International Union of Geodesy and Geophysics

The known relative motion of the African and Eurasian plates at the eastern end of the Azores-Gibraltar plate boundary implies consumption of oceanic lithosphere at the low rate of 1-1.5 cm/yr. This section of the plate boundary, which crosses the area 34-38' N, 6-14' W, has none of the characteristic features of zones of oceanic lithosphere consumption (e.g. arcuate trench, island arc volcanics, deep seismicity). A block of oceanic crustal and upper mantle material has been upthrust to form a 120 km long, 5 km high ridge, called Gorringe Ridge. Basalts, gabbros and ultramafics have been dredged from the northern face of this ridge. A mechanism for slow consumption is proposed which accounts for the anomalous features of this part of the plate boundary, and for the formation of Gorringe Ridge. Four deep seismic refraction lines show the major characteristics of the crustal structure to be 3-4km thick sediment sequences, low upper mantle velocities of 7.3-7-6 km s-' and typical oceanic moho depths of about 11 km below sea level. Continuous seismic reflection profiles show 1-2 km of basement relief in the Western Horseshoe and Tagus Abyssal Plains and define a zone of acoustically opaque sediment in the Eastern Horseshoe Abyssal Plain. The free-air gravity anomaly contour map shows 480 mgal. of relief. Closely-controlled models for the structure of Gorringe Ridge devised to fit north-south gravity profiles across the plate boundary require a large body with a density of at least 3.0 g cm-3 beneath the ridge to explain its associated 390 mgal. free-air anomaly. The plate boundary is not well defined by the relocated epicentres but crustal structures suggest a 100 km southward offset immediately west of Gorringe Ridge. The calculation of finite difference poles of rotation for the African plate relative to Eurasia shows there have been two major periods of relative motion across the plate boundary in this region during the past 72My. The slow compressive phase of the last 10 My was preceded 60-72 My before present by right lateral strike-slip motion at a rate of 5 . 5 cm/yr. The direction of these relative motions was respectively perpendicular and parallel to 060", a trend which is predominant in the bathymetry of this area and in the geology of southern Spain. This suggests that for the past 72 My a single line of weakness has existed in the lithosphere along which all motion between the African and Eurasian plates has been accommodated.

Although the science of geomagnetism is old, many fundamental questions still remain unanswered concerning fluid motions in the earth's core, the dynamo producing and sustaining the field, interpretation of results of surveys, drawing of charts, a reference field, the secular change, and magnetic anomalies and their geologic meaning. The World Magnetic Survey (WMS) was designed to overcome the principal deficiencies in surveys and to stimulate the use of the data in studies of the fundamental problems in geomagnetism.

ABSTRACT China has been said to have the largest putative shale gas resources in the world. The highest potential occurs in the Sichuan Basin, with the overmature Qiongzhusi (Cambrian) and Longmaxi (Silurian) Formations as prime exploration targets. Here, the likelihood of late gas formation is examined using less mature equivalents from the Georgina Basin (Australia) and the Baltic Basin (Lithuania). We consider the respective functions of kerogen and polar bitumen in gas generation with reference to the Eagle Ford, Yanchang, Niobrara, and Vaca Muerta Formations. Both of the lower Paleozoic shales are bitumen poor in a geochemical sense, this being in stark contrast to the Mesozoic shales, which are bitumen rich. Kerogen is, therefore, the major gas precursor in the Cambrian and Silurian of the Sichuan Basin. Graptolites and solid bitumen are petrographically dominant. The solid bitumen exhibits flow structures and is deduced to be highly polar because it is insoluble in dichloromethane. Secondary cracking kinetics determined for the Arthur Creek are closely similar to source rocks containing predominantly paraffinic oil. Late gas generation from very stable refractory kerogen structures via alpha-cleavage reactions at maturities above 2% equivalent vitrinite reflectance (Ro) was verified, and importantly, the upper ceiling for late gas generation in Paleozoic shales of the Sichuan Basin is set at 3% Ro. As far as the Qiongzhusi shale is concerned, raising the prospective acreage to a 3% Ro limit brings an additional contribution of 40 mg HC/g total organic carbon of late gas charge. The same is true for the extensive fairway of the Longmaxi shale along the western flank of the basin, close to the subcropping erosional edge.

In November 2021, Member States unanimously adopted the United Nations Educational Scientific and Cultural Organization (UNESCO) Recommendation on Open Science. As attention now turns to the implementation of the Recommendation, time is ripe for the science community to take an active role in governance of the evolving science system if a new era of open science is to serve the global public good. This paper discusses open science in terms of the paradigm shift needed, the potential and directions for the evolution of global science, and governance arrangements in the broader perspective of Anthropocene-related challenges, with the hydrological entry point at its core.

