Geoscience Community Research Articles

Geoscience Engagement in Global Development Frameworks

During 2015, the international community agreed three socio-environmental global development frameworks, the: (i) Sustainable Development Goals, (ii) Sendai Framework for Disaster Risk Reduction, and (iii) Paris Agreement on Climate Change. Each corresponds to important interactions between environmental processes and society. Here we synthesize the role of geoscientists in the delivery of each framework, and explore the meaning of and justification for increased geoscience engagement (active participation). We first demonstrate that geoscience is fundamental to successfully achieving the objectives of each framework. We proceed to characterize four types of geoscience engagement (framework design, promotion, implementation, and monitoring and evaluation), and present examples of engagement within the scope of the geoscience community. In the context of this characterization, we discuss: (i) our ethical responsibility to engage with these frameworks, noting the emphasis on societal cooperation within the Cape Town Statement on Geoethics; and (ii) the need for increased and higher quality engagement, including an improved understanding of the science-policy-practice interface. Facilitating increased engagement is necessary if we are to maximize geoscience’s positive impact on global development.

Geoconservation and geoscience in England: a mutually beneficial relationship

Geoconservation in England, as in Great Britain more widely, is very well established. Sites of national or international scientific importance, as determined by a systematic site assessment and selection exercise, can be protected by designation as Sites of Special Scientific Interest. Sites of local importance e.g. Local Geological Sites may also be taken into account when planning decisions are made that could have an impact on them. As a whole, the network of conserved geosites represents the key elements of our current understanding of the geology and geomorphology of England. Site selection and safeguard and management of this network are dependent on geoscience information, and in return continued geoscience fieldwork is dependent on having conserved sites available for study. Here, we review the relationship between geoconservation and geoscience, and how it has developed since the first geoconservation legislation nearly 70 years ago. We discuss the achievements, challenges and where and how this relationship needs to strengthen further to meet future needs of both geoscience and nature conservation. In a changing world, there will continue to be a need for innovative geoscience supported by effective geoconservation. Those interested in conserving England’s geological heritage will need to engage the wider geoscience community more than ever to deliver a shared vision for the natural environment.

Ellipsoids (v1.0): 3-D magnetic modelling of ellipsoidal bodies

Abstract. A considerable amount of literature has been published on the magnetic modelling of uniformly magnetized ellipsoids since the second half of the nineteenth century. Ellipsoids have flexibility to represent a wide range of geometrical forms, are the only known bodies which can be uniformly magnetized in the presence of a uniform inducing field and are the only finite bodies for which the self-demagnetization can be treated analytically. This property makes ellipsoids particularly useful for modelling compact orebodies having high susceptibility. In this case, neglecting the self-demagnetization may strongly mislead the interpretation of these bodies by using magnetic methods. A number of previous studies consider that the self-demagnetization can be neglected for the case in which the geological body has an isotropic susceptibility lower than or equal to 0.1 SI. This limiting value, however, seems to be determined empirically and there has been no discussion about how this value was determined. In addition, the geoscientific community lacks an easy-to-use tool to simulate the magnetic field produced by uniformly magnetized ellipsoids. Here, we present an integrated review of the magnetic modelling of arbitrarily oriented triaxial, prolate and oblate ellipsoids. Our review includes ellipsoids with both induced and remanent magnetization, as well as with isotropic or anisotropic susceptibility. We also discuss the ambiguity between confocal ellipsoids with the same magnetic moment and propose a way of determining the isotropic susceptibility above which the self-demagnetization must be taken into consideration. Tests with synthetic data validate our approach. Finally, we provide a set of routines to model the magnetic field produced by ellipsoids. The routines are written in Python language as part of the Fatiando a Terra, which is an open-source library for modelling and inversion in geophysics.

Big Remotely Sensed Data: tools, applications and experiences

The increased availability of large remote sensing datasets is generating heightened interest within the geoscience community, and more generally within human society. Indeed, remote sensing datasets that have commonly been analyzed as single scenes, or neighboring scenes, or temporally sequential scenes can now be analyzed en masse. This is due to the accumulation of large data volumes through time by increasing numbers of satellites, data access efficiencies due to technical advances and policy changes, and advances in hardware and software processing capabilities.

