Distribution and numbers of breeding ivory gulls Pagophila eburnea in Severnaja Zemlja, Russian Arctic     

ANDREJ E. VOLKOV  JACOBUS DE KORTE 《Polar research》1996,15(1):11-21

The ivory gull Pagophila eburnea has a semi-circumpolar distribution with breeding sites in the High Arctic. Data about ivory gulls in the Severnaja Zemlja Archipelago (Siberia) were collected from 1991 to 1995. The numbers of breeding ivory gulls and their egg-laying period arc correlated with the sea ice situation and weather during the first part of the summer. We estimate that the total potential breeding population of Severnaja Zemlja is about 2000 pairs, which makes up approximately 20% of the Russian and 14% of the world ivory gull breeding population. The percentage of the total breeding population which actually breeds varies annually. The most important breeding area of the ivory gull in Severnaja Zemlja is the Sedov Archipelago (A. Sedova) where a large colony (from 410 to about 1100 pairs in different years) was found on flat ground on Domašmj Island. Colonies from 10 to 100 breeding pairs, mostly on steep cliff faces, occur on O. Oktjabr'skoj Revoljucii and O. Boľševik. The ivory gull is included in the Red Data Book of Russia. Parts of Severnaja Zemlja. with important breeding sites, have become a nature reserve.  相似文献   

ANALYSIS OF THE COMMON MIDPOINT GATHER BY DECOMPOSITION INTO ELEMENTARY WAVEFRONTS1     

PIERRE THORE  ERIC DE BAZELAIRE 《Geophysical Prospecting》1991,39(4):453-471

The imaginary wavefront of a common midpoint gather of seismic data is analysed in terms of elementary wavefronts. The wavefronts emitted by the sources are split into a sequence of elementary circular wavefronts. Each such wavefront is independently transmitted through the subsurface and received by a group of receivers associated with the sources. The theory is first demonstrated in the case of a one-layer medium and is then extended to the case of a multilayer medium. We show that pairs of imaginary stationary points F and F' occur in the first medium through which all the rays, corresponding to the group of sources and receivers associated with the elementary wavefront pass. The location of the points is determined by 2n equations with 2n unknowns; (2n - 1) of these equations correspond to n layers of the medium, and an additional equation is given by the geometry of the CMP gather. Applying Fermat's principle between the points F and F', we obtain an algorithm for CMP ray tracing. The wavefront sampling problem is considered but not theoretically solved. Results obtained in the general case (a multilayer medium with lateral velocity variation) are presented and compared with those obtained by other modelling techniques.  相似文献   

ON THE BASAL BEDS OF THE SEDIMENTARY SERIES IN SOUTHWESTERN SHANSI     

E.LICENT  P.TEILHARD DE CHARDIN 《地质学报》1927,6(1):61-64

During the summer of 1926, when visiting some of the mountain rang-es of the Southwestern Shansi, we noticed, in two localities, some interestingfacts concerning the basal beds of the Sinian or the Cambrian, and their rela-tions with the underlying ctystalline rocks.  相似文献   

ON SOME NEOLITHIC (AND POSSIBLY PALAEOLITHIC) FINDS IN MONGOLIA,SINKIANG AND WEST CHINA     

德日進  楊鍾健 《地质学报》1933,(0)

In the course of the past two years,when they were in the field with theThird American (1930) and the Haardt-Citroen (1931) Central Asiatic Expedi-tions,the authors of the present note had opportunities for making a series ofarchaeological observations over an extensive area.It seems interesting to report  相似文献   

GEOLOGICAL STUDY OF THE DEPOSITS OF THE SANGKANHO BASIN.     

G.B.BARBOUR  E.LICENT  P.TEILHARD DE CHARDIN 《地质学报》1926,5(3)

This paper offers a preliminary statement of the results of investigations carried out in the South Sangkanho basin, in the mountains some 80 miles to the NW of Peking. Important fossiliferous deposits found in this area throw light on the conditions ruling in N. China during the transition from Pliocene  相似文献   

NOTE SUR LA STRUCTURE DES MONTAGNES A L''OUEST DE LINN MING KWAN (CHIHLI MERIDIONAL).     

PAR P.TEIHARD DE CHARDIN 《地质学报》1924,3(3):393-397

En Fevrier 1924, j'ai eu l'occasion, (guide par le P. Charvet, professeur a l'Institut des Hautes Etudes Industrielles de Tientsin), de traverser la region montagneuse comprise entre Linn Ming Kwan et le Zeu Chan, petit massif situe a une trentaine de kilometres ouest de Linn Ming  相似文献   

ON THE GEOLOGY OF THE NORTHERN, WESTERN AND SOUTHERN BORDERS OF THE ORDOS, CHINA   总被引：16，自引：0，他引：16  

TEILHARD DE CHARDIN  F. LICENT. 《地质学报》1924,3(1):37-44

During the last summer (1923), the authors of this paper were sent by the National Museum of Paris and by the French Ministere de l'Instruction publique for a geological mission in Inner Mongolia. Leaving from Pao T'eou, the geologists crossed the Oula Shan, took a view of the Scheiten Oula  相似文献   

Radiocarbon analyses along the EDML ice core in Antarctica     

R. S. W. VAN DE WAL  H. A. J. MEIJER  M. DE ROOIJ  C. VAN DER VEEN 《Tellus. Series B, Chemical and physical meteorology》2007,59(1):157-165

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Soil NO emissions modelling using artificial neural network     

CLAIRE DELON  DOMINIQUE SERÇA  CHRISTOPHE BOISSARD  RICHARD DUPONT  ALAIN DUTOT  PATRICIA LAVILLE  PATRICIA DE ROSNAY  ROBERT DELMAS 《Tellus. Series B, Chemical and physical meteorology》2007,59(3):502-513

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Atmospheric CO₂ during the 13th century AD: reconciliation of data from ice core measurements and stomatal frequency analysis     

THOMAS B. van HOOF  KARSTEN A. KASPERS  FRIEDERIKE WAGNER  RODERIK S. W. van de WAL  WOLFRAM M. KÜRSCHNER  HENK VISSCHER 《Tellus. Series B, Chemical and physical meteorology》2005,57(4):351-355

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