allow for the construction of robust conceptual models for a wide variety of subsurface projects, such as groundwater developments, aquifers remediation, CO2 sequestrations, etc. In the presentation, the concept of stochastic approaches in the field of hydrogeology is briefly introduced with comparisons to the deterministic counterparts. For the purpose, a very efficient tool of geostatistical theory and models are explained. Finally, an example in which the stochastic approach has practical meaning will be shown and the implications will be deduced.

Thursday, September 26, 2013

Dr. Justin Hougham, Washington State University
Title: Education at the Speed of Research
Host: Dr. Tom Hooyer

Fundamentally, integrated approaches to research-based scientific literacy must be developed to effectively cross disciplines, include stakeholders and situate research efforts into the consciousness of learners of all ages. Meaningful approaches to this challenge address education at all levels- students, teachers, and public. Further, meaningful opportunities exist to engage learners and the public synchronously as well as asynchronously into the processes, results and implications of research efforts. These efforts can be found in traditional venues such as print media and course materials, and also in emerging media and technologically enhanced web-based platforms. Examples of this will be presented based on expeditions to Greenland, French Polynesia, and in the Pacific Northwest for topics that include climate science and lignocellulosic biofuels. Addressing many entry points into the education system while supporting an online collection of materials supports learners and provides the infrastructure for education at the speed of research.

Thursday, October 3, 2013

John Jansen (McEllhiney Lecture), Cardno ENTRIX
Title: Keeping the pump primed; Aquifer sustainability
Host: Dr. Shangping Xu

How will groundwater resources fare in the future and how will that affect society? How can we ensure the sustainability of our aquifers through sound science? How should groundwater contractors and scientists confront economic and political challenges affecting the resource that is pivotal to the success of their businesses? How is “sustainability” defined and what tools and strategies can be used to protect ground­water systems as well as those who obtain and develop it? What information must be gathered and compiled to build consensus and present a compelling case to regulators and policymakers?

By attending the 2013 McEllhiney Lecture presentation, you will gain an understanding of:

  • How several different definitions of “sustainability” apply to the management of an aquifer, and how these different definitions may affect your business
  • States’ varying approaches to aquifer management, reflecting their local conditions and history—with specific consideration of how the approach in your state affects you and your business
  • How regulatory practices are evolving, and why they must balance local economic and political realities with environmental needs to be accepted and successful
  • Meaningful ways that you provide information and build consensus, to help the regulatory evolution move in a positive direction
  • Steps needed for successful management from all perspectives.

Thursday, October 10, 2013

Sophie-Charlotte Lappe; UW-Milwaukee
Title: Palaeomagnetism of Extraterrestrial Materials on the nm-μm Scale: A Case Study Using Synthetic Dusty Olivine
Host: Dr. Julie Bowles

This talk describes a mineral- and rock-magnetic study of synthetic dusty olivine. Natural dusty olivines are found in chondrules of chondritic meteorites. The mechanism of chondrule formation is one of the most important outstanding questions in cosmochemistry. Magnetic signals recorded by iron nanoparticles contained within dusty olivines could carry vital clues about their formation. This project focuses on examining the magnetic properties of dusty olivine with the aim of developing methods to extract quantitative palaeomagnetic information from it.

Dusty olivine samples were synthesised from natural and synthetic olivine precursors and given thermoremanent magnetisation (TRM) in known magnetic fields. Optical and Scanning Electron Microscopy prove the resemblance to natural materials. Powder X-ray diffraction shows the presence of metallic iron in face-centred-cubic (fcc) and body-centred-cubic (bbc) structures.

Magnetic susceptibility measurements show a stable magnetic signal of bcc-iron in all samples. First-order reversal curve (FORC) measurements show signals indicative of single-domain (SD) and single-vortex (SV) states. Different precursor materials yield different ratios of SD to SV states. Electron Holography confirms the presence of SD and SV states within the samples.

A comparative study of non-heating palaeointensity methods was conducted to determine the optimum palaeointensity method for dusty olivine. The best results were obtained using ARM normalisation. A new method for palaeointensity determination based on FORC measurements was found to work well for SD remanence carriers but to fail for SV states.

Scanning SQUID microscopy was used to measure the remanent magnetisation of μm-sized grains of dusty olivine. An ARM normalisation was derived and compared to the ARM normalisation for bulk samples. High AF demagnetisation fields were found to better isolate the SD component of remanence, yielding an improved calibration.

Synthetic dusty olivines closely resemble natural samples. Metallic iron particles in dusty olivine exhibit ideal properties of stable remanence carriers. ARM normalisation offers a non- heating method for palaeointensity determination yielding results comparable to conventional heating methods. Other non-heating palaeointensity methods based on FORC measurements promise good results for samples dominated by SD particles. Scanning SQUID microscopy offers a unique technique to conduct palaeointensity determinations at μm lengthscales.