Geoethics in Science Communication: The Relationship between Media and Geoscientists

The themes addressed by geoethics are becoming central to all scientific debate. A growing number of scientists now consider geoethics as an effective tool to increase, in the scientific community and society as a whole, the awareness of local and global environmental problems that humanity faces. Geoethics deals with ethical, social and cultural aspects related to geosciences. Geoethics addresses fundamental issues such as the prudent and sustainable use of geo-resources, management of natural hazards, defence of geoheritage as a common value to be protected and enhanced. But above all, geoethics aims to raise, in the community of geoscientists, their awareness of responsibilities in conducting scientific and professional activity. In order to extend this awareness to the whole of civil society and also to foster the recognition of the usefulness of geosciences in daily life, geoscience communication should be recognized as a fundamental activity connected with scientific and professional work, since geoscience knowledge is a tool to contribute to the construction of social knowledge for human communities. But today what is the role played by geosciences in the scientific mass culture? Are the geosciences part of a collective “cultural heritage”? Do the publishing world and media offer adequate space to geosciences? Through the analysis of two Italian case studies, the authors highlight the critical features of the relationship between geoscientists and the media and try to suggest some actions that are useful to make the relationship between these two separate fields more functional, with the goal of bringing citizens closer to geosciences and increasing the awareness of the individual and collective responsibility towards the Earth.

On the consistency of seismically imaged lower mantle slabs

The geoscience community is increasingly utilizing seismic tomography to interpret mantle heterogeneity and its links to past tectonic and geodynamic processes. To assess the robustness and distribution of positive seismic anomalies, inferred as subducted slabs, we create a set of vote maps for the lower mantle with 14 global P-wave or S-wave tomography models. Based on a depth-dependent threshold metric, an average of 20% of any given tomography model depth is identified as a potential slab. However, upon combining the 14 models, the most consistent positive wavespeed features are identified by an increasing vote count. An overall peak in the most robust anomalies is found between 1000–1400 km depth, followed by a decline to a minimum around 2000 km. While this trend could reflect reduced tomographic resolution in the middle mantle, we show that it may alternatively relate to real changes in the time-dependent subduction flux and/or a mid-lower mantle viscosity increase. An apparent secondary peak in agreement below 2500 km depth may reflect the degree-two lower mantle slow seismic structures. Vote maps illustrate the potential shortcomings of using a limited number or type of tomography models and slab threshold criteria.

URBAN GEOCHEMICAL STUDIES IN EUROPE

Urban soil is generally contaminated to a variable degree depending on its proximity to contamination sources. Traffic is one of the main sources of urban contamination; lead (Pb) from the use of leaded petrol, zinc (Zn) and cadmium (Cd) from tyre wear, antimony (Sb) from break pads, and the platinum group Nelements (PGEs) from the wear of catalytic converters, are some typical elements that often reach high concentrations in the urban environment. Lead was also a key ingredient in white paint, and in towns with a high proportion of white wooden houses very high concentrations were found in soil. Crematoria can or have emitted mercury (Hg). Coal and heavy oil fired municipal power and heating stations emit sulphur (S), silver (Ag), vanadium (V), bromine (Br) and barium (Ba). The use of impregnated wood may have resulted in high concentrations of arsenic (As), especially in kindergartens (nursery schools) and playgrounds. Building materials (plaster and paint) may also contain high concentrations of organic contaminants, especially polychlorinated biphenyls (PCBs), which again end up in urban soil. Coal and wood burning, the use of diesel fuel, and the production of coke, all lead to the emission of polycyclic aromatic hydrocarbons (PAHs). There exist countless other sources of local contamination in towns, and there is thus every reason to be concerned about the quality of the urban environment, and the suitability of soil for sensitive land uses, such as schools, playgrounds, parks and vegetable gardens. Contaminated urban soil may contaminate indoor dust and, therefore, to an increased human exposure to toxic chemicals. Consequently, the distribution of toxic contaminants in urban soil needs to be documented and known by city administration to avoid costly mistakes in land use planning, and further spreading of highly contaminated materials. The EuroGeoSurveys ‘Geochemistry’ Expert Group during the compilation of a proposal to the Directors for a European wide urban geochemistry project, using a harmonised sampling and analytical methodology, it discovered that many urban geochemical studies have been performed in Europe by National Geological Surveys, which are not known to the wider geoscientific community. Since, the results of these studies are directly related to our quality of life, the EuroGeoSurveys ‘Geo-chemistry’ Expert Group decided to publish at least one case study from each country in a book,which will be available in the second half of 2010. A concise description of some of these studies will be given in this paper.