Abstract. The International Union of Geodesy and Geophysics (IUGG) was established in 1919 to promote activities of already-existing international scientific societies dealing with geodesy, terrestrial magnetism and electricity, meteorology, physical oceanography, seismology, and volcanology. At the first General Assembly a Section of scientific hydrology was added, making a total of seven Sections of the Union. This paper introduces IUGG by presenting its current mission, structure, partners, and programs; discussing various international geophysical efforts before its origin; and describing the Union's development from the end of World War I to the beginning of World War II. During this period (1919–1939), the number of member countries increased from the 9 founding Member countries to 35; seven General Assemblies were held, each in a different international venue; and the number of delegates attending the assemblies increased from a few dozen to more than 800 scientists. At the Fifth General Assembly in 1933, the term “section” was replaced by “international association”. Each General Assembly of the Union, since the First General Assembly in Rome, Italy, in 1922 to the VII General Assembly in Washington, DC, USA, in 1939, is summarized, and the distinguished scientists who contributed to the Union's formation and it early development are introduced.

Abstract. International geoscientific unions (geounions) have been coordinating and promoting international efforts in Earth and space sciences since the beginning of the 20th century. Thousands of scientists from many nations and specific scientific disciplines have developed ways of cooperation through international unions and learned how to work together to promote basic geosciences. The unions have been initiating, developing, and implementing international cooperative programmes, setting scientific standards, developing research tools, educating and building capacity, and contributing to science for policy. This paper analyses the role of geounions in and their added value to the promotion of geoscience internationally in the arena of the existing and emerging professional societies of geoscientists. The history of the geounions and the development of international cooperation in geosciences are reviewed in the paper in the context of scientific and political changes over the last century. History is considered here to be a key element in understanding and shaping the future of geounions. Scientific and organisational aspects of their activities, including cooperation with international and intergovernmental institutions, are analysed using the example of the International Union of Geodesy and Geophysics (IUGG). The geounions' activities are compared to those of professional societies. Future development of scientific unions and their role in the changing global landscape of geosciences are discussed.

Abstract The International Geomagnetic Reference Field (IGRF) is a series of mathematical models of the main geomagnetic field and its secular variation, the models consisting of sets of spherical harmonic (or Gauss) coefficients. The IGRF has become a widely used means of deriving values of geomagnetic field components in, for example, studies of magnetic anomalies and investigations of charged particle motions in the ionosphere and the magnetosphere.

Abstract Spatial data can be represented in the two-dimensional frequency (wave-vector) domain. This much simplifies the achievement of any desired transfer response in a linear digital filter. Similar results have been obtained approximately by convolution (also termed correlation) in space with a weighted coefficient set. The equivalence of wave-vector filtering and a special form of convolution filtering is demonstrated. Given the availability of a fast Fourier transform, computational advantage lies with the former. The regional trend is removed from data prior to wave-vector filtering, and this combined procedure gives one solution to problems arising at the edge of the data. In the appendix, a computationally convenient form of the two-dimensional fast Fourier transform is given for arrays with side lengths not restricted to powers of two. Considerable savings in computing time and storage allocation are shown when real data are used.

We describe the global ionospheric impact of high-speed solar wind streams/corotating interaction regions (HSS/CIR), using a series of ten such events identified between December 1<sup>st</sup> 2007 and April 29th 2008. In the frequency domain they are characterized by the main spectral peaks corresponding to 27, 13.5, 9 and 6.75 days. The spectra of solar wind magnetic field, speed and proton density, as well as those of the geomagnetic indices AE and SYM-H are solely- dominated by these features. By contrast, the ionospheric NmF2 and to a lesser extent the hmF2 spectra have a much more complex structure, with secondary peaks adding to or replacing the main ones. We argue that this is evidence of the nonlinear nature of the magnetosphere ionosphere coupling, highlighted particularly in the NmF2 ionospheric response. Additionally, we show that hmF2 is more closely correlated than NmF2 to all parameters describing the solar wind and geomagnetic activity. Finally, the ionospheric response shows higher correlation with Bz than any other solar wind parameter, and higher with SYM-H than AE, indicating that for the low frequency part of the spectrum, high-latitude Joule heating and particle precipitation play a secondary role to that of prompt penetration electric fields in dictating the ionospheric response to geomagnetic activity, in the case of this sequence of HSS/CIR events.

