Radiocarbon ages of sediment core PG1414-2 from Beall Lake, Windmill Islands

A mid-Holocene climate optimum is inferred from a palaeosalinity reconstruction of a closed saline lake (Beall Lake) from the Windmill Islands, East Antarctica using an expanded diatom salinity weighted averaging (WA) regression and calibration model. The addition of 14 lakes and ponds from the Windmill Islands, East Antarctica, to an existing weighted averaging regression and calibration palaeosalinity model of 33 lakes from the Vestfold Hills, East Antarctica expands the number of taxa and lakes and the range of salinity in the existing model and improves the model's predictive ability. This improved model was used to infer Holocene changes in lake water salinity in Beall Lake, Windmill Islands. Six changes in diatom-inferred salinity in Beall Lake are put into broad chronological context based on three radiocarbon dates: as the East Antarctic Ice Sheet (EAIS) retreated from the Windmill Islands during the early Holocene (~9000-8130 corr. yr BP), Beall Lake formed as a melt water-fed freshwater lake, which gradually became more saline as marine influence increased from ~8000 corr. yr BP. Between ~8000 and 4800 corr. yr BP, the diatom assemblage included planktonic marine taxa such as Chaetoceros spp. and cryophilic taxa such as Fragilariopsis cylindrus, which indicate favourable summer growth conditions. A mid-Holocene warm period produced a climate that was warmer and more humid with increased precipitation and snow accumulation. This is reflected in the Beall Lake core as a reduction in the salinity of the lake diatom assemblage from ~4800-4600 corr. yr BP. Holocene isostatic uplift rates in the Windmill Islands vary from 5-6 m/1000 yr. By applying this uplift rate, it is calculated that the bedrock would have risen above sea level by ~4000 yr BP. The Beall Lake core diatom assemblage from ~4600-2900 corr. yr BP includes both marine cryophilic and planktonic taxa together with freshwater benthic and planktonic lacustrine taxa. This mix of species indicates the emergence of the lake from the sea around ~4600 corr. yr BP. From ~2800 corr. yr BP, retreat of the ice margin led to increasing melt water inputs and associated freshening of the lake basin until ~1900 corr. yr BP. The lake basin had no oceanic influence by this time, allowing a terrestrial freshwater flora to establish and thrive for the next ~1000 yr. At ~1850 corr. yr BP, a sudden and rapid salinity change is evident in Beall Lake. A late Holocene warm period between 2000 and 1000 yr BP has been observed in ice core records from Law Dome (an ice cap abutting the Windmill Islands to the east and north). It is therefore inferred that, at ~1850 corr. yr BP, summer temperatures within the Beall Lake catchment area were much higher than present summer temperatures. The climate optimum identified in the Beall Lake core ~4800 yr BP confirms mid-Holocene warming of the Windmill Islands and suggests a synchronous mid-Holocene climate optimum occurred across coastal East Antarctica. In addition, the abrupt climate change inferred at ~1850 yr BP suggests that higher resolution sampling of sediment cores from coastal East Antarctic limnological oases will provide more evidence of rapid climate change events over coastal East Antarctica in future.

Geochemical data derived from an absolutely dated shell-based chronology for the Irish Sea

The identification in various proxy records of periods of rapid (decadal scale) climate change over recent millennia, together with the possibility that feedback mechanisms may amplify climate system responses to increasing atmospheric CO2, highlights the importance of a detailed understanding, at high spatial and temporal resolutions, of forcings and feedbacks within the system. Such an understanding has hitherto been limited because the temperate marine environment has lacked an absolute timescale of the kind provided by tree-rings for the terrestrial environment and by corals for the tropical marine environment. Here we present the first annually resolved, multi-centennial (489-year), absolutely dated, shell-based marine master chronology. The chronology has been constructed by detrending and averaging annual growth increment widths in the shells of multiple specimens of the very long-lived bivalve mollusc Arctica islandica, collected from sites to the south and west of the Isle of Man in the Irish Sea. The strength of the common environmental signal expressed in the chronology is fully comparable with equivalent statistics for tree-ring chronologies. Analysis of the 14C signal in the shells shows no trend in the marine radiocarbon reservoir correction (DR), although it may be more variable before ~1750. The d13C signal shows a very significant (R**2 = 0.456, p < 0.0001) trend due to the 13C Suess effect.

