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Sample records for korea tectonic significance

  1. Middle Paleozoic metamorphism in the Hongseong area, South Korea, and tectonic significance for Paleozoic orogeny in northeast Asia

    NASA Astrophysics Data System (ADS)

    Oh, Chang-Whan; Imayama, Takeshi; Yi, Sang-Bong; Kim, Taeseong; Ryu, In-Chang; Jeon, Jimin; Yi, Keewook

    2014-12-01

    The Baekdong and Gwangcheon areas are located within the Hongseong collision belt of South Korea, and the discovery of late Permian-Triassic eclogites has confirmed this belt as an extension of the Qinling-Dabie-Sulu collision belt in China. The Qinling-Dabie-Sulu belt records a middle Paleozoic continental collision in addition to the late Permian-Triassic collision of the North and South China cratons. In this paper, we present evidence for middle Paleozoic igneous and metamorphic events in the Baekdong and Gwangcheon areas. Metabasites and meta-basaltic andesites in the Baekdong area originated in an arc tectonic setting at ca. 470-437 Ma, and underwent an intermediate-P/T metamorphism (6.2-8.2 kbar, 620-700 °C) at ca. 418-405 Ma. The meta-basaltic andesite in the Gwangcheon area underwent a high-pressure granulite facies metamorphism (close to the eclogite facies) at ca. 392-381 Ma. P-T values of 15.7-19.9 kbar and 860-890 °C were obtained for the peak metamorphism using conventional geothermobarometry, and conditions of 16-17 kbar and 870-920 °C were estimated by thermodynamic pseudosection analysis using the Perplex X program. Together with the late Permian-Triassic eclogites previously reported from the Hongseong area, these middle Paleozoic igneous activities that were related to subduction and metamorphism indicate that the Hongseong area underwent collision in the middle Paleozoic (418-381 Ma), in addition to the late Permian-Triassic collision, as recorded in the Qinling-Dabie-Sulu belt in China.

  2. Tectonic significance of serpentinites

    NASA Astrophysics Data System (ADS)

    Guillot, Stéphane; Schwartz, Stéphane; Reynard, Bruno; Agard, Philippe; Prigent, Cécile

    2015-04-01

    At plate boundaries, where deformation is localized along centimetre- to kilometre-scale shear zones, the influence of serpentinite on tectonic processes is linked to its unique rheological properties. In this paper we review the physical properties of serpentinites and their role in tectonic processes. At the ocean-continent transition, serpentinization weakens the upper mantle layer, promoting strain localization and allowing the normal faults in the distal margin to root at low angle. Similarly, at slow to ultra-slow spreading ridges, serpentinite is potentially very abundant at the seafloor and locally associated with domal structures. Extensional deformation is localized in a ~ 100 m thick shear zone at the footwall of detachment zones dominated by serpentine derived minerals. Within subduction zone, the depth of decoupling between the mantle wedge and the subducting slab corresponds to the stability depth of serpentine weak mineral. Dehydration of serpentine has also been hypothesized to play an important role in the origin of double seismic zones, however the exact mechanism through which dehydration promotes seismicity remains a matter of debate. During exhumation of high-pressure or ultrahigh-pressure rocks, the opposite trajectories of exhumation and subduction require a decoupling zone within the subducting slab. A serpentinized layer has the potential to become a decoupling zone between the oceanic crust and underlying lithosphere. The buoyancy of serpentinite also likely contributes to eclogite exhumation. Finally, along major strike-slip faults, serpentinites have been associated with fault creep, as well as low fault strength. The presence of serpentinite blocks along creeping segments of active faults worldwide is therefore likely to originate from fluids deriving from the progressive dehydration of the mantle wedge that move such bodies upward.

  3. 78 FR 51802 - Culturally Significant Objects Imported for Exhibition Determinations: “Silla: Korea's Golden...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-21

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE Culturally Significant Objects Imported for Exhibition Determinations: ``Silla: Korea's Golden Kingdom... determine that the objects to be included in the exhibition ``Silla: Korea's Golden Kingdom,'' imported...

  4. Current regional stress field and the resultant crustal deformation in SE Korea and their tectonic implication

    NASA Astrophysics Data System (ADS)

    Kim, M. C.; Cho, H.; Son, M.

    2014-12-01

    To determine current regional stress field and to characterize the resultant crustal deformation in SE Korea, Quaternary fault, focal mechanism, and geotechnical in-situ stress data were synthetically analyzed. The Quaternary faults are extensively observed along major inherited fault zones and show compatible orientations with general trends of the inherited faults. Most of the Quaternary faults have a top-to-the-west thrust geometry and kinematics and show a tendency of upward-decreasing dip angle and upward-narrowing gouge zone. Slip-sense indicators and paleo-stress field reconstructions indicate that the faults resulted from reverse or transpressional faulting under an E-W compression. All the magnetic fabrics (AMS) of the fault gouges also indicate the prevailing reverse-slip faulting under an ENE-WNW compression. The dominant oblate magnetic fabrics parallel to fault plane and the degrees of anisotropy increasing in proportion to their oblatenesses indicate that the fabrics have formed by a progressive deformation due to continuous simple shear during the last reactivation stage as reverse faulting. The focal mechanism study in and around the Korean Peninsula show the horizontally clustered P-axes in ENE-WSW direction and the girdle-distributed T-axes in NNW trend. The geotechnical in-situ stress data in south Korea also show NE- or ENE-trending maximum horizontal stress. The current crustal deformation in Korea thus can be characterized by contractional structures produced under a regional E-W or ENE-WSW compression stress field, and most of the Quaternary faults resulted from the local re-activation of appropriately oriented inherited major faults. Considering the tectonic setting and structural features in Asia during the Neogene, the current stress regime is interpreted to have been caused by the cooperation of westward shallow subduction of Pacific Plate and collision of Indian and Eurasian continents since about 5-3.5 Ma.

  5. Intraplate volcanism influenced by distal subduction tectonics at Jeju Island, Republic of Korea

    NASA Astrophysics Data System (ADS)

    Brenna, Marco; Cronin, Shane J.; Kereszturi, Gábor; Sohn, Young Kwan; Smith, Ian E. M.; Wijbrans, Jan

    2015-01-01

    The drivers behind the inception of, and the variable, pulsatory eruption rates at distributed intraplate volcanic fields are not well understood. Such broad areas of monogenetic volcanism cover vast areas of the world and are often heavily populated. Reliable models to unravel their behaviour require robust spatio-temporal frameworks within the fields, but an analysis of the potential proximal and distal regional volcano-tectonic processes is also needed. Jeju Island (Republic of Korea) is a volcanic field that has been extensively drilled and dated. It is also located near one of the world's best-studied tectonic plate boundaries: the subduction zone in southwestern Japan, which generates the Ryukyu and SW Japan arcs. A new set of 40Ar/39Ar ages collected from cores penetrating the entire Jeju eruptive pile, along with geochemical information, is used to construct a temporal and volumetric model for the volcano's growth. The overall pattern indicates inception of volcanism at ~1.7 Ma, with an initial 1.2 Myr of low-rate activity, followed by over an order of magnitude rise over the last 0.5 Myr. The magma flux at Jeju correlates well with increased extension rates in the arc/backarc region. In particular, we infer that the increased trenchward mantle flow, caused by the greater rollback of the Philippine Sea Plate, activated pre-existing shear weaknesses in the mantle beneath Jeju, resulting in mantle upwelling and decompression melting that caused a change in compositions and an increase in eruption rates at Jeju. Thus, the volcanic activity of an intraplate field system can be modulated by regional subduction processes occurring more than 650 km away. This model may explain the frequent observation of pulsatory behaviour seen in many monogenetic volcanic fields worldwide that lie within 1,000 km of subduction zones.

  6. Tectonic significance of Silurain magmatism in the Canadian Appalachians

    SciTech Connect

    Whalen, J.B.; Bevier, M.L. )

    1990-05-01

    New U-Pb ages for granites from the New Brunswick part of the Canadian Appalachians indicate that >90% of the undeformed felsic plutons are Silurian and not Devonian as previously thought. Silurian igneous and sedimentary assemblages were recently recognized throughout the Canadian Appalachians, although the petrogenetic types of magmas as well as the grades of metamorphism and deformation vary widely. Our data support proposed tectonic models that suggest relatively continuous subduction and orogenic activity in the Canadian Appalachians from Middle Ordovician to Middle Devonian time.

  7. The significance of tectonism in the glaciations of Greece

    NASA Astrophysics Data System (ADS)

    Bathrellos, George; Skilodimou, Hariklia; Maroukian, Habik

    2014-05-01

    In Greece, Middle to Late Pleistocene mountain glaciations appear to have been quite extensive, along the mountain range of Pindus, on Mt. Olympus and in the highlands of Peloponnesus. This study focuses on the Middle to Late Pleistocene glaciations based on the examination of cirque formations and their elevation changes due to vertical tectonism, in certain parts of Greece, namely Pindus, Mt. Olympus and Peloponnesus. An initial spatial database of these glacial forms was created including their location and mean elevation. Some of the glaciated sites have been taken from previous literature and others were recorded from topographic maps, air photos and field work. ArcGIS 10 software was used to process the glaciated sites. A map depicting the glaciated areas of Greek regions was compiled with over 230 cirques. A cirque's top, lip and margins of each location were mapped. So altitudes of apex and lip and mean altitude of each cirque ([apex+lip]/2), were calculated. A total number of 239 inactive cirques was recorded with limestone as the dominant lithology. As one moves to the south, in the case of Pindus range and its extension in the Peloponnesus, the number of cirques decreases. These glacial forms occur at altitudes varying from 2,770 to 1,600 m.a.s.l. Thus the preservation of ice for longer periods of time is more likely at altitudes higher than 1,600 m.a.s.l. Concerning the distribution of the mean elevations of cirques one should take into consideration the tectonic activity of the study area. Especially in the Pindus range, Mount Olympus, and Peloponnesus this process is in the form of uplift. This has increased the mean elevation of the cirques in every following ice age. So, in older times many cirques were a few hundred meters lower than the more recent glacial period.

  8. Devonian brachiopods of southwesternmost laurentia: Biogeographic affinities and tectonic significance

    USGS Publications Warehouse

    Boucot, A.J.; Poole, F.G.; Amaya-Martinez, R.; Harris, A.G.; Sandberg, C.A.; Page, W.R.

    2008-01-01

    Three brachiopod faunas discussed herein record different depositional and tectonic settings along the southwestern margin of Laurentia (North America) during Devonian time. Depositional settings include inner continental shelf (Cerros de Los Murcielagos), medial continental shelf (Rancho Placeritos), and offshelf continental rise (Rancho Los Chinos). Ages of Devonian brachiopod faunas include middle Early (Pragian) at Rancho Placeritos in west-central Sonora, late Middle (Givetian) at Cerros de Los Murcielagos in northwestern Sonora, and late Late (Famennian) at Rancho Los Chinos in central Sonora. The brachiopods of these three faunas, as well as the gastropod Orecopia, are easily recognized in outcrop and thus are useful for local and regional correlations. Pragian brachiopods dominated by Acrospirifer and Meristella in the "San Miguel Formation" at Rancho Placeritos represent the widespread Appohimchi Subprovince of eastern and southern Laurentia. Conodonts of the early to middle Pragian sulcatus to kindlei Zones associated with the brachiopods confirm the ages indicated by the brachiopod fauna and provide additional information on the depositional setting of the Devonian strata. Biostratigraphic distribution of the Appohimchi brachiopod fauna indicates continuous Early Devonian shelf deposition along the entire southern margin of Laurentia. The largely emergent southwest-trending Transcontinental arch apparently formed a barrier preventing migration and mixing of many genera and species of brachiopods from the southern shelf of Laurentia in northern Mexico to the western shelf (Cordilleran mio-geocline) in the western United States. Middle Devonian Stringocephalus brachiopods and Late Devonian Orecopia gastropods in the "Los Murcielagos Formation" in northwest Sonora represent the southwest-ernmost occurrence of these genera in North America and date the host rocks as Givetian and Frasnian, respectively. Rhynchonelloid brachiopods (Dzieduszyckia sonora) and

  9. Characteristics of the Cenozoic crustal deformations in SE Korea and its vicinity due to major tectonic events

    NASA Astrophysics Data System (ADS)

    Son, M.; Kim, J.; Song, C.; Sohn, Y.; Kim, I.

    2010-12-01

    The southeastern Korean Peninsula has experienced multiple crustal deformations according to changes of global tectonic setting during the Cenozoic. Characteristics of the crustal deformations in relation to major Cenozoic tectonic events are summarized as follows. (1) Collision of Indian and Eurasian continents and abrupt change of movement direction of the Pacific plate (50 ~ 43 Ma): The collision of Indian and Eurasian continents caused the eastward extrusion of East Asia block as a trench-rollback, and then the movement direction of the Pacific plate was abruptly changed from NNW to WNW. As a result, the strong suction-force along the plate boundary produced a tensional stress field trending EW or WNW-ESE in southeastern Korea, which resultantly induced the passive intrusion of NS or NNE trending mafic dike swarm pervasively. (2) Opening of the East Sea (25 ~ 16 Ma): The NS or NNW-SSE trending opening of the East Sea generated a dextral shear stress regime trending NNW-SSE along the eastern coast line of the Korean Peninsula. As a result, pull-apart basins were developed in right bending and overstepping parts along major dextral strike slip faults trending NNW-SSE in southeastern Korea. The basins can be divided into two types on the basis of geometry and kinematics: Parallelogram-shaped basin (rhombochasm) and wedged-shaped basin (sphenochasm), respectively. At that time, the basins and adjacent basement blocks experienced clockwise rotation and northwestward tilting, and the eastward propagating rifting also occurred. At about 17 Ma, the Yeonil Tectonic Line, which is the westernmost border fault of the Miocene crustal deformation in southeastern Korea, began to move as a major dextral strike slip fault. (3) Clockwise rotation of southeastern Japan Island (16~15 Ma): The collision of the Izu-Bonin Arc and southeastern Japan Island, as a result of northward movement of the Philippine sea-plate, induced the clockwise rotation of southeastern Japan Islands. The

  10. Tectonic significance of serpentinite from ocean to subduction (Invited)

    NASA Astrophysics Data System (ADS)

    Guillot, S.

    2013-12-01

    At plate boundaries, where deformation is localized along centimeter- to kilometer-scale shear zones, the influence of serpentinite on tectonic processes is linked to its unique rheological properties. Geophysical profiles at the Ocean-Continent Transition (OCT) indicate that the serpentinized mantle is about 5 km thick. Serpentinization weakens the upper mantle layer, promoting strain localization and allowing the normal faults in the distal margin of the OCT to root at low angle. The ongoing extension leads to buoyant flow of partially serpentinized mantle along low-angle detachment faults, leading to the horizontal stretching of the subcontinental mantle at the seafloor. At slow spreading ridges, 20 to 25% of the seafloor is composed of serpentinite associated with domal structures. Extensional deformation is localized in a ~100 to 200 m thick shear zone at the footwall of the detachment zone. Within the detachment fault, the mineralogy is complex; including talc, amphibole, and chorite indicating the addition of silica, calcium, and aluminum to serpentinites from hydrothermal fluids. Large-scale continental strike-slip faults can either slip by aseismic creep or move abruptly during earthquakes. Weak fault behavior can be caused by high fluid pressures, locally high geothermal gradients, or the presence of weak materials such as serpentinite. Along The San Andreas Fault (SAF), serpentinites have been associated with fault creep, as well as low fault strength. The SAFOD project (San Andreas Fault Observatory at Depth) intersects the Great Valley Formation at 3 km depth. Microstructural observations from core samples show evidence of deformation across the damaged zone. The deforming zones contain serpentinite clasts, talc and highly sheared siltstones dispersed in a matrix of saponite (Mg-rich smectite clay), which is one of the weakest phyllosilicates. Within subduction zone, decoupling between the mantle wedge and the subducting slab is inferred from modeling

  11. Shallow hydraulic fracturing measurements in Korea support tectonic and seismic indicators of regional stress.

    SciTech Connect

    Haimson, Bezalel Cecil; Lee, Moo Yul; Song, I.

    2003-07-01

    We have conducted five hydraulic fracturing stress measurement campaigns in Korea, involving 13 test holes ranging in depth from 30 to 250 m, at locations from North Seoul to the southern coast of the peninsula. The measurements reveal consistent crustal stress magnitudes and directions that suggest persistence throughout western and southern Korea. The maximum horizontal stress {sigma}{sub H} is oriented between ENE-WSW and E-W, in accord with plate movement and deformation, and with directions indicated by both focal mechanism solutions from earthquakes inland and offshore as well as borehole breakouts in mainland China close to its eastern coast. With respect to magnitudes, the vertical stress is the overall minimum stress at all tested locations, suggesting a thrust faulting regime within the relatively shallow depths reached by our tests. Typically, such a stress regime becomes one favoring strike-slip at greater depths, as is also indicated by the focal mechanism solutions around Korea.

  12. Ancient wells and their geoarchaeological significance in detecting tectonics of the Israel Mediterranean coastline region

    NASA Astrophysics Data System (ADS)

    Nir, Yaacov; Eldar, Iris

    1987-01-01

    Eight ancient water wells, representing the late Bronze Age to the Crusades period (ca. 3100 700 B.P.), have recently been excavated (six by the authors) and reopened at archaeological sites (tels) along the southern and central Mediterranean coast of Israel. Evidence of ancient freshwater levels directly reflects on possible neotectonics of the region and on eustatic changes of sea level. There is substantial disagreement about the tectonic stability of the Israel Mediterranean coastal region during the past 3500 yr, whether there was a large-magnitude tectonic event (one of the largest known for recent times) during the period in discussion or whether the region was tectonically quiet. We tested the instability hypothesis by using geoarchaeological data from the wells and found no evidence for significant tectonic deformation of the central and southern Israel coast in the past 3100 yr. The “ancient water-well” method can, with appropriate modifications, be used all around the Mediterranean and other coasts elsewhere in the world where ground-water-sea-level relations are alike. Now in the digging of wells we must not disdain reflection, but must devote much acuteness and skill to the consideration of the natural principles of things. Vitruvius Pollio, Architectura, Book VIII, Chapter VI (25 B.C.)

  13. Source process and tectonic implication of the January 20, 2007 Odaesan earthquake, South Korea

    NASA Astrophysics Data System (ADS)

    Abdel-Fattah, Ali K.; Kim, K. Y.; Fnais, M. S.; Al-Amri, A. M.

    2014-04-01

    The source process for the 20th of January 2007, Mw 4.5 Odaesan earthquake in South Korea is investigated in the low- and high-frequency bands, using velocity and acceleration waveform data recorded by the Korea Meteorological Administration Seismographic Network at distances less than 70 km from the epicenter. Synthetic Green functions are adopted for the low-frequency band of 0.1-0.3 Hz by using the wave-number integration technique and the one dimensional velocity model beneath the epicentral area. An iterative technique was performed by a grid search across the strike, dip, rake, and focal depth of rupture nucleation parameters to find the best-fit double-couple mechanism. To resolve the nodal plane ambiguity, the spatiotemporal slip distribution on the fault surface was recovered using a non-negative least-square algorithm for each set of the grid-searched parameters. The focal depth of 10 km was determined through the grid search for depths in the range of 6-14 km. The best-fit double-couple mechanism obtained from the finite-source model indicates a vertical strike-slip faulting mechanism. The NW faulting plane gives comparatively smaller root-mean-squares (RMS) error than its auxiliary plane. Slip pattern event provides simple source process due to the effect of Low-frequency that acted as a point source model. Three empirical Green functions are adopted to investigate the source process in the high-frequency band. A set of slip models was recovered on both nodal planes of the focal mechanism with various rupture velocities in the range of 2.0-4.0 km/s. Although there is a small difference between the RMS errors produced by the two orthogonal nodal planes, the SW dipping plane gives a smaller RMS error than its auxiliary plane. The slip distribution is relatively assessable by the oblique pattern recovered around the hypocenter in the high-frequency analysis; indicating a complex rupture scenario for such moderate-sized earthquake, similar to those reported

  14. Volcanic activity before and after large tectonic earthquakes: Observations and statistical significance

    NASA Astrophysics Data System (ADS)

    Eggert, Silke; Walter, Thomas R.

    2009-06-01

    The study of volcanic triggering and interaction with the tectonic surroundings has received special attention in recent years, using both direct field observations and historical descriptions of eruptions and earthquake activity. Repeated reports of clustered eruptions and earthquakes may imply that interaction is important in some subregions. However, the subregions likely to suffer such clusters have not been systematically identified, and the processes responsible for the observed interaction remain unclear. We first review previous works about the clustered occurrence of eruptions and earthquakes, and describe selected events. We further elaborate available databases and confirm a statistically significant relationship between volcanic eruptions and earthquakes on the global scale. Moreover, our study implies that closed volcanic systems in particular tend to be activated in association with a tectonic earthquake trigger. We then perform a statistical study at the subregional level, showing that certain subregions are especially predisposed to concurrent eruption-earthquake sequences, whereas such clustering is statistically less significant in other subregions. Based on this study, we argue that individual and selected observations may bias the perceptible weight of coupling. The activity at volcanoes located in the predisposed subregions (e.g., Japan, Indonesia, Melanesia), however, often unexpectedly changes in association with either an imminent or a past earthquake.

  15. Structural analysis and evolution of the Hadong-Sancheong-Hwagae area in the Yeongnam massif, Korea: a NS-trend tectonic frame in the Korean Peninsula

    NASA Astrophysics Data System (ADS)

    Deok-Seon, Lee; Ji-Hoon, Kang

    2016-04-01

    The Hadong-Sancheong-Hwagae area in the Jirisan province of the Yeongnam massif, Korea, is mainly composed of Precambrian Hadong anorthosite complex (HAC), Precambrian Jirisan metamorphic rock complex (JMRC), Jurassic˜Triassic granitoids which intrude them, and Cretaceous sedimentary rocks which unconformably cover them. Lithofacies distribution and tectonic frame of the Precambrian constituent rocks mainly show a NS trend, unlike a general NE trend of those in the Korean Peninsula. To unravel the geological structures associated with the NS-trend tectonic frame which was built in the HAC and JMRC, we researched the structural characteristics of each deformation phase based on the geometric and kinematic features and the forming sequence of rock structures of the multi-deformed HAC and JMRC. The results indicate that the pre-Late Paleozoic geological structures of this area were formed at least through the following three times of ductile deformation phases. The D1 deformation happened due to the large-scale top-to-the SE shearing, and formed sheath or A-type folds and a regional NE trend of tectonic frame in the HAC and JMRC. The D2 deformation occurred under the EW-directed tectonic compression, and formed a regional NS trend of active and passive folds and Hadong ductile shear zone over 2.3˜1.4 km width, and transposed most of D1 tectonic frame into D1-2 composite tectonic frame. The extensive Hadong shear zone, which was formed in the mylonitization process accompanying the passive folding, was persistently developed along the eastern boundary of HAC and JMRC which corresponds to a limb of passive fold on a geological map scale. It produced a very strong mylonitic structure and stretching lineation. The NE-trend D1 structural elements were mainly reoriented into NS trend by the powerful active and passive folding. The D3 deformation occurred under the NS-trend tectonic compression environment, and formed EW-trend kink or open folds, and partially rearranged

  16. Backarc mafic-ultramafic magmatism in Northeastern Vietnam and its regional tectonic significance

    NASA Astrophysics Data System (ADS)

    Thanh, Ngo Xuan; Hai, Tran Thanh; Hoang, Nguyen; Lan, Vu Quang; Kwon, Sanghoon; Itaya, Tetsumaru; Santosh, M.

    2014-08-01

    The geology of Northern Vietnam offers critical clues on the convergence history between the South China and Indochina blocks. We constrain the tectonic evolution of the South China and Indochina blocks using geochemical, mineral chemical and geochronological data collected from mafic-ultramafic rocks exposed in the Cao Bang area, Northeastern Vietnam. These rocks show significant enrichment in large ionic lithophile elements (LILEs) such as Cs, Rb, Ba, Th, U, and Pb and depletion in high field strength elements (HFSEs) such as Nb, Ta, Zr, and Ti showing [Nb/La]N between 0.28-0.41, [La/Yb]N = 3.94-10.00 and Zr/Y = 2.0-4.4. These geochemical features as well as the petrology and mineral chemistry of the Cao Bang mafic-ultramafic magmas are comparable to those of magmatic complexes formed in a back-arc environment. The basalts yield Rb-Sr whole rock ages of 263 ± 15 Ma, that are consistent with the zircon U-Pb and K-Ar ages reported in previous studies from the same area. The spatial and temporal distribution of the arc magmas within the Indochina block and along the southern margin of the South China block suggest that the Permo-Triassic mafic-ultramafic magmas formed during a tectonic event that is different from the subduction and collision event between the Indochina and South China blocks.

  17. An extraordinary palaeontinid from the Triassic of Korea and its significance

    NASA Astrophysics Data System (ADS)

    Nam, Kye Soo; Wang, Ying; Ren, Dong; Kim, Jong Heon; Szwedo, Jacek

    2017-01-01

    A new, extraordinary palaeontinid Hallakkungis amisanus Nam, Wang & Szwedo, gen. et sp. nov., from the Upper Triassic of the Amisan Formation in Boryeong City, Korea is described. It is the first Palaeontinidae from Korea. The newly described taxon displays a mosaic of characters present in presumed ancestors of this insect family and some highly advanced features.

  18. An extraordinary palaeontinid from the Triassic of Korea and its significance

    PubMed Central

    Nam, Kye Soo; Wang, Ying; Ren, Dong; Kim, Jong Heon; Szwedo, Jacek

    2017-01-01

    A new, extraordinary palaeontinid Hallakkungis amisanus Nam, Wang & Szwedo, gen. et sp. nov., from the Upper Triassic of the Amisan Formation in Boryeong City, Korea is described. It is the first Palaeontinidae from Korea. The newly described taxon displays a mosaic of characters present in presumed ancestors of this insect family and some highly advanced features. PMID:28098190

  19. An extraordinary palaeontinid from the Triassic of Korea and its significance.

    PubMed

    Nam, Kye Soo; Wang, Ying; Ren, Dong; Kim, Jong Heon; Szwedo, Jacek

    2017-01-18

    A new, extraordinary palaeontinid Hallakkungis amisanus Nam, Wang &Szwedo, gen. et sp. nov., from the Upper Triassic of the Amisan Formation in Boryeong City, Korea is described. It is the first Palaeontinidae from Korea. The newly described taxon displays a mosaic of characters present in presumed ancestors of this insect family and some highly advanced features.

  20. Emergence of the significant local warming of Korea in CMIP5 projections

    NASA Astrophysics Data System (ADS)

    Boo, Kyung-On; Shim, Sungbo; Kim, Jee-Eun

    2016-04-01

    According to IPCC AR5, anthropogenic influence on warming is obvious in local scales, especially in some tropical regions. Detection of significant local warming is important for adaptation to climate change of society and ecosystem. Recently much attention has focused on the time of emergence (ToE) for the signal of anthropogenic climate change against the natural climate variability. Motivated from the previous studies, this study analyzes ToE of regional surface air temperature over Korea. Simulations of CMIP5 15 models are used for RCP 2.6, 4.5 and 8.5. For each year, JJA and DJF temperature anomalies are calculated for the time period 1900-1929. For noise of interannual variability, natural-only historical simulations of CMIP5 12 models are used and the standard deviation of the time series is obtained. For signal of warming, we examine the year when the signal above 2 standard deviations is detected in 80% of the models using 30-year smoothed time series. According to our results, interannual variability is larger in land than ocean. Seasonally, it is larger in winter than in summer. Accordingly, ToE of summertime temperature is earlier than that in winter and is expected to appear in 2030s from three RCPs. The seasonal difference is consistent with previous studies. Wintertime ToE appears in 2040s for RCP85 and 2060s for RCP4.5. The different emergence time between RCP8.5 and RCP4.5 reflects the influence of mitigation. In a similar way, daily maximum and minimum temperatures are analyzed. ToE of Tmin appears earlier than that of Tmax and difference is small. Acknowledgements. This study is supported by the National Institute of Meteorological Sciences, Korea Meteorological Administration (NIMR-2012-B-2).

  1. Convergence of tectonic reconstructions and mantle convection models for significant fluctuations in seafloor spreading

    NASA Astrophysics Data System (ADS)

    Coltice, N.; Seton, M.; Rolf, T.; Müller, R. D.; Tackley, P. J.

    2013-12-01

    For 50 years of data collection and kinematic reconstruction efforts, plate models have provided alternative scenarios for plate motions and seafloor spreading for the past 200 My. However, these efforts are naturally limited by the incomplete preservation of very old seafloor, and therefore the time-dependence of the production of new seafloor is controversial. There is no consensus on how much it has varied in the past 200 My, and how it could have fluctuated over longer timescales. We explore how seafloor spreading and continental drift evolve over long geological periods using independently derived models: a recently developed geodynamic modelling approach and state-of-the-art plate reconstructions. Both kinematic reconstructions and geodynamic models converge on variations by a factor of 2 in the rate of production of new seafloor over a Wilson cycle, with concomitant changes of the shape of the area-age distribution of the seafloor between end members of rectangular, triangular and skewed distributions. Convection models show that significant fluctuations over longer periods (∼1 Gy) should exist, involving changes in ridge length and global tectonic reorganisations. Although independent, both convection models and kinematic reconstructions suggest that changes in ridge length are at least as significant as spreading rate fluctuations in driving changes in the seafloor area-age distribution through time.

  2. Significant Centers of Tectonic Activity as Identified by Wrinkle Ridges for the Western Hemisphere of Mars

    NASA Technical Reports Server (NTRS)

    Anderson, R.C.; Haldemann, A. F. C.; Golombek, M. P.; Franklin, B. J.; Dohm, J. M.; Lias, J.

