scholarly journals Spatiotemporal Evolution of Postseismic Deformation Following the 2001 Mw7.8 Kokoxili, China, Earthquake from 7 Years of Insar Observations

2018 ◽  
Vol 10 (12) ◽  
pp. 1988 ◽  
Author(s):  
Dezheng Zhao ◽  
Chunyan Qu ◽  
Xinjian Shan ◽  
Roland Bürgmann ◽  
Wenyu Gong ◽  
...  
Keyword(s):  
Linear Trend ◽  
Near Field ◽  
Surface Displacement ◽  
Rupture Zone ◽  
Postseismic Deformation ◽  
Far Field ◽  
The South ◽  
Large Area ◽  
Envisat Asar ◽  
The North

The 2001 Mw7.8 Kokoxili earthquake, which occurred in the north Tibetan Plateau, ruptured ~400 km of the westernmost portion of the Kunlun fault and produced significant time-dependent postseismic deformation over a large area around the rupture zone and nearby regions. To analyze the postseismic deformation features along different sections of the coseismic surface rupture, we describe the total cumulative postseismic deformation near the center of the rupture and produce velocity maps for the whole observation period and six sub-periods, using InSAR observations (ENVISAT/ASAR, 2003–2010) on five descending tracks. The results indicate that the postseismic deformation is asymmetrically distributed across the fault over a very broad area of ~300 km × 500 km. The south side of the fault exhibits larger displacements and a wider area of deformation that is steadily decaying from near-field to far-field, while the north side displays a narrow, rapidly diminishing deformation field. The maximum cumulative displacement in 2003–2010 reaches up to ~45–60 mm and the LOS peak-to-trough average velocity offset in 2003–2010 reaches ~13–16 mm/yr at ~92.5°E. The short-term postseismic velocity estimates in the six sub-periods reflect significant spatial variation and temporal differences on different sections. Motions to the south of the two ends of the rupture zone show more rapid velocity decay compared to near the main central rupture zone. The time- and distance-dependent timeseries of postseismic surface displacement reveal exponential decay in the near-field and a nearly linear trend in the far-field of the fault.

scholarly journals 30. Fireball radiants of the 1st–15th centuries

1968 ◽  
Vol 33 ◽  
pp. 308-318 ◽  
Author(s):  
I.S. Astapović ◽  
A. K. Terenteva
Keyword(s):  
Middle Ages ◽  
Ecliptic Plane ◽  
Meteor Shower ◽  
The South ◽  
13Th Century ◽  
Large Area ◽  
Process Data ◽  
Retrograde Motion ◽  
Julian Calendar ◽  
The North