ロウハーニー大統領の登場から核協議の進展へ -- 米国オバマ政権の対イラン外交の転換と日本

The recent rapprochement between Iran and the United States after Hassan Rouhani was elected president in June 2013 may represent an important geopolitical shift that would alter the politics of the Middle East. The main purpose of this paper is to evaluate this political shift, examine whether the interim nuclear agreement between Iran and the United States would lead to some structural shifts in the Middle East, and analyze to what extent this change can be sustainable for both sides. The main Part of this paper is divided into three sections. The first section examines in detail the process of Iran's Presidential election in June 2013, especially the sudden change of atmosphere which took place just three days before election day. The second section is devoted to analyzing the Obama administration’s shift to diplomacy with Iran. And the third section treats the on-going nuclear negotiations between Iran and P5+1, which is expected to reach a comprehensive solution. The paper argues that the dramatic shift in the US policy toward Iran is not limited to the bilateral relationships between the US and Iran, but it is related to several key issues in the Middle East, in particular to those in Syria, Iraq and Afghanistan. This changing process in Iranian politics and the path to diplomacy is profitable for Japanese national interest, and that Japan should also contribute to Iran's return to the international community.

中国と湾岸を結ぶ南アジア -- パキスタン・アフガニスタンの動向と関連させて

Pakistan is geographically situated between China and the Gulf. In order to balance its strategic position against the major security threat of India, Pakistan formed a special and stable strategic alliance with China against common threats since the period of the cold war even though the two countries have neither a political ideology nor political system in common. On the other hand Pakistan established another special relation with Saudi Arabia on the basis of Islamic identity. With its expanding economic capacity, China proposed a project by the name of "new silk road economic corridor" with the intention of expanding and multiplying trade routes with the Middle East and Europe. Within this framework Pakistan is expected to expand the role of an alternative land route that connects the Gulf and China for use if unfavorable emergencies occur in the Malacca route. However, the continuous political uncertainty in Afghanistan after the pullout of US-NATO fighting forces at the end of 2014 and sporadic outbreaks of terrorist acts by Pakistan Taliban in Pakistan have increased China's anxiety regarding Uyghur issues at home. Avoiding military options for the moment, China is trying to find ways to play an active role in the security issues of Afghanistan with help from Pakistan if available. On the other hand, it is noteworthy that the Pakistani government formed in the general election of 2008 completed its full term and transferred authority to the newly elected government in 2013, something never observed before in Pakistan's history. Coincidently, in Afghanistan the presidential election was carried out peacefully in 2014 in spite of the Taliban threat. Although it is too early to make any definite conclusion, constitutional processes, in spite of their defects, reflected to some extent wishes for normal life of the people of Pakistan and Afghanistan who were disgusted with weak governance and the prevalence of terrorism.

Sight distance for traffic safety analysis using GIS

Sight distance is of major importance for road safety either when designing new roads or analysing the alignment of existing roads. It is essential that available sight distance in roads is long enough for emergency stops or overtaking manoeuvres. Also, it is vital for engineers/researchers that the tools used for that analysis are both powerful and intuitive. Based on ArcGIS, the application to be presented not only performs an exhaustive sight distance calculation, but allows an accurate analysis of 3D alignment, using all new tools, from a Digital Elevation Model and vehicle trajectory. The software has been successfully utilised to analyse several two-lane rural roads in Spain. In addition, the software produces thematic maps representing sight distance in which supplementary information about crashes, traffic flow, speed or design consistency could be included, allowing traffic safety studies.