    2000-01-01

    The western hemisphere region of Mars has been the site of numerous scientific investigations regarding its tectonic evolution. For this region of Mars, the dominant tectonic region is the Tharsis province. Tharsis is characterized by an enormous system of radiating grabens and a circumferential system of wrinkle ridges. Past investigations of grabens associated with Tharsis have identified specific centers of tectonic activity. A recent structural analysis of the western hemisphere region of Mars which includes the Tharsis region, utilized 25,000 structures to determine the history of local and regional centers of tectonic activity based primarily on the spatial and temporal relationships of extensional features. This investigation revealed that Tharsis is more structurally complex (heterogeneous) than has been previously identified: it consists of numerous regional and local centers of tectonic activity (some are more dominant and/or more long lived than others). Here we use the same approach as Anderson et al. to determine whether the centers of tectonic activity that formed the extensional features also contributed to wrinkle ridge (compressional) formation.

  3. Paleoseismological research on Langshan Range Front Fault and its tectonics significance

    NASA Astrophysics Data System (ADS)

    Dong, S.; Zhang, P.; Yu, Z.; Lei, Q.

    2012-12-01

    The ~400-km-long, ~90-km-wide Ordos Block, the very famous loess plateau in China, east to Luliang Ranges, west to Zhuozi Shan, Yunwu Shan, south to Weibei hill area, north to the side of Yellow River,is the most stable and completed sub tectonic element in Sino-Korean Platform. Since Ordos Block locates between world-famous collision-related extrusion tectonics in Tibet and subduction-induced back-arc tectonics along the western Pacific, now it's still being effected by these two tectonics zones. The present and Cenozoic activity of Ordos Block and the peripheral tectonic zones plays the key role in understanding the dynamics mechanism, evolution process of, and the effect between these two tectonics zones of Cenozoic age and now. The ~160-km-long Lang Shan Range Front Fault in the northwest corner of the Hetao Basin is a very important basin-controlling striking NNE active fault, and plays key role in understanding the dynamics mechanism and earthquake risk of Hetao Basin, which is northern boundary zone of Ordos Block. We excavated several trenches across the fault, in which three trenches, Dongshen Village Trench, Qingshanbei Trench, and Wulanhushao Trench, we distinguished three, two and three paleoevents respectively, according to OSL and charcoal dating samples. We also obtain the fault slip rate combining detail topographic survey at the trenches' area and previous researchers' study. Based on field scratch on fault plane and the latest geomorphological evidence, almost no lateral slip amount was discovered, which is different from current viewpoint on the fault with left lateral slip amount. This is very helpful to analyse geodynamical balance of Hetao Basin in such complicated geodynamical environment. This paper displays how the geodynamic system works now combining previous scientists' conclusion.

  4. Post-depositional tectonic modification of VMS deposits in Iberia and its economic significance

    NASA Astrophysics Data System (ADS)

    Castroviejo, Ricardo; Quesada, Cecilio; Soler, Miguel

    2011-07-01

    The original stratigraphic relationships and structure of VMS deposits are commonly obscured by deformation. This can also affect their economic significance, as shown by several Iberian Pyrite Belt (IPB, SW Iberia) examples. The contrasting rheologic properties of the different lithologies present in an orebody (massive sulphide, feeder stockwork, alteration envelope, volcanic and sedimentary rocks) play a major role in determining its overall behaviour. Variscan thin-skinned tectonics led to stacking of the massive pyrite and stockwork bodies in duplex structures, resulting in local thickening and increased tonnage of minable mineralization. Furthermore, differential mechanical behaviour of the different sulphide minerals localised the detachments along relatively ductile sulphide-rich bands. The result was a geochemical and mineralogical reorganisation of most deposits, which now consist of barren, massive pyrite horses, bounded by base metal-rich ductile shear zones. Metal redistribution was enhanced by mobilisation of the base metal sulphides from the initially impoverished massive pyrite, through pressure-solution processes, to tensional fissures within the already ductile shear zones. In NW Iberia, VMS deposits were also strongly overprinted by the Variscan deformation during emplacement of the Cabo Ortegal and Órdenes allochthonous nappe complexes, but no stacking of the orebodies was produced. Original contacts were transposed, and the orebodies, their feeder zones and the country rock acquired pronounced laminar geometry. In lower-grade rocks (greenschist facies, Cabo Ortegal Complex), solution transfer mechanisms are common in pyrite, which remains in the brittle domain, while chalcopyrite shows ductile behaviour. In higher-grade rocks (amphibolite facies, Órdenes Complex), metamorphic recrystallisation overprints earlier deformation textures. The contrasting behaviour of the IPB and NW Iberian deposits is explained by key factors that affect their

  5. Volcanic activity before and after large tectonic earthquakes: Observations and statistical significance

    NASA Astrophysics Data System (ADS)

    Eggert, S.; Walter, T. R.

    2009-04-01

    The study of volcanic triggering and coupling to the tectonic surroundings has received special attention in recent years, using both direct field observations and historical descriptions of eruptions and earthquake activity. Repeated reports of volcano-earthquake interactions in, e.g., Europe and Japan, may imply that clustered occurrence is important in some regions. However, the regions likely to suffer clustered eruption-earthquake activity have not been systematically identified, and the processes responsible for the observed interaction are debated. We first review previous works about the correlation of volcanic eruptions and earthquakes, and describe selected local clustered events. Following an overview of previous statistical studies, we further elaborate the databases of correlated eruptions and earthquakes from a global perspective. Since we can confirm a relationship between volcanic eruptions and earthquakes on the global scale, we then perform a statistical study on the regional level, showing that time and distance between events follow a linear relationship. In the time before an earthquake, a period of volcanic silence often occurs, whereas in the time after, an increase in volcanic activity is evident. Our statistical tests imply that certain regions are especially predisposed to concurrent eruption-earthquake pairs, e.g., Japan, whereas such pairing is statistically less significant in other regions, such as Europe. Based on this study, we argue that individual and selected observations may bias the perceptible weight of coupling. Volcanoes located in the predisposed regions (e.g., Japan, Indonesia, Melanesia), however, indeed often have unexpectedly changed in association with either an imminent or a past earthquake.

  6. Relocation of earthquakes at southwestern Indian Ocean Ridge and its tectonic significance

    NASA Astrophysics Data System (ADS)

    Luo, W.; Zhao, M.; Haridhi, H.; Lee, C. S.; Qiu, X.; Zhang, J.

    2015-12-01

    The southwest Indian Ridge (SWIR) is a typical ultra-slow spreading ridge (Dick et al., 2003) and further plate boundary where the earthquakes often occurred. Due to the lack of the seismic stations in SWIR, positioning of earthquakes and micro-earthquakes is not accurate. The Ocean Bottom Seismometers (OBS) seismic experiment was carried out for the first time in the SWIR 49 ° 39 'E from Jan. to March, 2010 (Zhao et al., 2013). These deployed OBS also recorded the earthquakes' waveforms during the experiment. Two earthquakes occurred respectively in Feb. 7 and Feb. 9, 2010 with the same magnitude of 4.4 mb. These two earthquakes were relocated using the software HYPOSAT based on the spectrum analysis and band-pass (3-5 Hz) filtering and picking up the travel-times of Pn and Sn. Results of hypocentral determinations show that there location error is decreased significantly by joined OBS's recording data. This study do not only provide the experiences for the next step deploying long-term wide-band OBSs, but also deepen understanding of the structure of SWIR and clarify the nature of plate tectonic motivation. This research was granted by the Natural Science Foundation of China (41176053, 91028002, 91428204). Keywords: southwest Indian Ridge (SWIR), relocation of earthquakes, Ocean Bottom Seismometers (OBS), HYPOSAT References:[1] Dick, H. J. B., Lin J., Schouten H. 2003. An ultraslow-spreading class of ocean ridge. Nature, 426(6965): 405-412. [2] Zhao M. H., et al. 2013. Three-dimensional seismic structure of the Dragon Flag oceanic core complex at the ultraslow spreading Southwest Indian Ridge (49°39' E). Geochemistry Geophysics Geosystems, 14(10): 4544-4563.

  7. International Tectonic Map of the Circumpolar Arctic and its Significance for Geodynamic Interpretations

    NASA Astrophysics Data System (ADS)

    Petrov, O. V.; Morozov, A.; Shokalsky, S.; Leonov, Y.; Grikurov, G.; Poselov, V.; Pospelov, I.; Kashubin, S.

    2011-12-01

    In 2003 geological surveys of circum-arctic states initiated the international project "Atlas of Geological Maps of Circumpolar Arctic at 1:5 000000 scale". The project received active support of the UNESCO Commission for the Geological Map of the World (CGMW) and engaged a number of scientists from national academies of sciences and universities. Magnetic and gravity maps were prepared and printed by the Norwegian Geological Survey, and geological map was produced by the Geological Survey of Canada. Completion of these maps made possible compilation of a new Tectonic Map of the Arctic (TeMAr), and this work is now in progress with Russian Geological Research Institute (VSEGEI) in the lead of joint international activities. The map area (north of 60o N) includes three distinct roughly concentric zones. The outer onshore rim is composed of predominantly mature continental crust whose structure and history are illustrated on the map by the age of consolidation of craton basements and orogenic belts. The zone of offshore shelf basins is unique in dimensions with respect to other continental margins of the world. Its deep structure can in most cases be positively related to thinning and rifting of consolidated crust, sometimes to the extent of disruption of its upper layer, whereas the pre-rift evolution can be inferred from geophysical data and extrapolation of geological evidence from the mainland and island archipelagoes. The central Arctic core is occupied by abyssal deeps and intervening bathymetric highs. The Eurasia basin is commonly recognized as a typical oceanic opening separating the Barents-Kara and Lomonosov Ridge passive margins, but geodynamic evolution of Amerasia basin are subject to much controversy, despite significant intensification of earth science researchin the recent years. A growing support to the concept of predominance in the Amerasia basin of continental crust, particularly in the area concealed under High Arctic Large Igneous Province, is

  8. Deformation of the overriding slab during incipient subduction in centrifuge modeling and its tectonic significance

    NASA Astrophysics Data System (ADS)

    Mart, Yossi; Goren, Liran; Koyi, Hemin

    2015-04-01

    Analog models of subduction-related structural deformation emphasize the significance of differences in density and friction between the adjacent plates on the distortion of the overriding slab and its possible effect on the subduction procedure. Centrifuge experiments juxtaposed miniaturized lighter and denser lithospheres, which were floating on denser but less viscous asthenosphere. The lithosphere in the tests comprised brittle and ductile strata, which showed diversified styles of deformation, while factors of equivocal tectonic significance, such as lateral push or negative buoyancy, were not introduced into the experiments. The tests show that the juxtaposition of lighter and denser lithospheres would suffice to drive the denser lithosphere as a wedge between the asthenosphere and the lighter lithosphere, and that the rate of the process would depend on the rate of friction between the slabs, as well as on differential viscosity. It seems that the reduced friction in Nature was derived from the generation of serpentinites, which could be the main agent of lubrication. The underthrusting of the denser lithosphere leads to the uplift and collapse of the edge of the lighter slab, where extension, thinning, normal faulting and rifting took place, and diapiric ascent of parts of the ductile layer of the lighter slab occurred along several rifts. The analog experiments were carried out only to the stage where the denser slab was thrust under the lighter one, but the penetration of the lithosphere into the asthenosphere was not achieved. It seems plausible therefore, that only after eclogitization, and the upward motion of serpentinites, increased the density of the underthrust slab, would it dive and penetrate into the asthenosphere. The experiments indicate the plausibility of the constraints imposed on the subduction process by the deformation of the overthrust slab. The normal faults and rifts in the overthrust block could serve as conduits for the ascent of

  9. Tectonic state: its significance and characterization in the assessment of seismic effects associated with reservoir impounding

    USGS Publications Warehouse

    Castle, R.O.; Clark, M.M.; Grantz, A.; Savage, J.C.

    1980-01-01

    Any analysis of seismicity associated with the filling of large reservoirs requires an evaluation of the natural tectonic state in order to determine whether impoundment is the basic source, a mechanically unrelated companion feature, or a triggering stimulus of the observed seismicity. Several arguments indicate that the associated seismicity is usually a triggered effect. Among the elements of tectonic state considered here (existing fractures, accumulated elastic strain, and deformational style), deformational style is especially critical in forecasting the occurrence of impoundment-induced seismicity. The observational evidence indicates that seismicity associated with impounding generally occurs in areas that combine steeply dipping faults, relatively high strain rates, and either extensional or horizontal-shear strain. Simple physical arguments suggest: (1) that increased fluid pressures resulting from increased reservoir head should enhance the likelihood of seismic activity, whatever the tectonic environment; (2) that stress changes resulting from surface loading may increase the likelihood of crustal failure in areas of normal and transcurrent faulting, whereas they generally inhibit failure in areas of thrust faulting. Comparisons with other earthquake-producing artificial and natural processes (underground explosions, fluid injection, underground mining, fluid extraction, volcanic emissions) indicate that reservoir loading may similarly modify the natural tectonic state. Subsurface loading resulting from fluid extraction may be a particularly close analogue of reservoir loading; "seismotectonic" events associated with fluid extraction have been recognized in both seismically active and otherwise aseismic regions. Because the historic record of seismicity and surface faulting commonly is short in comparison with recurrence intervals of earthquake and fault-slip events, tectonic state is most reliably appraised through combined studies of historic

  10. Petrogenetic and tectonic significance of xenocrystic Precambrian zircon in Lower Cambrian tonalite, eastern Klamath Mountains, California

    SciTech Connect

    Wallin, E.T. )

    1990-11-01

    U-Pb analyses of zircon from a Lower Cambrian tonalite in the Yreka terrane, Klamath Mountains, California, reveal an inherited Precambrian zircon component within rocks that have generally been believed to be part of the ophiolitic Trinity complex. The isotopic data indicate that Lower Cambrian plutonic rocks in the eastern Klamath Mountains are probably not ophiolitic in origin. These Lower Cambrian rocks may be either tectonic blocks within a lower Paleozoic accretionary complex or part of a disrupted Lower Cambrian volcanoplutonic terrane.

  11. Tectonic significance of Neoproterozoic magmatism of Nakora area, Malani igneous suite, Western Rajasthan, India

    NASA Astrophysics Data System (ADS)

    Kumar, Naresh; Vallinayagam, G.

    2014-05-01

    Three magmatic phases are distinguished in the Neoproterozoic Nakora Ring Complex (NRC) of Malani Igneous Suite (MIS), namely (a) Extrusive (b) Intrusive and (c) Dyke phase. Magmatism at NRC initiated with minor amount of (basic) basalt flows and followed by the extensive/voluminous acid (rhyolites-trachytes) flows. The ripple marks are observed at the Dadawari area of NRC in tuffaceous rhyolite flow which suggests the aqueous condition of flows deposition. The emplacement of the magma appears to have been controlled by a well defined NE-SW tectonic lineament and cut by radial pattern of dykes. These NE-SW tectonic lineaments are the linear zones of crustal weakness and high heat flow. The spheroidal and rapakivi structures in the Nakora acid volcanics indicate the relationship between genetic link and magma mixing. Basalt-trachyte-rhyolite association suggests that the large amount of heat is supplied to the crust from the magma chamber before the eruption. The field (elliptical/ring structures), mineralogical and geochemical characteristics of Nakora granites attest an alkaline character in their evolution and consistent with within plate tectonic setting. The emplacement of these granites and associated volcanics is controlled by ring structures, a manifestation of plume activity and cauldron subsidence, an evidence of extensional tectonic environment. NRC granites are the product of partial melting of rocks similar to banded gneiss from Kolar Schist Belt of India. The present investigations suggest that the magmatic suites of NRC rocks are derived from a crustal source and the required heat supplied from a mantle plume.

  12. Hemorrhagic Fever with Renal Syndrome (HFRS) and Infectious Diseases of Military Significance in Korea

    DTIC Science & Technology

    1993-06-21

    were conducted throughout Korea to better characterize the distribu- tion of militarily important human infections. Antibodies to hantaviruses were...of antibodies to hantaviruses , rickettsiae, and hepatitis viruses’. Surveys were carried out in the rural areas surrounding Chorwon near the "Iron...20 yrs). The prevalence of antibodies to hantaviruses was 6.2" overall (Q30 yrs = 14.6%). Scrub typhus antibodies were present in 5% of individuals

  13. Distribution and erosion of the Paleozoic tectonic unconformities in the Tarim Basin, Northwest China: Significance for the evolution of paleo-uplifts and tectonic geography during deformation

    NASA Astrophysics Data System (ADS)

    Lin, Changsong; Yang, Haijun; Liu, Jingyan; Rui, Zhifeng; Cai, Zhenzhong; Zhu, Yongfeng

    2012-03-01

    The distribution and erosional features of the Paleozoic major tectonic unconformities in the Tarim Basin, and their genetic relation to the development of paleo-uplifts as well as the evolution of geodynamic settings, are documented in this paper based on the integral analysis of seismic, drilling, and outcrop data. During the Paleozoic, the Tarim Basin underwent three major tectonic deformation stages, which resulted in three angular unconformities and in significant changes in basin geomorphology and paleogeography. The tectonic deformation at the end of the Middle Ordovician was characterized by development of the southern central paleo-uplift, the northern depression, and the southeastern Tangguzibasi depression in the basin. The thickest denudation belts of the unconformity (Tg5-2) are distributed mainly along the thrust structural highs. A stronger deformation event took place at the end of the Late Ordovician and formed a huge uplift along the southwestern and southeastern basin margins and the western part of the Tabei uplift along the northern basin margin, producing an extensive angular unconformity (Tg5) with maximum erosion thickness of 1500-2000 m. This tectonic event resulted in an abrupt change in overall geography of the basin, from a deepwater marine environment at the late stages of the Late Ordovician to a littoral and neritic basin in the Early Silurian. The deformation that occurred at the end of the Middle Devonian was the strongest in the Paleozoic. It generated the most widespread angular unconformity (Tg3) within the basin and led to extensive erosion, with maximum denudation thickness of 3000-5000 m in the northern and northeastern parts of the basin. The topography of the basin during the late Devonian was characterized by a high in the northeast and a low in the southwest, forming an embayment basin opening to the southwest during the Early Devonian to Carboniferous. The transgression in general from southwest to northeast deposited

  14. Public health significance of major genotypes of Salmonella enterica serovar Enteritidis present in both human and chicken isolates in Korea.

    PubMed

    Kang, Min-Su; Oh, Jae-Young; Kwon, Yong-Kuk; Lee, Deog-Yong; Jeong, Ok-Mi; Choi, Byung-Kook; Youn, So-Youn; Jeon, Byung-Woo; Lee, Hye-Jin; Lee, Hee-Soo

    2017-02-17

    Salmonella enterica serovar Enteritidis is one of the most common serotypes implicated in Salmonella infections in both humans and poultry worldwide. It has been reported that human salmonellosis is mainly associated with the consumption of poultry products contaminated with serovar Enteritidis. The present study was to extensively analyze the public health risk of serovar Enteritidis isolates from chickens in Korea. A total of 127 chicken isolates were collected from clinical cases, on-farm feces, and chicken meat between 1998 and 2012 and 20 human clinical isolates were obtained from patients with diarrhea between 2000 and 2006 in Korea. To characterize the isolates from chickens and humans, we compared the pulsed-field gel electrophoresis (PFGE) patterns and multilocus variable-number tandem-repeat analysis (MLVA) profiles of the isolates. We further characterized representative isolates of different genotypes using a DNA microarray. PFGE revealed 28 patterns and MLVA identified 16 allelic profiles. The DNA microarray showed high genetic variability in plasmid regions and other fimbrial subunits of the isolates although the virulence gene contents of isolates from the same source and/or of the same genotype were unrelated. PFGE and MLVA showed that major genotypes were present in both human and chicken isolates. This result suggests that chickens in Korea pose a significant risk to public health as a source of serovar Enteritidis as has been noted in other countries.

  15. Detrital modes of the Pyeongan Supergroup (Late Carboniferous Early Triassic) sandstones in the Samcheog coalfield, Korea: implications for provenance and tectonic setting

    NASA Astrophysics Data System (ADS)

    Lee, Yong Il; Sheen, Dong-Hee

    1998-08-01

    Medium to coarse sandstones of the Carboniferous to Early Triassic Pyeongan Supergroup in the Samcheog coalfield, Korea, were studied to infer the provenance and tectonic settings of the source areas. Sandstone detrital modes change upwards stratigraphically. Sandstone types from the Manhang to Dosagog formations low to middle in the sequence are quartzarenite, and sublitharenite to litharenite, whereas sandstones of the Gohan and Donggo formations high in the sequence are feldspathic litharenite and arkose, respectively. Using various ternary diagrams, the provenance of the Manhang to Gohan formations is suggested to be a recycled orogen setting. Some Gohan Formation sandstones plot within the arc-related setting field, and the Donggo Formation sandstones plot within both continental block and recycled orogen fields. Results of quartz grain petrography are consistent with those of detrital modes. Quartz in sandstones of all units except the Donggo Formation indicates derivation from low-rank metamorphic sources. Quartz in Donggo sandstones was derived from medium- to high-rank metamorphic and plutonic source rocks. Considering the sandstone composition and palaeocurrent data, the Pyeongan Supergroup probably was deposited in a molasse foreland basin and was derived from a synbasinal orogenic belt, probably the Akiyoshi orogen located in southwest Japan.

  16. Rare earth element patterns in Archean high-grade metasediments and their tectonic significance

    NASA Technical Reports Server (NTRS)

    Taylor, Stuart Ross; Rudnick, Roberta L.; Mclennan, Scott M.; Eriksson, Kenneth A.

    1986-01-01

    REE data on metasedimentary rocks from two different types of high-grade Archean terrains are presented and analyzed. The value of REEs as indicators of crustal evolution is explained; the three geologic settings (in North America, Southern Africa, and Australia) from which the samples were obtained are described; and the data are presented in extensive tables and graphs and discussed in terms of metamorphic effects, the role of accessory phases, provenance, and tectonic implications (recycling, the previous extent of high-grade terrains, and a model of Archean crustal growth). The diversity of REE patterns in shallow-shelf metasediments is attributed to local provenance, while the Eu-depleted post-Archean patterns are associated with K-rich plutons from small, stable early Archean terrains.

  17. Detrital zircon U-Pb geochronology and tectonic implications of the Paleozoic sequences in western South Korea

    NASA Astrophysics Data System (ADS)

    Kim, Sung Won; Kwon, Sanghoon; Santosh, M.; Cho, D. L.; Ryu, In-Chang

    2014-12-01

    The Middle Paleozoic metasedimentary sequences of the western Gyeonggi Massif (Taean Formation and Wolhyeonri Complex), Imjingang Belt, and southwestern Okcheon Belt, provide clues to the successive tectonic events that occurred during the evolution of the Korean Peninsula. In this study, we present SHRIMP U-Pb ages of detrital zircon grains from the metasandstones of the Taean Formation and Yeoncheon Group of the Imjingang Belt and from quartzites in three Paleozoic formations of the southwestern Okcheon Belt. The zircon grains from all of the samples yielded similar U-Pb age spectra of Paleoarchean/Neoarchean to Middle Paleozoic, with a dominant age population within the Paleozoic. The maximum ages of deposition estimated from the youngest dominant concordant detrital zircons were 431-457 Ma for the western Gyeonggi Massif and Imjingang Belt, and 380-355 Ma for the southwestern Okcheon Belt. Permian metamorphic zircon overgrowths correlated with subduction prior to the Triassic collision were also found. Middle Paleozoic metamorphic zircon overgrowths that can be compared to those of the Yunkai-Wuishan Orogenic Belt of the Cathaysia Block were indentified in the Wolhyeonri Complex. The dominant zircon populations of this study and the available data for the Korean Peninsula compare well with those from the Yangtze Block, Cathaysia Block, and Qilian-Qinling Orogenic Belt, which were located at the northeastern margin of eastern Gondwana during the Early Paleozoic.

  18. Nature of ophiolite occurrences along the eastern margin of the Indian plate and their tectonic significance

    NASA Astrophysics Data System (ADS)

    Sengupta, S.; Ray, K. K.; Acharyya, S. K.; de Smeth, J. B.

    1990-05-01

    Upper Mesozoic to lower Eocene ophiolitic rocks occur in two parallel belts along the eastern margin of the Indian plate. The eastern belt passes through central Burma, Sumatra, and Java, and coincides with a zone of gravity highs resulting from steeply dipping mafic rocks. It denotes the locus of the subduction where these ophiolites were accreted just prior to middle Eocene time. In contrast, the western belt, which passes through Nagaland, Manipur, western Burma, and Andaman, is flanked to the east by a negative gravity anomaly zone. In it the ophiolites occur as rootless, subhorizontal bodies, tectonically overlying Eocene-Oligocene flysch sedimentary rocks. They are inferred to be nappes that propagated westward from the eastern belt during late Oligocene terminal collision of the Indian and Eurasian continental blocks. Ophiolite occurrences in Andaman and Mentawai islands belonging to the western belt are generally linked with active subduction west of the island arc. This subduction began only in late Miocene time, and thus it could not have produced the ophiolites, which had been emplaced on land much earlier.

  19. Density structure of the lithosphere in the southwestern United States and its tectonic significance

    USGS Publications Warehouse

    Kaban, M.K.; Mooney, W.D.

    2001-01-01

    We calculate a density model of the lithosphere of the southwestern United States through an integrated analysis of gravity, seismic refraction, drill hole, and geological data. Deviations from the average upper mantle density are as much as ?? 3%. A comparison with tomographic images of seismic velocities indicates that a substantial part (>50%) of these density variations is due to changes in composition rather than temperature. Pronounced mass deficits are found in the upper mantle under the Basin and Range Province and the northern part of the California Coast Ranges and adjacent ocean. The density structure of the northern and central/southern Sierra Nevada is remarkably different. The central/southern part is anomalous and is characterized by a relatively light crust underlain by a higher-density upper mantle that may be associated with a cold, stalled subducted plate. High densities are also determined within the uppermost mantle beneath the central Transverse Ranges and adjoining continental slope. The average density of the crystalline crust under the Great Valley and western Sierra Nevada is estimated to be up to 200 kg m~3 higher than the regional average, consistent with tectonic models for the obduction of oceanic crust and uppermost mantle in this region.

  20. The Cerro Aguas Calientes caldera, NW Argentina: An example of a tectonically controlled, polygenetic collapse caldera, and its regional significance

    NASA Astrophysics Data System (ADS)

    Petrinovic, I. A.; Martí, J.; Aguirre-Díaz, G. J.; Guzmán, S.; Geyer, A.; Paz, N. Salado

    2010-07-01

    Polygenetic, silicic collapse calderas are common in the central Andes. Here we describe in detail the Cerro Aguas Calientes caldera in NW Argentina, which comprises two caldera-forming episodes that occurred at 17.15 Ma and 10.3 Ma. We analyse the significance of its structural setting, composition, size and the subsidence style of both caldera episodes. We find that the caldera eruptions had a tectonic trigger. In both cases, an homogeneous dacitic crystal-rich (>60 vol.% of crystals) reservoir of batholithic size became unstable due to the effect of increasing regional transpression, which favoured local dilation through minor strike-slip faults from which ring faults nucleated and permitted caldera collapse. Both calderas are similar in shape, location and products. The 17.15 Ma caldera has an elliptical shape (17 × 14 km) elongated in a N30° trend; both intracaldera and extracaldera ignimbrites covered an area of around 620 km 2 with a minimum volume estimate of 140 km 3 (DRE). The 10.3 Ma episode generated another elliptical caldera (19 × 14 km), with the same orientation as the previous one, from which intracaldera and outflow ignimbrites covered a total area of about 1700 km 2, representing a minimum eruption volume of 350 km 3(DRE). In this paper we discuss the significance of the Cerro Aguas Calientes caldera in comparison with other well known examples from the central Andes in terms of tectonic setting, eruption mechanisms, and volumes of related ignimbrites. We suggest that our kinematic model is a common volcano-tectonic scenario during the Cenozoic in the Puna and Altiplano, which may be applied to explain the origin of other large calderas in the same region.

  1. The Cerro Aguas Calientes caldera, NW Argentina: an example of a tectonically controlled, polygenetic, collapse caldera, and its regional significance

    NASA Astrophysics Data System (ADS)

    Petrinovic, Ivan A.; Martí, Joan; Aguirre-Diaz, Gerardo J.; Guzmán, Silvina R.; Geyer, Adelina; Grosse, Pablo; Salado Paz, Natalia

    2010-05-01

    Polygenetic, silicic collapse calderas such as Cerro Galán, Pastos Grandes, La Pacana, Vilama, Negra Muerta, Farallón Negro, Cerro Guacha, among others are common in the central Andes. Here we describe in detail the Cerro Aguas Calientes caldera in NW Argentina, which comprises two caldera-forming episodes occurred at 17.15 Ma and 10.3 Ma, respectively. We analyse the significance of its structural setting, composition, size and the subsidence style of both caldera episodes. Our results reveal that the caldera eruptions had a tectonic trigger. In both cases, an homogeneous dacitic crystal-rich (>60 vol. % of crystals) reservoir of batholitic size became unstable due to the effect of increasing regional transpression, favouring local dilation throughout minor strike slip faults from which ring faults nucleated and permitted caldera collapse. Both episodes are similar in shape, location and products of the resulting calderas. The 17.15 Ma caldera has an elliptical shape (17 × 14 km) and is elongated in a N30° trend; both intracaldera and extracaldera ignimbrites covered an area of around 620 km2 with a minimum volume estimate of 138 km3 (DRE). The 10.3 Ma episode generated another elliptical caldera (19 ×14 km), with the same orientation as the previous one, from which intracaldera and outflow ignimbrites covered a total area of about 1,700 km2, representing a minimum eruption volume of 341 km3 (DRE). In this work we discuss the significance of the Cerro Aguas Calientes caldera in comparison with other well known examples from the central Andes in terms of tectonic setting, eruption mechanisms, and volumes of related ignimbrites. We suggest that our kinematic model is a common volcano-tectonic scenario during the Cenozoic in the Puna and Altiplano, which may be applied to explain the origin of other large calderas in the same region.