The works of E. Biot, published by the Institut National de France in 1848, made it possible to study material recorded in volumes 191 and 192 of the well-known 13th-century Encyclopaedia of Ma Touan-lin as well as records from other sources. They contain observational data of 24 centuries (especially from the 11th century) on more than 1500 fireballs, with descriptions of their positions with respect to the stars as well as descriptions of their physical, kinematic and other properties. The observation dates of the lunar calendar have been converted by Biot into dates of the Julian Calendar.We have been able to process data on 1220 fireballs. As a result of this radiants were obtained for 153 meteor showers, seven of which belong to great showers. Out of the remaining 146 radiants of the minor showers, 80 radiants are more certain than the remainder.The radiants were deduced from observations on dates recorded in short intervals from several years to several decades. First the dates of visibility were obtained along with the activity and radiants of great showers which are still active. In the Leonid shower, with retrograde motion, a shift of visibility dates to a much later period has been noted corresponding to a forward motion of the orbit's node, whereas a retrograde motion of the node is observed in the Quadrantids (i < 90°). In the Lyrids and Perseids, whose orbits are nearly perpendicular to the ecliptic plane, the nodes experienced no perturbations, and the visibility epochs for the showers remained the same during a period of 1000 years and longer. The motion of apsides resulted in a shift of the radiant; the increase of the ecliptical latitude indicated secular augmentation of the orbit's inclination (Geminids, η-Aquarids, Orionids, Leonids). The radiant of the Perseids was located in Cassiopeia, where the radiant of the present-day Cassiopeids is to be found. It appears that the Perseid stream began to cross the orbit of the Earth in 830 A.D.In the δ-Aquarids the North branch was active, while there is no evidence that the South branch had existed earlier than 900 years ago. The Virginids, Librids, Scorpionids, Sagittarids and Aurigids were quite appreciable and their studies furnish much interesting data. Particularly active were the Taurids; their North and South branches were observed over 1000 years back. The South Taurids were about half as active as the North Taurids (at present this relation is reversed). Very active were the Cygnids (July–August), which presented at that time a compact shower, now disrupted into a series of minor showers with radiants spread over a large area of the celestial sphere. Of definitive interest is the radiant of the great meteor shower observed in 1037 (August 21 by the Julian Calendar, September 9 by the Gregorian Calendar, 1950–0), α = 324°, δ = + 1°(1950–0).Some of the showers active in these early centuries are now unknown; on the other hand, some showers which are well known now were not observed in the Middle Ages. In the past millennium only those streams have survived whose orbits were so situated with respect to the orbits of the outer planets, that they were not subjected to any considerable perturbations produced by these planets.

scholarly journals Femtosecond Laser Precision Engineering: From Micron, Submicron, to Nanoscale

2021 ◽  
Vol 2021 ◽  
pp. 1-22
Author(s):  
Zhenyuan Lin ◽  
Minghui Hong
Keyword(s):  
Femtosecond Laser ◽  
High Efficiency ◽  
Near Field ◽  
Ambient Air ◽  
Optical Microscope ◽  
Far Field ◽  
Large Area ◽  
Precision Engineering ◽  
Processing Strategies ◽  
Near Field Effect

As a noncontact strategy with flexible tools and high efficiency, laser precision engineering is a significant advanced processing way for high-quality micro-/nanostructure fabrication, especially to achieve novel functional photoelectric structures and devices. For the microscale creation, several femtosecond laser fabrication methods, including multiphoton absorption, laser-induced plasma-assisted ablation, and incubation effect have been developed. Meanwhile, the femtosecond laser can be combined with microlens arrays and interference lithography techniques to achieve the structures in submicron scales. Down to nanoscale feature sizes, advanced processing strategies, such as near-field scanning optical microscope, atomic force microscope, and microsphere, are applied in femtosecond laser processing and the minimum nanostructure creation has been pushed down to ~25 nm due to near-field effect. The most fascinating femtosecond laser precision engineering is the possibility of large-area, high-throughput, and far-field nanofabrication. In combination with special strategies, including dual femtosecond laser beam irradiation, ~15 nm nanostructuring can be achieved directly on silicon surfaces in far field and in ambient air. The challenges and perspectives in the femtosecond laser precision engineering are also discussed.

Superposition of Cretaceous and Cenozoic deformation in northern Tibet: A far-field response to the tectonic evolution of the Tethyan orogenic system

2021 ◽  
Author(s):  
Ye Wang ◽  
Xuanhua Chen ◽  
Yaoyao Zhang ◽  
Zheng Yin ◽  
Andrew V. Zuza ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Early Cretaceous ◽  
Detrital Zircons ◽  
The Tibetan Plateau ◽  
Far Field ◽  
The South ◽  
Field Mapping ◽  
The North ◽  
Northern Tibetan Plateau ◽  
Field Response

