Search
Special issue on waterborne geophysics in Near Surface Geophysics

Guest editors Karl E. Butler and Luigi Sambuelli together with editor-in-chief Ugur Yaramanci report on the special issue on waterborne geophysics being published in the August 2009 issue of Near Surface Geophysics.

Water has been defined a ‘strategic resource’ and many analysts foresee that it will be the subject of conflicts in the future. Its increasing value, concerns about quality and quantity, industrial/agricultural versus public allocations, and the likely impacts of climate change have recently given rise to a geo-political way of looking at water resources and to coin the term ‘hydro-policy’.

Worldwide, 214 river or lake basins, populated by 40% of the world’s human population and covering more than 50% of the Earth’s land area, are shared by two or more countries. India and Bangladesh share the Ganges; Mexico and the USA the Colorado River; the USA and Canada share the Columbia, Red and St. Lawrence Rivers; Egypt, Ethiopia, Sudan, and Uganda the Nile; Switzerland, France, Germany, and the Netherlands share the Rhine while the Euphrates is shared by Turkey, Syria, and Iraq; China, Myanmar, Thailand, Laos, Cambodia, and Vietnam share the Mekong and many other examples can be found throughout the world. The same holds for some of the largest lakes on Earth including the Great Lakes of North America, the Tanganyika Lake in the East African Rift, and the Aral Sea in Central Asia. Bodies of fresh water, like the coasts of seas and oceans are attractors for human settlement, a fact that is immediately apparent from satellite photographs taken at night. As a result, knowledge of shallow water environments is a topical subject of dramatically growing importance.

Climate change, through the greenhouse effect, is giving more energy to the water cycle engine so that the definition of an extreme event will probably have to be revised. Heavy rains and consequent floods are likely to be more frequent than in the past and will be exacerbated by sea level rise. Improved knowledge of the connections between surface waters and groundwater will allow better management of water resources and can also contribute to emergency management and disaster planning.

Knowledge of sea, lake, and riverbed sediments are also important for a variety of other societal needs. Civil engineering projects, such as the construction of pipelines, bridges, and ports, and the dredging of harbours have obvious requirements for information on subsurface geotechnical properties and hazards. Information on sediment transport is important for assessing the environmental and hydrographic impact of floods as well as bridges, dams, and other structures designed for coastal protection or hydroelectric/wind/tidal power generation. The oil and gas industry requires information on shallow subsurface conditions relevant to drilling hazards and pipelines, while the mining industry recognizes vast seafloor mineral resources ranging from sand and gravel to massive sulphides and placer diamonds.

Returning to environmental applications, geophysical methods are increasingly being used to help assess how groundwater-surface water interactions are influencing water quality and supply. As one example, information on the hydraulic connections between rivers and adjacent well fields can be inferred from geophysical imaging of the riverbed. Such information can be used to help position wells in regions where they are less likely to yield ‘groundwater under the direct influence of surface water’ (i.e., a GWUDI designation). In other areas, electrical resistivity and EM induction techniques are contributing to efforts to mitigate the effects of saline groundwater that is threatening rivers and lakes. They are also being used to identify submarine discharge of fresh groundwater in coastal zones, which can influence marine ecosystems either positively or negatively (e.g., through fertilizer-driven eutrophycation of estuaries adjacent to agricultural areas).

In this special issue of Near Surface Geophysics we present a subset of the papers that were presented at a workshop entitled ‘High-resolution Geophysics for Shallow Water’ held in London, UK on 10 June 2007 in association with the 69th EAGE Conference and Exhibition. We do not pretend to give an exhaustive analysis of the geophysical methods that can be applied in shallow water surveys (seismic methods, although presented during the workshop, have not been collected here). Rather, we aim to show some interesting experiences around the world in this field.

Our intent, encouraged by Near Surface Geophysics, which kindly accepted to host a ‘bouquet’ of the papers presented in the workshop, is to make a broader geophysical community aware of the potential of well-known methods in less well-known environments and fields of application. The full set of papers presented at the workshop are accessible through the EAGE’s online publications database EarthDoc by selecting the Event titled ‘69th EAGE Conference and Exhibition – Workshop Package’ and entering ‘Wo2’ for the name of the Session.

Readers will find an illustration of the trends in waterborne electrical and EM induction methods for high-resolution sub-bottom imaging. A broad panorama of methods and environments, ranging from the well-field scale to long river stretches and sea-bottom surveys, is shown with a rich list of references. They can also read about multi-offset GPR methods for investigating hyporheic exchange processes (i.e., stream–streambed water cycling) in temperate and cold environments. In this paper detailed and accurate GPR data acquisition and processing allow the estimation of streambed porosity variations important for hydraulic and thermal modelling.

On a much larger scale, an airborne EM survey along about 700 km of streams in the upper Colorado River region is presented. Two days of airborne surveying, integrated with ground EM data and geochemical sampling, allowed a better comprehension of the origin of anomalous salinity values in some stretches of the river.

A paper on resistivity imaging presents a case study from Australia, where towed resistivity and EM induction methods are becoming common tools in assessing connections between rivers and aquifers, including natural saline groundwater that threatens sources of irrigation and drinking water. In this case, continuous resistivity imaging is used to identify the stretches of a perched river that contribute recharge to an underlying semi-confined aquifer.

