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1.
Fang Nianqiao Chen Xuefang Hu Chaoyong Yin Yong Ding Xuan Zhang Shihong Nie Haogang Institute of Marine Geology Geophysics China University of Geosciences Beijing China 《中国地质大学学报(英文版)》2000,11(3)
INTRODUCTIONSituated in the low latitudes and the extension of theWest Pacific Worm Pool,the Bay of Bengal and its neighbor-ing waterhosted a greatdeal of terrigenous sedim ents denudedfrom the Tibetan plateau and transported by the Gange-Brahmapoutra fluvial system . Although most parts of the seafloor in the area are occupied by the Bengal deep sea fan,thegreatest turbidite body in the world,turbidity current sedi-mentation does not serve as the only one dynamics to consti-tute the s… 相似文献
2.
Spatiotemporal changes of global extreme temperature events (ETEs) since 1981 and the meteorological causes 总被引：2，自引：0，他引：2
Xiao Song Zhao Zhang Yi Chen Pin Wang Ming Xiang Peijun Shi Fulu Tao 《Natural Hazards》2014,70(2):975-994
Of the various types of disasters caused by extreme climate and weather, extreme temperature events (ETEs) have led to a heightened awareness due to their increasing frequency, intensity, widespread distribution, and severe health impacts. Although many previous studies have surveyed the severe impacts of specific ETEs, few systematic studies have analyzed the temporal trends and the spatial patterns of this type of ETEs at the global scale. In the present study, disaster data from 1981 to 2010 compiled by Emergency Events Database were used to obtain a global view of the distribution of and the changes in the recorded ETEs. In addition, the daily maximum/minimum temperature data provided by National Centers for Environmental Prediction /Department of Energy Reanalysis 2 were used to explore the potential meteorological causes of these events. The results showed 2.7 and 6.4 increases in the frequencies of heat waves and cold spells per decade, respectively, since the 1980s. However, a large regional variability was found worldwide. Moreover, more than 40 % of the recorded ETEs occurred in Europe, and Asia experienced 33 and 26 % of the heat wave and cold spell events, respectively. Additionally, the global pattern for the occurrence frequency of ETEs in recent decades could be largely ascribed to the meteorological indexes: the heat stress index (HSI) and the cold stress index (CSI). The frequency of heat wave events increased from 1981 to 2010, and this trend is consistent with the increase in the HSI. However, the cold spell events did not appear to be reduced, as demonstrated by the disaster records, and this finding is inconsistent with the CSI trend. This result indicates that other factors also influence the occurrence of disaster events. 相似文献
3.
Natural Hazards - 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... 相似文献
4.
Data from the Greenland ice sheet and continental records from Europe have indicated climatic fluctuations during the last interglacial (Eemian: Oxygen Isotope Substage 5e). Similar fluctuations have not, however, been documented previously from marine environments. Here, we show the existence of two cold events during substage 5e in two marine, benthic foraminiferal, shelf records from northwest Europe and suggest that these cooling events are a result of fluctuations in the strength of the North Atlantic surface-water circulation. 相似文献
5.
JINGYUN ZHENG LINGLING DING ZHIXIN HAO QUANSHENG GE 《Boreas: An International Journal of Quaternary Research》2012,41(1):1-12
Zheng, J., Ding, L., Hao, Z. & Ge, Q. 2012 (January): Extreme cold winter events in southern China during AD 1650–2000. Boreas, Vol. 41, pp. 1–12. 10.1111/j.1502‐3885.2011.00225.x. ISSN 0300‐9483. We defined extreme cold winter events as those with occurrence probabilities lower than the 10th percentile of the probability density function, based on observed winter temperatures in southern China since 1951. Subsequently, we constructed impact severity levels using documentary evidence for those events during 1951–2000, considering three indexes for the freezing of rivers/lakes, widespread snow/ice storms, and cold damage to subtropical/tropical crops. Using these criteria we identified 50 extreme cold winters for the period AD 1650–1949 based on ～4000 pieces of comparable information extracted from local gazettes in southern China, after verification using data from three weather stations with long records. It was found that the frequencies of the extreme cold winter events since 1650 varied over time. The most frequent occurrences were found during AD 1650–1699 and in the first and second halves of the 19th century, with frequencies twice as high as in the second half of the 20th century. In contrast, the frequencies of extreme winters during the 18th century were close to that in the second half of the 20th century. High frequencies of extreme cold winters in AD 1650–1720 and AD 1795–1835 occurred during the sunspot Maunder and Dalton Minima. The intensities of some historical cold events, such as those during 1653–1654, 1670, 1690, 1861, 1892 and 1929, exceeded those of the coldest winter events since 1951. 相似文献
6.