The term “international administrative law” is understood in two separate ways. On one hand, the authors (diritto internazionale amministrativo) used this term regarding the administrative competencies of various international administrative unions, as provided by applicable international conventions. On the other hand, other authors (e.g. Karl Neumeyer, Paul Négulescu, Giuseppe Biscottini) used the term to exclusively refer to the norms of national law (diritto amministrativo internazionale, droit administratif international, internationales Verwaltungsrecht), which address certain foreign elements. This article follows the second understanding of the term “international administrative law.” For a long time, these norms had been quite rare in administrative law and, consequently, the legal scholarship did not pay much attention to the discipline of international administrative law. However, most recently, the sources of EU law increasingly require reflection of certain foreign elements in the norms of administrative law. In this respect, this article argues that international administrative law represents a legal discipline that is fully capable of addressing those problems arising by the application of these norms in administrative law.

Abstract. The International Union of Geodesy and Geophysics (IUGG) began anew after World War II with a new governance and membership structure. The technologies developed during the war were brought to bear in the extraordinary global scientific effort that was the International Geophysical Year (1957–1958). Major changes in the geopolitical landscape have brought about further changes in IUGG's structure. International scientific campaigns encompassing multiple disciplines became commonplace, and international scientific bodies were organized and networked. During this time period (1940–1999), 15 general assemblies and 2 extraordinary general assemblies were held, each in a different international venue. Summaries of each general assembly are presented, as well as overviews of the changes in IUGG's structure, finances, membership, and publications. The scientists, who led the Union and contributed to the development of the Union, are also presented.

The COVID-19 crisis and the environmental crisis share a range of similarities. Both crises take place on a global scale and affect all aspects of our lives. However, we humans respond differently to these challenges. Here, we compare and comment on characteristics of the COVID-19 crisis and the environmental crisis, explore how far these two crises are comparable, and what we can learn from actions that have been taken against the COVID-19 crisis. We discuss how human societies are affected by the respective crises, and analyze policy makers’ responses and offer pathways to better inform policy. We highlight the role of science, which significantly contributed to decision making throughout the COVID-19 crisis, but seems frequently underrepresented in the environmental crisis. We conclude that there are significant differences between the two crises in terms of perceptibility and thus communicability. While problems and solutions in the COVID-19 crisis are largely linearly correlated, the challenges of the environmental crisis are far more complex and decoupled, and thus appear much more complex and are often only perceived with difficulty by humans. Thus, tackling the environmental crisis is much more challenging than solving the COVID-19 crisis. To overcome the environmental crisis, purely technical approaches for combating symptoms are not sufficient. However, political interests are usually short-term, and do not correspond with the temporal and spatial scales of global change. There is an urgent need to improve institutionalized scientific advisory mechanisms and to empower global policy makers who are independent of local interest groups. Furthermore, we need the sound communication of complex interactions to the general public and the translation of scientific findings into action. One possibility to achieve this is to bring together natural scientists with expertise in biology, climate and geosciences and social scientists, psychologists, and, possibly, artists.

Nesse artigo, aplicações da minimização da norma L1 (ML1) e da norma L∞ (ML∞) na estimação de redes altimétricas foram investigadas. Redes de nivelamento simuladas pela Técnica de Monte Carlo e dados reais da rede brasileira de nivelamento foram empregados nos experimentos. Na identificação de outliers pela ML1, foi verificado que o ajustamento com pesos unitários apresentou condições vantajosas em relação ao modelo estocástico usual dos pesos proporcionais ao inverso do comprimento das linhas de nivelamento. O Classificador VL1, que estipula um Valor de Corte para os resíduos do ajustamento pela ML1 a partir do qual a respectiva observação passa a ser classificada como outlier, foi proposto. A taxa de sucesso dele na identificação de outliers foi superior à do procedimento data snooping iterativo em cenários de geometria da rede deficiente. Já a aplicação da ML∞ investigada é posterior ao tratamento de outliers. Um modelo estocástico alternativo para ajustamento da rede pelo MMQ que aproveitou a característica de minimização do máximo resíduo absoluto da rede no ajustamento pela ML∞ foi analisado. Além dessa minimização, o ajustamento da rede pelo MMQ com o modelo alternativo gerou, na significativa maioria dos casos, resíduos e precisão desses e dos parâmetros estimados mais homogêneos, com menor desvio padrão, que aqueles com o modelo estocástico usual. Todos os resultados são especialmente relevantes para o caso de redes altimétricas.

In South Africa, a Land Type Survey (LTSS) has been conducted of the entire country. The information available from the LTSS is readily and inexpensively made available to the public (in the form of maps and accompanying memoirs). This survey includes information on the climate, terrain and soils. The soil information given includes qualitative data (such as pedological classifications, soil profiles and soil types), as well as quantitative physical and chemical properties of representative soils tested. Such information is used primarily for agricultural purposes. This paper proposes an approach for inferring information, of relevance in reconnaissance geotechnical engineering surveys, from Land Type data, to supplement geotechnical investigation data. The proposed procedure was verified using actual information from a geotechnical report. This investigation indicated that general engineering properties can be inferred from qualitative pedological data. In addition, statistically significant engineering properties (including the grading, Atterberg Limits and the USCS and AASHTO classifications) were determined from quantitative pedological data, in 86% of cases, for the soils considered. It is evident from this research that data from the Land Type survey data can be successfully used for geotechnical investigation purposes for certain developments (such as roads and townships) where the depth of interest is relatively shallow.

