Geoscience international: the role of scientific unions

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

IUGG: beginning, establishment, and early development (1919–1939)

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.</p

Scenario-based earthquake hazard and risk assessment for Baku (Azerbaijan)

A rapid growth of population, intensive civil and industrial building, land and water instabilities (e.g. landslides, significant underground water level fluctuations), and the lack of public awareness regarding seismic hazard contribute to the increase of vulnerability of Baku (the capital city of the Republic of Azerbaijan) to earthquakes. In this study, we assess an earthquake risk in the city determined as a convolution of seismic hazard (in terms of the surface peak ground acceleration, PGA), vulnerability (due to building construction fragility, population features, the gross domestic product per capita, and landslide's occurrence), and exposure of infrastructure and critical facilities. The earthquake risk assessment provides useful information to identify the factors influencing the risk. A deterministic seismic hazard for Baku is analysed for four earthquake scenarios: near, far, local, and extreme events. The seismic hazard models demonstrate the level of ground shaking in the city: PGA high values are predicted in the southern coastal and north-eastern parts of the city and in some parts of the downtown. The PGA attains its maximal values for the local and extreme earthquake scenarios. We show that the quality of buildings and the probability of their damage, the distribution of urban population, exposure, and the pattern of peak ground acceleration contribute to the seismic risk, meanwhile the vulnerability factors play a more prominent role for all earthquake scenarios. Our results can allow elaborating strategic countermeasure plans for the earthquake risk mitigation in the Baku city

Scenario-based earthquake hazard and risk assessment for Baku (Azerbaijan)

A rapid growth of population, intensive civil and industrial building, land and water instabilities (e.g. landslides, significant underground water level fluctuations), and the lack of public awareness regarding seismic hazard contribute to the increase of vulnerability of Baku (the capital city of the Republic of Azerbaijan) to earthquakes. In this study, we assess an earthquake risk in the city determined as a convolution of seismic hazard (in terms of the surface peak ground acceleration, PGA), vulnerability (due to building construction fragility, population features, the gross domestic product per capita, and landslide’s occurrence), and exposure of infrastructure and critical facilities. The earthquake risk assessment provides useful information to identify the factors influencing the risk. A deterministic seismic hazard for Baku is analysed for four earthquake scenarios: near, far, local, and extreme events. The seismic hazard models demonstrate the level of ground shaking in the city: PGA high values are predicted in the southern coastal and northeastern parts of the city and in some parts of the downtown. The PGA attains its maximal values for the local and extreme earthquake scenarios. We show that the quality of buildings and the probability of their damage, the distribution of urban population, exposure, and the pattern of peak ground acceleration contribute to the seismic risk, meanwhile the vulnerability factors play a more prominent role for all earthquake scenarios. Our results can allow elaborating strategic countermeasure plans for the earthquake risk mitigation in the Baku city

Knowledge Exchange Through Science Diplomacy to Assist Disaster Risk Reduction. Progress in Disaster Science

This paper analyses science diplomacy efforts to reduce disaster risks and proposes establishing national knowledge exchange centers (KECs) to help individual states adhere to their Sendai Framework goals. KECs are considered to be interconnected globally and work together to promote resilience efforts by facilitating sharing of information and strategies in risk monitoring, assessment, and ultimately reduction across the globe. KECs can provide high-quality scientific evidence for informed decisionmaking along with a component related to disaster science media to ensure that appropriate knowledge reaches a variety of people who need it in different forms tailored for them. KECs can promote transdisciplinary education in disaster-related science diplomacy (i.e., disaster diplomacy). The United Nations Office for Disaster Risk Reduction (UNDRR) and the International Science Council (ISC) can provide assistance to KECs through UNDRR National Platforms and ISC Members

