20 research outputs found
Over de grens: Nederlands extreem geweld in de Indonesische onafhankelijkheidsoorlog, 1945-1949
Op 17 augustus 1945, twee dagen na de Japanse capitulatie, verklaarde Indonesië zich onafhankelijk. Nederland erkende dit niet en trachtte met geweld zelf de regie te voeren over het onvermijdelijke proces van dekolonisatie. Dit leidde tot vier jaren van moeizame onderhandelingen en bittere oorlogvoering. In 2005 verklaarde de Nederlandse regering dat Nederland die oorlog niet had moeten voeren. Over het geweld dat de Nederlandse militairen tijdens deze oorlog hadden toegepast, staat echter nog altijd het regeringsstandpunt uit 1969 overeind: er waren wel ‘excessen’, maar de krijgsmacht had zich in de regel ‘correct’ gedragen.Naarmate de aanwijzingen van extreem Nederlands geweld zich opstapelden, bleek dit officiële standpunt steeds moeilijker vol te houden. De Nederlandse regering besloot daarom in 2016 tot financiering van een groot onderzoeksprogramma. De belangrijkste conclusies daarvan zijn in dit boek te vinden. De auteurs maken aannemelijk dat de Nederlandse krijgsmacht op structurele basis extreem geweld toepaste en dat dit toen en ook lang daarna op allerlei manieren werd toegedekt. Dit alles past slecht bij een rooskleurig nationaal zelfbeeld – zoals eigenlijk de hele koloniale geschiedenis met dat zelfbeeld schuurt.Colonial and Global Histor
A decade of detailed observations (2008-2018) in steep bedrock permafrost at the Matterhorn Hörnligrat (Zermatt, CH)
The PermaSense project is an ongoing interdisciplinary effort between geo-science and engineering disciplines and started in 2006 with the goals of realizing observations that previously have not been possible. Specifically, the aims are to obtain measurements in unprecedented quantity and quality based on technological advances. This paper describes a unique >10-year data record obtained from in situ measurements in steep bedrock permafrost in an Alpine environment on the Matterhorn Hörnligrat, Zermatt, Switzerland, at 3500ma:s:l. Through the utilization of state-of-the-art wireless sensor technology it was possible to obtain more data of higher quality, make these data available in near real time and tightly monitor and control the running experiments. This data set (https://doi.org/10.1594/PANGAEA.897640,Weber et al., 2019a) constitutes the longest, densest and most diverse data record in the history of mountain permafrost research worldwide with 17 different sensor types used at 29 distinct sensor locations consisting of over 114.5 million data points captured over a period of 10 or more years. By documenting and sharing these data in this form we contribute to making our past research reproducible and facilitate future research based on these data, e.g., in the areas of analysis methodology, comparative studies, assessment of change in the environment, natural hazard warning and the development of process models. Finally, the cross-validation of four different data types clearly indicates the dominance of thawing-related kinematics
Hydromechanical Rock Slope Damage During Late Pleistocene and Holocene Glacial Cycles in an Alpine Valley
Subglacial water pressures influence groundwater conditions in proximal alpine valley rock slopes, varying with glacier advance and retreat in parallel with changing ice thickness. Fluctuating groundwater pressures in turn increase or reduce effective joint normal stresses, affecting the yield strength of discontinuities. Here we extend simplified assumptions of glacial debuttressing to investigate how glacier loading cycles together with changing groundwater pressures generate rock slope damage and prepare future slope instabilities. Using hydromechanical coupled numerical models closely based on the Aletsch Glacier valley in Switzerland, we simulate Late Pleistocene and Holocene glacier loading cycles including long‐term and annual groundwater fluctuations. Measurements of transient subglacial water pressures from ice boreholes in the Aletsch Glacier ablation area, as well as continuous monitoring of bedrock deformation from permanent Global Navigation Satellite Systems stations, help verify our model assumptions. While purely mechanical glacier loading cycles create only limited rock slope damage in our models, introducing a fluctuating groundwater table generates substantial new fracturing. Superposed annual groundwater cycles increase predicted damage. The cumulative effects are capable of destabilizing the eastern valley flank of our model in toppling‐mode failure, similar to field observations of active landslide geometry and kinematics. We find that hydromechanical fatigue is most effective acting in combination with long‐term loading and unloading of the slope during glacial cycles. Our results demonstrate that hydromechanical stresses associated with glacial cycles are capable of generating substantial rock slope damage and represent a key preparatory factor for paraglacial slope instabilities.ISSN:0148-0227ISSN:2169-9003ISSN:2169-901