  2. Structural geology and tectonic significance of foreland thrust belts, Tarim and Junggar basins, northwest China

    SciTech Connect

    McKnight, C.L.; Chu, J.; Corroll, A.R.; Hendrix, M.S.; Wang, X.; Graham, S.A.; Liang, Y.H.; Wang, Z.X.; Xiao, X.

    1989-03-01

    The Kalpin uplift, located on the northwestern margin of the Tarim basin is characterized by a series of thin, southeast-vergent thrust plates modified by strike-slip faults. Each thrust plate repeats a sedimentary sequence consisting of upper Proterozoic through Permian shallow marine to nonmarine carbonates and clastics. Tertiary rocks as young as Neogene are affected by the deformation. The most basinward thrust sheet abuts the Bachu uplift, an older structural feature trending almost perpendicular to the thrusts. Sedimentary rocks as old as late Proterozoic are exposed in the Bachu uplift, which apparently represents a west-vergent Late Silurian to Early Devonian thrust belt. An unconformable Silurian-Devonian contact, the presence of Devonian red beds, and another unconformable contact separating Devonian from Upper Carboniferous strata support the interpretation of a middle Paleozoic deformational event. Another unconformity, at the Carboniferous-Permian boundary, apparently coincides with the time of collision of the Tarim craton with the southern margin of central Asia. The Shihezi fold trend, located in the southern Junggar basin, consists of three lines of surface anticlines trending parallel to the axis of the Urumqi foredeep. A thick sequence of Mesozoic and Cenozoic nonmarine sedimentary rocks accumulated in the growing foredeep. Mesozoic and Paleogene strata are deformed in the southern foldbelt, with Jurassic rocks forming the cores of these thrusted anticlines. The Qigu oil field is located in this southern belt. Deformed Neogene and Quaternary strata are exposed in the thrusted anticlines of the middle and northern foldbelts. The Dushanzi oil field is located in the northern belt. The episodic development of compressional structures in northwestern China documents the accretion of a number of tectonic units to the growing southern margin of central Asia through time.

  3. Growth faults and salt tectonics in Houston diapir province: relative timing and exploration significance

    SciTech Connect

    Ewing, T.E.

    1983-09-01

    Oil and gas accumulation in Gulf Coast Tertiary strata is contolled mainly by regional growth faults and by salt-related structures. Salt forms the most prominent set of structures in the Houston diapir province of southeast Texas. Recent work in three study areas shows that the Tertiary growth-fault trends, so well displayed along strike to the south-west, continue through this salt basin as well, but they have been deformed by later salt movement. In the Katy area, seismic data disclose early (pre-Wilcox) salt pillows downdip of the Cretaceous reef trend. Salt stocks were injected upward from the pillows during Clayborne deposition, and were flanked by deep withdrawal basins and turtle structures. In Brazoria County, a major lower Frio growth-fault trend affecting the Houston delta system, was deformed by later salt domes, by a salt-withdrawal basin, and by a possible turtle structure at Chocolate Bayou. A productive geopressured aquifer exists in the salt-withdrawal basin bounded by the previously formed growth faults. In Jefferson County, in contrast, salt-tectonic activity and growth faulting appear to have been coeval. Early salt-cored ridges continued to rise throughout Frio deposition; growth faults occur both updip and downdip. Hydrocarbons accumulated over the salt domes in growth-fault anticlines and in stratigraphic traps. Recognition that shelf-margin growth faulting preceded the development of the present pattern of domes and basins has important implications for hydrocarbon exploration. Growth faults may be migration paths for hydrocarbons; furthermore, early formed traps, distorted by salt movement, may still be found to contain hydrocarbons.

  4. Tectonic significance of bimodal volcanism in the Archean Michipicoten greenstone belt, Ontario

    SciTech Connect

    Sylvester, P.J.

    1985-01-01

    In the lower volcanic cycle (2750 Ma old) of the Michipicoten greenstone belt, Ontario, a basal mafic unit (MV1) consisting mainly of basalt-basaltic andesite (49.4-56.4 wt.% SiO/sub 2/, 8.77-12.36 wt.% FeO/sub t/) with enriched ((La/Sm)/sub n/=1.9-2.6, Th=2.0-4.1 ppm, Sr=310-570 ppm) and depleted ((La/Sm)/sub n/=0.55-1.07, Th=0.16-0.71 ppm, Sr<250 ppm) trace element characteristics is locally overlain by a felsic unit (FV1) dominated volumetrically by rhyolite (71.9-79.6 wt.% SiO/sub 2/) and subordinate dacite (62.2-68.8 wt.% SiO/sub 2/). The mafic rocks are pillowed, massive flows and hyaloclastites suggesting subaqueous emplacement, whereas the felsic rocks are dominantly subaerial to shallow subaqueous pyroclastic deposits. The basalts of MV1 are similar chemically to modern tholeiites formed in primitive island arc/marginal basin complexes. In contrast, the rhyolites and dacites of FV1 exhibit the calc-alkaline chemical characteristics and rock associations typical of some continental inner arc volcanics. The juxtaposition of primitive island arc/marginal basin and continental inner arc tectonic settings occurs at the present time in the Tonga-Kermadec-New Zealand island arc. According to this model, MV1 is analogous to the basalt/basaltic andesite-dominated volcanism of the Tonga-kermadec island arc/Lau back-arc basin, whereas FV1 is the equivalent of the voluminous rhyolitic ignimbrites of the Taupo inner arc basin. The model suggests that the lower volcanic cycle of the Michipicoten belt formed on a basement consisting of small blocks of continental crust surrounded by oceanic crust.

  5. Early to Middle Ordovician back-arc basin in the southern Appalachian Blue Ridge: characteristics, extent, and tectonic significance

    USGS Publications Warehouse

    Tull, James; Holm-Denoma, Christopher S.; Barineau, Clinton I.

    2014-01-01

    Fault-dismembered segments of a distinctive, extensive, highly allochthonous, and tectonically significant Ordovician (ca. 480–460 Ma) basin, which contains suites of bimodal metavolcanic rocks, associated base metal deposits, and thick immature deep-water (turbiditic) metasediments, occur in parts of the southern Appalachian Talladega belt, eastern Blue Ridge, and Inner Piedmont of Alabama, Georgia, and North and South Carolina. The basin's predominantly metasedimentary strata display geochemical and isotopic evidence of a mixed provenance, including an adjacent active volcanic arc and a provenance of mica (clay)-rich sedimentary and felsic plutonic rocks consistent with Laurentian (Grenvillian) upper-crustal continental rocks and their passive-margin cover sequences. Geochemical characteristics of the subordinate intercalated bimodal metavolcanic rocks indicate formation in a suprasubduction environment, most likely a back-arc basin, whereas characteristics of metasedimentary units suggest deposition above Neoproterozoic rift and outer-margin lower Paleozoic slope and rise sediments within a marginal basin along Ordovician Laurentia's Iapetus margin. This tectonic setting indicates that southernmost Appalachian Ordovician orogenesis (Taconic orogeny) began as an extensional accretionary orogen along the outer margin of Laurentia, rather than in an exotic (non-Laurentian) arc collisional setting. B-type subduction polarity requires that the associated arc-trench system formed southeast of the palinspastic position of the back-arc basin. This scenario can explain several unique features of the southern Appalachian Taconic orogen, including: the palinspastic geographic ordering of key tectonic elements (i.e., back-arc, arc, etc.), and a lack of (1) an obducted arc sensu stricto on the Laurentian margin, (2) widespread Ordovician regional metamorphism, and (3) Taconic klippen to supply detritus to the Taconic foreland basin.

  6. Peralkaline granitoid magmatism in the Mongolian-Transbaikalian Belt: Evolution, petrogenesis and tectonic significance

    NASA Astrophysics Data System (ADS)

    Jahn, B. M.; Litvinovsky, B. A.; Zanvilevich, A. N.; Reichow, M.

    2009-12-01

    The Central Asian Orogenic Belt (CAOB) is well-known for its massive generation of juvenile crust in the Phanerozoic. In eastern CAOB, voluminous peralkaline and alkaline (alkali-feldspar) granitoids and genetically related bimodal volcanics were emplaced in three stages from Early Permian to late Mesozoic: 295-270 Ma, 230-190 Ma and 150-120 Ma. They occur as huge granitoid belts in extensional tectonic settings and form a complex network of about 12 million km 2 in area. Among them the 2500 km-long Mongolian-Transbaikalian Belt (MTB) is the most spectacular and it comprises more than 350 granite-syenite plutons and stocks, with numerous co-genetic volcanic fields. The three stages of granitoids have similar chemical compositions but show temporal variation in Nd isotopic composition. Initial ɛNd( T) values range from - 1 to - 5 for the Early Permian, 0 to + 4 for the early Mesozoic, and - 2 to - 3.5 for the late Mesozoic granitoids. The negative ɛNd( T) values observed in the MTB are not typical of the CAOB granitoids, which are generally characterized by positive values. However, several pieces of evidence suggest that the MTB peralkaline and alkali feldspar granitoids were produced from enriched mantle-derived sources. The evidence includes: (1) Felsic and mafic rocks formed in the same stage have similar initial Nd-Sr isotopic ratios and Sm-Nd model ages ( TDM). (2) The granitoid belts extend over thousands of kilometers and intersect distinct crustal provinces, but no correlation is found in chemical compositions between the granitoids and country rocks. (3) The abundant syenites are considered to be cogenetic or, in some cases, parental to the granites. Experimental and isotope data argue for the derivation of syenites from an enriched mantle source, thus the granites (and comendites) are regarded as mantle-derived. (4) A study of melt inclusions in quartz phenocrysts of comendite indicates a high liquidus temperature of 1000-1100 °C for the magma

  7. Age and tectonic significance of volcanic rocks in the northern Los Angeles Basin, California

    USGS Publications Warehouse

    McCulloh, Thane H.; Fleck, Robert J.; Denison, Rodger E.; Beyer, Larry A.; Stanley, Richard G.

    2002-01-01

    Volcanic rocks, mostly basalts and some andesites, are interbedded with middle Miocene strata and are overlain by younger rocks throughout the greater part of the Los Angeles Basin, California. Roughly correlative flows, previously dated radiometrically (or paleontologically) at about 16.4 to 10.7 Ma, crop out in five separate regions around the basin perimeter. Los Angeles Basin volcanic rocks have special meaning because they offer clues to tectonomagmatic events associated with onset of clockwise transrotation of the western Transverse Ranges region and to the timing and locus of the initial basin opening. Whole-rock 40Ar/39Ar dating of near-tholeiitic olivine basalts of the Topanga Formation (Hoots, 1931) from three sites in the easternmost Santa Monica Mountains, combined with 87Sr/86Sr dating of fossil carbonates from interstratified marine beds at nine sites, establish a new age of 17.4 Ma for these oldest known Topanga-age volcanics of the Los Angeles Basin. We also record three new 40Ar/39Ar ages (15.3 Ma) from andesitic flows of the lower Glendora Volcanics at the northeast edge of the basin, 70 km east of the Santa Monica Mountains. A whole-rock determination of 17.2±0.5 Ma for nearby altered olivine basalt in the unfossiliferous Glendora volcanic sequence is questionable because of a complex 40Ar/39Ar age spectrum suggestive of 39Ar recoil, but it may indicate an older volcanic unit in this eastern area. We hypothesize that the 17.4-Ma volcanics in the eastern Santa Monica Mountains are an early expression of deep crustal magmatism accompanying the earliest extensional tectonism associated with rifting. The extremely thick younger volcanic pile in the western and central parts of the range may suggest that this early igneous activity in the eastern area was premonitory. Paleomagnetic declination data are needed to determine the pre-transrotational orientation of the eastern Santa Monica Mountains volcanic sequence. The new age determinations do not

  8. Clinical Significance of Component Allergens in Fagales Pollen-Sensitized Peanut Allergy in Korea

    PubMed Central

    Park, Kyung Hee; Son, Young Woong; Lee, Sang Chul; Jeong, Kyunguk; Sim, Da Woon; Park, Hye Jung; Lee, Sooyoung; Lee, Jae-Hyun

    2016-01-01

    Purpose Clinical features of peanut allergy can range from localized to systemic reactions. Because peanut and birch pollen have cross-reactivity, peanut can lead to localized allergic reaction in Fagales pollen-sensitized oral allergy syndrome (OAS) patients without peanut sensitization per se. The purpose of this study was to discriminate true peanut food allergy from cross-reactive hypersensitivity in birch-sensitized peanut allergy. Methods Birch-sensitized (n=81) and peanut anaphylaxis patients (n=12) were enrolled. Peanut-related allergic reactions and sensitization profiles were examined. Specific IgE to Fagales tree pollens (birch, oak), peanut, and their component allergens (Bet v 1, Bet v 2, Ara h 1, Ara h 2, Ara h 3, Ara h 8, and Ara h 9) were evaluated. Based on these specific IgEs and clinical features, the patients were classified into 4 groups: group 1 (Fagales pollen allergy without OAS), group 2 (Fagales pollen allergy with OAS), group 3 (OAS with peanut anaphylaxis), and group 4 (peanut anaphylaxis). Results After peanut consumption, one-third of OAS patients experienced oral symptoms not associated with peanut sensitization. Ara h 1 or Ara h 2 was positive in peanut anaphylaxis patients, whereas Ara h 8 was positive in OAS patients. There were 4 patients with both peanut anaphylaxis and OAS (group 3). Both Ara h 2 and Ara h 8 were positive in these patients. Foods associated with OAS in Korea showed unique patterns compared to Westernized countries. Conclusions Ara h 2 and Ara h 8 may be important component allergens for discriminating peanut allergy. PMID:27582401

  9. Stratigraphy, geochemistry and tectonic significance of the Oligocene magmatic rocks of western Oaxaca, southern Mexico

    USGS Publications Warehouse

    Martiny, B.; Martinez-Serrano, R. G.; Moran-Zenteno, D. J.; MacIas-Romo, C.; Ayuso, R.A.

    2000-01-01

    the volcanic rocks, from 0.7042 to 0.7046 and 0 +2.6. The range of these isotope ratios and those reported for the basement rocks in this region suggest a relatively low degree of old crustal involvement for most of the studied rocks. The Pb isotopic compositions of the Tertiary magmatic rocks also show a narrow range [(206Pb/204Pb) = 18.67-18.75; (207Pb/204Pb) = 15.59-15.62; (208Pb/204Pb) = 38.44-38.59], suggesting a similar source region for the volcanic and plutonic rocks. Trace elements and isotopic compositions suggest a mantle source in the subcontinental lithosphere that has been enriched by a subduction component. General tectonic features in this region indicate a more active rate of transtensional deformation for the inland volcanic region than along the coastal margin during the main events of Oligocene magmatism. The lower degree of differentiation of the inland volcanic sequences, particularly the upper unit of the northern sector, compared to the plutons of the coastal margin, suggests that the differentiation of the Tertiary magmas in southern Mexico was controlled to a great extent by the characteristics of the different strain domains. (C) 2000 Elsevier Science B.V. All rights reserved.

  10. Comparison of evolution and tectonic significance of the Pindos and Vourinos ophiolite suites, northern Greece

    NASA Astrophysics Data System (ADS)

    Ross, John V.; Zimmerman, Jay

    1996-05-01

    The Pindos ophiolite, located on the western edge of the Sub-Pelagonian (Othris) zone, comprises a complex series of westward-verging thrust sheets dominantly composed of peridotite tectonite, phaneritic mafic and leucocratic rocks, and pillow lavas. Harzburgite tectonites from part of the east-central thrust sheet (Dramala Complex) show three well developed foliations. The oldest, compositional layering (S 0), has been isoclinally folded, and preferred orientations of elongate grains and aggregates of olivine and orthopyroxene parallel to the axial surfaces of the isoclines define the second foliation (S 1). Spinel lineations parallel fold axes of the isoclinal folds. Thermometric calculations from mineral compositions and grain sizes of olivines and pyroxenes associated with the oldest preserved foliations (compositional layering, S 0 = S 1) indicate that rocks of the tectonite suite equilibrated at depths of between 45 and 60 km, at temperatures between 1210°C and 925°C and at differential stresses from 5 to 10 MPa. In general, rocks indicative of higher temperatures of equilibration formed at lower values of differential stress. The third, and youngest, foliation is defined by bands of fine-grained olivine and pyroxene mylonite that cut across older structural elements. Mylonites equilibrated at temperatures between 650°C and 710°C, presumably indicative of shallower depths (30-20 km) than the older foliations, accompanied by differential stresses ranging from 200 to 300 MPa, and probably formed during obduction of the complex. The sense and orientation of shear determined from kinematic indicators within the mylonitic zones indicate an updip displacement vector inclined at an angle of 20° to 40° toward 016°, suggesting obduction to the east-northeast relative to the present position of the Pindos ophiolite. There is no direct evidence for the amount of rotation about a vertical axis that may have occurred during obduction or later tectonic transport

  11. Paragenesis and tectonic significance of base and precious metal occurrences along the San Andreas fault at Point Delgada, California.

    USGS Publications Warehouse

    McLaughlin, R.J.; Sorg, D.H.; Morton, J.L.; Theodore, T.G.; Meyer, C.E.; Delevaux, M.H.

    1985-01-01

    The mineralogy, geochemistry and origin of sulphide veins along cross faults in the San Andreas fault system are described and cited for a natural history of local plate tectonics and for 'a detailed understanding of the role of major strike-slip faults in the formation and tectonic translation of hydrothermal ore deposits'. -G.J.N.

  12. Geochonology and Tectonic Significance of post-collisional porphyry in Qulong area, southeast segment of the Gangdese belt, Tibet, China

    NASA Astrophysics Data System (ADS)

    Liu, D.; Zeren, Z.; Du, C.; Feng, L.; Nima, C.; Zhang, L.

    2012-12-01

    With the collision of Indian plate and Eura-Asian plate, there developed complicated tectono-magmanism during Meso-Cenozoic in Gangdese belt, Xizang Tibet. Therefore, it resulted that plentiful tectonism and post-collision high-K calc-alkaline magmatism related to mineralization distrubted from east to west in the belt. And this is quite significant for us to do some rearch on large-scale metallogenetics, uplifting epoch and EW-striking extension during the post-collision in Xizang-Qinghai Plateau. Zircon samples from Cangrila Granodiorite-porphyry in Qulong area, Southeast of Gangdese porphyry copper belt, Xiangbeishan diorite-porphyrite and from Jiama Granite-porphyry give LA-ICPMS U-Pb ages of 16.3Ma, 14. 4Ma, and 15.4Ma, respectively, and all these ages represent the porphyries' forming ages. From barren Xiangbeishan diorite-porphyrite through intermediately mineralized Jiama Granite-porphyry to stongly mineralized Cangrila Granodiorite-porphyry, the LA-ICPMS U-Pb ages of zircon become younger and younger. According to the regional data and geochemical characteristics, these porphyries were mainly derived directly from the thickened mafic lower-crust formed in south Tibet during collision and epeirogeny. During post-collisional extension stage, for inter-earth thermal flowing, SN-striking normal faulting systems across the Tibetan orogen caused rapid rising and localization of porphyry magmas and adequately separating of massive ore-bearing fluids from the magmatic hydrothermal systems. All these data indicate that Gandese belt has experienced from post-collisional extrusion changed into intra-plate extension since Miocene. During Miocene, Gangdese belt undergone violent intraplate extension, post-collisional porphyry intrusion and paroxysmal massive mineralization of porphyry-type, and all these was controlled by deep dynamics. Key Words: Qulong area; Gangdese tectonic belt; Tibet;Zircon La-ICP-MS U-Pb dating; intra-plate extension; Image Information For CL

  13. Tectonic and climatic significance of a late Eocene low-relief, high-level geomorphic surface, Colorado

    NASA Technical Reports Server (NTRS)

    Gregory, Kathryn M.; Chase, Clement G

    1994-01-01

    New paleobotanical data suggest that in the late Eocene the erosion surface which capped the Front Range, Colorado was 2.2-2.3 km in elevation, which is similar to the 2.5-km present elevation of surface remnants. This estimated elevation casts doubt on the conventional belief that the low-relief geomorphic surface was formed by lateral planation of streams to a base level not much higher than sea level and that the present deeply incised canyons must represent Neogene uplift of Colorado. Description of the surface, calculations of sediment volume, and isostatic balance and fluvial landsculpting models demonstrate that while the high elevation of the erosion surface was due to tectonic forces, its smoothness was mostly a result of climatic factors. A sediment balance calculated for the Front Range suggests that from 2 to 4 km of material were eroded by the late Eocene, consistent with fission track ages. This amount of erosion would remove a significant portionof the 7 km of Laramide upper crustal thickening. Isostatic modeling implies that the 2.2-3.3 km elevation was most likely created by lower crustal thickening during the Laramide. A numerical model of fluvial erosion and deposition suggests a way that a late Eocene surface could have formed at this high elevation without incision. A humid climate with a preponderance of small storm events will diffusively smooth topography and is a possible mechanism for formation oflow-relief, high-level surfaces. Paleoclimate models suggest a lack of large strom events in the late Eocene because of cool sea surface temperatures in the equatorial region. Return to a drier but stormier climate post-Eocene could have caused the incision of the surface by young canyons. By this interpretation, regional erosion surfaces may represent regional climatic rather than tectonic conditions.

  14. Provenance and U-Pb geochronology of the Upper Cretaceous El Chanate Group, northwest Sonora, Mexico, and its tectonic significance

    USGS Publications Warehouse

    Jacques-Ayala, C.; Barth, A.P.; Wooden, J.L.; Jacobson, C.E.

    2009-01-01

    The Upper Cretaceous El Chanate Group, northwest Sonora, Mexico, is a 2.8km thick clastic sedimentary sequence deposited in a continental basin closely related to volcanic activity. It consists of three formations: the Pozo Duro (oldest), the Anita, and the Escalante (youngest). Petrographic study, conglomerate pebble counts, and U-Pb geochronology of detrital zircons were performed to determine the source and age of this sequence, and to interpret its tectonic setting. In the sandstones of all three formations, the most abundant grains are those of volcanic composition (Q38F22L 40, Q35F19L46, and Q 31F22L47, respectively). The Pozo Duro Formation includes well-rounded quartz-arenite clast conglomerates, whereas conglomerates of the two upper units have clasts predominantly of andesitic and rhyolitic composition. The most likely source for these sediments was the Jurassic volcanic arc exposed in northern Sonora and southern Arizona. Zircons from five sandstone samples define two main age groups, Proterozoic and Mesozoic. The first ranges mostly from 1000 to 1800Ma, which suggests the influence of a cratonic source. This zircon suite is interpreted to be recycled and derived from the same source area as the quartz-rich sandstone clasts in the basal part of the section. Mesozoic zircons range from Triassic to Late Cretaceous, which confirms the proposed Late Cretaceous age for the sequence, and also corroborates Jurassic felsic source rocks. Another possible source was the Alisitos volcanic arc, exposed along the western margin of the Baja California Peninsula. Of regional significance is the great similarity between the El Chanate Group and the McCoy Mountains Formation of southeastern California and southwestern Arizona. Both are Cretaceous, were deposited in continental environments, and have similar zircon-age patterns. Also, both exhibit intense deformation and locally display penetrative foliation. These features strongly suggest that both units underwent

  15. Spatial variations in isostatic compensation mechanisms of the Ninetyeast Ridge and their tectonic significance

    NASA Astrophysics Data System (ADS)

    Sreejith, K. M.; Krishna, K. S.

    2013-10-01

    Ninetyeast Ridge (NER), one of the longest linear volcanic features on the Earth, offers an excellent opportunity of understanding the isostatic response to the interactions of mantle plume with the migrating mid-ocean ridge. Bathymetry, geoid, and gravity (shipborne and satellite) data along 72 closely spaced transects and 17 overlapping grids on the NER are analyzed and modeled to determine the effective elastic thickness (Te) beneath the entire ridge. The results of 2-D and 3-D flexural modeling of the NER show large spatial variations in Te values ranging from 4 to 35 km, suggesting that the ridge was compensated along its length by different isostatic mechanisms. The southern (south of 22°S latitude) and northern (north of 2°N latitude) parts of the NER have Te values of >10 and >23 km, respectively, revealing that the southern part was emplaced on a lithosphere of intermediate strength possibly on flank of the Indian plate, whereas the northern part was emplaced in an intraplate setting. In contrast, in the central part of the NER (between latitudes 22°S and 2°N), highly variable Te values (4-22 km) are estimated. The scattered Te values in the central NER suggest that this part may have evolved due to the occurrence of frequent ridge jumps caused by the interaction of Kerguelen hot spot with rapid northward migration of the Wharton spreading ridge. Residual Mantle Bouguer Anomaly (RMBA) map of the NER and adjacent basins reveals that the entire length of the NER is associated with a significant negative anomaly up to 200 mGal, indicating the presence of thickened crust or less dense mantle beneath the ridge. 3-D crustal thickness map of the NER, generated by inversion of the RMBA data, shows a thick crust ranging from 15 to 19 km. The present study clearly shows that NER possesses a highly segmented isostatic pattern with the occurrence of subcrustal underplating or subsurface loading.

  16. Significance of serum antibody test for toxocariasis in healthy healthcare examinees with eosinophilia in Seoul and Gyeongsangnam-do, Korea.

    PubMed

    Kim, Hong Seok; Jin, Yan; Choi, Min-Ho; Kim, Jae-Hwan; Lee, Young Ha; Yoon, Cheong Ha; Hwang, Eui-Hyuk; Kang, Hun; Ahn, Sang-Yong; Kim, Gi Jin; Hong, Sung-Tae

    2014-12-01

    There have been numerous reports on the relationship between eosinophilia and toxocariasis. The present study investigated seropositive rates of toxocariasis among healthy people with or without eosinophilia in urban and rural areas, and assessed risk factors for positive antibody test. A total of 610 healthy people, who visited health check-up (Medicheck®, Korea Association of Health Promotion), 310 from Seoul and 300 from Gyeongsangnam-do, were subjected for this study. Their serum samples were tested by ELISA with the crude antigen of Toxocara canis larvae. Cross-reactions with other tissue invading helminth antigens were also investigated. Total antibody positive rate of toxocariasis was 8.7% of the 610 subjects. When the subjects were grouped into 3 by their eosinophil counts, the antibody positive rates significantly differed by the groups; 5.9% (18/306) in the group<350/µL, 10.0% (11/110) in the group 350-500/µL, and 12.4% (24/194) in the group>500/µL (P=0.028). A total of 22 serum samples cross-reacted with other tissue-invading helminth antigens. A questionnaire analysis recognized drinking alcohol and smoking as significant risk factors of toxocariasis. In conclusion, toxocariasis antibody positive rate is correlated with eosinophil counts. It is recommended that healthy subjects with eosinophilia by routine health examination and risk factors undergo Toxocara serology by multiantigen ELISA to investigate etiology.

  17. CHARACTER AND REGIONAL SIGNIFICANCE OF GREAT FALLS TECTONIC ZONE, EAST-CENTRAL IDAHO AND WEST-CENTRAL MONTANA.

    USGS Publications Warehouse

    O'Neill, J. Michael; Lopez, David A.

    1985-01-01

    The Great Falls tectonic zone, here named, is a belt of diverse northeast-trending geologic features that can be traced from the Idaho batholith in the Cordilleran miogeocline, across thrust-belt structures and basement rocks of west-central and southwestern Montana, through cratonic rocks of central Montana, and into southwestern-most Saskatchewan, Canada. Geologic mapping in east-central Idaho and west-central Montana has outlined a continuous zone of high-angle faults and shear zones. Recurrent fault movement in this zone and strong structural control over igneous intrusion suggest a fundamental tectonic feature that has influenced the tectonic development of the Idaho-Montana area from a least middle Proterozoic time to the present. Refs.

  18. Petrogenesis and tectonic significance of the Eocene adakite-like rocks in western Yunnan, southeastern Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Ding, Huixia; Hou, Qingye; Zhang, Zeming

    2016-02-01

    Eocene magmatic rocks are widespread in western Yunnan, southeastern Tibetan Plateau. However, their petrogenesis and tectonic significance remain controversial. In this paper, we report geochemical and geochronological data of adakite-like rocks from the eastern part of western Yunnan. Zircon U-Pb dating reveals that they were emplaced at ca. 35 Ma. A geochemical study shows that these rocks have high SiO2 (68.97-72.44 wt.%), K2O (4.35-5.87 wt.%) and low MgO (0.61-1.16 wt.%), Y (6.65-12.6 ppm) and Yb (0.58-1.02 ppm) contents as well as high Sr/Y (74-228) and La/Yb (59-131) values, belonging to high-K calc-alkaline to shoshonitic adakite-like rocks. These rocks have high (87Sr/86Sr)i (0.70623-0.70653), low εNd(t) (- 4.5 to - 7.5) and slightly low radiogenic Pb isotopic compositions with (206Pb/204Pb)i = 18.042-18.179. Zircons of these rocks show εHf(t) values ranging from - 6.3 to + 1.2 and model ages (TDM2) of 1513-1035 Ma. The geochemical characteristics indicate that the Eocene adakite-like rocks from the eastern part of western Yunnan were derived from the partial melting of Neoproterozoic mafic rocks underplated in the lower crust of the western margin of the Yangtze Plate with input of mantle-derived potassic-ultrapotassic melt. Integration of published geochemical data clearly shows that zircon εHf(t) and whole-rock εNd(t) values of Eocene adakite-like rocks from the whole western Yunnan exhibit a trend of westward increase. We infer that the adakite-like rocks from the western part of western Yunnan were derived from the partial melting of late Paleozoic-Mesozoic mafic rocks formed as the lower crust of a continental magmatic arc during eastward subduction of the Paleo-Tethyan Ocean, and the Eocene magmatic rocks in western Yunnan were generated during the removal of thickened continental lithosphere triggered by the India and Asia collision.