TouchTerrain: A simple web-tool for creating 3D-printable topographic models

An open-source web-application, TouchTerrain, was developed to simplify the production of 3D-printable terrain models. Direct Digital Manufacturing (DDM) using 3D Printers can change how geoscientists, students, and stakeholders interact with 3D data, with the potential to improve geoscience communication and environmental literacy.No other manufacturing technology can convert digital data into tangible objects quickly at relatively low cost; however, the expertise necessary to produce a 3D-printed terrain model can be a substantial burden: knowledge of geographical information systems, computer aided design (CAD) software, and 3D printers may all be required. Furthermore, printing models larger than the build volume of a 3D printer can pose further technical hurdles.The TouchTerrain web-application simplifies DDM for elevation data by generating digital 3D models customized for a specific 3D printer's capabilities. The only required user input is the selection of a region-of-interest using the provided web-application with a Google Maps-style interface. Publically available digital elevation data is processed via the Google Earth Engine API. To allow the manufacture of 3D terrain models larger than a 3D printer's build volume the selected area can be split into multiple tiles without third-party software. This application significantly reduces the time and effort required for a non-expert like an educator to obtain 3D terrain models for use in class. The web application is deployed at http://touchterrain.geol.iastate.edu, while source code and installation instructions for a server and a stand-alone version are available at Github: https://github.com/ChHarding/TouchTerrain_for_CAGEO.

A Powerful New Tool for Research

A novel interface allows users of MATLAB and GMT, two software packages widely used by the geoscience community, to simultaneously harness the capabilities of both products.

Big mantle wedge, anisotropy, slabs and earthquakes beneath the Japan Sea

The Japan Sea is a part of the western Pacific trench-arc-backarc system and has a complex bathymetry and intense seismic activities in the crust and upper mantle. Local seismic tomography revealed strong lateral heterogeneities in the crust and uppermost mantle beneath the eastern margin of the Japan Sea, which was determined using P and S wave arrival times of suboceanic earthquakes relocated precisely with sP depth phases. Ambient-noise tomography revealed a thin crust and a thin lithosphere beneath the Japan Sea and significant low-velocity (low-V) anomalies in the shallow mantle beneath the western and eastern margins of the Japan Sea. Observations with ocean-bottom seismometers and electromagnetometers revealed low-V and high-conductivity anomalies at depths of 200–300km in the big mantle wedge (BMW) above the subducting Pacific slab, and the anomalies are connected with the low-V zone in the normal mantle wedge beneath NE Japan, suggesting that both shallow and deep slab dehydrations occur and contribute to the arc and back-arc magmatism. The Pacific slab has a simple geometry beneath the Japan Sea, and earthquakes occur actively in the slab down to a depth of ∼600km beneath the NE Asian margin. Teleseismic P and S wave tomography has revealed that the Philippine Sea plate has subducted aseismically down to the mantle transition zone (MTZ, 410–660km) depths beneath the southern Japan Sea and the Tsushima Strait, and a slab window is revealed within the aseismic Philippine Sea slab. Seismic anisotropy tomography revealed a NW-SE fast-velocity direction in the BMW, which reflects corner flows induced by the fast deep subduction of the Pacific slab. Large deep earthquakes (M>7.0; depth>500km) occur frequently beneath the Japan Sea western margin, which may be related to the formation of the Changbai and Ulleung intraplate volcanoes. A metastable olivine wedge is revealed within the cold core of the Pacific slab at the MTZ depth, which may be related to the deep seismicity. However, many of these results are still preliminary, due to the lack of seismic stations in the Japan Sea. The key to resolving these critical geoscientific issues is seismic instrumentation in the Japan Sea, for which international cooperation of geoscience communities in the East Asian countries is necessary.