A Method for Magma Viscosity Assessment by Lava Dome Morphology

Lava domes form when a highly viscous magma erupts on the surface. Several types of lava dome morphology can be distinguished depending on the flow rate and the rheology of magma: obelisks, lava lobes, and endogenic structures. The viscosity of magma nonlinearly depends on the volume fraction of crystals and temperature. Here we present an approach to magma viscosity estimation based on a comparison of observed and simulated morphological forms of lava domes. We consider a two-dimensional axisymmetric model of magma extrusion on the surface and lava dome evolution, and assume that the lava viscosity depends only on the volume fraction of crystals. The crystallization is associated with a growth of the liquidus temperature due to the volatile loss from the magma, and it is determined by the characteristic time of crystal content growth (CCGT) and the discharge rate. Lava domes are modeled using a finite-volume method implemented in Ansys Fluent software for various CCGTs and volcanic vent sizes. For a selected eruption duration a set of morphological shapes of domes (shapes of the interface between lava dome and air) is obtained. Lava dome shapes modeled this way are compared with the observed shape of the lava dome (synthesized in the study by a random modification of one of the calculated shapes). To estimate magma viscosity, the deviation between the observed dome shape and the simulated dome shapes is assessed by three functionals: the symmetric difference, the peak signal-to-noise ratio, and the structural similarity index measure. These functionals are often used in the computer vision and in image processing. Although each functional allows to determine the best fit between the modeled and observed shapes of lava dome, the functional based on the structural similarity index measure performs it better. The viscosity of the observed dome can be then approximated by the viscosity of the modeled dome, which shape fits best the shape of the observed dome. This approach can be extended to three-dimensional case studies to restore the conditions of natural lava dome growth

“Crust development inferred from numerical models of lava flow and its surface thermal measurements„

Propagation of a lava flow is governed by slope topography, magma rheology, heat exchange with the atmosphere and the underlying ter− rain, and the rate of the eruption. Highly viscous crust is formed due to cooling and solidification of the uppermost layer of the flow. We consider here two numerical model problems for lava flows, both based on the fundamental physics of a hot fluid flow: a model problem, where thermal conditions (e.g. temperature and heat flow) at the lava surface are unknown a priori (a direct model problem), and a model problem, where the lava surface conditions are known and determined from observations (an inverse model problem). In both models, the lava viscosity depends on temperature and the volume fraction of crystals. By way of solving the direct model problem, we perform a para− metric study of steady state lava flows to investigate the influence of the heat flux, viscosity, and effusion rate on the lava crust devel− opment. Numerical experiments show that a lava crust becomes thicker in the case of the nonlinear heat transfer compared to the case of a linear heat flow at the interface of lava with the atmosphere. Also, the crust thickens at lower lava effusion rates, while higher rates re− sult in a rapid lava advection, slower cooling, and development of a thinner crust. Moreover, a lava crust becomes thicker with a higher coefficient of conductive heat transfer, or a higher lava viscosity, or the growth of effective emissivity of the lava surface. By way of solv− ing the inverse model problem, we use an assimilation technique (that is, a method for an optimal combination of a numerical model of lava flows with observations) to propagate the temperature and heat flow, inferred from measurements at the interface between lava and the atmosphere, into the lava flow interior and to analyse the evolving lava crust. Results of thermal data assimilation illustrate that the physical parameters of lava flows, including the thickness of it crust, can be recovered from measured surface thermal data well enough at least for slow effusion rates. © 2019 the Istituto Nazionale di Geofisica e Vulcanologia. All rights reserved

IUGG in the 21st century

The International Union of Geodesy and Geophysics (IUGG) has vigorously responded to a number of the natural, scientific, and technological challenges and driving forces that have marked the 21st century thus far. This paper reviews the actions of the Union that were precipitated by disasters caused by natural hazard events, climatic and environmental changes, and important scientific advances, as well as the opportunities to support International Years and other cooperative programs. This period has also given rise to a number of structural changes within the Union. IUGG added an eighth association, the International Association of Cryospheric Sciences, and inaugurated the new categories of affiliate and honorary memberships, introduced new grants, science education, and recognition programs, and formed new Union commissions on climatic and environmental change, data and information, planetary sciences, and a working group on history. Electronic communication was welcomed as a cultural norm. Overall, the development of the scientific landscape in the 21st century and a healthy future for the Union requires emphasis on fundamental Earth and space sciences as well as on transdisciplinary science to resolve urgent problems of society. IUGG will continue to evolve throughout the coming decades in step with the changing world of science and its international organizations, by responding to challenging problems as they arise.</p