Although the Cenozoic Indo-Asian collision is largely responsible for the formation of the Tibetan plateau, the role of pre-Cenozoic structures in controlling the timing and development of Cenozoic deformation remains poorly understood. In this study we address this problem by conducting an integrated investigation in the northern foreland of the Tibetan plateau, north of the Qilian Shan-Nan Shan thrust belt, NW China. The work involves field mapping, U-Pb detrital-zircon dating of Cretaceous strata in the northern foreland of the Tibetan plateau, examination of growth-strata relationships, and construction and restoration of balanced cross sections. Our field mapping reveals multiple phases of deformation in the area since the Early Cretaceous, which was expressed by northwest-trending folding and northwest-striking thrusting that occurred in the early stages of the Early Cretaceous. The compressional event was followed immediately by extension and kinematically linked right-slip faulting in the later stage of the Early Cretaceous. The area underwent gentle northwest-trending folding since the late Miocene. We estimate the magnitude of the Early Cretaceous crustal shortening to be ∼35%, which we interpret to have resulted from a far-field response to the collision between the Lhasa and the Qiangtang terranes in the south. We suggest that the subsequent extension in the Early Cretaceous was induced by orogenic collapse. U-Pb dating of detrital zircons, sourced from Lower Cretaceous sedimentary clasts from the north and the south, implies that the current foreland region of the Tibetan plateau was a topographic depression between two highland regions in the Early Cretaceous. Our work also shows that the Miocene strata in the foreland region of the northern Tibetan plateau was dominantly sourced from the north, which implies that the rise of the Qilian Shan did not impact the sediment dispersal in the current foreland region of the Tibetan plateau where this study was conducted.

Chapter 8 Northwestern Spitsbergen

1997 ◽  
Vol 17 (1) ◽  
pp. 132-153
Author(s):  
W. Brian Harland ◽  
Paul A. Doubled Ay
Keyword(s):  
Fault Zone ◽  
Central Basin ◽  
Central Province ◽  
Quaternary Sediments ◽  
The South ◽  
Large Area ◽  
Southern Boundary ◽  
James I ◽  
Western Sector ◽  
The North

Northwestern Spitsbergen is bounded by Billefjorden and Wijde-fjorden in the east and by the coastline in the north and west round to the southwest by Kongsfjorden (Fig. 8.1). The southern boundary overlaps with the Central Basin (Chapter 4) and central western sector of Spitsbergen (Chapter 9) along Kongsfjorden and Sveabreen. At this boundary Devonian and older rocks are uncon-formably overlain, and finally obscured to the south, by the cover of Carboniferous through Paleogene strata. This sector contains Andree Land, Albert I Land, Haakon VII Land, James I Land and northern Dickson Land. It is deeply penetrated by fjords and largely covered by ice.Apart from Quaternary sediments and volcanics, Cenozoic plateau lavas and the overlying platform sequence (Carboniferous through Paleogene) to the south, the main consideration here is with Devonian sediments, mid-Paleozoic migmatites and granites, and Precambrian metasediments.The Northwestern sector is bounded and divided by faults. The eastern boundary is delineated by the Billefjorden Fault Zone (BFZ) and the southwestern boundary is the postulated Kongs-fjorden-Hansbreen Fault Zone (KHFZ). These faults separate the Central Province respectively from the Eastern and Western provinces. Two main N-S oriented faults divide the sector into three terranes: the Raudfjorden Fault (RFF), and the Breibogen Fault (BBF) (Fig. 8.1) as noted by Holtedahl (1914). The three terranes are introduced below. (1) The Andree Land-Dickson Land Terrane is a large area of Devonian strata bounded by the Breibogen Fault Zone and the Billefjorden Fault Zone. (2) The Biskayerfonna-Holtedahlfonna Terrane is a N-S belt bounded to the

Historical Inferences from the Linguistic Geography of the Nigerian Middle Belt

Africa ◽  
1971 ◽  
Vol 41 (4) ◽  
pp. 294-305 ◽  
Author(s):  
J. A. Ballard
Keyword(s):  
The Other ◽  
Political Systems ◽  
The South ◽  
Large Area ◽  
Archaeological Evidence ◽  
The Past ◽  
The North ◽  
Linguistic Evidence ◽  
Opening Paragraph ◽  
Eastern Half