Abstract. According to a 2019 United Nations report, of all the known species, up to 1 million face extinction globally. Despite being considered a pressing global risk with several international efforts to protect and to restore, biodiversity loss and the degradation of ecosystems continue at an alarming rate. In December 2022, the UN Biodiversity Conference (COP15) saw the adoption of the Kunming-Montreal Global Biodiversity Framework, where four overarching international goals for biodiversity and 23 targets were set. While this is a positive step towards addressing the drivers of biodiversity loss, we will need not just public and political will but also more effective methods to integrate and use scientific information to reach the goals and targets outlined. To facilitate this, scientists and research institutions need to establish alternative and new approaches to transform the way science is conducted, communicated, and integrated into the policymaking process. This will require the scientific community to become proficient at working in interdisciplinary and transdisciplinary teams, establishing connectivity across scientific disciplines and engaging in the policymaking process to ensure that the best available scientific evidence is not only comprehensible to decision-makers but also timely and relevant. This commentary details how scientists can embrace transformative change within and outside of their own communities to increase the impact of their research and help reach global targets that benefit society.

Various pedological soil classification systems exist worldwide, including an internationally accepted system and various national systems, many of which have been incorporated into databases that include maps. Various physical and chemical soil properties are used for classifying soils according to these pedological systems. This paper proposes an approach which may be used to determine the engineering properties of soils from the physical and chemical properties that are used to pedologically classify soils by systems, and, in particular, the South African Binomial System. These engineering properties include the USCS and AASHTO classification groups which may, in turn, be used as a means of rapidly determining the general suitability of areas for proposed development, particularly during the reconnaissance investigation stages of transportation route locations and township developments, with a resultant saving of time and money. The model was verified using data from the study area, as well as from an area located approximately 190 km from the study area. A total of 88% of the classification groups determined by the model, in the study area, were correct. Furthermore, only 6% of the classifications were incorrect by a maximum of two groups. The classifications determined for the soils outside the study area were all correct.

The paucity of women physicists in positions of influence worldwide has implications for industry, government, and academia, as well as for the future of the profession itself. Women from more than 45 countries discussed the importance of having women in leadership positions and shared their experiences and successes. While implementation will differ among countries, we report a set of recommendations addressing the preparation of women for leadership, the selection process, and the responsibilities of institutions.

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(1957). Ionospheric Studies in India During the International Geophysical Year. IETE Journal of Research: Vol. 3, No. 3, pp. 193-197.

Under the umbrella of the IAG (International Association of Geodesy) the symposium ‘Multi-sensor Systems for Engineering Geodesy’ was held at the XXV General Assembly of the International Union of Geodesy and Geophysics (IUGG) at the end of June, early July 2011 in Melbourne, Australia. The convenors of this symposium were Dorota Grejner-Brzezinska and Hans-Joerg Kutterer. The symposium included two oral sessions with in total ten presentations and one poster session with seven posters. In this issue of the journal four revised papers from the conference are presented, namely the first, fourth, fifth and sixth paper. In addition, two papers were selected which deal with the topic of the use, and their integration, of GNSS and multi-sensors in engineering geodesy and navigation applications. Many applications in engineering geodesy and navigation nowadays rely on GNSS positioning. Due to its limitations the use of multi-sensors as an alternative and/or backup to GNSS positioning has become an increasingly important field of research. In the coming years the IAG Sub-Commission 4.1 ‘Alternatives and Backups to GNSS’ under Commission 4 ‘Positioning and Applications’ will place special emphasis on research and other activities that address multi-sensor system theory and applications. Important topics include integrated guidance, navigation, positioning and orientation of airborne and land-based platforms. The primary sensors of interest will be inertial navigation systems (INS); however, the important role of other emerging techniques, such as pseudolites, vision-based sensors, ultrasonic and magnetic sensors etc., used in navigation, engineering geodesy and environmental monitoring is also recognised. New concepts and innovations in navigation algorithms, sensor calibration, synchronization and inter-calibration, real-time sensor information processing, sensor and data fusion, and automation techniques for information extraction from multi-sensor systems using expert systems continue to be investigated. Furthermore the progress in new applications (not limited to conventional engineering geodesy and navigation) of multi-sensor systems (e.g., in transportation, engineering, car navigation, environmental monitoring personal navigation, indoor navigation) is an important research focus in the years to come.