State of the Net

My SEG staff colleagues and I continually research the latest innovations within scholarly publishing to improve SEG publications and our digital offerings. Additionally, SEG has new and established channels to share your research with the geoscience community — be it through press releases, podcasts, author interviews, social media, or traditional search and discovery. As of last month, Kudos, a free author service aimed at aiding researchers in more clearly articulating and sharing their work — in plain English — to laypeople, peers, and the public, launched in the SEG Digital Library.

Linked Geoscience Data in practice: where W3C standards meet domain knowledge, data visualization and OGC standards

The geoscience community is now facing both the challenge and the opportunity caused by the vast amount of datasets that can be made available on the Web. An efficient “data environment” on the Web has the potential to enable geoscientists to conduct their research in ways that never existed before. Standards developed by the Open Geospatial Consortium have already been used widely to build data services among different subjects in geosciences. In recent years, the Linked Open Data approach initiated by the World Wide Web Consortium has received increasing attention. In this paper, the author presents a pilot study that uses a domain specific knowledge base and data visualization techniques to leverage the functionality of geoscience data services in the Web of Data. The study focuses on the topic of the geologic time scale. Detailed works such as semantic modeling and encoding, multilingual vocabularies, exploratory data visualization, web map service and processing, and the query of linked data are introduced through real-world datasets. This study faces a broad perspective of the Linked Geoscience Data and leverages the functionalities of existing standards into a new level for geoscience applications.

Xarray: N-D labeled Arrays and Datasets in Python

xarray is an open source project and Python package that provides a toolkit and data structures for N-dimensional labeled arrays. Our approach combines an application programing interface (API) inspired by pandas with the Common Data Model for self-described scientific data. Key features of the xarray package include label-based indexing and arithmetic, interoperability with the core scientific Python packages (e.g., pandas, NumPy, Matplotlib), out-of-core computation on datasets that don’t fit into memory, a wide range of serialization and input/output (I/O) options, and advanced multi-dimensional data manipulation tools such as group-by and resampling. xarray, as a data model and analytics toolkit, has been widely adopted in the geoscience community but is also used more broadly for multi-dimensional data analysis in physics, machine learning and finance.

SEG News

Recognizing the importance of the Middle East region for both SEG and the oil and gas industry, a delegation of SEG representatives, led by SEG President Bill Abriel, visited the region in early January. The trip was an opportunity for SEG to showcase its involvement in the region, engage with top leaders from various oil and gas companies and academic institutions, and promote the array of SEG offerings to those in the geosciences community. Tom Agnew, SEG associate executive director of programs, and Yogaani Bhatia, SEG Middle East regional manager, accompanied Abriel on the trip.

A new CT scan methodology to characterize a small aggregation gravel clast contained in a soft sediment matrix

Abstract. Over the past decades, X-ray computed tomography (CT) has been increasingly applied in the geosciences community. CT scanning is a rapid, non-destructive method allowing the assessment of relative density of clasts in natural archives samples. This study focuses on the use of this method to explore instantaneous deposits as major contributors to sedimentation of high-elevation lakes in the Alps, such as the Lake Lauvitel system (western French Alps). This lake is located within a very steep valley prone to episodic flooding and features gullies ending in the lake. This variety of erosion processes leads to deposition of sedimentary layers with distinct clastic properties. We identified 18 turbidites and 15 layers of poorly sorted fine sediment associated with the presence of gravels since AD 1880. These deposits are respectively interpreted as being induced by flood and wet avalanche. This constitutes a valuable record from a region where few historical records exist. This CT scan approach is suitable for instantaneous deposit identification to reconstruct past evolution and may be applicable to a wider variety of sedimentary archives alongside existing approaches.