Readers will also find a more theoretical work dealing with uncertainty propagation using some common mixing rules. This paper investigates the uncertainty that can be expected when, for example, from the bulk conductivity obtained from an electrical tomography, one wants to estimate the porosity of a saturated geological material.

Geophysics on shallow water is a growing field, destined to become more varied in response to evolving applications and more common as experimental approaches give rise to purpose-built commercial instruments. The accompanying figure clearly shows the increase of interest during the last 35 years, in just one of the non-seismic techniques suitable to study shallow water environments. It is our opinion that this field of application will require further improvements in acquisition, processing, and interpretation tools to be able to tackle the challenges presented by growing populations seeking water, energy and mineral resources exploited in an always more sustainable way.

(This article is published in First Break August 2009)

Call for papers: Special Issue on Magnetic Resonance Sounding Methods

Submission deadline: 1 November 2009

The 4th International Workshop Magnetic Resonance Sounding on 20–22 October 2009 in Grenoble, France will spread the experience of development and application of MRS methods to a broad hydrogeophysical community.

Near Surface Geophysics will dedicate a special issue to Magnetic Resonance Sounding Methods. All workshop participants are invited to submit a full paper based on their abstract to this special issue. However, we also welcome contributions from those who did not participate in the workshop but wish to submit a paper on this topic.

Authors are invited to submit their full papers through the Manuscript Central website of Near Surface Geophysics: http://mc.manuscriptcentral.com/nsg. For more information about the journal and the guidelines for authors, please visit the Near Surface Geophysics website at http://www.nearsurfacegeophysics.org.

Timing will be rather short and we encourage you to start writing your paper now.

Guest editors:

Anatoly Legchenko, LTHE, anatoli.legtchenko@hmg.inpg.fr

Juan Plata, Geological and Mining Institute of Spain (IGME), jl.plata@igme.es

Ugur Yaramanci, Leibniz Institute for Applied Geophysics (LIAG), ugur.yaramanci@liag-hannover.de

Call for papers: Special Issue on Student-based Research

Abstract deadline: 1 July 2009

In the current competitive and demanding financial climate, finding the time and funding to undertake truly innovative, unique research is becoming increasingly problematic for everyone involved in near-surface geophysics. With such a broad subject area, it is vital that new application-based technologies are developed in order to ensure that near-surface geophysics remains at the cutting-edge of modern science. As a large majority of the most forward-looking work is driven by student-based projects, their work has a pivotal role in the development of research and, therefore, the technologies of the future. Undergraduate and postgraduate projects often provide the best opportunity for open, novel research development without the political and commercial restrictions of larger-scale, formal funding programmes. Unfortunately, much of this work remains unpublished or, at best, confined to dissertations, theses or technical reports. As such, this ‘Special Issue on Student-based Research’ aims to provide a showcase for the best student-led research currently being undertaken in the near-surface geophysics discipline. Ultimately, the students of today are the world-leading scientists of tomorrow and, as such, we hope that this special issue of Near Surface Geophysics will play a part in highlighting the excellence, quality and international standing of our student community.

We wish to promote student-based research and encourage current undergraduate and postgraduate students to submit high-quality papers to the special issue as lead or major co-authors. Papers with non-student authors are also welcome but their content must contain a significant component of student-related research. Topics of interest are only required to fulfil the scope of Near Surface Geophysics but we are particularly interested in

  • Innovative measurement, assessment and monitoring techniques,
  • New and emerging geophysical methods and sensor technologies,
  • New numerical/analytical modelling and inversion techniques applied to practical problems,
  • The development of novel, integrated, multi-technique imaging and characterization approaches,
  • The application of current geophysical techniques to new application areas,
  • The analysis and re-evaluation of current data that leads to new perspectives on existing problems,
  • Novel and interesting case histories/studies.

In addition, we welcome papers that highlight the quality and novelty of student-based research and how it benefits the near-surface geophysics community in terms of educational, economic and professional development.

Authors will be requested to submit final papers in one of two formats: either a ‘Standard Paper’ (a full-length paper of typically 8–12 journal pages) or a ‘Short Paper’ (a ‘letters’ style paper of less than 8 journal pages). It is envisaged that the short papers will predominantly highlight new techniques, methodologies or scientific advances, whilst the standard papers will involve a greater degree of discussion, critical evaluation and practical application (e.g., case histories, multi-technique approaches, new application areas, etc.). In either case, the guest editors will ensure that the papers conform to the high quality standards of Near Surface Geophysics.

Please inform the EAGE Editorial Office, Ms. Wendel van der Sluis (ws@eage.org), about your intention to contribute and provide a one-page draft abstract, stating the intended format of your paper (standard or short), by 1 July 2009. Successful authors will be required to submit their full papers by 1 November 2009.

If authors wish to informally discuss their intended submission prior to the abstract deadline, please contact the guest editors directly by e-mail.

Guest Editors:
Nigel Cassidy, Keele University, UK, n.j.cassidy@esci.keele.ac.uk
Jamie Pringle, Keele University, UK, j.k.pringle@esci.keele.ac.uk

<< 1 2 3 >>