Driven by increasing demand for food and industrial consumption, world’s maize supply is under stress. Besides, the extreme temperature events are now exposing more threat to maize yield with ongoing climate change. Thus, a comprehensive analysis on maize exposure (exposure is defined as the cultivated area which is exposed to extreme temperature stress), vulnerability (here it means how much yield losses with each temperature increase/decrease at a national scale), and adaptation to extreme temperature is essential to better understand the effects on global maize production, especially in major production countries. It was found that warming trends during the growing season have extensively dominated the main maize-growing areas across the globe. And along with this mean temperature trend was the increasing heat stress and decreasing cold stress among most regions. Moreover, from 1981 to 2011, maize yield losses caused by heat stress in China, India, and the USA were 1.13, 0.64 and 1.12% per decade, respectively, while Mexico has been experiencing a reduction of yield loss due to decreased cold stress of 0.53% per decade. Furthermore, during the period of 2021–2051, the extreme heat stress would increase substantially, while the low temperature was estimated to drop slightly during the growing seasons. Such pattern had also been found over the key reproductive stage of maize. Accordingly, through the sensitivity test of two adaption measures, improved high-temperature-tolerant varieties and changing maize calendar earlier could both mitigate extreme meteorological stress on maize, while the former method would be the most effective way to do so. Our study could provide a paradigm for other crops and other countries in the world to analyze their exposure and vulnerability to the temperature stress and make corresponding adaptation measures.
相似文献7.
1961-2012年辽宁省极端气温事件气候变化特征 总被引：3，自引：1，他引：2
利用辽宁省52个气象台站逐日平均气温、 最高气温和最低气温数据, 使用国际通用的10种极端气候指数, 研究了1961-2012年辽宁省极端气温事件的气候变化特征. 结果表明: 年平均极端气温事件空间分布存在明显的地区差异. 时间尺度上, 1961-2012年辽宁省年及四季极端暖事件(暖昼日数、 暖夜日数、 夏季日数、 热带夜数和热浪持续指数)呈增加趋势, 极端冷事件(冷昼日数、 冷夜日数、 结冰日数、 霜冻日数和寒潮持续指数)呈减少趋势; 极端暖事件在20世纪90年代中期开始明显增加, 极端冷事件在20世纪80年代末期开始显著减少; 极端暖事件的变化速率要小于极端冷事件. 辽宁省气温日较差有增大的趋势, 极端暖(冷)事件的增加(减少)在秋季(冬季)最为显著. 空间变化上, 极端气温事件在全省基本都呈一致的增加或减少的分布. 多数极端气温事件均存在8 a左右的周期, 检测到的突变的时间大致在20世纪80年代中期到90年代末期. 20世纪80年代末期辽宁省气候变暖后, 极端暖事件和冷事件均有明显的增加和减少. 相似文献
8.
H. Daniel Stillwell 《Natural Hazards》1992,6(2):131-159
Natural hazards and disasters occur widely throughout the world. Disasters can be costly both in terms of human lives and property and ecosystem disruption. Higher death tolls in developing nations may be the result of poverty, rapid population growth, urbanization, and inadequate communication facilities. The purpose of this study is to show patterns of major catastrophic events in Latin America so that their impacts can be evaluated and compared.Latin America was selected because of the variety of recent events commanding wide attention: earthquakes in Mexico, volcanic eruptions in Colombia, hurricanes and floods in Haiti, and drought and mudflows in Brazil. Spatial and temporal aspects of natural disasters are presented in nine tables and 21 maps. The tables give selected disaster data by country for volcanic eruptions, earthquakes, landslides, and atmospheric disturbances from the 16th century to 1989. Most data is derived from disasters occurring during the 20th century and include number of events, people killed, people affected, and U.S.$ damage. Maps show environmental settings for disasters and allow detailed comparison among countries. Floods account for the greatest number of major events in the most countries, earthquakes cause the most deaths and damage, while droughts affect the most people. Peru surpasses all others in susceptibility to major disasters. Assessment of vulnerability to hazards, improved economic opportunities, and an increased social and political concern for poor people should help reduce future losses from natural disasters in Latin America. 相似文献
9.