  19. Tectonic significance of large-scale chaotic deposits in a Cretaceous fore-arc basin: Valle Formation, Cedros Island (Mexico)

    SciTech Connect

    Smith, D.P.; Busby-Spera, C.J. )

    1990-05-01

    A mappable, deep-marine slide deposit (olistostrome) within medial-Cretaceous fore-arc basin strata (Valle Formation), located on Cedros Island, Baja California Norte, records the initiation of intrabasinal faulting. Studies of both modern and ancient olistostromes show that olistostromes can form in all physiographic provinces (including shelf and abyssal plain) and tectonic settings of the marine environment. A variety of triggering mechanisms have been suggested for olistostromes, including tectonism, sea level changes, diapirism, rapid sedimentation that overloads steep slopes, migration of gas hydrates, or combinations of the above. The olistostrome in the Valle Formation ranges in thickness from 0 to at least 180 m, and extends areally for at least 34 km{sup 2}. It can be divided into two parts. The basal 30-40 m contains large (up to 8 m) angular blocks (allolistoliths) derived from the Jurassic substrate. The allolistoliths decrease in abundance upsection, whereas internally coherent intraformational slide blocks (endolistoliths), which reach tens of meters in width, increase. Beds composing the endolistoliths are alternating mudstone and sandstone turbidites that were deposited on a tectonically stable basin plain or rise setting before catastrophic failure of the sedimentary pile produced the olistostrome. Intrabasinal faulting is invoked as a cause of the sediment failure because of the presence of allolistoliths, which must have been shed into the basin from uplifted( ) basin floor scarps. Allolistoliths occur sporadically throughout at least 400 m of coarse-clastic sediment gravity-flow deposits that cap the olistostrome, suggesting that intrabasinal faulting continued to affect the basin long after the olistrostrome formed.

  20. Tectonic and flexural significance of Middle Devonian graben-fill sequence in new Albany shale, central Kentucky

    SciTech Connect

    Barnett, S.F.; Ettensohn, F.R.; Mellon, C. )

    1989-08-01

    The third tectonic phase of the Acadian orogeny began in the late Middle Devonian, and the sedimentary record of that event is largely restricted to the deeper, more proximal portions of the Appalachian foreland and Illinois intercratonic basins. Much of the intervening area, on and near the Cincinnati arch, was uplifted and subjected to erosion by movement on the peripheral bulge accompanying the initiation of the third tectonic phase. However, bulge movement also reactivated basement fault systems in Kentucky and created a series of grabens that were filled with eroded sediments and debris flows from adjacent horsts. Although rarely preserved, a buried Devonian graben along Carpenter Fork in Boyle County, central Kentucky, reveals such a sequence. The graben is bounded by upthrown blocks of Middle Devonian Boyle Dolomite, which also floors the graben. Within the graben a black-shale unit, apparently absent elsewhere, conformably overlies the Boyle and grades upward into debris-flow deposits represented by the Duffin breccia facies of the New Albany Shale. The Duffin contains clasts of the shale, as well as of chert, silicified fossils, and fine to boulder-size dolostone clasts eroded from the Boyle high on the flanks of the graben. The underlying shale also exhibits evidence of penecontemporaneous soft-sediment deformation related to the debris-flow emplacement of Boyle residue in the graben and due to later loading by the Duffin.

  1. Variation of palaeostress patterns along the Oriente transform wrench corridor, Cuba: significance for Neogene Quaternary tectonics of the Caribbean realm

    NASA Astrophysics Data System (ADS)

    Rojas-Agramonte, Y.; Neubauer, F.; Handler, R.; Garcia-Delgado, D. E.; Friedl, G.; Delgado-Damas, R.

    2005-02-01

    In this study, we address the late Miocene to Recent tectonic evolution of the North Caribbean (Oriente) Transform Wrench Corridor in the southern Sierra Maestra mountain range, SE Cuba. The region has been affected by historical earthquakes and shows many features of brittle deformation in late Miocene to Pleistocene reef and other shallow water deposits as well as in pre-Neogene, late Cretaceous to Eocene basement rocks. These late Miocene to Quaternary rocks are faulted, fractured, and contain calcite- and karst-filled extension gashes. Type and orientation of the principal normal palaeostress vary along strike in accordance with observations of large-scale submarine structures at the south-eastern Cuban margin. Initial N-S extension is correlated with a transtensional regime associated with the fault, later reactivated by sinistral and/or dextral shear, mainly along E-W-oriented strike-slip faults. Sinistral shear predominated and recorded similar kinematics as historical earthquakes in the Santiago region. We correlate palaeostress changes with the kinematic evolution along the boundary between the North American and Caribbean plates. Three different tectonic regimes were distinguished for the Oriente transform wrench corridor (OTWC): compression from late Eocene-Oligocene, transtension from late Oligocene to Miocene (?) (D 1), and transpression from Pliocene to Present (D 2-D 4), when this fault became a transform system. Furthermore, present-day structures vary along strike of the Oriente transform wrench corridor (OTWC) on the south-eastern Cuban coast, with dominantly transpressional/compressional and strike-slip structures in the east and transtension in the west. The focal mechanisms of historical earthquakes are in agreement with the dominant ENE-WSW transpressional structures found on land.

  2. Tectonic significance of mantle sources for mafic synextensional dikes in metamorphic core complexes, southern Arizona and northern Sonora

    SciTech Connect

    Wright, J.E. ); Haxel, G.B. ); Simmons, A.M.

    1992-01-01

    Synextensional microdiorite and lamprophyre dikes in the metamorphic core complexes (MCCs) of southern Arizona represent magmatism unambiguously associated with middle Tertiary crustal extension. These 24--20 Ma dikes are shoshonitic and primitive. Petrographic and geochemical data and AFC modeling suggest absence of an essential crustal source component. Dikes from individual MCCs have closely similar sr and Pb isotopic compositions that do not correlate with degree of fractionation, indicating little or no crustal assimilation. Minimal crustal interaction is consistent with emplacement of the dikes in a strongly extensional tectonic regime. Samples from the two MCC belts differ isotopically and chemically. Isotopic and trace element data indicate a minimum of three mantle sources, two lithospheric and one asthenospheric. The predominant lithospheric source for dikes in the northern belt was LILE-depleted Proterozoic lithosphere (EM1-like), whereas in the southern belt it was LILE-enriched lithosphere (trending toward EM2) strongly influenced by Proterozoic to Tertiary subduction. The asthenospheric source was available under both MCC belts but more widely or frequently tapped beneath the more highly extended northern belt. The presence of an asthenospheric component in some of the MCC dikes is the only known exception to the observation that asthenosphere-derived Cenozoic basalts first appeared in Arizona ca Ma. By the later stages of middle Tertiary crustal extension, the subduction zone beneath Arizona evidently had fragmented or became inactive, so that it did not form a barrier to ascent of asthenosphere-derived magmas. Continued study will evaluate the belief that these data support tectonic models for middle tertiary crustal extension in which the asthenospheric mantle is active rather than passive.

  3. Two contrasting metamorphosed ultramafic-mafic complexes from greenstone belts, the northern Kaapvaal Craton and their significance in Archaen tectonics

    NASA Technical Reports Server (NTRS)

    Smit, C. A.; Vearncombe, J. R.

    1986-01-01

    The character of Archaean ultramafic-mafic complexes can, given their prominance in greenstone belts, provide critical clues to help deduce the tectonic setting of these belts. Here are described two contrasting, metamorphosed, ultramafic-mafic complexes, the first a partially serpentinized dunitic body with associated chromite from Lemoenfontein, one of several peridotitic bodies occurring as discrete lenses and pods in granulite facies gneisses of the northern Kaapvaal craton. The second, the Rooiwater complex is a major layered igneous body, now metamorphosed in the amphibolite facies, but without pervasive deformation, which crops out in the northern Murchison greenstone belt. The Lemoenfontein chromites and associated ultramafic rocks are lithologically and chemically similar to their Phanerozoic equivalents of ophiolitic origin, interpreted as obducted oceanic crust. The Lemoenfontein complex is a remnant of Archaean oceanic material. In contrast, the Rooiwater complex is, despite the lack of exposed intrusive contacts, similar to layered igneous complexes such as Ushushwana or Bushveld. These complexes are intrusive in continental environments. It is concluded that contrasting ultramafic-mafic complexes represent a heterogeneity in greenstone belts with either oceanic or continental environments involved.

  4. Tectonic activity as a significant source of crustal tetrafluoromethane emissions to the atmosphere: Observations in groundwaters along the San Andreas Fault

    NASA Astrophysics Data System (ADS)

    Deeds, Daniel A.; Kulongoski, Justin T.; Mühle, Jens; Weiss, Ray F.

    2015-02-01

    Tetrafluoromethane (CF4) concentrations were measured in 14 groundwater samples from the Cuyama Valley, Mil Potrero and Cuddy Valley aquifers along the Big Bend section of the San Andreas Fault System (SAFS) in California to assess whether tectonic activity in this region is a significant source of crustal CF4 to the atmosphere. Dissolved CF4 concentrations in all groundwater samples but one were elevated with respect to estimated recharge concentrations including entrainment of excess air during recharge (Cre; ∼30 fmol kg-1 H2O), indicating subsurface addition of CF4 to these groundwaters. Groundwaters in the Cuyama Valley contain small CF4 excesses (0.1-9 times Cre), which may be attributed to an in situ release from weathering and a minor addition of deep crustal CF4 introduced to the shallow groundwater through nearby faults. CF4 excesses in groundwaters within 200 m of the SAFS are larger (10-980 times Cre) and indicate the presence of a deep crustal flux of CF4 that is likely associated with the physical alteration of silicate minerals in the shear zone of the SAFS. Extrapolating CF4 flux rates observed in this study to the full extent of the SAFS (1300 km × 20-100 km) suggests that the SAFS potentially emits (0.3- 1) ×10-1 kg CF4 yr-1 to the Earth's surface. For comparison, the chemical weathering of ∼ 7.5 ×104km2 of granitic rock in California is estimated to release (0.019- 3.2) ×10-1 kg CF4 yr-1. Tectonic activity is likely an important, and potentially the dominant, driver of natural emissions of CF4 to the atmosphere. Variations in preindustrial atmospheric CF4 as observed in paleo-archives such as ice cores may therefore represent changes in both continental weathering and tectonic activity, including changes driven by variations in continental ice cover during glacial-interglacial transitions.

  5. The tectonic significance of pre-Scandian 40Ar/39Ar phengite cooling ages in the Caledonides of western Norway

    USGS Publications Warehouse

    Andersen, T.B.; Berry, H.N.; Lux, D.R.; Andresen, A.

    1998-01-01

    Ordovician (Caradoc) time. The data also suggest that the Caledonian margin of Baltica may have experienced a more protracted tectonism during the Caledonian cycle than previously models focusing on Early Caledonian and Tremadoc (or older) ophiolite obduction and the Scandian continental collision between Baltica and Laurentia.

  6. Tectonic activity as a significant source of crustal tetrafluoromethane emissions to the atmosphere: observations in groundwaters along the San Andreas Fault

    USGS Publications Warehouse

    Deeds, Daniel A.; Kulongoski, Justin T.; Muhle, Jens; Weiss, Ray F.

    2015-01-01

    Tetrafluoromethane (CF4) concentrations were measured in 14 groundwater samples from the Cuyama Valley, Mil Potrero and Cuddy Valley aquifers along the Big Bend section of the San Andreas Fault System (SAFS) in California to assess whether tectonic activity in this region is a significant source of crustal CF4 to the atmosphere. Dissolved CF4 concentrations in all groundwater samples but one were elevated with respect to estimated recharge concentrations including entrainment of excess air during recharge (CreCre; ∼30 fmol kg−1 H2O), indicating subsurface addition of CF4 to these groundwaters. Groundwaters in the Cuyama Valley contain small CF4 excesses (0.1–9 times CreCre), which may be attributed to an in situ release from weathering and a minor addition of deep crustal CF4 introduced to the shallow groundwater through nearby faults. CF4 excesses in groundwaters within 200 m of the SAFS are larger (10–980 times CreCre) and indicate the presence of a deep crustal flux of CF4 that is likely associated with the physical alteration of silicate minerals in the shear zone of the SAFS. Extrapolating CF4 flux rates observed in this study to the full extent of the SAFS (1300 km × 20–100 km) suggests that the SAFS potentially emits (0.3–1)×10−1 kg(0.3–1)×10−1 kg CF4 yr−1 to the Earth's surface. For comparison, the chemical weathering of ∼7.5×104 km2∼7.5×104 km2 of granitic rock in California is estimated to release (0.019–3.2)×10−1 kg(0.019–3.2)×10−1 kg CF4 yr−1. Tectonic activity is likely an important, and potentially the dominant, driver of natural emissions of CF4 to the atmosphere. Variations in preindustrial atmospheric CF4 as observed in paleo-archives such as ice cores may therefore represent changes in both continental weathering and tectonic activity, including changes driven by variations in continental ice cover during glacial–interglacial transitions.

  7. Tectonic significance of lithicwacke-polymictic conglomerate petrofacies association within Upper Cretaceous torchlight sandstone, Big Horn basin, Wyoming

    SciTech Connect

    Khandaker, N.I.; Vondra, C.F.

    1987-05-01

    The Torchlight Sandstone belonging to the Upper Cretaceous Frontier Formation in the Big Horn basin, Wyoming, shows a distinctive lithicwacke-polymictic conglomerate is composed of granule-cobble-sized clasts of quartzite, chert, andesite, and argillite, and phyllite. The survival of phyllite, argillite, and neovolcanic andesite clasts indicate that the detritus underwent very little subaerial transport before it was deposited along the proximal margin of the foreland basin. A petrologically heterogeneous upland source of high to moderate relief is indicated by the clast size and composition. Hydrodynamic structures, in conjunction with textural attributes, and compositional data indicate that detritus moved southeast from its source terrane and was deposited by a high-energy distributary complex. The lithicwacke petrofacies is dominated by higher chert and quartz content with a subordinate amount of labile components including paleovolcanic clasts and fine-grained matrix. The development of phyllosilicate matrix around quartz and chert grains preserved the primary porosity and permeability of the sandstone. Absence of any noticeable quartz overgrowth apparently contributed to the preservation of good reservoir quality in this petrofacies. Considering its (Torchlight Sandstone) close proximity to the thrust belt and to the locus of andesite volcanism in the northwest and west, it is suggested that the extrabasinal detritus within the foreland basin can provide significant clues as to the timing of the thrust events and volcanicity in the adjacent region. New perspectives for hydrocarbon exploration and regional correlation may be gained by employing this petrofacies association.

  8. Geology and tectonic significance of a Late Proterozoic anorogenic silicic supersuite, Laurentian Appalachians, Virginia and North Carolina

    SciTech Connect

    Tollo, R.P. . Dept. of Geology); Bartholomew, M.J. ); Rankin, D.W. )

    1994-03-01

    Magmatic activity associated with regional extension produced more than 20 granitoid plutons within the Laurentian Appalachians of Virginia and North Carolina. The plutons constitute a supersuite that spans on age range of at least 760--700 Ma. The supersuite, which includes granitoids of the Crossnore Complex and the Robertson River Igneous Suite, among others, is geochemically consanguineous with silicic volcanic rocks at Mt. Rogers (760 Ma) and Battle Mountain (700 ma) in virginia. Variable in size, typically elongate to dike-like in form, and ranging from monzogranite to alkali feldspar syneite, most plutons record a sequence of multiple intrusions that, in the large robertson River batholith, spanned at least 35 m.y. The plutons define a compositionally coherent, metaluminous to (relatively rare) mildly peralkaline supersuite that is characterized by high Zr, Nb, Ga, Y, REE (not Eu), Fe/Mg, and Ga/Al, relatively to well-documented I-, S-, and M-type granitoids. These compositional features and mineralogic characteristics including the abundance of largely hypersolvus feldspar assemblages, occurrence of Fe-rich ferromagnesian silicates, and the ubiquitous presence of fluorite and allanite indicate that the plutons collectively may be classified as A-subtype granitoids. The Appalachian supersuite represents a significant, long-lived, temporally episodic period of magmatism that ended with encratonic rifting but not the development of oceanic crust. Individual plutons evolved independently and were not restricted to the vicinity of proto-Iapetan embayments. Younger (580--560 Ma) granitoids of the New York promontory are chemically indistinguishable from the supersuite.

  9. [South] Korea.

    PubMed

    1987-04-01

    The Republic of Korea occupies approximately 38,000 square miles in the southern position of a mountaineous peninsula. It shares a land boundary with North Korea. With a population of more than 40 million people, South Korea has 1 of the highest population densities in the world. The language spoken is a Uralic language, closely akin to Japanese, Hungarian, Finnish, and Mongolian, and the traditional religions are Shamanism and Buddhism. Over the course of time, South Korea has been invaded and fought over by its neighbors. The US and the Soviet Union have never been able to reach a unification agreement for North and South Korea. The 3rd Republic era, begun in 1963, saw a time of rapid industrialization and a great deal of economic growth. The 5th Republic began with a new constitution and new elections brought about the election of a president to a 7-year term of office beginning in 1981. Economic growth has been remarkable over the last 25 years despite the fact that North Korea possesses most of the mineral and hydroelectric resources and the existing heavy industrial base built by the Japanese while South Korea has the limited agricultural resources and had, initially, a large unskilled labor pool. Serious industrial growth began in South Korea in the early 1960s and the GNP grew at an annual rate of 10% during the period 1963-78. Current GNP is now, at $2000, well beyond that of its neighbors to the north. The outlook for longterm growth is good; however, the military threat posed by North Korea and the absence of foreign economic assistance has resulted in Korea spending 1/3 of its budget on defense. South Korea is active in international affairs and in the UN. Economic realities have forced Korea to give economics priority in their foreign policy. There has been an on-again, off-again quality to dialogue between the 2 nations. However, the US is committed to maintaining peace on the Korean peninsula. In order to do so, they have supplied manpower and

  10. Syndepositional tectonics recorded by soft-sediment deformation and liquefaction structures (continental Lower Permian sediments, Southern Alps, Northern Italy): Stratigraphic significance

    NASA Astrophysics Data System (ADS)

    Berra, F.; Felletti, F.

    2011-04-01

    The Lower Permian succession of the Central Southern Alps (Lombardy, Northern Italy) was deposited in fault-controlled continental basins, probably related to transtensional tectonics. We focussed our study on the stratigraphic record of the Lower Permian Orobic Basin, which consists of a 1000 m thick succession of prevailing continental clastics with intercalations of ignimbritic flows and tuffs (Pizzo del Diavolo Formation, PDV) resting on the underlying prevailing pyroclastic flows of the Cabianca Volcanite. The PDV consists of a lower part (composed of conglomerates passing laterally to sandstones and distally to silt and shales), a middle part (pelitic, with carbonates) and an upper part (alternating sandstone, silt and volcanic flows). Syndepositional tectonics during the deposition of the PDV is recorded by facies distribution, thickness changes and by the presence of deformation and liquefaction structures interpreted as seismites. Deformation is recorded by both ductile structures (ball-and-pillow, plastic intrusion, disturbed lamination, convolute stratification and slumps) and brittle structures (sand dykes and autoclastic breccias). Both the sedimentological features and the geodynamic setting of the depositional basin confidently support the interpretation of the described deformation features as related to seismic shocks. The most significant seismically-induced deformation is represented by a slumped horizon (about 4 m thick on average) which can be followed laterally for more than 5 km. The slumped bed consists of playa-lake deposits (alternating pelites and microbial carbonates, associated with mud cracks and vertebrate tracks). The lateral continuity and the evidence of deposition on a very low-angle surface along with the deformation/liquefaction of the sediments suggest that the slump was triggered by a high-magnitude earthquake. The stratigraphic distribution of the seismites allows us to identify time intervals of intense seismic activity

  11. Tectonic Geomorphology.

    ERIC Educational Resources Information Center

    Bull, William B.

    1984-01-01

    Summarizes representative quantitative tectonic-geomorphology studies made during the last century, focusing on fault-bounded mountain-front escarpments, marine terraces, and alluvial geomorphic surfaces (considering stream terraces, piedmont fault scarps, and soils chronosequences). Also suggests where tectonic-geomorphology courses may best fit…

  12. Intrusion of horizontal dikes: tectonic significance of Middle Proterozoic diabase sheets widespread in the upper crust of the southwestern United States

    USGS Publications Warehouse

    Howard, K.A.

    1991-01-01

    Initially horizontal sheet intrusions of Middle Proterozoic diabase are abundant in a region 650 by 300 km across in Arizona and California. The diabase forms discordant sheets in basement granite and gneiss and sills in overlying shelf sedimentary sequences. Massive granite is the most common basement host for the sheets, probably because it fractured more easily than foliated hosts during sheet emplacement. Steep feeder dikes are rare compared to the sheets. The diabase in many places is exposed in fault blocks that were tilted during Tertiary tectonic extension. Structure sections restored from the map patterns of upended blocks shows that the sheets were intruded at levels throughout the upper crust, therefore it is concluded that the crust was under tectonic compression or in an isotropic state of stress at the time of diabase intrusion about 1.1 Ga. -from Author

  13. Sediment transport on macrotidal flats in Garolim Bay, west coast of Korea: significance of wind waves and asymmetry of tidal currents

    NASA Astrophysics Data System (ADS)

    Lee, Hee J.; Jo, Hyung R.; Chu, Yong S.; Bahk, Kyung S.

    2004-05-01

    A self-recording instrument, named Tidal Sediment Dynamics Observational System (TISDOS), was built to monitor transport characteristics of nearbed sediments on tidal flats. It was deployed on a tidal flat in the semi-enclosed Garolim Bay, west coast of Korea, over a 15-day period between 5 and 20 January 2002 to examine sediment-transport processes during winter seasons. The measurements involved brief durations of high waves allowing for observation of wave effects upon the sediment transport on the tidal flat. Time series of various hydrodynamic parameters (water depth, current velocities, wave height, suspended sediment concentration, and bed level) from point measurements show characteristic interrelationships between parameters on both temporal and spatial scales. The tidal flat is dominated by flooding currents up to 2 times stronger than ebb currents. The current speeds measured simultaneously at two stations along a cross-shore transect varied in harmony with water depth, reaching the maximum during spring tide that was steadily decreased onshore. The onshore decrease in current speed was compatible with a fining textural trend from sand on the lower flat to mud toward the upper flat. Both the maximum water depth and current speed during individual tidal cycles also show semi-diurnal asymmetry that was highlighted during spring tide. Waves were of critical importance in resuspending bed material and thus yielding higher suspended sediment concentrations. On the middle flat, the suspended sediment concentrations were highest, exceeding 400 mg/l at 0.5 m above the seabed during large waves (relative wave height, 0.33) under weakest neap currents. In this wavy climate, the suspended sediment concentration increased over time during ebb, in strong contrast with a gradual decrease through time after mid-flood peaks under tidal currents without waves. The daily vertical flux of suspended sediments trapped in a plastic bottle also indicates the significance of

  14. Tree Tectonics

    NASA Astrophysics Data System (ADS)

    Vogt, Peter R.

    2004-09-01

    Nature often replicates her processes at different scales of space and time in differing media. Here a tree-trunk cross section I am preparing for a dendrochronological display at the Battle Creek Cypress Swamp Nature Sanctuary (Calvert County, Maryland) dried and cracked in a way that replicates practically all the planform features found along the Mid-Oceanic Ridge (see Figure 1). The left-lateral offset of saw marks, contrasting with the right-lateral ``rift'' offset, even illustrates the distinction between transcurrent (strike-slip) and transform faults, the latter only recognized as a geologic feature, by J. Tuzo Wilson, in 1965. However, wood cracking is but one of many examples of natural processes that replicate one or several elements of lithospheric plate tectonics. Many of these examples occur in everyday venues and thus make great teaching aids, ``teachable'' from primary school to university levels. Plate tectonics, the dominant process of Earth geology, also occurs in miniature on the surface of some lava lakes, and as ``ice plate tectonics'' on our frozen seas and lakes. Ice tectonics also happens at larger spatial and temporal scales on the Jovian moons Europa and perhaps Ganymede. Tabletop plate tectonics, in which a molten-paraffin ``asthenosphere'' is surfaced by a skin of congealing wax ``plates,'' first replicated Mid-Oceanic Ridge type seafloor spreading more than three decades ago. A seismologist (J. Brune, personal communication, 2004) discovered wax plate tectonics by casually and serendipitously pulling a stick across a container of molten wax his wife and daughters had used in making candles. Brune and his student D. Oldenburg followed up and mirabile dictu published the results in Science (178, 301-304).

  15. Collision tectonics

    SciTech Connect

    Coward, M.P.; Ries, A.C.

    1985-01-01

    The motions of lithospheric plates have produced most existing mountain ranges, but structures produced as a result of, and following the collision of continental plates need to be distinguished from those produced before by subduction. If subduction is normally only stopped when collision occurs, then most geologically ancient fold belts must be collisional, so it is essential to recognize and understand the effects of the collision process. This book consists of papers that review collision tectonics, covering tectonics, structure, geochemistry, paleomagnetism, metamorphism, and magmatism.

  16. Active tectonics

    SciTech Connect

    Not Available

    1986-01-01

    This study is part of a series of Studies in Geophysics that have been undertaken for the Geophysics Research Forum by the Geophysics Study Committee. One purpose of each study is to provide assessments from the scientific community to aid policymakers in decisions on societal problems that involve geophysics. An important part of such assessments is an evaluation of the adequacy of current geophysical knowledge and the appropriateness of current research programs as a source of information required for those decisions. The study addresses our current scientific understanding of active tectonics --- particularly the patterns and rates of ongoing tectonic processes. Many of these processes cannot be described reasonably using the limited instrumental or historical records; however, most can be described adequately for practical purposes using the geologic record of the past 500,000 years. A program of fundamental research focusing especially on Quaternary tectonic geology and geomorphology, paleoseismology, neotectonics, and geodesy is recommended to better understand ongoing, active tectonic processes. This volume contains 16 papers. Individual papers are indexed separately on the Energy Database.

  17. The tectonic significance of K/Ar illite fine-fraction ages from the San Luis Formation (Eastern Sierras Pampeanas, Argentina)

    NASA Astrophysics Data System (ADS)

    Wemmer, Klaus; Steenken, André; Müller, Stefan; de Luchi, Mónica G. López; Siegesmund, Siegfried

    2011-04-01

    The Sierra de San Luis forms the southern tip of the Eastern Sierras Pampeanas in central Argentina. Two narrow belts of low-grade phyllites and quartz arenites, i.e. the San Luis Formation, have accommodated part of the strain-related differential exhumation of the medium- to high-grade metamorphic domains that constitute to the basement complex of the sierra. Eleven phyllite samples were subjected to the K/Ar fine-fraction dating technique. Results are interpreted in relation to the Kübler index of the illites, which indicate epimetamorphic conditions for the majority of the samples. Obtained ages between 330 and 290 Ma cover a period of compressional tectonics in the late Mississippian (Visean/Serpukhovian boundary) followed by the subsidence during the formation of the Paganzo Basin in the provinces of La Rioja and San Luis. These tectonic movements are coincident with the Toco orogeny in northern Chile and southern Bolivia. This suggests that the older K/Ar ages document the compressional stage and that younger ages record the cooling of the basement during the subsequent extensional uplift of the basement.

  18. Timing, Structural Styles, and Tectonic Significance of Neogene Basin Inversion Across the South China Sea and Indonesian Back-Arc Region

    NASA Astrophysics Data System (ADS)

    Dorobek, S. L.; Olson, C. C.