Opening ParagraphThis paper examines the distribution of languages in the Nigerian Middle Belt, draws certain historical inferences from the patterns of distribution, and assesses non-linguistic evidence tending to confirm or refute these inferences. The Middle Belt is taken as an area roughly inscribed by the Hausa-speaking area to the north, and the Yoruba, Edo, and Ibo-speaking areas to the south. Geographically it is an area which has a certain climatic coherence, falling between the sahel to the north and the forest to the south (Pullan, 1962; Buchanan, 1953). It is also an area of much more strikingly broken terrain than those to the north or south, with not only the complex relief of the Jos Plateau, but also many ranges of hills, particularly along its northern frontier and in its eastern half. This terrain appears to have militated against the establishment of large coherent political systems in the past and it is only in the plains of the Niger and Benue valleys that there is a record of extensive state systems in recent history, those of the Nupe and Jukun. On the other hand, archaeological evidence indicates that the Nok culture extended over a very large area of the Middle Belt, not by any means confined to the plains (Fagg, 1959, 1969), and there is evidence of a certain measure of cultural unity today (Murdock, 1959).

Geological Studies in the Dublin District. I. The Heavy Minerals of the Granite and the Contiguous Rocks in the Ballycorus District

1928 ◽  
Vol 65 (1) ◽  
pp. 12-25 ◽  
Author(s):  
F. Smithson
Keyword(s):  
Geological Structure ◽  
Heavy Minerals ◽  
East Side ◽  
The South ◽  
Large Area ◽  
Lower Carboniferous ◽  
North West ◽  
The North ◽  
South West ◽  
The Hill

From the southern shores of Dublin Bay there stretches to the south-west a broad granite intrusion with rocks of supposed Ordovician age on both sides of it. These rocks are metamorphosed near the granite, and the belt of metamorphism is wider on the south-east than on the north-west side, indicating, no doubt, that the plane of junction dips more steeply on the latter side. Near Dublin the Lower Carboniferous rocks rest unaltered upon the granite. On the south-east side, in the northern part of the county of Wicklow, the belt of Ordovician rocks is only some 2 miles wide, and a large area of supposed Cambrian rocks lies between it and the sea. Around the hill of Carrickgollogan a. patch of similar rocks appears incongruously in the middle of the Ordovician belt. After a study of the region to the south of Dublin one seems to be naturally drawn towards this small area around Carrickgollogan, for it presents a problem, the key to which may explain the geological structure of a much wider area.

scholarly journals Results from a geological reconnaissance around Svartenhuk Halvø, West Greenland

1973 ◽  
Vol 50 ◽  
pp. 1-26
Author(s):  
V Münther
Keyword(s):  
Fault Zones ◽  
The South ◽  
Large Area ◽  
The West ◽  
North East ◽  
The North ◽  
South West ◽  
Early Tertiary ◽  
Lateral Extent ◽  
Tectonic Movements

