The middle pleistocene deposits of Waverley Wood Pit,Warwickshire, England     

F. W. Shotton  D. H. Keen  G. R. Coope  A. P. Currant  P. L. Gibbard  M. Aalto  S. M. Peglar  J. E. Robinson 《第四纪科学杂志》1993,8(4):293-325

A complex of channels underlying the Baginton-Lillington Gravel (Baginton Formation) at Waverley Wood Quarry, Warwickshire is described. Fossil pollen and plant macrofossils, Coleoptera, Ostracoda, Mollusca and Mammalia are described from the channel-fill deposits. Consideration of all the evidence allows the identification of four separate stages of channel fill which largely occurred under a cool temperate climate. At the top of Channel 2 evidence for a cold, continental climatic episode can be recognised, suggesting that the whole complex was deposited under a fluctuating climate at the end of a temperate stage. At two levels in the channels human artefacts were recovered confirming the presence of Palaeolithic people in Warwickshire during the deposition of the sediments. Amino-acid geochronology suggests an age within the ‘Cromerian Complex’ Stage for the channels. The small vertebrate and molluscan faunas indicate that the deposits are no older than the latter part of the ‘Cromerian Complex’ Stage of East Anglia. The regional stratigraphic significance of the Waverley Wood succession is outlined.  相似文献   

Palaeolimnology of Lake Piene-Kuuppalanlampi (Kurkijoki, Karelian Republic, Russia): isolation history, lake ecosystem development and long-term agricultural impact     

Juha Miettinen  Elisabeth Grönlund  Heikki Simola  Pertti Huttunen 《Journal of Paleolimnology》2002,27(1):29-44

The post-glacial history of Lake Pieni-Kuuppalanlampi, western Lake Ladoga region, was studied by means of stratigraphic pollen and diatom analyses. Diatoms were analysed to track the isolation history of the basin and the limnological effects of the early land-use phases indicated by pollen analysis. Chrysophycean stomatocysts and Isoëtes spores were also employed in the limnological reconstructions. Sediment dating was provided by six conventional radiocarbon dates.The lower part of the 370-cm long sediment sequence represents early Holocene, large lake conditions: the (freshwater) Yoldia and Ancylus stages of the Baltic basin, with a short-term lagoonal or isolation phase at the end of Yoldia. The basin was isolated due to Ancylus lake regression at 9785 cal B.P. For the small-lake sequence (0–250 cm) we used diatom inferences (WA-method) for hindcasting water chemistry. The post-isolation limnology of Pieni-Kuuppalanlampi reflects the development of vegetation on its small hill-top catchment. In its early development, the lake was mesotrophic, but became more acidic (pH about 6) and oligotrophic after the decline of temperate hardwood trees and the spread of spruce to the area after around 5000 B.P. The lake ecosystem appears to have reacted sensitively to agricultural land-use in the catchment from AD 400–800 onwards: inferred total phosphorus levels and pH both rise during these periods.  相似文献   

New climatic classification of Nepal     

Ramchandra Karki  Rocky Talchabhadel  Juha Aalto  Saraju Kumar Baidya 《Theoretical and Applied Climatology》2016,125(3-4):799-808

  相似文献   

Impacts of land management on ecosystem service delivery in the Baiyangdian river basin   总被引：1，自引：0，他引：1  

Yang Bai  Bo Jiang  Juha M. Alatalo  Changwei Zhuang  Xiaoyuan Wang  Lijuan Cui  Weihua Xu 《Environmental Earth Sciences》2016,75(3):258

  相似文献   

Singularity elements for seepage analysis     

J. Aalto 《国际地质力学数值与分析法杂志》1985,9(2):185-196

A technique for locating the nodal points of standard isoparametric quadrilateral elements properly around a discharge velocity singularity point in a soil seepage flow problem is presented. It is based on the analytical solution of the problem in an infinite medium and gives simple formulae for calculating the nodal coordinates. The effectiveness of the method is justified with examples.  相似文献   