    2005-12-01

    Basin inversion is a common phenomenon in many intracontinental extensional or transtensional settings that are subjected to later contractional deformation. Numerous examples of inverted Paleogene rift basins are found in the Indonesian back-arc region and southern and western parts of the South China Sea. Inversion was widespread across the broad region, mainly began in latest Oligocene-early Miocene time, and locally continues to the present day. Most basins were fully inverted in less than 15 Myr and inversion typically involved reactivation of preexisting extensional fault systems that formed during Paleogene rifting. We examined the tectonic styles and regional timing of basin inversion across this region in order to understand the tectonic and geodynamic reasons for the inversion. The timing of regional inversion and structural styles associated with inversion reflect roughly N-S to NNW-SSE oriented intraplate compressive stress, which suggests that incipient collision of Australian continental crust along the eastern Indonesian archipelago and `South Chinese/Vietnamese' crust along the Borneo/South Palawan margin were responsible for the widespread inversion. A fundamental change from uncoupled to coupled subduction along the Indonesian trench and Borneo/South Palawan margin, coincident with the incipient subduction of continental crust along these convergent margins during latest Oligocene-early Miocene time, may explain why intraplate compressive stress was transmitted across the Indonesian back-arc and southern South China Sea (Sunda Shelf) region. Prior to late Oligocene time, subduction was essentially uncoupled and Paleogene rift basins across the Indonesian backarc and Sunda Shelf region were thermally subsiding. The rheology of Sundaland and offshore Southeast Asian continental lithosphere also was especially conducive to widespread, nearly synchronous basin inversion during Neogene time, which likely reflects the low viscosity nature of the mantle

  19. Petrology and tectonic significance of gabbros, tonalites, shoshonites, and anorthosites in a late Paleozoic arc-root complex in the Wrangellia Terrane, southern Alaska

    SciTech Connect

    Beard, J.S. ); Barker, F. )

    1989-11-01

    Plutonic rocks intrusive into the late Paleozoic Tetelna Formation of southern Alaska are the underpinnings of the late Paleozoic Skolai arc of the Wrangellia Terrane. There are four groups of intrusive rocks within the Skolai arc: (1) Gabbro-diorite plutons that contain gabbroic to anorthositic cumulates along with a differentiated series of gabbros and diorites of basaltic to andesitic composition; (2) Silicic intrusions including tonalite, granodiorite, and granite; (3) Monzonitic to syenitic plutonic rocks of the Ahtell complex and related dikes and sills; (4) Fault-bounded bytownite anorthosite of uncertain age and association. These anorthosites may be related to post-Skolai, Nikolai Greenstone magmatism. The silicic rocks yield discordant U-Pb zircon ages of 290-320 Ma (early to late Pennsylvanian). The monzonitic rocks of the Ahtell complex have shoshonitic chemistry. Similar shoshonitic rocks are widespread in both the Wrangellia terrane and the neighboring Alexander terrane and intrude the contact between the two. In modern oceanic arcs, shoshonitic rocks are typically associated with tectonic instability occurring during the initial stages of subduction or just prior to or during termination or flip of an established subduction zone. The nature of any tectonic instability which may have led to the cessation of subduction in the Skolai arc is unclear. Possibilities include collision of the arc with a ridge, an oceanic plateau, another arc, or a continental fragment. One possibility is that the shoshonitic magmatism marks the late Paleozoic amalgamation of Wrangellia and the Alexander terrane. The scarcity of arc rocks predating the shoshonites in the Alexander terrane supports this possibility, but structural corroboration is lacking.

  20. Tectonic significance of the Dongqiao ophiolite in the north-central Tibetan plateau: Evidence from zircon dating, petrological, geochemical and Sr-Nd-Hf isotopic characterization

    NASA Astrophysics Data System (ADS)

    Liu, Tong; Zhai, Qing-guo; Wang, Jun; Bao, Pei-sheng; Qiangba, Zhaxi; Tang, Suo-han; Tang, Yue

    2016-02-01

    The Dongqiao ophiolite occurs in the central segment of the Bangong-Nujiang suture zone, in north-central Tibet, China. It is still debated on the tectonic setting of the Dongqiao ophiolite despite after more than 30 years' studies. The Dongqiao ophiolite has a complete section of a typical ophiolite, composed of harzburgite, dunite, layered and isotropic gabbros, pillow and massive basalts, as well as radiolarian chert. Whole-rock geochemical analyses show that harzburgite displays a broad U-shaped REE pattern and has a fore-arc affinity, whereas basalts show affinities of E-MORB, OIB and IAB. The basalts were probably formed in different tectonic settings, that is, mid-ocean ridge, oceanic island and island arc. The gabbros and basalts are characterized by positive εNd(t) (+1.6 to +6.7) and εHf(t) (+8.1 to +13.9) values. Zircon U-Pb dating yielded ages of 188 ± 1 Ma for the layered gabbro and 181 ± 1 Ma for the amphibole gabbro. The new ages and the published age data of the Dingqing and Dong Co ophiolites led us to conclude that the Bangong-Nujiang Ocean existed from the Late Triassic to Early Cretaceous. The new geochemical data also suggested that the Dongqiao ophiolite was a typical SSZ-type ophiolite formed in an initial fore-arc oceanic basin. Fore-arc ophiolites are probably widely distributed along the Bangong-Nujiang suture zone. If so, the Tethys Ocean of the Bangong-Nujiang area probably existed as a fore-arc oceanic basin during the Late Triassic to Early Jurassic.

  1. The geometry of the Wadati-Benioff zone under southern Central America and its tectonic significance: results from a high-resolution local seismographic network

    NASA Astrophysics Data System (ADS)

    Protti, Marino; Gu¨ndel, Federico; McNally, Karen

    1994-07-01

    We present here a detailed geometry of the Wadati-Benioff zone under Costa Rica, obtained from seismicity recorded by a dense local seismographic network jointly operated by the Costa Rica Volcanological and Seismological Observatory, National University, and the Charles F. Richter Seismological Laboratory, University of California, Santa Cruz. Underneath the Nicaragua-Costa Rica border the Wadati-Benioff zone smoothly contorts (from steep to shallow dip angles, NW to SE), but does not show evidence of a brittle tear, as postulated by others. However, further to the SE, NE of Puerto Caldera, Costa Rica, the Wadati-Benioff zone does show a segmentation (the Quesada Sharp Contortion) at intermediate depths ( h > 70km). NW of this sharp contortion the deepest portion of the seismically active slab dips at about 80° and reaches maximum depths ranging from 200 km, near the Nicaragua-Costa Rica border, to 135 km under Ciudad Quesada. To the SE the deeper portion of the Wadati-Benioff zone dips at about 60° and the seismicity does not extend below depths ranging from 125 km, behind the volcanic arc, to 50 km, east of Quepos. In southern Costa Rica, east of 83°55'W, we find no evidence of the Wadati-Benioff zone deeper than 50 km. The obtained geometry and other known tectonic features related to the subduction of the Cocos plate under the Caribbean plate along the southern terminus of the Middle America Trench (Nicaragua and Costa Rica) correlate well with along-trench variations in age of the subducted Cocos plate. Some of these tectonic features are: (1) the shallowing of Middle America Trench bathymetry from NW to SE; (2) variations in the energy release within the subducted slab; (3) differences in coupling between Cocos and Caribbean plates; (4) the termination of the Central America Volcanic Chain in central Costa Rica; (5) distinct stress field variations on the overriding Caribbean plate. The subduction of the Cocos Ridge under southern Costa Rica is partially

  2. Spiral tectonics

    NASA Astrophysics Data System (ADS)

    Hassan Asadiyan, Mohammad

    2014-05-01

    Spiral Tectonics (ST) is a new window to global tectonics introduced as alternative model for Plate Tectonics (PT). ST based upon Dahw(rolling) and Tahw(spreading) dynamics. Analogues to electric and magnetic components in the electromagnetic theory we could consider Dahw and Tahw as components of geodynamics, when one component increases the other decreases and vice versa. They are changed to each other during geological history. D-component represents continental crust and T-component represents oceanic crust. D and T are two arm of spiral-cell. T-arm 180 degree lags behind D-arm so named Retard-arm with respect to D or Forward-arm. It seems primary cell injected several billions years ago from Earth's center therefore the Earth's core was built up first then mantel and finally the crust was build up. Crust building initiate from Arabia (Mecca). As the universe extended gravitation wave swirled the earth fractaly along cycloid path from big to small scale. In global scale (order-0) ST collect continents in one side and abandoned Pacific Ocean in the other side. Recent researches also show two mantels upwelling in opposite side of the Earth: one under Africa (tectonic pose) and the other under Pacific Ocean (tectonic tail). In higher order (order-1) ST build up Africa in one side and S.America in the other side therefore left Atlantic Ocean meandered in between. In order-n e.g. Khoor Musa and Bandar-Deylam bay are seen meandered easterly in the Iranian part but Khoor Abdullah and Kuwait bay meandered westerly in the Arabian part, they are distributed symmetrically with respect to axis of Persian Gulf(PG), these two are fractal components of easterly Caspian-wing and westerly Black Sea-wing which split up from Anatoly. Caspian Sea and Black Sea make two legs of Y-like structure, this shape completely fitted with GPS-velocity map which start from PG and split up in the Catastrophic Point(Anatoly). We could consider PG as remnants of Ancient Ocean which spent up

  3. Behavior of Eupcheon fault Using Fault Monitoring Data in South Korea

    NASA Astrophysics Data System (ADS)

    Cho, S.; Hwang, J.; Park, D.; Choi, W.; Chang, C.

    2013-12-01

    In the early 1960s, the Fault Monitoring System(FMS) was adopted in several countries including U.S., Japan and Taiwan, where fault movement related with tectonics have occurred frequently. In Korea, only the Korea Hydro & Nuclear Power Co. Ltd. - Central Research Institute (KHNP-CRI) has been managing FMS. The first FMS of South Korea had been installed to monitor the Eupcheon fault located in Gyeoungju city from 2009. The system is equipped with in-situ measuring units including strainmeter, creepmeter, Global Navigation Satellite System (GNSS), seismometer, and groundwater level meter. This paper presents the behavior of the Eupcheon fault based on the monitored data from EFMS in 2012. These data reveal that the earthquakes near Eupcheon fault did not lead to considerable changes in underground stress and displacement as the data in 2011. The creepmeter is sensitive to the temperature so that the data from the creepmeter showed the seasonal variation. The GNSS and strainmeter data have influenced by the tides. For this reason, it is required to employ a calibration system considering the external parameters such as tides and temperature variations. The KHNP-CRI is currently developing technical systems for data correction and analysis to predict the long-term behavior characteristics of Eupcheon fault. It is expected that the enhanced monitoring system contributes significantly in geo-tectonic safety assessment of nuclear plants and other critical facilities related to the national security.

  4. The Deccan tholeiite lavas and dykes of Ghatkopar-Powai area, Mumbai, Panvel flexure zone: Geochemistry, stratigraphic status, and tectonic significance

    NASA Astrophysics Data System (ADS)

    Sheth, Hetu C.; Zellmer, Georg F.; Demonterova, Elena I.; Ivanov, Alexei V.; Kumar, Rohit; Patel, Rakesh Kumar

    2014-04-01

    Mumbai City, situated on the western Indian coast, is well known for exposures of late-stage Deccan pillow basalts and spilites, pyroclastic rocks, rhyolite lavas, and trachyte intrusions. These rock units, and a little-studied sequence of tholeiitic flows and dykes in the eastern part of Mumbai City, constitute the west-dipping limb of a regional tectonic structure called the Panvel flexure. Here we present field, petrographic, major and trace element and Sr-Nd isotopic data on these tholeiitic flows and dykes, best exposed in the Ghatkopar-Powai area. The flows closely resemble the Mahabaleshwar Formation of the thick Western Ghats sequence to the east, in Sr-Nd isotopic ratios and multielement patterns, but have other geochemical characteristics (e.g., incompatible trace element ratios) unlike the Mahabaleshwar or any other Formation. The flows may have originated from a nearby eruptive center, possibly offshore of Mumbai. Two dykes resemble the Ambenali Formation of the Western Ghats in all geochemical characteristics, though they may not represent feeders of the Ambenali Formation lavas. Most dykes are distinct from any of the Western Ghats stratigraphic units. Some show partial (e.g., Sr-Nd isotopic) similarities to the Mahabaleshwar Formation, and these include several dykes with unusual, concave-downward REE patterns suggesting residual amphibole and thus a lithospheric source. The flows and dykes are inferred to have undergone little or no contamination, by lower continental crust. Most dykes are almost vertical, suggesting emplacement after the formation of the Panvel flexure, and indicate considerable east-west lithospheric extension during this late but magmatically vigorous stage of Deccan volcanism.

  5. Tectonic significance of magnetic and gravity data across northern California (lat. 39[degree]N. to lat. 41[degree]N. )

    SciTech Connect

    Griscom, A.; Roberts, C.W.; Halvorson, P.F. )

    1993-04-01

    Aeromagnetic and isostatic residual gravity maps of an east-west transect across northern California show important tectonic features. A linear magnetic anomaly and west-sloping gradient extends over 300 km along the Franciscan-Great Valley contact (FGC) and across the Klamath Mountains province (KM) north to lat. 40[degree]45'N. The anomaly source lies at depths of 5--10 km beneath the KM and the FGC, and implies that the Franciscan complex of the Coast Ranges is thrust (and wedged) at least 80 km eastward beneath the KM to approximately long. 122[degree]40 minutes W. Calculations on a circular gravity low of [minus]50 mGal centered at the circular Bald Rock pluton (diameter about 15 km) in the Sierran foothills indicate a pluton thickness of about 15 km. The nearby Cascade and Merrimac plutons are located on the gradients of this gravity anomaly, have a relatively minor effect on it, and thus are interpreted to be thick (up to 5 km) laccolithic sills that emanate from the Bald Rock pluton, thinning away from it to a feather edge. Model studies indicate that the northeast contact of the Feather River periodotite body (FRPB) north of lat. 39[degree]40 minutes N. generally dips steeply northeast or vertical. The same contact south of this latitude dips east at angles of about 45[degree] to depths of at least 10 km. Magnetic patterns extending from the northern Sierra across the Cascades to the Klamath Mountains suggest that the FRPB may correlate with the Trinity ophiolite.

  6. Crustal structure across the post-spreading magmatic ridge of the East Sub-basin in the South China Sea: Tectonic significance

    NASA Astrophysics Data System (ADS)

    He, Enyuan; Zhao, Minghui; Qiu, Xuelin; Sibuet, Jean-Claude; Wang, Jian; Zhang, Jiazheng

    2016-05-01

    The 140-km wide last phase of opening of the South China Sea (SCS) corresponds to a N145° direction of spreading with rift features identified on swath bathymetric data trending N055° (Sibuet et al., 2016). These N055° seafloor spreading features of the East Sub-basin are cut across by a post-spreading volcanic ridge oriented approximately E-W in its western part (Zhenbei-Huangyan seamounts chain). The knowledge of the deep crustal structure beneath this volcanic ridge is essential to elucidate not only the formation and tectonic evolution of the SCS, but also the mechanism of emplacement of the post-spreading magmatism. We use air-gun shots recorded by ocean bottom seismometers to image the deep crustal structure along the N-S oriented G8G0 seismic profile, which is perpendicular to the Zhenbei-Huangyan seamounts chain but located in between the Zhenbei and Huangyan seamounts, where topographic changes are minimum. The velocity structure presents obvious lateral variations. The crust north and south of the Zhenbei-Huangyan seamounts chain is ca. 4-6 km in thickness and velocities are largely comparable with those of normal oceanic crust of Atlantic type. To the south, the Jixiang seamount with a 7.2-km thick crust, seems to be a tiny post-spreading volcanic seamount intruded along the former extinct spreading ridge axis. In the central part, a 1.5-km thick low velocity zone (3.3-3.7 km/s) in the uppermost crust is explained by the presence of extrusive rocks intercalated with thin sedimentary layers as those drilled at IODP Site U1431. Both the Jixiang seamount and the Zhenbei-Huangyan seamounts chain started to form by the intrusion of decompressive melt resulting from the N-S post-spreading phase of extension and intruded through the already formed oceanic crust. The Jixiang seamount probably formed before the emplacement of the E-W post-spreading seamounts chain.

  7. Upper-crust Tomographic Structure of the Southern Korea Peninsula from Local Earthquakes

    NASA Astrophysics Data System (ADS)

    Kim, K. H.; Park, J. H.; Kang, S. Y.

    2015-12-01

    We derived the three dimensional P wave velocity model for the uppermost 14 km of crust in the southern Korea peninsula using travel-time data from local earthquakes which are recorded by two nation-wide seismic networks operated by Korea Meteorological Administration and Korea Institute of Geoscience and Mineral Resources. Earthquakes in the study occurred between 2001 and 2014. 19,935 P wave arrivals from 747 earthquakes observed by 184 seismic stations are selected for the 3-D tomographic inversion. In order to secure best possible data for tomography inversion, we applied a strict criteria during the selection of earthquakes and travel-times. The study area is parameterized by 10km×10km×4km grid for velocity inversion and 1km×1km×1km grid for travel time calculations. Checkerboard resolution test are used to demonstrate the ray coverage and the resolution for the given station-event configurations. The results indicate P-wave velocity model at shallow depths less than 2 km are not properly resolved mainly due to the insufficient ray coverage. The model at deeper depths greater than 14 km also suffered by lack of ray coverage. Thus, we limit our interpretations of the preliminary P wave velocity model to areas that are illuminated by enough rays. P wave velocity model indicates there are significant lateral velocity variations across the southern Korea peninsula. Most distinguished feature in the velocity model is the higher velocity anomaly beneath the southeastern Korea peninsula. The anomaly regions is distinguished by well-defined tectonic boundary. At 8 km depth, lower velocity anomaly is observed in Gyeonggi massif and high-mountain regions in the southern Korea peninsula. The 3-D velocity model is compared with geophysical and geological observations.

  8. The exploration potential of offshore northwest Korea (P. D. R. K. )

    SciTech Connect

    Cunningham, P.; Bishopp, D. )

    1991-03-01

    Recent political changes have demonstrated that previously taboo countries are now becoming fair game for western explorationists. Numerous areas or basins that have not been the focus of high technology - Technologically Attenuated Basins (TABs) - offer a new challenge for the new venture groups of E and P companies. Most recently the USSR together with other Eastern European countries continue to be a source of technical interest and frustration. The People's Democratic Republic of Korea, North Korea, possibly the most isolated of the Communist block, contains several TABs where there has been minimal exploration. One such TAB is West Korea Bay, which covers an area of 25,000 km{sup 2} containing at least one major Tertiary basin. The tectonic evolution of the Tertiary basin is similar to the intracratonic Chinese basins with significant differences, notably the Songnim and Daebo orogenies (Middle Triassic to Upper Jurassic and Jurassic to middle Cretaceous) that resulted in extensive igneous activity, folding, and thrust faulting, followed by an extensional stress regime during the Mesozoic and Cainozoic. Very few wells have been drilled in West Korea Bay in the past decade (one per 2,500 km{sup 2}). Though commercially unsuccessful, the wells have proven the existence of oil, mature source rocks, and reservoirs (Jurassic, Cretaceous, and Oligo-Miocene). Structural plays such as rotated Jurassic and Cretaceous fault blocks predominate, but there is also potential for higher risk stratigraphic potential in the Jurassic and Tertiary, with expected field size distributions in the 20-180 MMBOR range.

  9. Intermittent Plate Tectonics

    NASA Astrophysics Data System (ADS)

    Silver, P. G.; Behn, M. D.

    2006-12-01

    prevent the ultimate closure of the Pacific basin and thus the cessation of subduction. More noteworthy is where subduction is not initiating. First, there is no evidence for subduction initiation anywhere within the Atlantic basin (excluding the Caribbean and Scotia), despite the mature 100-200 my age of passive-margin oceanic lithosphere. The formation of the Alpine-Himalayan chain represents the cessation of roughly 10,000 km of subduction at about 35-50 ma, Yet, no new subduction zones have initiated south of India or Africa, the two major continents that participated in the collision. These examples illustrate that subduction does not immediately initiate following a continent-continent collision, and may lag by 10s if not 100s of millions of years. The stoppage of plate tectonics, or even a dramatic reduction in subduction flux, would have significant thermal consequences for the mantle. It would effectively mark a temporary switch to "stagnant-lid" tectonics, analogous to that found on Venus, resulting in a significant increase in global mantle potential temperature (30- 100°C per 100 my) and a possibly widespread increase in magmatic activity. Such a hiatus may have occurred in the Mid-Proterozoic (1.1-1.6Ga), an era characterized by the virtual absence of orogenic activity, the longest-lived passive margin (600 My), and the production of enigmatic "anorogenic" granites found over thousands of kilometers in a belt presently stretching from southwestern to northeastern North America.

  10. Tectonic Maps of the Poles

    NASA Technical Reports Server (NTRS)

    2002-01-01

    These tectonic relief maps of the north (left, view large [540k]) and south (right, view large [411k]) poles are the result of new satellite-based technologies which are being used to analyze tectonic activity in the Earth's crust. These maps, known as Digital Tectonic Activity Maps (DTAMs), synoptically depict the architecture of the Earth's crust including current and past tectonic activity. This is significant because it permits researchers to view broad zones of activity over the entire surface of the Earth, rather than focusing on single boundary features. By looking at these 'big pictures,' scientists can possibly identify regions of activity which were not previously recognized or mapped using traditional methods. For more information, see: DTAM web site Putting Earthquakes in Their Place Images courtesy Brian Montgomery, NASA GSFC; data by Paul Lowman and Jacob Yates, NASA GSFC

  11. Tsunami Catalog in Korea

    NASA Astrophysics Data System (ADS)

    Jin, Sobeom; Hyun, Seung Gyu; Noh, Myunghyun

    2015-04-01

    Significant tsunamis are described in historic and instrumental earthquake sources for all regions around the Korean Peninsula. According to the low seismicity near the Peninsula, there are relatively few tsunami events in Korea. Most of the tsunami events are associated with big earthquakes at the eastern margin of the East Sea. One historical event is associated with a volcanic eruption. For that reason, the eastern coast of the Korean Peninsula is the affectable area for tsunami. One historical event at the Yellow Sea area is inferred a result from a big earthquake in China. And one plate boundary earthquake between the Philippine Plate and the Eurasian Plate affected to an island located in south of the Korean Peninsula. We confirmed the historic tsunami events by review the foreign literatures. More detailed information is presented for the instrumental earthquake source events. This work was supported by the Nuclear Safety Research Program through the Korea Radiation Safety Foundation (KORSAFe) and the Nuclear Safety and Security Commission (NSSC), Republic of Korea (Grant No. 1305001).

  12. Recent Advances in Mars Tectonics

    NASA Technical Reports Server (NTRS)

    Golombek, M. P.; Banerdt, W. B.

    1999-01-01

    Since the publication of the "Stress and Tectonics on Mars" chapter in the Mars book (the last comprehensive summary of our knowledge on the topic) considerable advances have been made in certain areas of Martian tectonics and significant advances are expected with the return of Mars Global Surveyor data. This abstract will summarize the advances in our knowledge of tectonic features and processes on Mars since the Mars book and point towards new areas of research that can be expected from the Mars Global Surveyor data. Two out of three areas of study that were discussed as future directions of work in the Mars chapter have had significant work directed towards them. One area is the field of structural mapping and understanding the timing of tectonic activity on Mars in the framework of the global stratigraphy. Although the general development and relative timing of the development of the Tharsis province on Mars had been understood for some time, actual placement of mapped tectonic features in a global stratigraphic framework has only recently been completed. The second area of study mentioned in the Mars chapter was the impact of improved topography and gravity on modeling loads and deriving stresses in the Martian lithosphere. Mars Global Surveyor is on the brink of returning vastly improved topographic and gravity fields and these newer data sets can be used to better define the size and shape of Tharsis and to quantify loads and derived stresses in the Martian lithosphere. Additional information is contained in the original extended abstract.

  13. Nation Building in Korea

    DTIC Science & Technology

    1995-04-01

    opportunity to rebuild South Korea . He saw it as “something almost unique in history. It is the opportunity of an army in a foreign land to contribute...problems. The North Korean invasion in 1950 wedded South Korea to the United States and confronted the United States with the enormous task of...elections in Korea .8 After failing to achieve agreement to peninsula-wide elections, the United Nations sponsored elections in South

  14. Geomorphology, tectonics, and exploration

    NASA Technical Reports Server (NTRS)

    Sabins, F. F., Jr.

    1985-01-01

    Explorationists interpret satellite images for tectonic features and patterns that may be clues to mineral and energy deposits. The tectonic features of interest range in scale from regional (sedimentary basins, fold belts) to local (faults, fractures) and are generally expressed as geomorphic features in remote sensing images. Explorationists typically employ classic concepts of geomorphology and landform analysis for their interpretations, which leads to the question - Are there new and evolving concepts in geomorphology that may be applicable to tectonic analyses of images?

  15. Tectonics on Triton

    NASA Technical Reports Server (NTRS)

    Croft, Steven K.

    1993-01-01

    Tectonic features on Triton have been mapped as part of a larger study of the geology of Triton. Few purely tectonic structures are found on Triton: some grabens and possibly some compressive ridges. However, most of the other structures seen (primarily cryovolcanic in origin) exhibit tectonic control. A regional tectonic network has the following dominant orientations: N-S, E-W, NE-SW, and NW-SE. Most of the orientations are consistent with tidal deformations related to Triton's decreasing orbital radius. Localized quasi-concentric patterns may be due to interior processes such as mantle plumes.

  16. Tectonic features on Titan

    NASA Astrophysics Data System (ADS)

    Cook, C.; Barnes, J.

    2011-10-01

    This research is based on the exploration of tectonic patterns on Titan from a global perspective. Several moons in the outer solar system display known stress fields driven or modified by global forces which affect patterns of tectonism. Patterns such as these are seen in Europa's tidal forces, Enceladus' tiger strips, and Ganymede's global expansion. Given its proximity to Saturn, as well as its eccentric orbit, tectonic features and global stresses may be present on Titan as well. Titan displays visible tectonic structures, such as mountain chains along its equator (Radebaugh et al. 2007), as well as the unexplored Virgae.

  17. Earthquakes and plate tectonics

    USGS Publications Warehouse

    Spall, H.

    1977-01-01

    An explanation is to be found in plate tectonics, a concept which has revolutionized thinking in the Earth sciences in the last 10 years. The theory of plate tectonics combines many of the ideas about continental drift (originally proposed in 1912 by Alfred Wegener in Germany) and sea-floor spreading (suggested originally by Harry Hess of Princeton University). 

  18. Origin of microseism observed in South Korea

    NASA Astrophysics Data System (ADS)

    Sheen, D.; Shin, J.; You, S.; Rhie, J.

    2009-12-01

    Ambient seismic noise has been widely used for imaging crustal structure as an alternative passive source, even where traditional seismic imaging is not possible due to low seismicity. Long before the sensational applications of seismic noise, the origin of the noise has already been studied to understand its nature and characteristics for several decades. In this study, we investigate the origin of microseism observed in South Korea. Annual spectrograms in the microseismic frequency range up to 0.4 Hz show coherent peaks at about 0.2 Hz in the winter, which is at the frequency band of the double-frequency microseism. However, the primary microseism is only rarely observed in South Korea when the Pacific typhoon is close to the Southern Sea of Korea. Polarization analysis and noise cross correlation indicate that the energy of the double-frequency microseism comes dominantly from the east of the Korean Peninsula. Comparison of the results from the operational wave model of the Korea Meteorological Administration and seismic data shows a strong correlation of spectral amplitude of seismic data with the significant wave heights and periods of ocean waves, implying that the primary and the double-frequency microseism observed in South Korea are generated at the Southern Sea of Korea and at nearby shorelines of the east coast of Japan, respectively.

  19. Terrorism in South Korea.

    PubMed

    Wang, Soon Joo; Choi, Jin Tae; Arnold, Jeffrey

    2003-01-01

    South Korea has experienced > 30 suspected terrorism-related events since 1958, including attacks against South Korean citizens in foreign countries. The most common types of terrorism used have included bombings, shootings, hijackings, and kidnappings. Prior to 1990, North Korea was responsible for almost all terrorism-related events inside of South Korea, including multiple assassination attempts on its presidents, regular kidnappings of South Korean fisherman, and several high-profile bombings. Since 1990, most of the terrorist attacks against South Korean citizens have occurred abroad and have been related to the emerging worldwide pattern of terrorism by international terrorist organizations or deranged individuals. The 1988 Seoul Olympic Games provided a major stimulus for South Korea to develop a national emergency response system for terrorism-related events based on the participation of multiple ministries. The 11 September 2001 World Trade Center and Pentagon attacks and the 2001 United States of America (US) anthrax letter attacks prompted South Korea to organize a new national system of emergency response for terrorism-related events. The system is based on five divisions for the response to specific types of terrorist events, involving conventional terrorism, bioterrorism, chemical terrorism, radiological terrorism, and cyber-terrorism. No terrorism-related events occurred during the 2002 World Cup and Asian Games held in South Korea. The emergency management of terrorism-related events in South Korea is adapting to the changing risk of terrorism in the new century.

  20. Preliminary publications Book 1 from Project on Mineral Resources, Metallogenesis and Tectonics of Northeast Asia

    USGS Publications Warehouse

    Ariunbileg, Sodov; Badarch, Gombosuren; Berzin, Nikolai A.; Bulgatov, Alexander N.; Chimed, Noosoi; Deikunenko, Aleksey V.; Dejidmaa, Gunchin; Diggles, Michael F.; Distanov, Elimir G.; Dorjgotov, Dangindorjiin; Gerel, Ochir; Gordienko, Ivan V.; Gotovsuren, Ayurzana; Hwang, Duk-Hwan; Khanchuk, Alexander I.; Koch, Richard D.; Miller, Robert J.; Nokleberg, Warren J.; Obolenskiy, Alexander A.; Ogasawara, Masatsugu; Orolmaa, Demberel; Oxman, Vladimir S.; Parfenov, Leonid M.; Popeko, Ludmila I.; Prokopiev, Andrey V.; Smelov, Alexander P.; Sotnikov, Vitaliy I.; Sudo, Sadahisa; Timofeev, Vladimir F.; Tret'yakov, Felix F.; Vernikovsky, Valery A.; Ye, Mao; Zadgenizov, Alexander P.

    1999-01-01

    This report consists of preliminary data tables, maps, and interpretative articles compiled in late 1997 and early 1998 for a new project on the Mineral Resources, Metallogenesis, and Tectonics of Northeast Asia (Eastern and Southern Siberia, Mongolia, North-eastern China, South Korea, and Japan).

  1. Plate tectonics: Metamorphic myth

    NASA Astrophysics Data System (ADS)

    Korenaga, Jun

    2016-01-01

    Clear evidence for subduction-induced metamorphism, and thus the operation of plate tectonics on the ancient Earth has been lacking. Theoretical calculations indicate that we may have been looking for something that cannot exist.

  2. Tectonic Plate Movement.

    ERIC Educational Resources Information Center

    Landalf, Helen

    1998-01-01

    Presents an activity that employs movement to enable students to understand concepts related to plate tectonics. Argues that movement brings topics to life in a concrete way and helps children retain knowledge. (DDR)

  3. Planetary Tectonics and Volcanism

    NASA Technical Reports Server (NTRS)

    Zuber, Maria T.