Walter Finsinger Daniele Colombaroli Jacques‐Louis De Beaulieu Verushka Valsecchi Boris Vannière Elisa Vescovi Emmanuel Chapron André F. Lotter Michel Magny Willy Tinner 《第四纪科学杂志》2010,25(8):1239-1247
Despite the high potential of pollen records for climate reconstruction, pollen–climate relationships may be biased due to past and present human activities on the landscape. We use (i) transfer functions based on modern pollen–climate relationships to infer seasonal temperature and summer precipitation for the period 11 500–4500 cal. a BP and (ii) lake‐level change records based on different sedimentary proxies in multiple cores that are mainly indicative for summer hydrology at Lago dell'Accesa (central Italy). Quantitative reconstructions indicate lowest summer precipitation during two phases (8500–7700 cal. a BP and after 6000 cal. a BP) and a gradual winter temperature increase from 11 500 to ca. 8000 cal. a BP. Lowest summer precipitation was reconstructed during these phases characterised by vegetation shifts from open forests dominated by summergreen oaks (Quercus) to forests dominated by evergreen oaks (Quercus ilex), which are at present most abundant where summer drought is stronger. Similarly, the lake‐level record indicates two long‐lasting low summer precipitation phases (8800–7700 and 6400–4400 cal. a BP) that were interrupted by short‐term high summer precipitation events. Based on the broad agreement between the pollen‐inferred summer precipitation and the low‐frequency lake‐level changes, we suggest that the duration of the high summer precipitation events may have been too short to maintain drought‐sensitive trees, which may have been affected by high mortality rates when summer dry conditions returned. Although past and modern pollen–climate relationships may very likely have been affected by human activities since the Neolithic (i.e. when exploitation of the landscape started), we reject the hypothesis of a significant anthropogenic bias in the pollen‐based climate reconstruction. In addition, we suggest that pollen‐based and lake‐level reconstructions may have different inherent abilities of capturing high‐ and low‐frequency precipitation signals. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
10.
In developed countries regional development issues have increased in importance at just that moment when manufacturing is steadily declining. This paper examines the role of industry in regional development by reconsidering the openness of regional economies and the nature of inter-industry linkages. It concludes that peripheral regions share the problems of peripheral nations in the capitalist world economy. 相似文献
11.
A. D. Couper 《GeoJournal》1981,2(2):107-110
The arab oil producing countries have characteristics of both less developed and more developed countries. They are diversifying their economies and entering into shipping. There are arguments for and against some participation in shipping, but industrialisation generates shipping requirements. These are being met on a Pan Arab basis and by joint ventures with traditional maritime nations. 相似文献
12.
A. D. Couper 《GeoJournal》1978,2(2):107-110
The arab oil producing countries have characteristics of both less developed and more developed countries. They are diversifying their economies and entering into shipping. There are arguments for and against some participation in shipping, but industrialisation generates shipping requirements. These are being met on a Pan Arab basis and by joint ventures with traditional maritime nations. 相似文献
13.
《地学前缘(英文版)》2023,14(2):101515
The assessment of detrital zircon age records is a key method in basin analysis, but it is prone to several biases that may compromise accurate sedimentary provenance investigations. High to ultrahigh temperature (HT-UHT) metamorphism (especially if T > 850 °C) is herein presented as a natural cause of bias in provenance studies based on U-Pb detrital zircon ages, since zircon from rocks submitted to these extreme and often prolonged conditions frequently yield protracted, apparently concordant, geochronological records. Such age spreading can result from disturbance of the primary U-Pb zircon system, likewise from (re)crystallization processes during multiple and/or prolonged metamorphic events. In this contribution, available geochronological data on Archean, Neoproterozoic and Palaeozoic HT-UHT metamorphic rocks, acquired by different techniques (SIMS and LA-ICP-MS) and showing distinct compositions, are reassessed to demonstrate HT-UHT metamorphism may result in modes and age distributions of unclear geological meaning. As a consequence, it may induce misinterpretations on U-Pb detrital zircon provenance analyses, particularly in sedimentary rocks metamorphosed under such extreme temperature conditions. To evaluate the presence of HT-UHT metamorphism-related bias in the detrital zircon record, we suggest a workflow for data acquisition and interpretation, combining a multi-proxy approach with: (i) in situ U-Pb dating coupled with Hf analyses to retrieve the isotopic composition of the sources, and (ii) the integration of a petrochronological investigation to typify fingerprints of the HT-UHT metamorphic event. The proposed workflow is validated in the investigation of one theoretical and one natural example allowing a better characterization of the sedimentary sources, maximum depositional ages, and the tectonic setting of the basin. Our workflow allows to the appraisal of biases imposed by HT-UHT metamorphism and resulting disturbances in the U-Pb detrital zircon record, particularly for sedimentary rocks that underwent HT-UHT metamorphism and, finally, suggests ways to overcome these issues. 相似文献
14.
