Is climate change a driver of armed conflict?     

Ole Magnus Theisen  Nils Petter Gleditsch  Halvard Buhaug 《Climatic change》2013,117(3):613-625

The world is generally becoming less violent, but the debate on climate change raises the specter of a new source of instability and conflict. In this field, the policy debate is running well ahead of its academic foundation—and sometimes even contrary to the best evidence. Although comparative research on security implications of climate change is rapidly expanding, major gaps in knowledge still exist. Taken together, extant studies provide mostly inconclusive insights, with contradictory or weak demonstrated effects of climate variability and change on armed conflict. This article reviews the empirical literature on short-term climate/environmental change and intrastate conflict, with special attention to possible insecurity consequences of precipitation and temperature anomalies and weather-related natural disasters. Based on this assessment, it outlines priorities for future research in this area.  相似文献   

Inverse eigenvalue problems for the mantle — II     

Ole H. Hald 《Geophysical Journal International》1983,72(1):139-164

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The kinematical structure of gravitationally lensed arcs     

Ole Möller  Edo Noordermeer 《Monthly notices of the Royal Astronomical Society》2006,365(2):496-508

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Reinvestigation of the classic late‐glacial Bølling Sø sequence,Denmark: chronology,macrofossils, Cladocera and chydorid ephippia     

Ole Bennike  Kaarina Sarmaja‐Korjonen  Anna Seppnen 《第四纪科学杂志》2004,19(5):465-478

The late‐glacial Bølling period was first identified by Johs. Iversen on the basis of pollen results from Lake Bølling Sø in Denmark. Because there were no radiocarbon dates from the sequence the Bølling Chronozone (12 000–13 000 ¹⁴C yr BP) was later established on the basis of dates from other sites. A new project is reinvestigating the sediments from the Bølling Sø sequence with AMS radiocarbon dating and multiproxy analyses. Here we present results of AMS radiocarbon dating, macrofossil analyses, cladoceran analyses (Cladocera concentrations and chydorid ephippia) and Pediastrum analyses (concentrations). The AMS dates on land plant remains show that the lower part of the sequence is around 12 500 ¹⁴C yr BP, and thus clearly pre‐dates the Allerød chronozone. However, construction of a chronology for the sequence was problematic, partly because of reworking of macroscopic plant remains. The climate ameliorated after glacial conditions to such an extent that growth of plants could begin at ca. 12 500 ¹⁴C yr BP, but the results of multiproxy analyses show little evidence for a further warming period during the pre‐Allerød part of the sequence. Lake productivity was low, and tree birch rare or maybe absent. This may reflect widespread occurrence of dead ice, unstable soils, heavy in‐wash of minerogenic matter to the lake, resulting in turbid water and rapid sedimentation. The early pioneer vegetation was characterised by Salix polaris and Dryas octopetala, and by herbs. The Allerød Chronozone, and especially its initial part, appears to have been relatively warm but reduced cladoceran concentrations and increased proportion of chydorid ephippia suggest that climate cooled in the middle Allerød and that the late Allerød was colder than the early part. The early Younger Dryas was probably colder than the late Younger Dryas. Clear warming is apparent at the beginning of the Holocene, where the first macrofossil evidence of trees (Betula pubescens, Populus tremula) is found. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

Surface cracks—geomorphological indicators for late Quaternary halotectonic movements in Northern Germany     

Jacob Hardt  Ben Norden  Klaus Bauer  Ole Toelle  Jenny Krambach 《地球表面变化过程与地形》2021,46(14):2963-2983

Loading and unloading effects of the Scandinavian Ice Sheet triggered halotectonic movements in Northern Germany. We present newly detected geomorphological features—termed surface cracks—which indicate a relation between ice sheet-induced salt movement and surface processes. As a part of the Central European Basin System, numerous Zechstein salt structures are abundant in the North German Basin. On the basis of high-resolution digital terrain data, more than 160 surface cracks were mapped in Northern Germany, which were grouped into 30 clusters. Almost all of the surface cracks occur above the top regions of Zechstein salt structures. The surface cracks can be several kilometres long, up to more than 20 m deep and more than 100 m wide. The comparison of the shape of the salt structures and the orientation of the cracks reveals a geometric dependency, indicating that the cracks preferably occur near the crest margins of the salt structures. Furthermore, 3D seismic data from two sites show that subsurface faults originating from salt movement exist beneath the surface cracks. We interpret the cracks as surface ruptures due to ice sheet-induced halotectonic movements. The cracks occur in a variety of Quaternary sediments and landforms. This indicates that widespread halokinetic movements occurred in the region after the last (Weichselian) deglaciation and likely before the thawing of the permafrost, possibly in a time frame from c. 30–20 ka until c. 15 ka.  相似文献   