    1997-01-01

    The study of tectonic and volcanological processes on the terrestrial planets, with particular emphasis on Venus, in order to better understand the internal structures and thermal and stress histories of these bodies is reported.

  4. Plate tectonics on Venus

    NASA Technical Reports Server (NTRS)

    Anderson, D. L.

    1981-01-01

    The high surface temperature of Venus implies a permanently buoyant lithosphere and a thick basaltic crust. Terrestrial-style tectonics with deep subduction and crustal recycling is not possible. Overthickened basaltic crust partially melts instead of converting to eclogite. Because mantle magmas do not have convenient access to the surface the Ar-40 abundance in the atmosphere should be low. Venus may provide an analog to Archean tectonics on the earth.

  5. Active tectonics and human survival strategies

    NASA Astrophysics Data System (ADS)

    King, Geoffrey; Bailey, Geoffrey; Sturdy, Derek

    1994-10-01

    Tectonic movements continuously remould the surface of Earth in response to plate motion. Yet such deformation is rarely taken into account when assessing landscape change and its impact on human land use, except perhaps as an occasional hazard to human life or a temporary disruption in the longer term patterns of human history. However, active tectonics also create and sustain landscapes that can be beneficial to human survival, forming a complex topography of potentially fertile sedimentary basins enclosed by mountain barriers that can facilitate the control and explotation of food resources, especially animal prey. We discuss the tectonic history of northwest Greece and show how the Paleolithic sites of the region are located to take advantage of tectonically created features at both a local and a regional scale. We suggest that the association of significant concentrations of early Paleolithic sites with tectonically acitve regions is not coincidental and that on the longer time spans of human biological evolution, active tectonics has been an important selective agent contributing to the development of the human species as an intelligent predator.

  6. Introduction to Regional Geology, Tectonics, and Metallogenesis of Northeast Asia

    USGS Publications Warehouse

    Parfenov, Leonid M.; Badarch, Gombosuren; Berzin, Nikolai A.; Hwang, Duk-Hwan; Khanchuk, Alexander I.; Kuzmin, Mikhail I.; Nokleberg, Warren J.; Obolenskiy, Alexander O.; Ogasawara, Masatsugu; Prokopiev, Andrei V.; Rodionov, Sergey M.; Smelov, Alexander P.; Yan, Hongquan

    2007-01-01

    This introduction presents an overview of the regional geology, tectonics, and metallogenesis of Northeast Asia. The major purposes are to provide a relatively short summary of these features for readers who are unfamiliar with Northeast Asia; a general scientific introduction for the succeeding chapters of this volume; and an overview of the methodology of metallogenic and tectonic analysis employed for Northeast Asia. The introduction also describes how a high-quality metallogenic and tectonic analysis, including synthesis of an associated metallogenic-tectonic model will greatly benefit refinement of mineral deposit models and deposit genesis; improvement of assessments of undiscovered mineral resources as part of quantitative mineral resource assessment studies; land-use and mineral exploration planning; improvement of interpretations of the origins of host rocks, mineral deposits, and metallogenic belts; and suggestions for new research. The compilation, synthesis, description, and interpretation of metallogenesis and tectonics of major regions, such as Northeast Asia (Eastern Russia, Mongolia, northern China, South Korea, and Japan) and the Circum-North Pacific (Russian Far East, Alaska, and Canadian Cordillera) requires a complex methodology. The methodology includes: (1) definitions of key terms; (2) compilation of a regional geologic base map that can be interpreted according to modern tectonic concepts and definitions; (3) compilation of a mineral deposit database that enables the determination of mineral deposit models, and relations of deposits to host rocks and tectonic origins; (4) synthesis of a series of mineral deposit models that characterize the known mineral deposits and inferred undiscovered deposits of the region; (5) compilation of a series of maps of metallogenic belts constructed on the regional geologic base map; and (6) formulation of a unified metallogenic and tectonic model. The summary of regional geology and metallogenesis in this

  7. Mantle plumes and continental tectonics.

    PubMed

    Hill, R I; Campbell, I H; Davies, G F; Griffiths, R W

    1992-04-10

    Mantle plumes and plate tectonics, the result of two distinct modes of convection within the Earth, operate largely independently. Although plumes are secondary in terms of heat transport, they have probably played an important role in continental geology. A new plume starts with a large spherical head that can cause uplift and flood basalt volcanism, and may be responsible for regional-scale metamorphism or crustal melting and varying amounts of crustal extension. Plume heads are followed by narrow tails that give rise to the familiar hot-spot tracks. The cumulative effect of processes associated with tail volcanism may also significantly affect continental crust.

  8. Task 1 quarternary tectonics

    SciTech Connect

    Bell, J.W.

    1994-12-31

    Activities on the task of quarternary tectonics for the Yucca Mountain Site investigations are described. Technical topics include: A preliminary reveiw of Bare Mountain Trench; A preliminary detailed lineament map of the Southwestern part of the proposed repository; A discussion on the 1994 Double Spring Flat, Nevada earthquake; and evidence for temporal clustering.

  9. The Plate Tectonics Project

    ERIC Educational Resources Information Center

    Hein, Annamae J.

    2011-01-01

    The Plate Tectonics Project is a multiday, inquiry-based unit that facilitates students as self-motivated learners. Reliable Web sites are offered to assist with lessons, and a summative rubric is used to facilitate the holistic nature of the project. After each topic (parts of the Earth, continental drift, etc.) is covered, the students will…

  10. Tectonic Evolution of Mars

    NASA Technical Reports Server (NTRS)

    Phillips, Roger J.

    1992-01-01

    The Final Technical Report on tectonic evolution of Mars is presented. Two papers and an abstract are included. Topics addressed include: scientific rationale and requirements for a global seismic network on Mars, permanent uplift in magmatic systems with application to the Tharsis Region of Mars, and the geophysical signal of the Martian global dichotomy.

  11. Dance Education in Korea

    ERIC Educational Resources Information Center

    Byeon, Jae-Kyung

    2012-01-01

    Despite a structured physical education system and related policies, dance education in Korea largely exists as a course in name only, without achieving its unique goals. It lacks standards within the physical education curriculum, which indicates that dance education is not conducted properly. Thus, the content and level of dance education vary…

  12. Korea's School Grounds Projects

    ERIC Educational Resources Information Center

    Park, Joohun

    2003-01-01

    This article describes two projects which Korea has undertaken to improve its school grounds: (1) the Green School Project; and (2) the School Forest Pilot Project. The Korean Ministry of Education and Human Resources Development (MOE&HRI) recently launched the Green School Project centred on existing urban schools with poor outdoor…

  13. Studies in geophysics: Active tectonics

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Active tectonics is defined within the study as tectonic movements that are expected to occur within a future time span of concern to society. Such movements and their associated hazards include earthquakes, volcanic eruptions, and land subsidence and emergence. The entire range of geology, geophysics, and geodesy is, to some extent, pertinent to this topic. The needs for useful forecasts of tectonic activity, so that actions may be taken to mitigate hazards, call for special attention to ongoing tectonic activity. Further progress in understanding active tectonics depends on continued research. Particularly important is improvement in the accuracy of dating techniques for recent geologic materials.

  14. When Did Plate Tectonics Begin

    NASA Astrophysics Data System (ADS)

    Brown, M.

    2015-12-01

    Present-day plate tectonics on Earth is characterized by asymmetric (one-sided) subduction, but how do we recognize the imprint of subduction in the geologic record? How do we weigh global (commonly younger) vs local (commonly older) datasets or distinguish initiation from episodic from continuous subduction? How reliable are data gaps? Characteristics of the Paleozoic record of subduction include calc-alkaline magmatism, blueschist/UHP metamorphism and collisional orogenesis, and ophiolites as representatives of former ocean lithosphere. Are these characteristic rocks preserved in Proterozoic, Archean and Hadean crust? Does a hotter mantle, higher heat production and weaker lithosphere modify or eliminate these features? What preceded subduction and how do we recognize that regime? Are rock associations or geochemical fingerprints reliable? Does reworking and overprinting modify geochemical fingerprints? Proposals for the start of plate tectonics have been based on: persistence of isotope anomalies/fractionated chemical domains in the mantle; changes in chemistry of magmatic rocks, rates of crustal growth vs reworking, and sites of growth; the metamorphic record, particularly the first appearance of contrasting thermal gradients or eclogite (including evidence from mineral inclusions in diamonds) or UHP metamorphic rocks; stabilization of cratonic lithosphere and formation of supercratons, and the beginning of the Proterozoic supercontinent cycle; the end of the flat Earth, emergence of continents, development of significant topography, changes in the style of orogeny and the rise in atmospheric oxygen; and, the appearance of passive margins and changes in the style of sedimentation. Estimates of the timing have varied from the Hadean to Neoproterozoic. I will summarize evidence for a growing consensus that the late Mesoarchean to early Paleoproterozoic was a 700 Myr long period of transition to continuous (?) subduction and global (?) mobile-lid plate tectonics.

  15. Venusian tectonics: Convective coupling to the lithosphere?

    NASA Technical Reports Server (NTRS)

    Phillips, R. J.

    1987-01-01

    The relationship between the dominant global heat loss mechanism and planetary size has motivated the search for tectonic style on Venus. Prior to the American and Soviet mapping missions of the past eight years, it was thought that terrestrial style plate tectonics was operative on Venus because this planet is approximately the size of the Earth and is conjectured to have about the same heat source content per unit mass. However, surface topography mapped by the altimeter of the Pioneer Venus spacecraft did not show any physiographic expression of terrestrial style spreading ridges, trenches, volcanic arcs or transform faults, although the horizontal resolution was questionable for detection of at least some of these features. The Venera 15 and 16 radar missions mapped the northern latitudes of Venus at 1 to 2 km resolution and showed that there are significant geographic areas of deformation seemingly created by large horizontal stresses. These same high resolution images show no evidence for plate tectonic features. Thus a fundamental problem for venusian tectonics is the origin of large horizontal stresses near the surface in the apparent absence of plate tectonics.

  16. Tectonic connections to interior processes on Venus

    NASA Technical Reports Server (NTRS)

    Phillips, R. J.

    1992-01-01

    The ultimate goal of geophysical/geological exploration of Venus is to relate the present tectonic (and volcanic) state of the lithosphere to interior processes, particularly mantle convection, operating both now and in the past. The Magellan mission has provided a spectacular view of the surface, and upcoming gravity measurements, particularly if the Magellan orbit is circularized, will provide significant constraints on the state of the interior. This extended abstract focuses on several controversial issues regarding venusian tectonics and its relationship to geodynamic mechanisms in the planet's interior. The origin of highlands, coronae diapir structures, and trenches and subduction are discussed.

  17. Plate tectonics, habitability and life

    NASA Astrophysics Data System (ADS)

    Spohn, Tilman; Breuer, Doris

    2016-04-01

    The role of plate tectonics in defining habitability of terrestrial planets is being increasingly discussed (e.g., Elkins-Tanton, 2015). Plate tectonics is a significantly evolved concept with a large variety of aspects. In the present context, cycling of material between near surface and mantle reservoirs is most important. But increased heat transport through mixing of cold lithosphere with the deep interior and formation of continental crust may also matter. An alternative mechanism of material cycling between these reservoirs is hot-spot volcanism combined with crust delamination. Hot-spot volcanism will transport volatiles to the atmosphere while delamination will mix crust, possibly altered by sedimentation and chemical reactions, with the mantle. The mechanism works as long as the stagnant lithosphere plate has not grown thicker than the crust and as long as volcanic material is added onto the crust. Thermal evolution studies suggest that the mechanism could work for the first 1-2 Ga of planetary evolution. The efficiency of the mechanism is limited by the ratio of extrusive to intrusive volcanism, which is thought to be less than 0.25. Plate tectonics would certainly have an advantage by working even for more evolved planets. A simple, most-used concept of habitability requires the thermodynamic stability of liquid water on the surface of a planet. Cycling of CO2between the atmosphere, oceans and interior through subduction and surface volcanism is an important element of the carbonate-silicate cycle, a thermostat feedback cycle that will keep the atmosphere from entering into a runaway greenhouse. Calculations for a model Earth lacking plate tectonics but degassing CO2, N, and H2O to form a surface ocean and a secondary atmosphere (Tosi et al, 2016) suggest that liquid water can be maintained on the surface for 4.5Ga. The model planet would then qualify as habitable. It is conceivable that the CO2 buffering capability of its ocean together with silicate

  18. Identifying active interplate and intraplate fault zones in the western Caribbean plate from seismic reflection data and the significance of the Pedro Bank fault zone in the tectonic history of the Nicaraguan Rise

    NASA Astrophysics Data System (ADS)

    Ott, B.; Mann, P.

    2015-12-01

    The offshore Nicaraguan Rise in the western Caribbean Sea is an approximately 500,000 km2 area of Precambrian to Late Cretaceous tectonic terranes that have been assembled during the Late Cretaceous formation of the Caribbean plate and include: 1) the Chortis block, a continental fragment; 2) the Great Arc of the Caribbean, a deformed Cretaceous arc, and 3) the Caribbean large igneous province formed in late Cretaceous time. Middle Eocene to Recent eastward motion of the Caribbean plate has been largely controlled by strike-slip faulting along the northern Caribbean plate boundary zone that bounds the northern margin of the Nicaraguan Rise. These faults reactivate older rift structures near the island of Jamaica and form the transtensional basins of the Honduran Borderlands near Honduras. Recent GPS studies suggest that small amount of intraplate motion within the current margin of error of GPS measurements (1-3 mm/yr) may occur within the center of the western Caribbean plate at the Pedro Bank fault zone and Hess Escarpment. This study uses a database of over 54,000 km of modern and vintage 2D seismic data, combined with earthquake data and results from previous GPS studies to define the active areas of inter- and intraplate fault zones in the western Caribbean. Intraplate deformation occurs along the 700-km-long Pedro Bank fault zone that traverses the center of the Nicaraguan Rise and reactivates the paleo suture zone between the Great Arc of the Caribbean and the Caribbean large igneous province. The Pedro Bank fault zone also drives active extension at the 200-km-long San Andres rift along the southwest margin of the Nicaraguan Rise. Influence of the Cocos Ridge indentor may be contributing to reactivation of faulting along the southwesternmost, active segment of the Hess Escarpment.

  19. Tectonics of Atlantic Canada

    USGS Publications Warehouse

    Williams, H.; Dehler, S.A.; Grant, A.C.; Oakey, G.N.

    1999-01-01

    The tectonic history of Atlantic Canada is summarized according to a model of multiple ocean opening-closing cycles. The modern North Atlantic Ocean is in the opening phase of its cycle. It was preceded by an early Paleozoic lapetus Ocean whose cycle led to formation of the Appalachian Orogen. lapetus was preceded by the Neoproterozoic Uranus Ocean whose cycle led to formation of the Grenville Orogen. The phenomenon of coincident, or almost coincident orogens and modern continental margins that relate to repeated ocean opening-closing cycles is called the Accordion Effect. An understanding of the North Atlantic Ocean and its continental margins provides insights into the nature of lapetus and the evolution of the Appalachian Orogen. Likewise, an understanding of lapetus and the Appalachian Orogen raises questions about Uranus and the development of the Grenville Orogen. Modern tectonic patterns in the North Atlantic may have been determined by events that began before 1000 m.y.

  20. Earth's Decelerating Tectonic Plates

    SciTech Connect

    Forte, A M; Moucha, R; Rowley, D B; Quere, S; Mitrovica, J X; Simmons, N A; Grand, S P

    2008-08-22

    Space geodetic and oceanic magnetic anomaly constraints on tectonic plate motions are employed to determine a new global map of present-day rates of change of plate velocities. This map shows that Earth's largest plate, the Pacific, is presently decelerating along with several other plates in the Pacific and Indo-Atlantic hemispheres. These plate decelerations contribute to an overall, globally averaged slowdown in tectonic plate speeds. The map of plate decelerations provides new and unique constraints on the dynamics of time-dependent convection in Earth's mantle. We employ a recently developed convection model constrained by seismic, geodynamic and mineral physics data to show that time-dependent changes in mantle buoyancy forces can explain the deceleration of the major plates in the Pacific and Indo-Atlantic hemispheres.

  1. An Update on Tectonics

    NASA Astrophysics Data System (ADS)

    Geissman, John W.; Faccenna, Claudio; Niemi, Nathan A.

    2014-10-01

    In February 1982, the first issue of Tectonics was published. In the editorial policy statement for the journal, founding editors John Dewey, Paul Tapponier, and Clark Burchfiel wrote, "The central theme of Tectonics is the mechanical and thermal evolution of the lithospheric crust and mantle and the way that this is reflected in cratons, basins and mountains from the broad regional scale to the fine scale." The editors further stated, "We expect that papers on these and related topics would emanate from a wide variety of earth science disciplines ranging from physical modeling to geological field observation." Finally, with the confidence from this incredible team of editors, they noted, "We are aiming for a very rapid review process, allowing a maximum of about 1 month between submission and notification to the author of acceptance or rejection."

  2. Tectonically Asymmetric Earth

    NASA Astrophysics Data System (ADS)

    Doglioni, C.; Carminati, E.; Crespi, M.; Cuffaro, M.; Panza, G. F.; Riguzzi, F.

    2011-12-01

    The net rotation, or so-called W-ward drift of the lithosphere, implies a decoupling of the plates relative to the underlying asthenosphere, and a relative "E-ward" mantle flow. This polarized flow can account for a number of asymmetries. When comparing the W-directed versus the E- to NE-directed subduction zones, as a general observation, they have the subduction hinge diverging versus converging relative to the upper plate; low versus high topography and structural elevation respectively; deep versus shallow trenches and foreland basins; shallow versus deep decollement; low versus high basement involvement; high versus low heat flow and gravity anomaly; shallow versus deep asthenosphere; etc. The western limbs of rift zones have in average a deeper bathymetry, and show S-waves faster in the lithosphere and slower in the asthenosphere with respect to the eastern limb. These asymmetries can be recognized when moving along the "tectonic equator", which describes the fastest flow of plates relative to the mantle, and it undulates relative to the geographic equator, with an angle of about 30°. Shear-wave splitting alignments tend to parallel the tectonic flow, apart along the subduction zones where they become orthogonal, as a flow encountering an obstacle. The estimates of the net rotation span from 0.2° to 1.2° Ma. However, only a net rotation >1° Ma is required in order to satisfy the aforementioned tectonically asymmetric Earth. In our reconstructions, the best fit for the tectonic equator has a pole of rotation at latitude 56.4° and longitude 136.7°, with an angular velocity of 1.2036°/Ma. This velocity can be obtained only if the source of the so-called volcanic trails or plumes are sourced from the middle of the low-velocity layer, at the top of the asthenosphere, i.e., within the decoupling layer of the plates relative to the underlying mantle. The tectonic equator lies close to the revolution plane of the Moon about the Earth. All these data and

  3. The global tectonic pattern

    NASA Astrophysics Data System (ADS)

    Doglioni, Carlo

    1990-07-01

    The relative motion vectors between the lithosphere and the underlying mantle appear to follow global flow lines which can be constructed by linking axes of extension and compression over the Earth's surface. The flow lines for the last 40 Ma are generally WNW-ESE (E-W), with an undulation of an about 15,000 km wavelength, showing a gradual and progressive variation in orientation. The undulation, which is sharper to the east, may reflect the mantle flow around an unstable rotation axis. The westward motion of the lithospheric plates could be interpreted as a result of differential angular velocity induced by the deceleration of the earth's rotation or, in a toroidal field, by the effects induced by lateral heterogeneities both in the lithosphere and in the mantle. In this light, plate tectonics is a consequence of variable decoupling at the base of the lithosphere as a function of mantle anisotropies. Simply stated, when there is compression or transpression between two plates, it is the eastern plate which moves more rapidly westwards relative to the underlying mantle. If there is extension or transtension, it is the western plate that moves faster westwards. Lithospheric subduction, especially if it dips westward, produces an obstacle to the eastward flow of the mantle. This is referred to as the Nail Effect. The eastward roll-back of the subduction hinge due to the mantle push will generate back-arc extension. Subductions following the mantle flow (E or NE-dipping) are associated to thicker thrust belts with huge exposures of basement rocks in the hinterland and shallow foreland basins. The subductions contrasting the mantle flow (W or SW-dipping) are characterized by shallow thrust belts with deep foreland basin and coeval extension in the back. E-dipping subductions are passive responses to actively thrusting plates: the base plate and intra-lithospheric decollements are connected to the surface and can uplift deep rocks. The W-dipping subductions are

  4. Universal planetary tectonics (supertectonics)

    NASA Astrophysics Data System (ADS)

    Kochemasov, G. G.

    2009-04-01

    Universal planetary tectonics (supertectonics) G. Kochemasov IGEM of the Russian Academy of Sciences, Moscow, Russia, kochem.36@mail.ru The wave planetology [1-3 & others] proceeds from the following: "planetary structures are made by orbits and rotations". A uniform reason makes uniform structures. Inertia-gravity waves arising in planetary bodies due to their movements in Keplerian elliptical orbits with periodically changing accelerations warp these bodies in such way that they acquire polyhedron shapes (after interference of standing waves of four directions). Strong Newtonian gravity makes bodies larger than ~400 to 500 km in diameter globular and polyhedra are rarely seen. Only geomorphologic, geologic and geophysical mapping can develop these hidden structures. But small bodies, normally less than ~ 300 to 400 km in diameter, often show parts of the polyhedra, rarely fully developed forms (the asteroid Steins and satellite Amalthea present rather perfect forms of "diamond"). Depending on warping wavelengths (they make harmonics) various Plato's figures superimposed on each other can be distinguished. The fundamental wave 1 produces a tetrahedron, intrinsically dichotomic figure in which a vertex (contraction) always is opposed to a face (expansion). From the recent examples the best is the saturnian northern hexagon (a face) opposed to the southern hurricane (a vertex). The first overtone wave 2 is responsible for creation of structural octahedra. Whole ‘diamonds" and their parts are known [4, 5]. Other overtones produce less developed (because of smaller wave amplitudes) planetary shapes complicating main forms. Thus, the first common structural peculiarity of planetary bodies is their polyhedron nature. Not less important is the second common structural peculiarity. As all globular or smaller more or less isometric bodies rotate, they have an angular momentum. It is inevitably different in tropic and extra-tropic belts having uneven radii or distances to

  5. East Asia: Korea.

    DTIC Science & Technology

    2007-11-02

    contusions, concussions, fractured skulls , ruptured occipital bones, facial lacerations, injuries to eyes and noses, and damaged blood vessels in the... Alienation "The principal reason the military cannot preside over a civilian government is that we officers have a strong tendency of confusing...KOREA socially alienated classes that could be potentially rebel- lious. Chong reacted by inviting the principals of the nation’s leading high

  6. South Korea Leads the Warfight

    DTIC Science & Technology

    2007-01-01

    warfighting command in a doctrinally supporting relationship to the ROK armed forces. The evolution to a Korean -led defense of the Republic of Korea is a...T he Republic of Korea –U.S. alliance is embarking on the most profound transformation affecting American forces on the peninsula since the Korean ...War. For the last 57 years, the United States has led the war- fighting command responsible for the defense of the Republic of Korea (ROK). As the ROK

  7. The history of tectonism on Venus: A stratigraphic analysis

    NASA Astrophysics Data System (ADS)

    Ivanov, Mikhail A.; Head, James W.

    2015-08-01

    The surface of Venus displays several tectonized terrains in which the morphologic characteristics of the original materials are almost completely erased by superposed tectonic structures whose large dimensions (»100 km) suggest formation related to mantle convection. The characteristics of these tectonized terrains are in contrast to volcanic units in which tectonic structures are less significant or absent and thus do not obscure the volcanic character of the units. We describe the temporal distribution of tectonized terrains, their stratigraphic relationships with volcanic units, and how these outline the major episodes in the geological evolution of Venus. Five major tectonized units make up ~20% of the planet: (1) tessera (t, 7.3%), (2) densely lineated plains (pdl, 1.6%), (3) ridged plains/ridge belts (pr/rb, 2.4%), (4) groove belts (gb, 8.1%), and (5) rift zones (rz, 5.0%). Clear relationships of relative age are often seen among the tectonic and volcanic units at the global scale and define three contrasting regimes of volcanic and tectonic resurfacing. The majority of tectonized terrains (t through gb) are the products of tectonic resurfacing and are embayed by the vast volcanic plains and, thus, are older. There are no units with either mildly- or non-tectonized surfaces that interleave the tectonic terrains, which would be expected if the tectonic resurfacing operated only during specific repetitive phases in discrete regions. These tectonized terrains (t through gb) thus define a tectonically dominated regime of resurfacing that occurred at a global-scale near the beginning of the observable geological history of Venus. This ancient tectonic regime began with formation of tessera and was followed by formation of pdl and pr/rb. Groove belts formed near the end of this regime. Branches of groove belts compose the tectonic components of many coronae, suggesting that these features are genetically related (e.g., mutual development of mantle diapirs and

  8. Martian plate tectonics

    NASA Astrophysics Data System (ADS)

    Sleep, N. H.

    1994-03-01

    The northern lowlands of Mars have been produced by plate tectonics. Preexisting old thick highland crust was subducted, while seafloor spreading produced thin lowland crust during late Noachian and Early Hesperian time. In the preferred reconstruction, a breakup margin extended north of Cimmeria Terra between Daedalia Planum and Isidis Planitia where the highland-lowland transition is relatively simple. South dipping subduction occured beneath Arabia Terra and east dipping subduction beneath Tharsis Montes and Tempe Terra. Lineations associated with Gordii Dorsum are attributed to ridge-parallel structures, while Phelegra Montes and Scandia Colles are interpreted as transfer-parallel structures or ridge-fault-fault triple junction tracks. Other than for these few features, there is little topographic roughness in the lowlands. Seafloor spreading, if it occurred, must have been relatively rapid. Quantitative estimates of spreading rate are obtained by considering the physics of seafloor spreading in the lower (approx. 0.4 g) gravity of Mars, the absence of vertical scarps from age differences across fracture zones, and the smooth axial topography. Crustal thickness at a given potential temperature in the mantle source region scales inversely with gravity. Thus, the velocity of the rough-smooth transition for axial topography also scales inversely with gravity. Plate reorganizations where young crust becomes difficult to subduct are another constraint on spreading age. Plate tectonics, if it occurred, dominated the thermal and stress history of the planet. A geochemical implication is that the lower gravity of Mars allows deeper hydrothermal circulation through cracks and hence more hydration of oceanic crust so that more water is easily subducted than on the Earth. Age and structural relationships from photogeology as well as median wavelength gravity anomalies across the now dead breakup and subduction margins are the data most likely to test and modify hypotheses

  9. Complex Tectonism on Ganymede

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Complex tectonism is evident in these images of Ganymede's surface. The solid state imaging camera on NASA's Galileo spacecraft imaged this region as it passed Ganymede during its second orbit through the Jovian system. The 80 kilometer (50 mile) wide lens-shaped feature in the center of the image is located at 32 degrees latitude and 188 degrees longitude along the border of a region of ancient dark terrain known as Marius Regio, and is near an area of younger bright terrain named Nippur Sulcus. The tectonism that created the structures in the bright terrain nearby has strongly affected the local dark terrain to form unusual structures such as the one shown here. The lens-like appearance of this feature is probably due to shearing of the surface, where areas have slid past each other and also rotated slightly. Note that in several places in these images, especially around the border of the lens-shaped feature, bright ridges appear to turn into dark grooves. Analysis of the geologic structures in areas like this are helping scientists to understand the complex tectonic history of Ganymede.

    North is to the top-left of the image, and the sun illuminates the surface from the southeast. The image covers an area about 63 kilometers (39 miles) by 120 kilometers (75 miles) across at a resolution of 188 meters (627 feet) per picture element. The images were taken on September 6, 1996 at a range of 18,522 kilometers (11,576 miles) by the solid state imaging (CCD) system on NASA's Galileo spacecraft.

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov.

  10. Retrospective salt tectonics

    SciTech Connect

    Jackson, M.P.A.

    1996-12-31

    The conceptual breakthroughs in understanding salt tectonics can be recognized by reviewing the history of salt tectonics, which divides naturally into three parts: the pioneering era, the fluid era, and the brittle era. The pioneering era (1856-1933) featured the search for a general hypothesis of salt diapirism, initially dominated by bizarre, erroneous notions of igneous activity, residual islands, in situ crystallization, osmotic pressures, and expansive crystallization. Gradually data from oil exploration constrained speculation. The effects of buoyancy versus orogeny were debated, contact relations were characterized, salt glaciers were discovered, and the concepts of downbuilding and differential loading were proposed as diapiric mechanisms. The fluid era (1933-{approximately}1989) was dominated by the view that salt tectonics resulted from Rayleigh-Taylor instabilities in which a dense fluid overburden having negligible yield strength sinks into a less dense fluid salt layer, displacing it upward. Density contrasts, viscosity contrasts, and dominant wavelengths were emphasized, whereas strength and faulting of the overburden were ignored. During this era, palinspastic reconstructions were attempted; salt upwelling below thin overburdens was recognized; internal structures of mined diapirs were discovered; peripheral sinks, turtle structures, and diapir families were comprehended; flow laws for dry salt were formulated; and contractional belts on divergent margins and allochthonous salt sheets were recognized. The 1970s revealed the basic driving force of salt allochthons, intrasalt minibasins, finite strains in diapirs, the possibility of thermal convection in salt, direct measurement of salt glacial flow stimulated by rainfall, and the internal structure of convecting evaporites and salt glaciers. The 1980`s revealed salt rollers, subtle traps, flow laws for damp salt, salt canopies, and mushroom diapirs.

