Characteristics of Crustal Structure and Their Relation with Major Earthquakes in Western China

2015 ◽  
Vol 58 (1) ◽  
pp. 83-95
Author(s):  
JIANG Di-Di ◽  
JIANG Wei-Wei ◽  
XU Yi ◽  
HAO Tian-Yao ◽  
HU Wei-Jian ◽  
...  
Keyword(s):  
Crustal Structure ◽  
Western China

Earthquake relocation and 3-dimensional crustal structure of P-wave velocity in cen-tral-western China

2004 ◽  
Vol 17 (1) ◽  
pp. 20-30 ◽  
Author(s):  
Zhi-xian Yang ◽  
Xiang-wei Yu ◽  
Yue-jun Zheng ◽  
Yun-tai Chen ◽  
Xiao-xi Ni ◽  
...  
Keyword(s):  
Wave Velocity ◽  
Crustal Structure ◽  
P Wave ◽  
Western China ◽  
Earthquake Relocation ◽  
3 Dimensional ◽  
P Wave Velocity

Statistical analysis of irregular wave-guide influences on regional seismic discriminants in China: Additional results for Pn/Sn, Pn/Lg, and Pg/Sn

1998 ◽  
Vol 88 (6) ◽  
pp. 1504-1510
Author(s):  
Guangwei Fan ◽  
Thorne Lay
Keyword(s):  
Crustal Structure ◽  
Seismic Waves ◽  
Low Frequency ◽  
Multivariate Regression Analysis ◽  
Crustal Thickness ◽  
Western China ◽  
The Tibetan Plateau ◽  
Sediment Thickness ◽  
Amplitude Ratios ◽  
Short Period

Abstract Reducing scatter in measurements of regional-phase amplitude ratios is desirable for seismic discrimination applications and also provides insight into crustal structure controls on energy partitioning of regional seismic waves. Our previous analysis (Fan and Lay, 1998) of the regional seismic discriminant, Pg/Lg, indicated that variations in crustal structure cause path-specific fluctuations of those amplitude ratios for earthquakes recorded at broadband station WMQ in western China. In this study, we extend our multivariate regression analysis to Pn/Sn, Pn/Lg, and Pg/Sn amplitude ratios recorded at WMQ in frequency bands of 0.75 to 1.5 Hz, 1.5 to 3.0 Hz, and 3.0 to 6.0 Hz for the suite of path-specific parameters: path length, mean path elevation, variance of topography along the path, rms topographic slope variations, mean crustal thickness, and mean sediment thickness. Optimal three- and four-parameter models all achieve reductions in variance of the measurements relative to conventional distance corrections. At low frequency, the improvements for ratios involving Pg can be more than a factor of 2. For all short-period amplitude ratios, mean path elevation seems to play an important role. While crustal thickness and sediment thickness affect ratios involving Pg, topographic variance and surface slope variations have more influence on ratios involving Pn. Strong crustal variations associated with the structure of the Tibetan Plateau are responsible for much of the amplitude variations.

TBE in China

2020 ◽  
Keyword(s):  
Western China ◽  
Ixodes Persulcatus ◽  
West China ◽  
North West ◽  
Haemaphysalis Concinna ◽  
Viral Subtype ◽  
Japanese Military ◽  
Natural Foci ◽  
Far Eastern ◽  
The Brain

The first TBE patients in China were reported in 1943, and the TBEV was isolated from the brain tissues of 2 patients in 1944 by Japanese military scientists,1 and from patients and ticks (Ixodes persulcatus and Haemaphysalis concinna) in 1952 by Chinese researchers.2 The Far Eastern viral subtype (TBEV-FE) is the endemic subtype that has been isolated from all 3 known natural foci (northeastern China, western China, and southwestern China).14 Recently a new “Himalayan subtype” of the TBEV (TBEV-HIM) was isolated from wild rodent Marmoata himalayana in the Qinghai-Tibet Plateau15. The main vector of the TBEV in China is I. persulcatus.3 One recent report suggests that the TBEV-SIB is prevalent in the Uygur region (North West China)13 but epidemiological modelling indicates that the TBEV may occur even widely all over China (Figure 3).4 Likely, the disease is often missed by clinicians due to a lack of the availability of specific diagnostic assays16.

Prince Henri d'Orleans (1867–1901): geographical and botanical exploration between inner Asia and southwest China

1978 ◽  
Vol 8 (4) ◽  
pp. 399-399
Author(s):  
WILLIAM GARDENER
Keyword(s):  
Southwest China ◽  
Western China ◽  
Left Bank ◽  
Inner Asia ◽  
Botanical Exploration ◽  
Western Yunnan ◽  
Westerly Direction ◽  
Chinese Province ◽  
The Right ◽  
North Western

Prince Henri d'Orleans, precluded by French law from serving his country in the profession of arms, had his attention turned early towards exploration. In 1889, accompanied by the experienced traveller Gabriel Bonvalet, he set out from Paris to reach Indo-China overland by way of Central Asia, Tibet and western and south western China. The journey made contributions in the problems of the whereabouts of Lap Nor and the configuration of the then unexplored northern plateau of Tibet; and in botany it produced some species new to science. The party reached Indo-China in 1890. In 1895, having organised an expedition better equipped for topographical survey and for investigations in the fields of natural history and ethnography, Prince Henri set out from Hanoi with the intention of exploring the Mekong through the Chinese province of Yunnan. After proceeding up the left bank of the Salween for a brief part of its course and then alternating between the right and left banks of the Mekong as far up as Tzeku, the party found it advisable to enter Tibet in a north westerly direction through the province of Chamdo and instead crossed the south eastern extremity of the country, the Zayul, by a difficult track which led them to the country of the Hkamti Shans in present day Upper Burma, and thence to India completing a journey of 2000 miles, "1500 of which had been previously untrodden" (Prince Henri). West of the Mekong, the journey established that the Salween, which some geographers had claimed took its rise in or near north western Yunnan, in fact rose well north in Tibet, and that, contrary to previous opinions, the principal headwater of the Irrawaddy rose no further north than latitude 28°30'. Botanical collections were confined to Yunnan, where the tracks permitted mule transport, and they produced a number of species new to science and extended the range of distribution of species already known.

Sign in / Sign up

Export Citation Format

Share Document