V. Bout-Roumazeilles N. Combourieu Nebout O. Peyron E. Cortijo A. Landais V. Masson-Delmotte 《Quaternary Science Reviews》2007,26(25-28):3197-3215
High-resolution clay mineralogical analyses were performed on sediment deposited during the last 50,000 yr in the Alboran sea (ODP Site 976). The clay mineral record is compared with pollen assemblages and with annual precipitation (Pann) and mean temperatures of the coldest month (MTCO) reconstructed with the modern analog technique (MAT). Enhanced contribution of palygorskite, a typical wind-blown clay mineral, characterizes the North Atlantic cold climatic events. Coeval development of the semi-arid vegetation (Artemisia rich) associated with a drastic fall of reconstructed precipitations and temperatures, suggest cold and arid continental conditions in the West Mediterranean area during North Atlantic cold events. The clay mineral association, especially the palygorskite content and the illite-to-kaolinite ratio, indicate western Morocco as one of the major source of the clay-size fraction during the North Atlantic cold events. The maximum abundance of Artemisia associated with the presence of Argania pollen both indicate Morocco as the main origin for pollen during these cold periods. The comparison of these pollen and clay mineral-specific features allows us to pinpoint western Morocco as the dominant source of wind-blown particles during North Atlantic cold events. These specific mineralogical composition and palynological assemblages reveal enhanced aridity over North Africa and intensification of winds favouring dust erosion and transport from North Africa toward the Alboran Sea during the North Atlantic cold events. According to atmospheric models, such a meridian transport (1) likely results from the development of strong and stable anticyclonic conditions over the tropical Atlantic and North Africa, similar to today's summer meteorological configuration and (2) implies a northward position of the westerly winds during North Atlantic cold events. Finally the synoptic situation over the West Mediterranean during the North Atlantic cold events is compared with the North Atlantic Oscillation (NAO), suggesting that during the cold Atlantic events, weather regimes over Europe and North Africa may have been systematically shifted towards a positive NAO situation. 相似文献
15.
Independence,dependence and fragmentation in the South Pacific 总被引：1，自引：0，他引：1
J. Connell Dr. 《GeoJournal》1981,5(6):583-588
Since the 1960s most island groups of the South Pacific have achieved independence and many new nations have been established; only the very smallest islands remain colonies. Most of the small nations are extremely small yet secession movements in many areas have resulted in fragmentation producing the break-up of the Gilbert and Ellice Islands and the disintegration of the Trust Territory of the Pacific Islands. This has emphasized the distinctive characteristics of the Pacific nations: their small size (in population and in area) and limited natural resources, their isolation from each other and from markets and fragmentation within multiple island countries. The extension of outside interests into the Pacific has brought rapid economic changes, the emergence of cash cropping and the decline of subsistence agriculture, increased dependence on imports (especially food, resulting in some nutritional problems) and rapid urbanization, producing growing dependence and inequality which regional ties between the Pacific nations have not been able to overcome. Outmigration from the smallest nations to USA and New Zealand is likely to be maintained and the unusual characteristics of these small island nations suggest that strategies of development that appear viable elsewhere have little chance of success in the Pacific. 相似文献
16.
The Abric Romani continental pollen record provides evidence of abrupt climate variations during the last glaciation. The pollen record reveals a pattern of high-frequency variations similar to that in ice cores as shown by oxygen isotopes or dust content. Analyses of 14 travertine samples yield coherent U-series ages in correct stratigraphic order, ranging from 40,000 to 70,000 yr. According to changes in the composition and structure of the vegetation, five paleoclimatic phases have been differentiated; the oldest, ranging from 70,200 to 65,500 yr ago, records thermophilous taxa which correspond to the last warm events of isotopic stage 5. The next phase, from 65,500 to 56,800 yr, records a cold, humid climate that correlates with isotope stage 4. During the third phase, from 56,800 to 49,500 yr, relatively warm and cold events alternate. The fourth phase, from 49,500 to 46,200 yr, records a cold, dry climate. The fifth phase, ranging from 46,200 to 40,800 yr, records a milder phase that is similar in appearance to the beginning of the Holocene. 相似文献
17.