  11. Mars tectonics and volcanism

    NASA Technical Reports Server (NTRS)

    Solomon, Sean C.

    1990-01-01

    The focus of this research was on three broad areas: (1) the relation between lithospheric stress in the vicinity of a growing volcano and the evolution of eruption characteristics and tectonic faulting; (2) the relation between elastic lithosphere thickness and thermal structure; and (3) a synthesis of constraints on heat flow and internal dynamics on Mars. The two reports presented are: (1) Heterogeneities in the Thickness of the Elastic Lithosphere of Mars--Constraints on Heat Flow and Internal Dynamics; and (2) State of Stress, Faulting, and Eruption Characteristics of Large Volcanoes on Mars.

  12. Quarternary tectonics, Task 1

    SciTech Connect

    Bell, J.W.

    1993-09-30

    Activities conducted for the evaluation of the geology and seismotectonics stability of Yucca Mountain as a potential site for the underground disposal of high-level radioactive wastes continued. Tasks concerned with quaternary tectonics include: scheduling of photography of Little Skull Mountain area; the collection and dating of rock varnish samples from the 1932 Cedar Mountain earthquake area for carbon 14 AMS and cation-ratio analysis; collection of samples for thermoluminescence dating from the 1932 Cedar Mountain earthquake area; mapping of the northern area of Crater Flat; and surveying of the May 17, 1993 Eureka the Valley earthquake area.

  13. Tectonic stress - Models and magnitudes

    NASA Technical Reports Server (NTRS)

    Solomon, S. C.; Bergman, E. A.; Richardson, R. M.

    1980-01-01

    It is shown that global data on directions of principal stresses in plate interiors can serve as a test of possible plate tectonic force models. Such tests performed to date favor force models in which ridge pushing forces play a significant role. For such models the general magnitude of regional deviatoric stresses is comparable to the 200-300 bar compressive stress exerted by spreading ridges. An alternative approach to estimating magnitudes of regional deviatoric stresses from stress orientations is to seek regions of local stress either demonstrably smaller than or larger than the regional stresses. The regional stresses in oceanic intraplate regions are larger than the 100-bar compression exerted by the Ninetyeast Ridge and less than the bending stresses (not less than 1 kbar) beneath Hawaii.

  14. North Korea: A Geographical Analysis.

    ERIC Educational Resources Information Center

    Palka, Eugene J., Ed.; Galgano, Francis A., Ed.

    North Korea is a country about the size of the state of New York, inhabited by about 23 million people. It came into existence after the conclusion of World War II following decades of occupation of the Korean Peninsula by the Japanese empire. Dividing the peninsula into North and South Korea was the politically expedient solution to one of the…

  15. Fires and smoke in Korea

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Moderate resolution Imaging Spectroradiometer (MODIS) on the Terra satellite detected several fires burning in South Korea on June 6, 2002. The smoke is blanketing both South and North Korea, and may be mingling with smoke from other fires in China. Beneath the haze, colored water at the southern tip of the Peninsula suggests sediment or phytoplankton in the coastal waters.

  16. Earthquakes and plate tectonics.

    USGS Publications Warehouse

    Spall, H.

    1982-01-01

    Earthquakes occur at the following three kinds of plate boundary: ocean ridges where the plates are pulled apart, margins where the plates scrape past one another, and margins where one plate is thrust under the other. Thus, we can predict the general regions on the earth's surface where we can expect large earthquakes in the future. We know that each year about 140 earthquakes of magnitude 6 or greater will occur within this area which is 10% of the earth's surface. But on a worldwide basis we cannot say with much accuracy when these events will occur. The reason is that the processes in plate tectonics have been going on for millions of years. Averaged over this interval, plate motions amount to several mm per year. But at any instant in geologic time, for example the year 1982, we do not know, exactly where we are in the worldwide cycle of strain build-up and strain release. Only by monitoring the stress and strain in small areas, for instance, the San Andreas fault, in great detail can we hope to predict when renewed activity in that part of the plate tectonics arena is likely to take place. -from Author

  17. 15 CFR 746.4 - North Korea.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false North Korea. 746.4 Section 746.4... CONTROLS § 746.4 North Korea. (a) Licensing Requirements. As authorized by section 6 of the Export... Democratic People's Republic of Korea (North Korea), except food and medicines classified as...

  18. Astrophysical Cause of Tectonics

    NASA Astrophysics Data System (ADS)

    Mensur, O.

    2016-05-01

    Tectonic earthquakes, of Mw (6 ± 5%)+, are found forming a strengthening-peaking-waning pattern distinguishable from respectively quiescent times so well that the pattern means discovery of a universal natural mechanism that necessitates expanding on classical physics. The pattern is seen only during Earth's alignments to two other heavenly bodies in our solar system lasting for more than 3 days. This empirical proof of astrophysical origins of seismotectonics is immediately obvious and verifiable. The find is consequential due to sheer size of processes and energies involved in defining the pattern that now enables all-or-nothing negative forecasting by foretelling dates without strong quakes. Near co-planarity of a solar system's planets, which is for our solar system typically regarded an oddity, is in fact a necessary condition for active geophysics as a life system.

  19. Intermittent plate tectonics?

    PubMed

    Silver, Paul G; Behn, Mark D

    2008-01-04

    Although it is commonly assumed that subduction has operated continuously on Earth without interruption, subduction zones are routinely terminated by ocean closure and supercontinent assembly. Under certain circumstances, this could lead to a dramatic loss of subduction, globally. Closure of a Pacific-type basin, for example, would eliminate most subduction, unless this loss were compensated for by comparable subduction initiation elsewhere. Given the evidence for Pacific-type closure in Earth's past, the absence of a direct mechanism for termination/initiation compensation, and recent data supporting a minimum in subduction flux in the Mesoproterozoic, we hypothesize that dramatic reductions or temporary cessations of subduction have occurred in Earth's history. Such deviations in the continuity of plate tectonics have important consequences for Earth's thermal and continental evolution.

  20. River history and tectonics.

    PubMed

    Vita-Finzi, C

    2012-05-13

    The analysis of crustal deformation by tectonic processes has gained much from the clues offered by drainage geometry and river behaviour, while the interpretation of channel patterns and sequences benefits from information on Earth movements before or during their development. The interplay between the two strands operates at many scales: themes which have already benefited from it include the possible role of mantle plumes in the breakup of Gondwana, the Cenozoic development of drainage systems in Africa and Australia, Himalayan uplift in response to erosion, alternating episodes of uplift and subsidence in the Mississippi delta, buckling of the Indian lithospheric plate, and changes in stream pattern and sinuosity along individual alluvial channels subject to localized deformation. Developments in remote sensing, isotopic dating and numerical modelling are starting to yield quantitative analyses of such effects, to the benefit of geodymamics as well as fluvial hydrology.

  1. Plate Tectonics: A Paradigm under Threat.

    ERIC Educational Resources Information Center

    Pratt, David

    2000-01-01

    Discusses the challenges confronting plate tectonics. Presents evidence that contradicts continental drift, seafloor spreading, and subduction. Reviews problems posed by vertical tectonic movements. (Contains 242 references.) (DDR)

  2. A tectonic resurfacing model for Venus

    NASA Technical Reports Server (NTRS)

    Solomon, Sean C.

    1993-01-01

    Two remarkable aspects of the population of impact craters on Venus are that craters at all sizes are indistinguishable from a random population and that the vast majority of craters have not been significantly modified by tectonic strain or by volcanic flows external to the crater rim, despite evidence from Magellan images that volcanic and tectonic features are widespread on Venus. One interpretation of these observations is that most of the surface dates from the end of a catastrophic global resurfacing event that ceased about 500 My ago, and that the small fraction of craters volcanically embayed or modified by deformation indicates that volcanic and tectonic activity subsequent to that time has been at much lower levels. An alternative model, in which resurfacing occurs episodically in patches a few hundred kilometers in extent and there is a wider spectrum of surface ages, also appears to be consistent with the characteristics of impact craters on Venus. A number of potential mechanisms for catastrophic resurfacing of Venus have been proposed, ranging from geologically sudden convective destabilization of the global lithosphere to strongly time-dependent heat flux and melt generation in the underlying mantle. In most of these geophysical models, resurfacing occurs implicitly or explicitly by volcanism. We explore the hypothesis that, at least in the geologically recent history of Venus, the primary resurfacing mechanism has been tectonic deformation rather than volcanism. We show how such a hypothesis provides at least as good an explanation of a wide range of observations as do volcanic resurfacing models. Finally, we explore the implications of tectonic resurfacing hypothesis for the controversy over the recent resurfacing history of the planet.

  3. Tectonics and metallogenic provinces

    USGS Publications Warehouse

    Guild, P.W.

    1983-01-01

    Various theories have been advanced to explain the well-known uneven distribution of metals and ore-deposit types in space and time. Primordial differences in the mantle, preferential concentration of elements in the crust, the prevalence of ore-forming processes at certain times and (or) places, and combinations of one or several of these factors have all been called upon to account for the "metallogenic provinces," which can be defined loosely as regions containing similar deposits of one or a group of metals or minerals. Because many, perhaps most, provinces have complex, multistage origins, the relative importance of inheritance vs. process is still controversial. In recent years the geographic relationship of many geologically young provinces to present-day plate-tectonic positions (accreting or consuming margins, intraplate structures, etc.) has been widely recognized, and the presumption is strong that older provinces had similar relationships to former plates. As most ore deposits resulted from a favorable conjunction of geological processes that are no longer operative, elucidation of their genesis requires reconstruction of the geologic history of the province, with particular emphasis on events coeval with mineralization. Tectonic analysis is an important aspect of this reconstruction; data from orbiting satellites have contributed greatly to this analysis, as the voluminous literature of the past decade testifies. Both the synoptic view of large areas and the ability to emphasize faint contrasts have revealed linear, curvilinear, and circular features not previously recognized from field studies. Some of these undoubtedly reflect basement structures that have contributed to the development, or limit the extent, of metallogenic provinces. Their recognition and delineation will be increasingly valuable to the assessment of resources available and as guides to exploration for the ores needed by future generations. ?? 1983.

  4. Greenstone belt tectonics: Thermal constraints

    NASA Technical Reports Server (NTRS)

    Bickle, M. J.; Nisbet, E. G.

    1986-01-01

    Archaean rocks provide a record of the early stages of planetary evolution. The interpretation is frustrated by the probable unrepresentative nature of the preserved crust and by the well known ambiguities of tectonic geological synthesis. Broad constraints can be placed on the tectonic processes in the early Earth from global scale modeling of thermal and chemical evolution of the Earth and its hydrosphere and atmosphere. The Archean record is the main test of such models. Available general model constraints are outlined based on the global tectonic setting within which Archaean crust evolved and on the direct evidence the Archaean record provides, particularly the thermal state of the early Earth.

  5. Occupational Infection in Korea

    PubMed Central

    Ahn, Yeon-Soon; Jeong, Jae Sim

    2010-01-01

    Occupational infection is a human disease caused by work-associated exposure to microbial agents through human and environmental contact. According to the literature, occupational infection was the third leading cause of occupational disease (861 cases, 8.0%), and health care, agricultural, forestry, and fishery workers were risk groups in Korea. In addition, most high-risk groups have not been protected by workers' compensation, which could lead to underestimation of the exact spectrum and magnitude of the problem, and may also result in a lack of development and implementation of occupational infection management. Through a review of national guidelines and documentations on prevention and control of occupational infection, a management strategy would promote adherence to worker safety regulations if it is explicit with regard to the agent and mode of infection in each of the high-risk groups. PMID:21258592

  6. Occupational Asthma in Korea

    PubMed Central

    Kim, Kyoo Sang

    2010-01-01

    Occupational asthma (OA) is the leading occupational respiratory disease. Cases compensated as OA by the Korea Workers' Compensation and Welfare Service (COMWEL) (218 cases), cases reported by a surveillance system (286 cases), case reports by related scientific journals and cases confirmed by the Occupational Safety and Health Research Institute (OSHRI) over 15 yr from 1992 to 2006 were analyzed. Annual mean incidence rate was 1.6 by compensation and 3.5 by surveillance system, respectively. The trend appeared to increase according to the surveillance system. Incidence was very low compared with other countries. The most frequently reported causative agent was isocyanate followed by reactive dye in dyeing factories. Other chemicals, metals and dust were also found as causative agents. OA was underreported according to compensation and surveillance system data. In conclusion, a more effective surveillance system is needed to evaluate OA causes and distribution, and to effectively prevent newly developing OA. PMID:21258586

  7. Continental tectonics in the aftermath of plate tectonics

    NASA Technical Reports Server (NTRS)

    Molnar, Peter

    1988-01-01

    It is shown that the basic tenet of plate tectonics, rigid-body movements of large plates of lithosphere, fails to apply to continental interiors. There, buoyant continental crust can detach from the underlying mantle to form mountain ranges and broad zones of diffuse tectonic activity. The role of crustal blocks and of the detachment of crustal fragments in this process is discussed. Future areas of investigation are addressed.

  8. EPA Collaboration with South Korea

    EPA Pesticide Factsheets

    EPA, the Ministry of Environment of Korea, and partner agencies in both countries cooperate to strengthen environmental governance, improve air and water quality, and reduce exposure to toxic chemicals.

  9. North Korea: Terrorism List Removal

    DTIC Science & Technology

    2010-01-06

    Chin Se-ku. Yongbyon nuclear facility can be disabled within a year. JongAng Ilbo (internet version), March 13, 2007. 30 Abductions by N. Korea not...3007. 33 Choe Sang- hun and David E. Sanger, North Korea claims U.S. will remove sanctions, International Herald Tribune, September 4, 2007, p. 5...spring of 2007 to smuggle conventional arms, including machine guns , automatic rifles, and anti-tank rocket launchers, to the Tamil Tigers in Sri

  10. Tectonics: Changing of the plates

    NASA Astrophysics Data System (ADS)

    Brandon, Alan

    2016-10-01

    The composition of Earth's crust depends on the style of plate tectonics and of the melting regimes in the mantle. Analyses of the oldest identified rocks suggest that these styles and the resulting crust have changed over Earth's history.

  11. Tectonic Terminology: Some Proposed Changes

    ERIC Educational Resources Information Center

    Hill, Mason L.

    1978-01-01

    Plate tectonics concepts require a definition of fault, a new term to compliment epeirogeny, and a clarification of transform fault characteristics. This article makes proposals for these changes. (Author/MA)

  12. Jadeitites and Plate Tectonics

    NASA Astrophysics Data System (ADS)

    Harlow, George E.; Tsujimori, Tatsuki; Sorensen, Sorena S.

    2015-05-01

    Jadeitite is a relatively rare, very tough rock composed predominantly of jadeite and typically found associated with tectonic blocks of high-pressure/low-temperature metabasaltic rocks (e.g., eclogite, blueschist) in exhumed serpentinite-matrix mélanges. Studies over the past ˜20 years have interpreted jadeitite either as the direct hydrous fluid precipitate from subduction channel dewatering into the overlying mantle wedge or as the metasomatic replacement by such fluids of oceanic plagiogranite, graywacke, or metabasite along the channel margin. Thus, jadeitites directly sample and record fluid transport in the subduction factory and provide a window into this geochemical process that is critical to a major process in the Earth system. They record the remarkable transport of large ion lithophile elements, such as Li, Ba, Sr, and Pb, as well as elements generally considered more refractory, such as U, Th, Zr, and Hf. Jadeitite is also the precious form of jade, utilized since antiquity in the form of tools, adornments, and symbols of prestige.

  13. Salt tectonics on Venus

    SciTech Connect

    Wood, C.A.; Amsbury, D.

    1986-05-01

    The discovery of a surprisingly high deuterium/hydrogen ratio on Venus immediately led to the speculation that Venus may have once had a volume of surface water comparable to that of the terrestrial oceans. The authors propose that the evaporation of this putative ocean may have yielded residual salt deposits that formed various terrain features depicted in Venera 15 and 16 radar images. By analogy with models for the total evaporation of the terrestrial oceans, evaporite deposits on Venus should be at least tens to hundreds of meters thick. From photogeologic evidence and in-situ chemical analyses, it appears that the salt plains were later buried by lava flows. On Earth, salt diapirism leads to the formation of salt domes, anticlines, and elongated salt intrusions - features having dimensions of roughly 1 to 100 km. Due to the rapid erosion of salt by water, surface evaporite landforms are only common in dry regions such as the Zagros Mountains of Iran, where salt plugs and glaciers exist. Venus is far drier than Iran; extruded salt should be preserved, although the high surface temperature (470/sup 0/C) would probably stimulate rapid salt flow. Venus possesses a variety of circular landforms, tens to hundreds of kilometers wide, which could be either megasalt domes or salt intrusions colonizing impact craters. Additionally, arcurate bands seen in the Maxwell area of Venus could be salt intrusions formed in a region of tectonic stress. These large structures may not be salt features; nonetheless, salt features should exist on Venus.

  14. Korea's developmental program for superconductivity

    NASA Technical Reports Server (NTRS)

    Hong, Gye-Won; Won, Dong-Yeon; Kuk, Il-Hyun; Park, Jong-Chul

    1995-01-01

    Superconductivity research in Korea was firstly carried out in the late 70's by a research group in Seoul National University (SNU), who fabricated a small scale superconducting magnetic energy storage system under the financial support from Korea Electric Power Company (KEPCO). But a few researchers were involved in superconductivity research until the oxide high Tc superconductor was discovered by Bednorz and Mueller. After the discovery of YBaCuO superconductor operating above the boiling point of liquid nitrogen (77 K)(exp 2), Korean Ministry of Science and Technology (MOST) sponsored a special fund for the high Tc superconductivity research to universities and national research institutes by recognizing its importance. Scientists engaged in this project organized 'High Temperature Superconductivity Research Association (HITSRA)' for effective conducting of research. Its major functions are to coordinate research activities on high Tc superconductivity and organize the workshop for active exchange of information. During last seven years the major superconductivity research has been carried out through the coordination of HITSRA. The major parts of the Korea's superconductivity research program were related to high temperature superconductor and only a few groups were carrying out research on conventional superconductor technology, and Korea Atomic Energy Research Institute (KAERI) and Korea Electrotechnology Research Institute (KERI) have led this research. In this talk, the current status and future plans of superconductivity research in Korea will be reviewed based on the results presented in interim meeting of HITSRA, April 1-2, 1994. Taejeon, as well as the research activity of KAERI.

  15. Tectonics of the central Andes

    NASA Technical Reports Server (NTRS)

    Bloom, Arthur L.; Isacks, Bryan L.; Fielding, Eric J.; Fox, Andrew N.; Gubbels, Timothy L.

    1989-01-01

    Acquisition of nearly complete coverage of Thematic Mapper data for the central Andes between about 15 to 34 degrees S has stimulated a comprehensive and unprecedented study of the interaction of tectonics and climate in a young and actively developing major continental mountain belt. The current state of the synoptic mapping of key physiographic, tectonic, and climatic indicators of the dynamics of the mountain/climate system are briefly reviewed.

  16. Tectonic significance of the Valera Fault Zone, Northwestern Venezuela

    SciTech Connect

    Rodrigues, J.; Bueno, E.; Ostos, M. )

    1993-02-01

    A detailed structural study was performed at the southern end of the north-south to north-northwest Valera fault zone. The area is particularly interesting, since it lies close to the triple point were the Maracaibo and Lara blocks meet the South American plate. The fault zone is associated with an anticlinorium with the following structural features: (a) conic folds with hinges oriented N26-35E; (b) a main, left-lateral, north-northwest to north-south fault population; (c) a secondary set of dextral west-northwest faults; and (d) two secondary sets of left-lateral northwest and northeast faults. The structural pattern and the dynamic analysis of the faults, which indicated a N 46-50 W shortening, is compatible with the spatial arrangement of structures associated with a north-south to north-northwest sinistral strike-slip fault. A regional interpretation based on seismic sections tied to wells suggests a continuous and complex structural evolution including: (a) early Eocene northwesterly trending normal faulting, at the forebulge developed during the emplacement of the Lara nappes; (b) Early Neogene NW reverse faulting and inversion of early normal faults, at the transpressive zone that bounded the Maracaibo and Lara blocks; (c) Late Neogene development of the sinistral Valera fault zone to accomodate the tangential component of the relative movement between the two blocks.

  17. Tectonic significance of Currant Creek formation, north-central Utah

    SciTech Connect

    Isby, J.S.; Picard, M.D.

    1984-07-01

    The Currant Creek Formation is composed of conglomerate, sandstone, and fine-grained clastic rocks that crop out along the northwestern margin of the Uinta basin in north-central Utah. Lateral gradations in grain size define proximal, medial, and distal parts of coalescing alluvial-fan deposits that prograded eastward from the active Sevier-Laramide orogenic belt during Maestrichtian through Paleocene (.) time. Paleocurrent directions indicate a dominant southerly transport direction and a minor easterly component. Strong east and southeasterly directions, measured in imbricated clasts and in sand lenses in conglomerate, indicate multiple source areas for the detritus. Source of the coarse-grained detritus in the Currant Creek Formation was the Charleston thrust sheet. Conglomeratic clasts are composed of Precambrian and Cambrian quartzite, chert derived from Cambrian and Mississippian carbonate beds, and Pennsylvanian sandstone. These rocks are exposed in the upper plate of the Charleston thrust near Deer Creek Reservoir, Mount Timpanogos, and Strawberry Reservoir. At Big and Little Cottonwood Canyons, the same rocks are exposed in the lower plate.

  18. Planetary Geophysics and Tectonics

    NASA Technical Reports Server (NTRS)

    Parmentier, E. M.

    1997-01-01

    Research supported by grant NAGW-1928 has addressed a variety of problems related to planetary evolution. One important focus has been on questions related to the role of chemical buoyancy in planetary evolution with application to both Venus and the Moon. We have developed a model for the evolution of the Moon (Hess and Parmentier, 1995) in which dense, highly radioactive, late stage magma ocean cumulates sink forming a core. This core heats the overlying, chemically layered mantle giving rise to a heated, chemically well-mixed layer that thickens with time. This Mixed layer eventually becomes hot enough and thick enough that its top begins to melt at a pressure low enough that melt is buoyant, thus creating mare basalts from a high pressure source of the correct composition and at an appropriate time in lunar evolution. In work completed during the last year, numerical experiments on convection in a chemically stably stratified fluid layer heated from below have been completed. These results show us how to calculate the evolution of a mixed layer in the Moon, depending on the heat production in the ilmenite- cumulate core and the chemical stratification of the overlying mantle. Chemical stratification of the mantle after its initial differentiation is would trap heat in the deep interior and prevent the rapid rise of plumes with accompanying volcanism. This trapping of heat in the interior can explain the thickness of the lunar lithosphere as a function of time as well as the magmatic evolution. We show that heat transported to the base of the lithosphere at a rate determined by current estimates of radioactivity in the Moon would not satisfy constraints on elastic lithosphere thickness from tectonic feature associated with basin loading. Trapping heat at depth by a chemically stratified mantle may also explain the absence of global compressional features on the surface that previous models predict for an initially hot lunar interior. For Venus, we developed a

  19. Planetary Geophysics and Tectonics

    NASA Technical Reports Server (NTRS)

    Zuber, Maria

    2005-01-01

    The broad objective of this work is to improve understanding of the internal structures and thermal and stress histories of the solid planets by combining results from analytical and computational modeling, and geophysical data analysis of gravity, topography and tectonic surface structures. During the past year we performed two quite independent studies in the attempt to explain the Mariner 10 magnetic observations of Mercury. In the first we revisited the possibility of crustal remanence by studying the conditions under which one could break symmetry inherent in Runcorn's model of a uniformly magnetized shell to produce a remanent signal with a dipolar form. In the second we applied a thin shell dynamo model to evaluate the range of intensity/structure for which such a planetary configuration can produce a dipole field consistent with Mariner 10 results. In the next full proposal cycle we will: (1) develop numerical and analytical and models of thin shell dynamos to address the possible nature of Mercury s present-day magnetic field and the demise of Mars magnetic field; (2) study the effect of degree-1 mantle convection on a core dynamo as relevant to the early magnetic field of Mars; (3) develop models of how the deep mantles of terrestrial planets are perturbed by large impacts and address the consequences for mantle evolution; (4) study the structure, compensation, state of stress, and viscous relaxation of lunar basins, and address implications for the Moon s state of stress and thermal history by modeling and gravity/topography analysis; and (5) use a three-dimensional viscous relaxation model for a planet with generalized vertical viscosity distribution to study the degree-two components of the Moon's topography and gravity fields to constrain the primordial stress state and spatial heterogeneity of the crust and mantle.

  20. Fractal Tectonics and Erosion

    NASA Astrophysics Data System (ADS)

    Turcotte, Donald L.

    Tectonic processes build landforms that are subsequently destroyed by erosional processes. Landforms exhibit fractal statistics in a variety of ways; examples include (1) lengths of coast lines; (2) number-size statistics of lakes and islands; (3) spectral behavior of topography and bathymetry both globally and locally; and (4) branching statistics of drainage networks. Erosional processes are dominant in the development of many landforms on this planet, but similar fractal statistics are also applicable to the surface of Venus where minimal erosion has occurred. A number of dynamical systems models for landforms have been proposed, including (1) cellular automata; (2) diffusion limited aggregation; (3) self-avoiding percolation; and (4) advective-diffusion equations. The fractal statistics and validity of these models will be discussed. Earthquakes also exhibit fractal statistics. The frequency-magnitude statistics of earthquakes satisfy the fractal Gutenberg-Richter relation both globally and locally. Earthquakes are believed to be a classic example of self-organized criticality. One model for earthquakes utilizes interacting slider-blocks. These slider block models have been shown to behave chaotically and to exhibit self-organized criticality. The applicability of these models will be discussed and alternative approaches will be presented. Fragmentation has been demonstrated to produce fractal statistics in many cases. Comminution is one model for fragmentation that yields fractal statistics. It has been proposed that comminution is also responsible for much of the deformation in the earth's crust. The brittle disruption of the crust and the resulting earthquakes present an integrated problem with many fractal aspects.

  1. Optimal Planet Properties For Plate Tectonics Through Time And Space

    NASA Astrophysics Data System (ADS)

    Stamenkovic, Vlada; Seager, Sara

    2014-11-01

    Both the time and the location of planet formation shape a rocky planet’s mass, interior composition and structure, and hence also its tectonic mode. The tectonic mode of a planet can vary between two end-member solutions, plate tectonics and stagnant lid convection, and does significantly impact outgassing and biogeochemical cycles on any rocky planet. Therefore, estimating how the tectonic mode of a planet is affected by a planet’s age, mass, structure, and composition is a major step towards understanding habitability of exoplanets and geophysical false positives to biosignature gases. We connect geophysics to astronomy in order to understand how we could identify and where we could find planet candidates with optimal conditions for plate tectonics. To achieve this goal, we use thermal evolution models, account for the current wide range of uncertainties, and simulate various alien planets. Based on our best model estimates, we predict that the ideal targets for plate tectonics are oxygen-dominated (C/O<1) (solar system like) rocky planets of ~1 Earth mass with surface oceans, large metallic cores super-Mercury, rocky body densities of ~7000kgm-3), and with small mantle concentrations of iron 0%), water 0%), and radiogenic isotopes 10 times less than Earth). Super-Earths, undifferentiated planets, and especially hypothetical carbon planets, speculated to consist of SiC and C, are not optimal for the occurrence of plate tectonics. These results put Earth close to an ideal compositional and structural configuration for plate tectonics. Moreover, the results indicate that plate tectonics might have never existed on planets formed soon after the Big Bang—but instead is favored on planets formed from an evolved interstellar medium enriched in iron but depleted in silicon, oxygen, and especially in Th, K, and U relative to iron. This possibly sets a belated Galactic start for complex Earth-like surface life if plate tectonics significantly impacts the build up

  2. Petrologic implications of plate tectonics.

    PubMed

    Yoder, H S

    1971-07-30

    Petrologists can make significant contributions to the plate tectonic concept. Fixing the stability fields of the principal rock types involved will provide the limits of pressure and temperature of the various environments. Experimental determination of the partition coefficients of the trace elements will be helpful. Studies of the partial melting behavior of possible parental materials in the absence and presence of water, especially the undersaturated region, will contribute to the understanding of magma production. Experimental observations on the rheological properties of the peridotites below and just above the solidus will lead to a better evaluation of the convective mechanism. Measurement of the fundamental properties of rocks, such as the density of solids and liquids at high pressures and temperatures, would contribute to understanding the concepts of diapiric rise, magma segregation, and the low-velocity zone. Broader rock sampling of the oceanic areas of all environments will do much to define the petrologic provinces. The field petrologist specializing in the Paleozoic regions and Precambrian shields can contribute by examining those regions for old plate boundaries and devising new criteria for their recognition.