An assessment of arctic sea ice concentration retrieval based on “HY-2” scanning radiometer data using field observations during CHINARE-2012 and other satellite instruments     

SHI Lijiang  LU Peng  CHENG Bin  KARVONEN Juha  WANG Qimao  LI Zhijun  HAN Hongwei 《海洋学报(英文版)》2015,(3)

A retrieval algorithm of arctic sea ice concentration (SIC) based on the brightness temperature data of “HY-2” scanning microwave radiometer has been constructed. The tie points of the brightness tempe...  相似文献   

Insights from isotope stratigraphy     

Alcides N. Sial  Juha A. Karhu  Valderez P. Ferreira 《Precambrian Research》2010

  相似文献   

The meso-scale drivers of temperature extremes in high-latitude Fennoscandia     

Juha Aalto  Peter C. le Roux  Miska Luoto 《Climate Dynamics》2014,42(1-2):237-252

Extreme temperatures are key drivers controlling both biotic and abiotic processes, and may be strongly modified by topography and land cover. We modelled mean and extreme temperatures in northern Fennoscandia by combining digital elevation and land cover data with climate observations from northern Finland, Norway and Sweden. Multivariate partitioning technique was utilized to investigate the relative importance of environmental variables for the variation of the three temperature parameters: mean annual absolute minima and maxima, and mean annual temperature. Generalized additive modeling showed good performance, explaining 84–95 % of the temperature variation. The inclusion of remotely sensed variables improved significantly the modelling of thermal extremes in this system. The water cover variables and topography were the most important drivers of minimum temperatures, whereas elevation was the most important factor controlling maximum temperatures. The spatial variability of mean temperatures was clearly driven by geographical location and the effects of topography. Partitioning technique gave novel insights into temperature-environment relationship at the meso-scale and thus proved to be useful tool for the study of the extreme temperatures in the high-latitude setting.  相似文献   

The impact of extreme weather and climate change on inland waterway transport     

Juha Schweighofer 《Natural Hazards》2014,72(1):23-40

Similarly to other modes of transport, inland waterway transport has to deal with weather events, affecting navigation conditions and the infrastructure on inland waterways. Most significant extreme weather events result from high precipitation, droughts and temperatures below zero degrees Celsius. Heavy rainfall, in particular in association with snow melt, may lead to floods resulting in suspension of navigation and causing damage to the inland waterway infrastructure as well as the property and health of human beings living in areas exposed to flooding. Long periods of drought may lead to reduced discharge and low water levels, limiting the cargo-carrying capacity of vessels and increasing the specific costs of transportation. Temperatures below zero degrees Celsius over a longer period may cause the appearance of ice on waterways, leading to suspension of navigation and possible damage to infrastructure, for example, buoys. Neither extreme weather events as well as climate change are new phenomena nor is their general occurrence expected to change suddenly. However, due to climate change, extreme weather events may change positively or adversely in severity and frequency of occurrence, depending on the respective weather event and the location of its occurrence. This paper gives an overview of the impact of extreme weather events on inland waterway transport in Europe, focussed on the Rhine–Main–Danube corridor, followed by a discussion on how climate change will change these events and their impacts.  相似文献   

A Molecular Ring in the Liner Ngc 5218     

E. Olsson  S. Aalto  S. HÜttemeister 《Astrophysics and Space Science》2005,295(1-2):155-160

High resolution OVRO CO 1–0 observations of the inner 30 in the LINER galaxy NGC 5218 reveal the presence of a double centrally peaked molecular concentration with extensions out to a radius of 12. The molecular mass detected is 2.4 × 10⁹ M and the gas surface density is high, 3000 M pc square in the inner 500 pc. The SFR is 2–3 M yr^–1 and the SFE is 13, which are low or moderate values for that gas surface density. We interpret the inner feature as a rotating molecular ring with a radius of 200 pc. We furthermore suggest that the LINER activity in NGC 5218 is not caused by an aging starburst, but by a buried AGN.  相似文献