Prediction of the Sungpan-Pingwu earthquakes, August 1976

1980 ◽  
Vol 70 (4) ◽  
pp. 1199-1223
Author(s):  
Robert E. Wallace ◽  
Ta-Liang Teng
Keyword(s):  
Fracture Zone ◽  
Time Window ◽  
Substantial Reduction ◽  
Good Time ◽  
Large Space ◽  
Republic Of China ◽  
Plant Behavior ◽  
The North ◽  
Axis Parallel ◽  
Mass Evacuation

abstract On August 16, 22, and 23, 1976, a succession of three large earthquakes (M = 7.2, 6.8, 7.2) occurred in the Sungpan-Pingwu area of Szechuan Province, People's Republic of China. Their successful predictions resulted in a substantial reduction in the loss of lives. The epicenters of these events progressed from north to south along the Huya Fault, a NNW-striking fault between the NE-trending Lungmenshan fracture zone and the north-trending Mienchiang fracture zone in western Szechuan. The greatest intensity reported was IX; isoseismals were crudely elliptical with the long axis parallel to the trend of the Huya Fault. The predictions were made with a reasonably good magnitude window (less than 0.5 magnitude unit), a rather large space window (about 150 km ×150 km), and a remarkably good time window (within a day). The detailed prediction process began with field monitoring some 6 yr before the Sungpan-Pingwu events and ended with the final issuance of warning and mass evacuation. During the few weeks preceding the earthquakes, about 1,300 observations of noninstrumental anomalies and precursory phenomena were reported by scientists and lay brigades: outgassings, fireballs and other earthquake lights, abnormal animal and plant behavior, and telluric currents.

Examining Industrial Clusters from an Ecological Perspective: Evidences from North-East China

2012 ◽  
Vol 13 (2) ◽  
pp. 60-84
Author(s):  
Ge Li ◽  
Ramudu Bhanugopan ◽  
Alan Fish
Keyword(s):  
Differential Equations ◽  
Logistic Model ◽  
Industrial Clusters ◽  
Ecological Perspective ◽  
Positive Outcomes ◽  
Republic Of China ◽  
North East ◽  
The North ◽  
Regional Cluster ◽  
Key Factor

Industrial clusters are increasingly seen as essential in effectively combining, developing and enhancing like-minded businesses. Industrial clusters irrespective of their location are providing positive outcomes for ecological derivatives in supporting effective industrial developments. This perspective is addressed within this paper via employing the ‘Logistic Model of Ecology’; through the application of differential equations. This paper explains key interspecies relationships; competition, predation and symbiosis, operating within a regional cluster in the Jilin Province in the north-east of The Peoples’ Republic of China. The paper draws the conclusion that ‘intense competition’ is the key factor contributing to the successful existence of the cluster.

scholarly journals A Mesoproterozoic iron formation

2018 ◽  
Vol 115 (17) ◽  
pp. E3895-E3904 ◽  
Author(s):  
Donald E. Canfield ◽  
Shuichang Zhang ◽  
Huajian Wang ◽  
Xiaomei Wang ◽  
Wenzhi Zhao ◽  
...  
Keyword(s):  
Organic Matter ◽  
Time Window ◽  
Iron Formation ◽  
The North ◽  
Fe Oxidation ◽  
Organic Biomarkers ◽  
Rock Eval ◽  
Fe Reduction ◽  
Rule Out ◽  
Xiamaling Formation

We describe a 1,400 million-year old (Ma) iron formation (IF) from the Xiamaling Formation of the North China Craton. We estimate this IF to have contained at least 520 gigatons of authigenic Fe, comparable in size to many IFs of the Paleoproterozoic Era (2,500–1,600 Ma). Therefore, substantial IFs formed in the time window between 1,800 and 800 Ma, where they are generally believed to have been absent. The Xiamaling IF is of exceptionally low thermal maturity, allowing the preservation of organic biomarkers and an unprecedented view of iron-cycle dynamics during IF emplacement. We identify tetramethyl aryl isoprenoid (TMAI) biomarkers linked to anoxygenic photosynthetic bacteria and thus phototrophic Fe oxidation. Although we cannot rule out other pathways of Fe oxidation, iron and organic matter likely deposited to the sediment in a ratio similar to that expected for anoxygenic photosynthesis. Fe reduction was likely a dominant and efficient pathway of organic matter mineralization, as indicated by organic matter maturation by Rock Eval pyrolysis combined with carbon isotope analyses: Indeed, Fe reduction was seemingly as efficient as oxic respiration. Overall, this Mesoproterozoic-aged IF shows many similarities to Archean-aged (>2,500 Ma) banded IFs (BIFs), but with an exceptional state of preservation, allowing an unprecedented exploration of Fe-cycle dynamics in IF deposition.