The Importance of Microbial Iron Sulfide Oxidation for Nitrate Depletion in Anoxic Danish Sediments     

Sarka Vaclavkova  Christian Juncher Jørgensen  Ole Stig Jacobsen  Jens Aamand  Bo Elberling 《Aquatic Geochemistry》2014,20(4):419-435

Nitrate (NO₃ ^?) reduction processes are important for depleting the NO₃ ^? load from agricultural source areas before the discharge water reaches surface waters or groundwater aquifers. In this study, we experimentally demonstrate the co-occurrence of microbial iron sulfide oxidation by NO₃ ^? (MISON) and other NO₃ ^?-depleting processes in a range of contrasting sediment types: sandy groundwater aquifer, non-managed minerotrophic freshwater peat and two brackish muddy sediments. Approximately 1/3 of the net NO₃ ^? reduction was caused by MISON in three of the four environments despite the presence of organic carbon in the sediment. An apparent salinity limitation to MISON was observed in the most brackish environment. Addition of high surface area synthetically precipitated iron sulfide (FeS _x ) to the aquifer sediment with the lowest natural FeS _x reactivity increased both the relative fraction of NO₃ ^? reduction linked to MISON from approximately 30–100 % and the absolute rates by a factor of 17, showing that the potential for MISON-related NO₃ ^? reduction is environmentally significant and rate limited by the availability of reactive FeS _x .  相似文献   

Meteorological Observations in 2000 at the Arctic Station,Qeqertarsuaq (69°15'N), Central West Greenland     

Niels Nielsen  Ole Humlum  Birger Ulf Hansen 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(1):155-158

An automatic meteorological station has been operating at the Arctic Station (69°15'N, 53°31'W) in West Greenland since 1990. This paper summarizes meteorological parameters during 2000 including snow and sea ice cover, ground temperatures and active layer development, and presents comments on the local permafrost thickness.  相似文献   

Meteorological Observations in 1995 at the Arctic Station,Qeqertarsuaq (Godhavn), Central West Greenland/Concentrational Agriculture: Types,Functions, and Derivation/Den Danske Nationalkomité for Geografi     

Ole Humlum  Niels Nielsen  Morten Rasch  Birger Ulf Hansen  Sofus Christiansen 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(1):119-129

In October 1990 an automatic meteorological station was established at the Arctic Station (69°15'N, 53°31'W), Qeqertarsuaq (Godhavn), Central West Greenland, The station register parameters each 20 min, and the parameters have been described in an earlier paper in this journal by Nielsen et al. (1995). The present paper summarises main points of the climate during 1995.

Concentrational agriculture, defined as types of agriculture based on local concentration of plant nutrients, encompasses two main types: shifting cultivation and infield-outfield systems. They may ecologically be characterised by their mode of concentration: either by a vertical or a horisontal transfer (‘pumping’) of nutrients, respectively. The use of the general term ‘concentrational agriculture’ for the two forms is advocated by demonstrating that functional substitution of one by the other is possible, and by showing that the one type theoretically can be derived from the other. Historically, infield-outfield systems are supposed to be developed from some form of shifting cultivation.

Kort beretning om virksomheden i 1995

Justering af medlemskredsen. I forbindelse med valg af repræsentanter fandt en justering af repræsentationsområder sled (Århus Universilet har ikke længere fagområdet ‘kulturgeografi’). Videnskabernes Selskab har i samme forbindelse bifaldet, at fire observatører, repræsenterende undervisningstrinene i geografi deltager i møderne.  相似文献   

Editorial     

Ole Mertz PhD 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(2)

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Small island sustainability in the Pacific: Introduction to the special issue     

Katherine V. Gough  Tim Bayliss-Smith  John Connell  Ole Mertz 《Singapore journal of tropical geography》2010,31(1):1-9

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