On extracting sediment transport information from measurements of luminescence in river sediment

AbstractAccurately quantifying sediment transport rates in rivers remains an important goal for geomorphologists, hydraulic engineers, and environmental scientists. However, current techniques for measuring long‐time scale (102–106 years) transport rates are laborious, and formulae to predict transport are notoriously inaccurate. Here we attempt to estimate sediment transport rates by using luminescence, a property of common sedimentary minerals that is used by the geoscience community for geochronology. This method is advantageous because of the ease of measurement on ubiquitous quartz and feldspar sand. We develop a model from first principles by using conservation of energy and sediment mass to explain the downstream pattern of luminescence in river channel sediment. We show that the model can accurately reproduce the luminescence observed in previously published field measurements from two rivers with very different sediment transport styles. The model demonstrates that the downstream pattern of river sand luminescence should show exponential‐like decay in the headwaters which asymptotes to a constant value with further downstream distance. The parameters from the model can then be used to estimate the time‐averaged virtual velocity, characteristic transport lengthscale, storage time scale, and floodplain exchange rate of fine sand‐sized sediment in a fluvial system. The sediment transport values predicted from the luminescence method show a broader range than those reported in the literature, but the results are nonetheless encouraging and suggest that luminescence demonstrates potential as a sediment transport indicator. However, caution is warranted when applying the model as the complex nature of sediment transport can sometimes invalidate underlying simplifications.

Social geology — integrating sustainability concepts into Earth sciences

Most geologists would argue that geoscientific knowledge, experience, and guidance is critical for addressing many of society’s most acute environmental challenges, yet few geologists are directly engaged in current discourses around sustainable development. That is surprising given that several attributes make modern geoscience well placed to make critical contributions to contemporary sustainability thinking. Here, we argue that if geoscientists are to make our know-how relevant to sustainability science, two aspects seem clear. Firstly, the geoscience community needs to substantially broaden its constituency, not only forging interdisciplinary links with other environmental disciplines but also drawing from the human and behavioral sciences. Secondly, the principles and practices of ‘sustainability’ need to be explicitly integrated into geoscience education, training and continued professional development.

Customer-Oriented Evaluation of Geoheritage—on the Example of Volcanic Geosites in the West Sudetes, SW Poland

Thirty geosites representing ancient volcanism in the West Sudetes are subject to quantitative, multi-variant evaluation that takes into account the geoscientific background and likely preferences of visitors. To account for the diversity of visitors, different weightings of criteria included in the evaluation procedures are applied. Four rankings were prepared: a ‘non-weighted’ one and three ‘customer-oriented’. Differences between rankings are relatively small, although notable individual exceptions are noted. Top positions in different rankings are invariably occupied by the same group of geosites which are highlights of the region, although apparently for different purposes. However, scientific, educational, additional and scenic values may be causally related. Some geosites are of outstanding significance for the geoscientific community but appear less appealing to others, particularly unaware visitors. The results of the exercise may assist in resource allocation for developing interpretative facilities and diversifying the level of interpretation between geosites.

The Inventory of Geological Heritage of the State of São Paulo, Brazil: Methodological Basis, Results and Perspectives

An inventory of geological sites based on solid and clear criteria is a first step for any geoconservation strategy. This paper describes the method used in the geoheritage inventory of the State of Sao Paulo, Brazil, and presents its main results. This inventory developed by the geoscientific community aimed to identify geosites with scientific value in the whole state, using a systematic approach. All 142 geosites representative of 11 geological frameworks were characterised and quantitatively evaluated according to their scientific value and risk of degradation, in order to establish priorities for their future management. An online database of the inventory is under construction, which will be available to be easily consulted and updated by the geoscientific community. All data were made available to the State Geological Institute as the backbone for the implementation of a future state geoconservation strategy.

Forging a paradigm shift in disaster science

Despite major advancements in knowledge on disaster risks and disasters caused by natural hazards, the number and severity of disasters are increasing. Convolving natural, engineering, social and behavioral sciences and practices with policymaking should significantly reduce disaster risks caused by natural hazards. To this end, a fundamental change in scientific approaches to disaster risk reduction is needed by shifting the current emphasis on individual hazard and risk assessment dominant in the geoscientific community to a transdisciplinary system analysis with action-oriented research on disaster risk reduction co-produced with multiple stakeholders, including policymakers. This paradigm shift will allow for acquisition of policy-relevant knowledge and its immediate application to evidence-based policy and decision making for disaster risk reduction. The need for the paradigm shift is more critical now than ever before because of the increasing vulnerability and exposure of society to disaster risk and the need for cross-cutting actions in policy and practice related to climate change and sustainability.