Bivalves from the Innviertel Group of Allerding in the North Alpine Foreland Basin (lower Miocene, Upper Austria)

2020 ◽  
Vol 297 (1) ◽  
pp. 47-100
Author(s):  
Oleg Mandic ◽  
Simon Schneider ◽  
Mathias Harzhauser ◽  
Wolfgang Danninger
Keyword(s):  
Shallow Water ◽  
Time Window ◽  
Foreland Basin ◽  
Migration Route ◽  
Central Paratethys ◽  
Seagrass Meadows ◽  
The North ◽  
North Alpine Foreland Basin ◽  
Alpine Foreland ◽  
Alpine Foreland Basin

During the Ottnangian (Burdigalian, early Miocene), the North Alpine Foreland Basin operated as a sea-way connecting the Central Paratethys Sea with the Rhône Basin in the Western Mediterranean. Within this short time window, an intensive faunal exchange between the two paleo-biogeographic units occurred, which is reflected in macrofossil assemblages. The extraordinarily rich fossil record of the study site, Allerding, located in the westernmost Central Paratethys, provides valuable insights into the composition and origins of the bivalve fauna colonizing the marine gateway. The site documents the early Ottnangian marine transgression over deeply weathered crystalline basement, grading from fossil bearing shallow water clay and sand into the open marine "Schlier" facies of the Ottnang Formation. Despite considerable taphonomic overprint including aragonite leaching and mechanical abrasion of bivalve shells under turbulent shallow-water conditions, a total of 46 species are recorded, including two new species (Lima allerdingensis n. sp. and Astarte danningeri n. sp.). The dominance of suspension feeders, and the presence of several deposit feeders and chemosymbiotic taxa point to well diversified inshore settings, including low intertidal mudflats, as well as seagrass meadows. An abundance of primary and secondary hardgrounds is reflected in the high number of cementing and byssate species, as well as in the occurrence of species drilling actively into hard substrate. Finally, the dominance of active burrowers suggests a patchwork of habitats, where sandy and muddy soft bottoms occur interspersed. Biostratigraphic analysis constrains the deposits to the early to middle Ottnangian, based on the presence of the index species Flexopecten davidi and the concurrence of several taxa, which have their last or first occurrences within this interval. These are predominantly taxa persisting into the Badenian, therefore allowing for a straightforward differentiation between late Eggenburgian and early Ottnangian assemblages. While a few Central Paratethys endemics reflect a continued semi-isolated position of the area, the majority of the newly arriving species are shared with the Mediterranean and NE Atlantic, documenting the establishment of a faunal migration route via the North Alpine Foreland Basin. In the present study the lectotypes of Nucula mayeri Hörnes, 1865, Saccella subfragilis (Hörnes, 1875) and Lucinoma wolfi (Hoernes, 1875) are designated.

Petrology of a transform fault zone and adjacent ridge segments

1971 ◽  
Vol 268 (1192) ◽  
pp. 423-441 ◽  
Keyword(s):  
Oceanic Crust ◽  
Fault Zone ◽  
Fracture Zone ◽  
Volcanic Eruptions ◽  
Spreading Ridge ◽  
Transform Fault ◽  
Transform Faults ◽  
Near Surface ◽  
The North ◽  
Transform Fault Zone

The Verna Fracture Zone in the North Atlantic (9 to 11° N), which has been identified as a transform fault zone, contains exposures of serpentinized peridotites, while its adjacent ridge segments are floored mainly by typical abyssal ocean ridge basalts. This petrologic contrast correlates with the greater frequency of volcanic eruptions along the actively spreading ridge segments compared to the transform fault zone. Where rifting components occur across transform faults, exposures of the deeper zone of oceanic crust may result. The bathymetry of the Verna Fracture Zone suggests that some uplift parallel to the fracture zone as well as rifting led to exposures of deeper rocks. The basalts from the adjacent ridge axes contain ‘xenocrysts’ of plagioclase and olivine and more rarely of chromite. These appear to have a cognate origin, perhaps related to cooling and convection in near surface magma chambers. The basalts from the ridge axes, offset and on opposite sides of the transform fault, have similar features and compositions. The plagioclase peridotites have mineralogical features which indicate equilibration in the plagioclase pyrolite facies, suggesting maximum equilibration depths of around 30 km for a temperature of around 1200 °C. The chemical characteristics of the Vema F.Z. peridotites suggest that they may be undifferentiated mantle, emplaced as a subsolidus hot plastic intrusion or as a crystal mush. The abundance of peridotites and serpentinized peridotites is believed to reflect their abundance in seismic layer three of the oceanic crust.