白垩纪大火成岩省与地幔对流 总被引：2，自引：0，他引：2
白垩纪事件是全球非常明显和重要的一次地质突发事件,包括洋壳的超巨量形成,地磁正超时达41Ma之久(124~83 Ma),海水温度大幅度升高,黑色页岩沉积和石油形成的大量增长,海平面的快速上升,大气CO2水平的急剧升高,以及伴生的生物灭绝事件等。中—新生代的大火成岩省与冈瓦纳超大陆的裂解伴生,是超级地幔热柱产生的结果,而与欧亚超大陆的形成伴生分散火成岩省,是超级冷地幔下降流的结果,两者的联合构成全地幔对流的格局。全地幔对流模型为白垩纪地质演化、生物演化和环境演化的突变提供地球深部过程的约束。 相似文献
18.
面向灾害风险评估的热带气旋路径及强度随机模拟综述 总被引：1，自引：0，他引：1
历史热带气旋记录时间序列较短空间差异大,热带气旋灾害风险评估经常面临样本不足,特别是超强台风及巨灾记录历史样本的问题,从而导致传统概率统计方法失效。过去20多年来,逐渐发展出一套完整的方法体系进行热带气旋路径及强度随机模拟,其特点是充分利用历史总体样本信息,生成大量符合历史样本特征的热带气旋路径及强度随机事件样本集,从而有效地解决了局地历史样本不足的问题。在回顾热带气旋的年频次、季节分布、路径分布、强度及影响范围时空规律研究进展基础上,系统综述了用于热带气旋路径及随机模拟的起始点模型、行进模型、终止点模型、洋面强度模型、陆地衰减模型及结果检验方法等领域的进展及不足,然后对其在世界各地的应用进行了概述,并对未来研究改进方向及应用领域进行了展望。 相似文献
19.
A comparison of selected global disaster risk assessment results 总被引：1，自引：0，他引：1
We compare country risk rankings derived from two recently published global disaster risk analyses. One set of country rankings
is based on the Disaster Risk Index (DRI) developed by the United Nations Environment Program (UNEP) Division of Early Warning
and Assessment Global Resource Information Database project under a contract to the United Nations Development Program (UNDP).
The other is based on an index of disaster mortality risk developed by the Global Natural Disaster Risk Hotspots project implemented
by Columbia University, the World Bank and associated partners. We convert data from these sources into two comparable indexes
of disaster mortality risk and rank countries according to the resulting values for a set of natural hazards common to both
studies. The country rankings are moderately correlated, ranging from .41 to .56 for individual hazards to .31 for multi-hazard
mortality risks. We identify the top 25 countries according to the mortality risk values we recomputed from each study’s results
to show the degree to which countries are highly ranked in common. The numbers of countries common to both lists for individual
hazards range from 7 to 16 out of 25. The correspondence among the top 25 ranked countries is lowest for earthquakes and floods.
Only 6 out of 25 countries are common to both lists in the multi-hazard case. We suggest that while the convergence in the
results for some hazards is encouraging, more work is needed to improve data and methods, particularly with respect to assessing
the role of vulnerability in the creation of risk and the calculation of multi-hazard risks.
The views expressed are the authors’ and do not necessarily reflect those of SM2 Consulting Multi-Hazards and Risk Holistic
Solutions or the United Nations Development Program. 相似文献
20.
Boris Vannire Gilles Bossuet Anne‐Vronique Walter‐Simonnet Pascale Ruffaldi Thierry Adatte Michel Rossy Michel Magny 《第四纪科学杂志》2004,19(8):797-808
This paper presents the results of a multiproxy investigation including volume magnetic susceptibility (κ), mineral and pollen analyses of Late Glacial sediments from Lake Lautrey (Jura, France). Small‐scale lithological variations have been identified with high stratigraphic resolution in order to establish lithostratigraphic correlations between cores. κ measurements, combined with mineralogical analyses, provide information on past sedimentary processes. This combined approach reflects major changes in terrestrial habitats and soil processes which may relate to the climatic events characterising the Late Glacial climatic warming and cooling phases. During warm intervals, the record indicates increased lake productivity via carbonate precipitation and decreased input of detrital material. In contrast, cooler intervals show reduced lake productivity, catchment area instability and increased detrital inputs. Several short interruptions in reforestation and in soil stabilisation can be identified and linked with abrupt colder events occurring through the Bølling. A general trend of warming is recorded from the coldest part of the Younger Dryas. Three tephra layers were also detected. The mineral composition analyses show that the upper tephra layer corresponds to the Laacher See eruption (Eifel, Germany) while the lower ones may relate to the volcanic activity of the Chaîne des Puys (Massif Central, France) around 13 000 cal. yr BP. These two events, recognised for the first time outside the Massif Central region, may provide additional chronostratigraphic markers for the Late Glacial sedimentary records of the Jura mountains and northern Alps. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献