Svartenhuk Halvø is built up primarily of Tertiary basalts; these overlie Cretaceous and early Tertiary sediments, and overlap onto the Precambrian basement. The basalt series can be divided into a lower and an upper series; although displaced by faults, the boundary between these series can be followed across the peninsula. The thickness of the lower basalt series is estimated to be about 2-3 km in the south of the peninsula and barely 1 km in the north; the sub-aquatic basalt breccia is included in these thicknesses. FauIts causing repetitions of the lava succession have resulted in the series being preserved over a rather large area. The general dip of the lavas is 3-4 dregrees towards SW in the east and 8-10 degrees, also towards SW, in the west. Locally dips between 10 and 20 degrees or even steeper are seen; these are the resulf of drag along fault zones in Arfertuarssuk fjord and Kugssineq valley, and between Svartenhuk Halvø and Ubekendt Ejland. The youngest fault has a displacement of 500 m or more and has downthrown the basement area to the north-east in relation to the sediment-basalt breccia-basalt series to the south-west. The upper basalt series has by far the greater lateral extent and covers the gneiss and metasediment area to the north and north-east at least as far as the Inland lee. The dip of the flows in this part of the basalt series is considerably lower than in much of the lower basalt series, but faults repeating the succession are also frequently encountered within the upper basalts. The tectonic movements evidence a strong E-W (or NE-SW) tension, never a compression; the weak anticlinal and synclinal structures which are seen are interpreted as resulfing from differential sagging. The lower basalt series is thought to have arisen from fissure eruptions, with the main area of eruption in the east. The lavas are very rich in olivine (i. e. are pieritic). The upper basalt series probably arose from central eruptions and smaller fissure eruptions, and the area of eruption is thought to have shifted to the west. The upper lavas become poorer in olivine; andesitic lavas represent perhaps a closing phase, more local in its distribution and perhaps resulting from magmatic assimilation of pre-basaltic sediments. "Iron basalt" and intrabasaltic breccia have not been noted on Svartenhuk Halvø.

Near-field/far-field study of the end-effects regime produced by large area ratio nozzles

2013 ◽  
Vol 134 (5) ◽  
pp. 4057-4057
Author(s):  
Raymundo M. Rojo ◽  
Charles E. Tinney ◽  
Woutijn J. Baars ◽  
Joseph H. Ruf
Keyword(s):  
Field Study ◽  
Near Field ◽  
Area Ratio ◽  
Far Field ◽  
Large Area ◽  
End Effects

scholarly journals A precipitation-based regionalization for Western Iran and regional drought variability

2008 ◽  
Vol 12 (6) ◽  
pp. 1309-1321 ◽  
Author(s):  
T. Raziei ◽  
I. Bordi ◽  
L. S. Pereira
Keyword(s):  
Linear Trend ◽  
Climatic Variability ◽  
Annual Precipitation ◽  
Time Variability ◽  
Positive Trend ◽  
The South ◽  
Western Iran ◽  
The North ◽  
Precipitation Regimes

Abstract. The spatial distribution of the seasonal and annual precipitation was analyzed in western Iran using data from 140 stations covering the period 1965–2000. Applying the Precipitation Concentration Index (PCI), the intra-annual precipitation variability was also studied. Furthermore, nine precipitation-derived parameters were used to regionalize climate in western Iran using principal component analysis and clustering techniques. Results suggest that five spatially homogenous sub-regions can be identified characterized by different precipitation regimes. The spatial pattern of seasonal precipitation seems to be highly controlled by the wide latitudinal extent of the region and by the pronounced orographic relieves, and the time of occurrence of the maximum precipitation varies from spring in the north to winter in the south. The time variability of dry and wet periods in the identified sub-regions was analyzed using the Precipitation Index (PI) and the existence of any long-term trend was tested. Results show that the northern and southern regions of western Iran are characterized by different climatic variability. Furthermore, a negative long-term linear trend in the north and a weak positive trend in the south of the study area have been detected though they are not statistically significant.

Mixing of brine waste in Puck Bay (the south Baltic Sea) in the light of in-situ measurements

2016 ◽  
Vol 45 (1) ◽  
Author(s):  
Małgorzata Robakiewicz
Keyword(s):  
Baltic Sea ◽  
Coastal Waters ◽  
Near Field ◽  
Monitoring Program ◽  
The South ◽  
The North ◽  
North Eastern ◽  
North Eastern Part ◽  
Puck Bay

AbstractIn the north-eastern part of Poland, the underground gas stores are being constructed by diluting salt deposits. Brine, a by-product of the technology applied, is discharged into the coastal waters of the south Baltic Sea by a system of diffusers. To assess the intensity of brine mixing in the near-field of the discharge installation, a monitoring program was carried out. The results demonstrated that under the mildly dynamic conditions of Puck Bay, the discharge of brine (saturation 250 kg m

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