Imaging the sea surface using a dual-sensor towed streamer

Geophysics ◽  
2010 ◽  
Vol 75 (6) ◽  
pp. V111-V118 ◽  
Author(s):  
Okwudili Orji ◽  
Walter Söllner ◽  
Leiv Jacob Gelius
Keyword(s):  
Seismic Data ◽  
Time Window ◽  
Finite Difference Methods ◽  
Surface Profile ◽  
Sea Surface ◽  
Data Sets ◽  
The North ◽  
Dual Sensor ◽  
The North Sea ◽  
Time Invariant

Sea-surface profile and reflection coefficient estimates are vital input parameters to various seismic data processing applications. The common assumption of a flat sea surface when processing seismic data can lead to misinterpretations and mislocations of events. A new method of imaging the sea surface from decomposed wavefields has been developed. Wavefield separation is applied to the data acquired by a towed dual-sensor streamer containing collocated pressure and vertical particle velocity sensors to obtain upgoing and downgoing wavefields of the related sensors. Time-gated upgoing and downgoing wavefields corresponding to a given sensor are then extrapolated to the sea surface where an imaging condition is applied so that the time-invariant shape of the sea surface can be recovered. By sliding the data time-window, the temporal changes of the sea surface can be correspondingly estimated. Ray tracing and finite-difference methods were used to generate different controlled data sets used in this feasibility study to demonstrate the imaging principle and to test the image accuracy. The method was also tested on a first field data example of a marginal weather line from the North Sea.

International Law of the Sea in North Natuna Sea

2020 ◽  
Vol 7 (11) ◽  
pp. 354-367
Author(s):  
Yulian Azhari
Keyword(s):  
International Law ◽  
United States Of America ◽  
Historical Analysis ◽  
Law Of The Sea ◽  
People’S Republic Of China ◽  
Military Bases ◽  
People's Republic Of China ◽  
Republic Of China ◽  
The North ◽  
International Attention

The dispute that occurred in the North Natuna Sea has attracted international attention, including the superpower United States of America and the People's Republic of China and countries in the Southeast Asian region. This escalation of tensions occurred when the People's Republic of China built military bases in areas considered the nine dash lines that the PRC claims as part of their country. International law continues to fail to enforce the North Natuna Sea. It is clear that international law has so far tried - and failed - to contain China's advances in the North Natuna Sea. Existing confidence-building measures must match China's increasingly hegemonic claims. If not, the rules-based order will face continued erosion and smaller countries in Southeast Asia will suffer the consequences. This study uses a qualitative approach with socio-historical analysis to reveal past events, especially in the field of maritime law, which are unknown to the international community.  

Pottery from Hooper Bay Village, Alaska

1952 ◽  
Vol 18 (1) ◽  
pp. 18-29 ◽  
Author(s):  
Wendell Oswalt
Keyword(s):  
Organic Material ◽  
Preliminary Analysis ◽  
Good Time ◽  
Bristol Bay ◽  
Alaska Peninsula ◽  
The North ◽  
Great Area ◽  
The Face ◽  
Southern Section ◽  
Archaeological Excavations

Archaeological excavations along coastal Alaska from Cape Prince of Wales south to the Alaska Peninsula, a distance of approximately 2000 miles, were not initiated until 1948, when Giddings (1949) began work in the north at Cape Denbigh, and Larsen (1950) began at Bristol Bay in the southern section of this great area (see Fig. 7). During the summer of 1950 the writer carried out excavations at Hooper Bay, in approximately the center of the unworked region. Although the Hooper Bay Village material includes about 2000 artifacts and 1500 pot and lamp sherds, this paper is limited to a preliminary analysis of the cooking pots. The importance of pottery in determining the sequence within Eskimo prehistory has been neglected, in the face of the abundance of organic material which the frozen middens and house remains yield. The full significance of Alaskan pottery was not emphasized until de Laguna (1947) made her detailed study of the ware; also, Larsen (1950, p. 186) pointed out that potsherds are particularly good time indicators in a region like southwestern Alaska, where the preservation is poor. In this paper the Hooper Bay sherds are considered with particular reference to their position within the Bristol Bay-Norton Sound region and their relationship to finds of similar pottery in the north.

Geophysical investigations in the Ungava Bay – Hudson Strait region of Northern Canada

1970 ◽  
Vol 7 (4) ◽  
pp. 1062-1076 ◽  
Author(s):  
A. C. Grant ◽  
K. S. Manchester
Keyword(s):  
Glacial Erosion ◽  
Northern Canada ◽  
The North ◽  
Axis Parallel ◽  
Geophysical Investigations ◽  
Magnetic Profile ◽  
Local Detail

Continuous seismic profiler surveys have defined the limits of the Paleozoic outlier in Ungava Bay, and indicate that similar rocks occur to the north beneath Hudson Strait. These surveys have shown also that the strata underlying Hudson Strait are down-warped to form a synclinal structure with its axis parallel to the bathymetric trend of the Strait. Extrapolations based upon the dips and thicknesses indicated on the seismic profiler records and on physiographic evidence, suggest that the southwestern side of Hudson Strait has been down-faulted relative to the block of Paleozoic strata in Ungava Bay. These relationships postulated on the basis of seismic profiler results are supported by aeromagnetic, sea-magnetometer, and sea-gravimeter data from that region. A seismic and magnetic profile from Frobisher Bay indicates that a Paleozoic outlier occurs there as well. Although the submarine physiography of this region is primarily controlled by structure and secondarily modified by sub-aerial erosion, glacial erosion may account for local detail.

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