Natural hazards and climate change are not drivers of disasters

Many nations face challenges in assessing, understanding, and responding to the time-dependent nature of disaster risk. Changes in the intensity of occurrences of extreme events coupled with changes in vulnerability and exposure alter the impacts of natural hazards on society in mostly negative ways. Here an interrelationship between natural hazard (NH), climate change (CC), vulnerability (V), exposure (E), and decisionmaking (DM) is considered. While NHs trigger disasters and CC is likely to intensify occurrences of disasters, V and E present major drivers of disasters. Informed DM on disaster risk reduction should be based on scientific evidence from NH and CC, knowledge of V and E, and relevant options for actions on preventive disaster measures as a part of preparedness and public awareness

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

Seismic hazard assessment of the Shillong Plateau using a probabilistic approach

Seismotectonic processes of the Shillong Plateau (SP) have been influenced by the Himalayan orogeny, the India-Burmese subduction, and the Bengal Basin evolution leading to high seismic activity in the region. With a goal of assessing seismic hazards in the SP and providing a scientific information to engineering and disaster risk management communities, a probabilistic seismic hazard analysis is employed to determine hazard in highly-populated districts of SP and particularly in Shillong, Nongpoh, and Tura cities, located within the districts. This analysis is based on the use of historical and instrumentally recorded regional earthquakes since 1411 and deals with uncertainties related to earthquake magnitudes, rupture locations, and the frequency of ground motion exceedance. Individual hazard curves indicate that the Barapani fault possesses the highest frequency of seismic hazard for Shillong city and Nongpoh, and the Eocene hinge zone and Dauki faults are responsible for the highest frequency of seismic hazard at Tura. The results of the hazard assessment together with those obtained earlier using a scenario-based approach demonstrate that although the Oldham fault located near Tura can produce a great, but rare earthquake, few other nearby faults are capable of producing smaller magnitude events with a higher probability of occurrence

Active cloaking and illusion of electric potentials in electrostatics

Cloaking and illusion has been demonstrated theoretically and experimentally in several research fields. Here we present for the first time an active exterior cloaking device in electrostatics operating in a two-horizontally-layered electroconductive domain, and use the superposition principle to cloak electric potentials. The device uses an additional current source pattern introduced on the interface between two layers to cancel the total electric potential to be measured. Also, we present an active exterior illusion device allowing for detection of a signal pattern corresponding to any arbitrarily chosen current source instead of the existing current source. The performance of the cloaking/illusion devices is demonstrated by three-dimensional models and numerical experiments using synthetic measurements of the electric potential. Sensitivities of numerical results to a noise in measured data and to a size of cloaking devices are analysed. The numerical results show quite reasonable cloaking/illusion performance, which means that a current source can be hidden electrostatically. The developed active cloaking/illusion methodology can be used in subsurface geo-exploration studies, electrical engineering, live sciences, and elsewhere. © 2021, The Author(s)

Guest Editorial: Special Issue on “Lithosphere Dynamics and Earthquake Hazard Forecasting”

Brilliant scientific ideas coupled with quantitative modelling and laboratory experiments have determined progress in seismology and geodynamics for the last several decades. Methods of nonlinear geophysics, inverse problems, mathematical statistics, extreme theory and data analysis have improved knowledge of the structure of the Earth’s lithosphere, earthquake generation, predictability, and seismic hazards. This Special Issue of Surveys in Geophysics “Lithosphere Dynamics and Earthquake Hazard Forecasting” is dedicated to the 100th anniversary of the birth of Professor Vladimir (Volodya) Keilis-Borok (1921–2013), a distinguished mathematical geophysicist. For more than 60 years, the topics of seismology, nonlinear dynamics of the lithosphere, and earthquake prediction were central in Keilis-Borok's research.Open Access funding enabled and organized by Projekt DEAL.https://www.springer.com/journal/10712hj2022Geolog