Thursday, October 17, 2013

Dr. Aleksey Smirnov, Associate Professor of Geophysics at Michigan Technological University
Title: Reading magnetic record from deep time: An insight into the geodynamo and early Earth evolution
Host: Dr. Julie Bowles

Data on the long-term behavior and configuration of the geomagnetic field during the Precambrian are crucial in understanding the origin and nature of Earth’s early geodynamo. These data are also important for investigating potential causative links between the geomagnetic field evolution and the evolution of atmosphere and biosphere. For example, a weak or unstable field of a primordial geodynamo could result in weaker magnetosphere shielding and, hence, a stronger effect on the atmosphere and biosphere from solar and cosmic radiation. In addition, long-term trends in the strength and global secular variation of geomagnetic field may provide important insight into the timing of some important transitions in the Earth’s interior such as the formation and initial growth of the solid inner core. In the absence of strict theoretical constraints, paleomagnetic data become a principal source of information about the Precambrian field. However, our knowledge of the field history during the first four billion years of Earth history remains very limited. In particular, the database on the field strength (paleointensity) contains only a handful of reliable data points. However, novel paleointensity techniques show great promise for obtaining reliable paleointensity determinations even from the oldest rocks. Recent advances in understanding the long-term intensity and secular variation of geomagnetic field in the Precambrian will be presented and discussed in the context of current models of the long-term geomagnetic and thermal evolution of our planet.

Thursday, October 24, 2013

Graduate Students
GSA Practice Presentations

Thursday, November 7, 2013

Joe Lourigan and Bill Phelps, Hydrogeologists for the Wisconsin Department of Natural Resources
Title: Molybdenum and Boron in Southeast Wisconsin Groundwater
Host: Dr. Weon Shik Han

High levels of molybdenum have been found in groundwater in a large area in southeastern Wisconsin. In the area, samples from a significant number of private water supply wells have shown molybdenum levels above the state’s groundwater quality enforcement standard (ES) of 40 micrograms per liter (ug/L). Some molybdenum concentrations exceed 100 ug/L. In addition to molybdenum, high levels of boron were also detected in two private water supply wells in the area. Both molybdenum and boron occur naturally in soils and bedrock but both are also associated with disposal of certain wastes, such as coal ash.

Previous groundwater studies suggest that naturally occurring elevated levels of molybdenum (> 5 ug/L) in groundwater in North America are not common. Naturally occurring molybdenum concentrations in groundwater, potentially associated with shale bedrock sources (Ohio, Illinois, Alberta CA), are generally lower than the concentrations found in southeast Wisconsin. Sites around the country with molybdenum levels as high as those seen in southeast Wisconsin have been linked to contamination site releases, not naturally occurring conditions.

At first, the elevated molybdenum concentrations were found in private wells located near the We Energies Oak Creek Power Plant property and the Hunts Disposal Landfill located in Caledonia, WI. In 2011, the WDNR conducted an investigation into the occurrence of the high concentrations of molybdenum and boron in groundwater, which intended to evaluate and, if possible, find a source of the elevated molybdenum and boron concentrations.

WDNR staff collected water samples from 24 private water supply wells, 33 groundwater monitoring wells associated with the We Energies ash disposal and Hunts Landfill sites, coal ash and leachate samples from the We Energies sites and leachate samples from the Hunts Landfill. Collected samples were analyzed for major ions, several manufactured compounds (e.g., solvents), some natural elements, including certain metals associated with coal ash, and for isotopes of molybdenum, boron and strontium. Samples were also analyzed for tritium, a non-stable isotope of hydrogen useful in evaluating groundwater age.

Follow-up sampling in 2012 showed that the affected area is potentially much larger than originally thought. This was confirmed when a much larger volume of sample data, collected by private well owners in the beginning of 2013, showed that the affected area covers parts of Milwaukee, Racine, Waukesha and Kenosha Counties. Drinking water with too much molybdenum in can cause digestive problems and gout like symptoms. The Wisconsin Department of Health has determined a new drinking water health advisory level of 90 ug/L. This talk discusses the discovery of elevated molybdenum concentrations in southeast Wisconsin private water supply wells and the WDNR’s groundwater investigation.

Thursday, November 14, 2013

Dr. Woonsup Choi; Department of Geography, UW-Milwaukee
Title: Urbanization and rainfall-runoff relationships in the Milwaukee River basin
Host: Dr. Weon Shik Han

The study examined the runoff-rainfall relationship in the Milwaukee River basin, with a focus on four catchments that have different degrees of urbanization. A range of statistical methods were employed to analyze temperature, precipitation, and streamflow data, including the Mann-Kendall test for trend, double-mass technique, and quantile regression. The results are mixed, with respect to the generally known relationship between runoff and land cover. One of the common results between the catchments is that annual runoff showed wider variability against annual precipitation in recent decades. Overall, there are signs of changes in the rainfall-runoff relationship, but the extent to which they can be attributed to land cover change is uncertain.

Thursday, November 21, 2013

Dr. Greg Valentine, State University of New York, University at Buffalo
Title: Hills and Holes (scoria cones and maars)
Host: Dr. Barry Cameron

Small volume basaltic volcanoes are the most abundant volcano type on Earth. Scoria cones form when rising basaltic magma erupts explosively due to expansion of its own volatile gases. Previously assumed to be relatively benign, recent work is showing that scoria cone-forming eruptions can actually be quite explosive with plumes reaching altitudes of 10 km or more. I will describe new research that elucidates the magma history and shallow conduit processes that control those complexities. Extremely violent phreatomagmatic explosions can occur if rising magma encounters groundwater, resulting in formation of a negative landform called a maar. I will discuss recent advances in our understanding of maars based upon new field data and experiments (with dynamite!).