  3. Source contributions to carbonaceous aerosol concentrations in Korea

    NASA Astrophysics Data System (ADS)

    Jeong, Jaein I.; Park, Rokjin J.; Woo, Jung-Hun; Han, Young-Ji; Yi, Seung-Muk

    2011-02-01

    We estimated the source contributions to carbonaceous aerosol concentration in Korea on the basis of Intercontinental Chemical Transport Experiment Phase B (INTEX-B) anthropogenic emissions and satellite-derived biomass burning emissions by using a nested version of GEOS-Chem with a spatial resolution of 0.5° × 0.667° for the period March 2006-February 2007. First, we evaluated the model by comparing the simulated and observed aerosol concentrations at East Asia Network (EANET) sites and at a site in Korea. The results indicate that the model reproduces the variability and magnitudes of the observed SO 42-, NO 3-, and NH 4+ concentrations in Korea and those of the observed PM 10 concentrations in East Asia. However, the organic carbon (OC) and black carbon (BC) aerosol concentrations estimated by the model are lower than those observed in Korea by a factor of 2, especially in winter. This underestimation is likely due to extremely low domestic anthropogenic emissions and lack in seasonal variation. Source adjustments using a simple fitting and the Emission Database for Global Atmospheric Research (EDGAR) monthly allocation factors for seasonal variation yield significantly improved model results ( R2 increased from 0.58 to 0.84), which can then be used to estimate the source contributions to the OC and BC concentrations in Korea. We found that domestic anthropogenic emissions are the most important factors, contributing 74% (9% from fossil fuels and 65% from biofuels) and 78% (42% from fossil fuels and 36% from biofuels) to the OC and BC concentrations, respectively, on an annual mean basis in Korea. The trans-boundary transport of Chinese sources is another important factor, contributing 13% and 20% to the OC and BC concentrations, respectively. The contributions of wildfires and biogenic sources to the annual mean carbonaceous aerosol concentration in Korea are relatively small (4% and 6%, respectively).

  4. Successful Control of Lymphatic Filariasis in the Republic of Korea

    PubMed Central

    Cheun, Hyeng-Il; Kong, Yoon; Cho, Shin-Hyeong; Lee, Jong-Soo; Chai, Jong-Yil; Lee, Joo-Shil; Lee, Jong-Koo

    2009-01-01

    A successful experience of lymphatic filariasis control in the Republic of Korea is briefly reviewed. Filariasis in the Republic of Korea was exclusively caused by infection with Brugia malayi. Over the past several decades from the 1950s to 2006, many investigators exerted their efforts to detection, treatment, and follow-up of filariasis patients in endemic areas, and to control filariasis. Mass, combined with selective, treatments with diethylcarbamazine to microfilaria positive persons had been made them free from microfilaremia and contributed to significant decrease of the microfilarial density in previously endemic areas. Significant decrease of microfilaria positive cases in an area influenced eventually to the endemicity of filariasis in the relevant locality. Together with remarkable economic growth followed by improvement of environmental and personal hygiene and living standards, the factors stated above have contributed to blocking the transmission cycle of B. malayi and led to disappearance of this mosquito-borne ancient disease in the Republic of Korea. PMID:19967079

  5. Korea Research Reactor -1 & 2 Decommissioning Project in Korea

    SciTech Connect

    Park, S. K.; Chung, U. S.; Jung, K. J.; Park, J. H.

    2003-02-24

    Korea Research Reactor 1 (KRR-1), the first research reactor in Korea, has been operated since 1962, and the second one, Korea Research Reactor 2 (KRR-2) since 1972. The operation of both of them was phased out in 1995 due to their lifetime and operation of the new and more powerful research reactor, HANARO (High-flux Advanced Neutron Application Reactor; 30MW). Both are TRIGA Pool type reactors in which the cores are small self-contained units sitting in tanks filled with cooling water. The KRR-1 is a TRIGA Mark II, which could operate at a level of up to 250 kW. The second one, the KRR-2 is a TRIGA Mark III, which could operate at a level of up 2,000 kW. The decontamination and decommissioning (D & D) project of these two research reactors, the first D & D project in Korea, was started in January 1997 and will be completed to stage 3 by 2008. The aim of this decommissioning program is to decommission the KRR-1 & 2 reactors and to decontaminate the residual building structure s and the site to release them as unrestricted areas. KAERI (Korea Atomic Energy Research Institute) submitted the decommissioning plan and the environmental impact assessment reports to the Ministry of Science and Technology (MOST) for the license in December 1998, and was approved in November 2000.

  6. The Diabetes Epidemic in Korea

    PubMed Central

    2016-01-01

    Diabetes is one of the foremost public health issues worldwide that can lead to complications in many organ systems, and has become a significant cause of morbidity and mortality in Korea. According to data from the National Health Insurance Service (NHIS), about 2.7 million Koreans (8.0%) aged 30 years or older had type 2 diabetes mellitus (T2DM) in 2013. The prevalence of T2DM increased with age and rose from 5.6% in 2006 to 8.0% in 2013. Using data based on The Health Screening Service of the NHIS, 25% of Korean adults were reported to have prediabetes in 2013. The prevalence of an impaired fasting glucose tended to increase over time from 21.5% in 2006 to 25.0% in 2013. Even though nationwide health screening has been regularly conducted as a public service, the proportion of undiagnosed cases of diabetes was still reported to be on the higher side in the latest study. Based on the results of these epidemic studies, further actions will be needed to effectively implement lifestyle changes on a social level and increase measures for the early detection of diabetes to stem the tide of the epidemic. PMID:27586447

  7. Mimas: Tectonic structure and geologic history

    NASA Technical Reports Server (NTRS)

    Croft, Steven K.

    1991-01-01

    Mimas, the innermost of the major saturnian satellites, occupies an important place in comparative studies of icy satellites. It is the smallest icy satellite known to have a mostly spherical shape. Smaller icy objects like Hyperion and Puck are generally irregular in shape, while larger ones like Miranda and Enceladus are spherical. Thus Mimas is near the diameter where the combination of increasing surface gravity and internal heating begin to have a significant effect on global structure. The nature and extent of endogenic surface features provide important constraints on the interior structure and history of this transitional body. The major landforms on Mimas are impact craters. Mimas has one of the most heavily cratered surfaces in the solar system. The most prominent single feature on Mimas is Herschel, an unrelaxed complex crater 130 km in diameter. The only other recognized landforms on Mimas are tectonic grooves and lineaments. Groove locations were mapped by Schenk, but without analysis of groove structures or superposition relationships. Mimas' tectonic structures are remapped here in more detail than previously has been done, as part of a general study of tectonic features on icy satellites.

  8. Occupational Diseases in Korea

    PubMed Central

    Kim, Eun A

    2010-01-01

    Korea has industrialized since the 1970s. Pneumoconiosis in coal miners was the most common occupational disease in the 1970s to 1980s. With the industrialization, the use of many chemicals have increased since the 1970s. As a consequence, there were outbreaks of occupational diseases caused by poisonous chemicals, such as heavy metal poisoning, solvent poisoning and occupational asthma in the late 1980s and early 1990s with civil movement for democracy. Many actions have been taken for prevention by the government, employers and employees or unions. In the 1990s most chemical related diseases and pneumoconiosis have rapidly decreased due to improving work environment. In the late 1990s, cerebro-cardiovascular diseases related to job stress or work overloads have abruptly increased especially after the economic crisis in 1998. After the year 2000, musculoskeletal disorders became a major problem especially in assembly lines in the manufacturing industry and they were expanded to the service industry. Mental diseases related to job stress have increased. Infectious diseases increased in health care workers and afforestation workers. Occupational cancers are increasing because of their long latency, although the use of carcinogenic substances are reduced, limited, and even banned. PMID:21258589

  9. Dust Obscures Korea

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The dust cloud over eastern Asia was so thick on March 21, 2002, that the Korean Peninsula completely disappeared from view in this Sea-viewing Wide Field-of-view Sensor (SeaWiFS) image of the region. Parts of South Korea report that visibility at the surface is less than 50 m (165 feet). Airports throughout the region canceled flights due to the poor visibility. Eyewitnesses in China report that the dust was so thick in Beijing at times that visibility was limited to 100 m (330 feet), while in parts of the Gansu Province visibility was reported at less than 10 m (33 feet). Chinese officials say this is the worst dust storm to hit in more than 10 years. Dust from an earlier event still colors the air to the east of Japan. (The island of Honshu is just peeking out from under the cloud cover in these images.) Image courtesy the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  10. Tectonics of Western Canada From GPS Observations

    NASA Astrophysics Data System (ADS)

    Mazzotti, S.; Flueck, P.; Hyndman, R. D.; Dragert, H.; Craymer, M.; Schmidt, M.

    2002-12-01

    Western Canada can be divided into three main current tectonic domains: The Cascadia subduction zone, the Queen Charlotte transform margin, and the Yukon intraplate deformation region. Well-developed GPS monitoring of present-day deformation has contributed substantially to our knowledge of the dynamics of the Cascadia margin. To the north, although seismicity and plate tectonics model indicate significant deformation, our understanding of the detailed tectonics is still sparse. We present a summary of GPS measurements obtained in western Canada and adjacent regions over the last 10 years that allow us to better apprehend these three tectonic systems. Along the Cascadia margin, the Juan de Fuca (JF) plate subducts beneath North America (NA). The crustal velocity field is well constrained by continuous and campaign GPS data that show a northeastward motion that decreases landward from ~10 to ~5 mm/yr. This deformation pattern indicates significant elastic shortening of the forearc due to the locking of the subduction thrust. The northernmost Cascadia region corresponds to a transition between subduction and transform regimes. GPS campaign data suggest that this transition is accommodated by internal deformation and underthrusting of the Explorer plate beneath the NA margin. Further to the north, the Queen Charlotte Fault (QCF) accommodates the strike-slip motion between the Pacific (PA) and the NA plates. The slight obliquity of the PA/NA motion relative to the QCF direction implies some convergence along this margin. GPS campaign data in the Queen Charlotte Islands indicate velocities of 5-15 mm/yr northward with respect to NA. These results suggest a complex interaction between strain loading along the locked QCF, strain loading along a subduction thrust just offshore, and potential long-term deformation of the NA margin up to the Alaska Panhandle. The PA/NA transform margin changes to a convergence system in the Gulf of Alaska, where the Yakutat Terrane is

  11. Molecular tectonics: from simple tectons to complex molecular networks.

    PubMed

    Hosseini, Mir Wais

    2005-04-01

    Molecular networks in the crystalline phase are infinite periodic molecular assemblies formed under self-assembly conditions between self-complementary or complementary tectons. These millimeter-size structures may be regarded as hypermolecules formed by supramolecular synthesis using reversible intertecton interactions. Molecular tectonics, based on molecular recognition events and their iteration, is the approach dealing with design and preparation of molecular networks in the solid state. In this Account, an overview of the rational behind this approach is presented. A variety of molecular networks based on van der Waals interactions and hydrogen and coordination bonding possessing diverse connectivity and topology are discussed.

  12. Distribution of lichen flora on South Korea.

    PubMed

    Hur, Jae-Seoun; Harada, Hiroshi; Oh, Soon-Ok; Lim, Kwang-Mi; Kang, Eui-Sung; Lee, Seung Mi; Kahng, Hyung-Yeel; Kim, Hyun-Woo; Jung, Jae-Sung; Koh, Young Jin

    2004-06-01

    After an overview on the temporary situation of the lichenology in South Korea, localities of 95 macrolichen taxa are reported for South Korea. In this revised lichen flora of South Korea, 16 species are apparently new to the territory. Voucher specimens have been deposited in the Korean Lichen Research Institute (KoLRI) at Sunchon National University in Korea, and duplicates have also been donated to the National History Museum and Institute, in Chiba, (CBM) Japan.

  13. Water Tectonics: Evidence That Hydration Plays a Role in Tectonism

    NASA Astrophysics Data System (ADS)

    Lowry, A. R.; Schutt, D.; Perez-Gussinye, M.; Buehler, J. S.; Berry, M. A.; Ma, X.; Ravat, D.

    2015-12-01

    Several new observations provide evidence that water may play a more important role in tectonism than previously realized. Among these, • Thermodynamical modeling suggests that hydration promotes crustal mineral assemblages with lowered vP/vS and decreased density. This sheds new light on the significance of low crustal vP/vS measured in the western U.S. Cordillera from joint inversion of EarthScope USArray receiver functions and gravity. vP/vS, previously interpreted in terms of quartz abundance, is strikingly low throughout the highest-elevation regions of the western Cordillera. • Rheological modeling of flexural rigidity measurements also can be used to map water variations, primarily in the uppermost mantle. Mantle hydration estimated from flexural rigidity exhibits very similar spatial distribution to crustal hydration inferred from vP/vS, with the notable exception that the Wyoming craton has dry mantle lithosphere but a hydrous crust. • In hydrated lithosphere of the high-elevation western U.S. Cordillera, Moho temperatures estimated from Pn velocities are systematically colder than predictions by simple geothermal models of surface heat flow. These differences can only be reconciled by invoking a previously unrecognized advective term in the deep thermal transfer. • New and improved estimates of magnetic bottom are much deeper than the depth of the magnetite Curie temperature in some apparently hydrous lithosphere (notably, east of the Siletzia accreted terrane). This may indicate exotic magnetic mineralogies thought to occur only under hydrous conditions. Lithospheric hydration may be driven either by dehydration of subducted slab or by entrainment of water into upwellings passing through the mantle transition zone. Conceptualizing hydration as a large-scale process accompanied by increased buoyancy and decreased ductile strength, coupled with widespread changes in mineralogy, mass and energy transfer may help to illuminate many otherwise

  14. 15 CFR 746.4 - North Korea.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Democratic People's Republic of Korea (North Korea), except food and medicines classified as EAR99... goods as described in this section to North Korea. (4) TSU for operation technology and software for lawfully exported commodities as set forth in § 740.13(a) and sales technology as set forth in § 740.13...

  15. Special Education in South Korea: Daegu University

    ERIC Educational Resources Information Center

    Kim, Byung Ha; Rhee, Kun Yong; Burns, Carol; Lerner, Janet W.

    2009-01-01

    Daegu University has enjoyed a long and remarkable history of special education. Daegu University is large University located in Daegu, South Korea, a large city in South Korea that is south of Seoul. Since the 1970's, South Korea has achieved unusual and comprehensive growth in its economy, and the field of special education continued to thrive…

  16. 76 FR 35740 - North Korea Sanctions Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-20

    ... Part 510 North Korea Sanctions Regulations AGENCY: Office of Foreign Assets Control, Treasury. ACTION... amending the North Korea Sanctions Regulations to implement Executive Order 13570 of April 18, 2011. OFAC..., the Department of the Treasury's Office of Foreign Assets Control published the North Korea...

  17. Tectonics of the Easter plate

    NASA Technical Reports Server (NTRS)

    Engeln, J. F.; Stein, S.

    1984-01-01

    A new model for the Easter plate is presented in which rift propagation has resulted in the formation of a rigid plate between the propagating and dying ridges. The distribution of earthquakes, eleven new focal mechanisms, and existing bathymetric and magnetic data are used to describe the tectonics of this area. Both the Easter-Nazca and Easter-Pacific Euler poles are sufficiently close to the Easter plate to cause rapid changes in rates and directions of motion along the boundaries. The east and west boundaries are propagating and dying ridges; the southwest boundary is a slow-spreading ridge and the northern boundary is a complex zone of convergent and transform motion. The Easter plate may reflect the tectonics of rift propagation on a large scale, where rigid plate tectonics requires boundary reorientation. Simple schematic models to illustrate the general features and processes which occur at plates resulting from large-scale rift propagation are used.

  18. Caribbean paleomagnetism and tectonic evolution

    SciTech Connect

    MacDonald, W.D.

    1985-01-01

    Approximately fifty papers treating diverse aspects of Caribbean paleomagnetism have appeared since Creer's pioneering work in the early 1960s. Apparently anomalous early results were initially attributed to anomalous geomagnetic field behavior, to unusual mineralogic effects in rock magnetism and to complex remagnetizations. Eventually the importance of structural and tectonic influences were recognized in paleomagnetic data of the Caribbean area, as elsewhere. Large tectonic rotation is evident from the unusual paleomagnetic declination found at many Caribbean localities. Latitudinal transport, with its plate motion implications, is more subtly expressed in the paleomagnetic inclination parameter, with its typically large relative variance. A review of Caribbean paleomagnetic data is given to form a basis for composing realistic tectonic models.

  19. Plate tectonics, damage and inheritance.

    PubMed

    Bercovici, David; Ricard, Yanick

    2014-04-24

    The initiation of plate tectonics on Earth is a critical event in our planet's history. The time lag between the first proto-subduction (about 4 billion years ago) and global tectonics (approximately 3 billion years ago) suggests that plates and plate boundaries became widespread over a period of 1 billion years. The reason for this time lag is unknown but fundamental to understanding the origin of plate tectonics. Here we suggest that when sufficient lithospheric damage (which promotes shear localization and long-lived weak zones) combines with transient mantle flow and migrating proto-subduction, it leads to the accumulation of weak plate boundaries and eventually to fully formed tectonic plates driven by subduction alone. We simulate this process using a grain evolution and damage mechanism with a composite rheology (which is compatible with field and laboratory observations of polycrystalline rocks), coupled to an idealized model of pressure-driven lithospheric flow in which a low-pressure zone is equivalent to the suction of convective downwellings. In the simplest case, for Earth-like conditions, a few successive rotations of the driving pressure field yield relic damaged weak zones that are inherited by the lithospheric flow to form a nearly perfect plate, with passive spreading and strike-slip margins that persist and localize further, even though flow is driven only by subduction. But for hotter surface conditions, such as those on Venus, accumulation and inheritance of damage is negligible; hence only subduction zones survive and plate tectonics does not spread, which corresponds to observations. After plates have developed, continued changes in driving forces, combined with inherited damage and weak zones, promote increased tectonic complexity, such as oblique subduction, strike-slip boundaries that are subparallel to plate motion, and spalling of minor plates.

  20. Epidemiology of Biliary Atresia in Korea

    PubMed Central

    2017-01-01

    Biliary atresia (BA) is the major cause of cholestasis and the leading indication for liver transplantation (LT). However, the incidence of BA in Korea has not been reported. The aim of this study was to investigate the incidence and clinical outcomes of BA in Korea. We used the Korean universal health insurance database and extracted data regarding BA patients younger than 18 years of age admitted between 2011 and 2015. The incidence of BA was calculated by dividing the number of BA patients by the number of live births. Two hundred forty infants were newly diagnosed with BA. A total of 963 BA patients younger than 18 years of age were followed up for 5 years. The overall incidence of BA was 1.06 cases per 10,000 live births. The incidence of BA was 1.4 times higher for female patients than for male patients. Additionally, significant seasonal variation was observed; in particular, the incidence of BA was 2 times higher from June through August than from December through February. Congenital anomalies were found in 38 of 240 patients (15.8%). Congenital heart diseases were major associated congenital anomalies (6.3%). Several complications developed during the study period, including cholangitis (24.0%), varix (6.2%), and gastrointestinal bleeding (4.4%). Three hundred and one of the 963 BA patients under 18 years of age (31.3%) received LT for BA. The incidence of BA is higher in Korea than that in Western countries. We also report significant gender-associated differences and seasonal variation with respect to the incidence of BA. PMID:28244293

  1. Venus magmatic and tectonic evolution

    NASA Technical Reports Server (NTRS)

    Phillips, R. J.; Hansen, V. L.

    1993-01-01

    Two years beyond the initial mapping by the Magellan spacecraft, hypotheses for the magmatic and tectonic evolution of Venus have become refined and focused. We present our view of these processes, attempting to synthesize aspects of a model for the tectonic and magmatic behavior of the planet. The ideas presented should be taken collectively as an hypothesis subject to further testing. The quintessence of our model is that shear and buoyancy forces in the upper boundary layer of mantle convection give rise to a spatially and temporally complex pattern of strain in a one-plate Venusian lithosphere and modulate the timing and occurrence of magmatism on a global basis.

  2. Health impact assessment in Korea

    SciTech Connect

    Kang, Eunjeong; Lee, Youngsoo; Harris, Patrick; Koh, Kwangwook; Kim, Keonyeop

    2011-07-15

    Recently, Health Impact Assessment has gained great attention in Korea. First, the Ministry of Environment introduced HIA within existing Environment Impact Assessment. Second, the Korea Institute for Health and Social Affairs began an HIA program in 2008 in alliance with Healthy Cities. In this short report, these two different efforts are introduced and their opportunities and challenges discussed. We believe these two approaches complement each other and both need to be strengthened. We also believe that both can contribute to the development of health in policy and project development and ultimately to improvements in the Korean population's health.

  3. Complaining Behavior of Academic Library Users in South Korea

    ERIC Educational Resources Information Center

    Oh, Dong-Geun

    2004-01-01

    This study investigates the influences of the antecedent factors on the complaints and resulting behaviors of 582 university library users in South Korea. There were statistically significant relationships between personal norms and negative word of mouth and indirect voice behaviors, between service importance and negative word-of-mouth behavior,…

  4. Seismology: tectonic strain in plate interiors?

    PubMed

    Calais, E; Mattioli, G; DeMets, C; Nocquet, J-M; Stein, S; Newman, A; Rydelek, P

    2005-12-15

    It is not fully understood how or why the inner areas of tectonic plates deform, leading to large, although infrequent, earthquakes. Smalley et al. offer a potential breakthrough by suggesting that surface deformation in the central United States accumulates at rates comparable to those across plate boundaries. However, we find no statistically significant deformation in three independent analyses of the data set used by Smalley et al., and conclude therefore that only the upper bounds of magnitude and repeat time for large earthquakes can be inferred at present.

  5. Tectonics and Terranes in the Undergraduate Curriculum.

    ERIC Educational Resources Information Center

    Lambert, Richard St J.

    1989-01-01

    Gives the background to the philosophy for the introductory teaching of global tectonics and the terrane concept. Provides a discussion of local and general considerations, the curriculum, and terrane tectonics. (RT)

  6. Comment on "Intermittent plate tectonics?".

    PubMed

    Korenaga, Jun

    2008-06-06

    Silver and Behn (Reports, 4 January 2008, p. 85) proposed that intermittent plate tectonics may resolve a long-standing paradox in Earth's thermal evolution. However, their analysis misses one important term, which subsequently brings their main conclusion into question. In addition, the Phanerozoic eustasy record indicates that the claimed effect of intermittency is probably weak.

  7. Petroleum occurrences and plate tectonics

    SciTech Connect

    Olenin, V.B.; Sokolov, B.A.

    1983-01-01

    This paper analyzes the mechanisms of petroleum formation and petroleum accumulation proposed in recent years by some Russian and foreign investigators from the viewpoint of the new global or plate tectonics. On the basis of discussion and the facts, the authors conclude that the mechanisms proposed are in contradiction to reality and their use in practical application is at least premature.

  8. Statistical description of tectonic motions

    NASA Technical Reports Server (NTRS)

    Agnew, Duncan Carr

    1993-01-01

    This report summarizes investigations regarding tectonic motions. The topics discussed include statistics of crustal deformation, Earth rotation studies, using multitaper spectrum analysis techniques applied to both space-geodetic data and conventional astrometric estimates of the Earth's polar motion, and the development, design, and installation of high-stability geodetic monuments for use with the global positioning system.

  9. Incorporation of New and Old Tectonics Concepts Into a Modern Course in Tectonics.

    ERIC Educational Resources Information Center

    Hatcher, Robert D., Jr.

    1983-01-01

    Describes a graduate-level tectonics course which includes the historical basis for modern tectonics concepts and an in-depth review of pros/cons of plate tectonics. Tectonic features discussed include: ocean basins; volcanic arcs; continental margins; continents; orogenic belts; foreland fold and thrust belts; volcanic/plutonic belts of orogens;…

  10. Recent advances in the cretaceous stratigraphy of Korea

    NASA Astrophysics Data System (ADS)

    Chang, Ki-Hong; Suzuki, Kazuhiro; Park, Sun-Ok; Ishida, Keisuke; Uno, Koji

    2003-06-01

    A subrounded, accidental, zircon grain from a rhyolite sample of the Oknyobong Formation has shown an U-Pb CHIME isochron age, 187 Ma, implying its derivation from a Jurassic felsic igneous rock. Such a lower limit of the geologic age of the Oknyobong Formation, combined with its pre-Kyongsang upper limit, constrains that the Oknyobong Formation belongs to the Jasong Synthem (Late Jurassic-early Early Cretaceous) typified in North Korea. The Jaeryonggang Movement terminated the deposition of the Jasong Synthem and caused a shift of the depocenter from North Korea to the Kyongsang Basin, Southeast Korea. The Cretaceous-Paleocene Kyongsang Supergroup of the Kyongsang Basin is the stratotype of the Kyongsang Synthem, an unconformity-bounded unit in the Korean Peninsula. The unconformity at the base of the Yuchon Volcanic Group is a local expression of the interregionally recognizable mid-Albian tectonism; it subdivides the Kyongsang Synthem into the Lower Kyongsang Subsynthem (Barremian-Early Albian) and the Upper Kyongsang Subsynthem (Late Albian-Paleocene). The latter is unconformably overlain by Eocene and younger strata. The Late Permian to Early Jurassic radiolarian fossils from the chert pebbles of the Kumidong and the Kisadong conglomerates of the Aptian-Early Albian Hayang Group of the Kyongsang Basin are equivalent with those of the cherts that constitute the Jurassic accretionary prisms in Japan, the provenance of the chert pebbles in the Kyongsang Basin. Bimodal volcanisms throughout the history of the Kyongsang Basin is exemplified by the felsic Kusandong Tuff erupted abruptly and briefly in the Late Aptian when semi-coeval volcanisms were of intermediate and mafic compositions. The mean paleomagnetic direction shown by the Kusandong Tuff is in good agreement with the Early Cretaceous directions known from North China, South China and Siberia Blocks.

  11. Life in South Korea Today.

    ERIC Educational Resources Information Center

    Lew, Seok-Choon

    1988-01-01

    Characterizes the past 40 years in South Korea as a time of modernization, industrialization, urbanization, and internationalization. Discusses Korean religion and social values; family, kinship, and social life; education; housing, food, and clothing; leisure and sports; and the maintenance of national identity. Examines the Korean synthesis of…

  12. Inclusive Education in South Korea

    ERIC Educational Resources Information Center

    Kim, Yong-Wook

    2014-01-01

    The purpose of this paper is to examine the current implementation of inclusive education in South Korea and discuss its challenges. The history of special education is first described followed by an introduction to policies relevant to special and inclusive education. Next, a critical discussion of the state of inclusive education follows built…

  13. Rural Development in South Korea.

    ERIC Educational Resources Information Center

    Brandt, Vincent S. R.

    1979-01-01

    Reviews development in rural areas of South Korea since the late nineteenth century, with particular emphasis on rural to urban migration, governmental investment in agriculture, transportation and mass communications, development projects, social leveling processes, upgraded living standards, and cooperative village improvement projects. Journal…

  14. Korea Earth Observation Satellite Program

    NASA Astrophysics Data System (ADS)

    Baek, Myung-Jin; Kim, Zeen-Chul

    via Korea Aerospace Research Institute (KARI) as the prime contractor in the area of Korea earth observation satellite program to enhance Korea's space program development capability. In this paper, Korea's on-going and future earth observation satellite programs are introduced: KOMPSAT- 1 (Korea Multi Purpose Satellite-1), KOMPSAT-2 and Communication, Broadcasting and Meteorological Satellite (CBMS) program. KOMPSAT-1 satellite successfully launched in December 1999 with Taurus launch vehicle. Since launch, KOMPSAT-1 is downlinking images of Korea Peninsular every day. Until now, KOMPSAT-1 has been operated more than 2 and half years without any major hardware malfunction for the mission operation. KOMPSAT-1 payload has 6.6m panchromatic spatial resolution at 685 km on-orbit and the spacecraft bus had NASA TOMS-EP (Total Ozone Mapping Spectrometer-Earth Probe) spacecraft bus heritage designed and built by TRW, U.S.A.KOMPSAT-1 program was international co-development program between KARI and TRW funded by Korean Government. be launched in 2004. Main mission objective is to provide geo-information products based on the multi-spectral high resolution sensor called Multi-Spectral Camera (MSC) which will provide 1m panchromatic and 4m multi-spectral high resolution images. ELOP of Israel is the prime contractor of the MSC payload system and KARI is the total system prime contractor including spacecraft bus development and ground segment. KARI also has the contract with Astrium of Europe for the purpose of technical consultation and hardware procurement. Based on the experience throughout KOMPSAT-1 and KOMPSAT-2 space system development, Korea is expecting to establish the infrastructure of developing satellite system. Currently, KOMPSAT-2 program is in the critical design stage. are scheduled to launch in 2008 and in 2014, respectively. The mission of CBMS consists of two areas. One is of space technology test for the communications mission, and the other is of a real

  15. Tectonic factors controlling initiation and distribution of Silurian reefs in Illinois basin, southwestern Indiana

    SciTech Connect

    Furer, L.C. )

    1989-08-01

    The authors discuss the relative effects of differential compaction and tectonics on the distribution, growth, geometry, and age of Silurian reefs in the Illinois basis. Their working hypothesis is that both differential compaction and tectonics have had a significant effect on the reefs, each at a different time. Examples are given.

  16. Mobilization of evaporites in tectonically active terrains

    NASA Astrophysics Data System (ADS)

    Stiros, Stathis C.

    2015-04-01

    The role of evaporites, mostly halite, during seismic sequences is investigated using evidence from certain earthquakes with magnitude between approximately 6.0 and 7.2 which occurred in the last 60 years in the Zagros Mts. (Iran) and the Ionian Sea (Greece); i.e. two seismically active areas, characterized by evaporite-associated decollements and more shallow decollements combined with mature, along-thrusts intrusions. Studied earthquakes produced either large scale surface deformation, or were covered by high-resolution and accuracy GPS and INSAR data, permitting to fully recognize the deformation pattern. In all cases an "atypical", tectonic deformation pattern was observed, ranging from apparently "impossible" patterns (thrust and normal faults, sub-parallel and homothetic; 1953 Cephalonia earthquake, Greece) to rather diffuse tectonic patterns, even to "phantom" earthquakes (Zagros). Careful analysis and modeling of the surface deformation data, in combination with the available geological, geophysical and seismological data permits to recognize, and even to quantify differences between deformation observed, and that expected in ordinary environments. In particular, it was found that during earthquakes evaporites were mobilized, and this led either to a secondary deformation of the overburden, fully detached from the basement, or to significant aseismic (post-seismic) deformation. Anomalies in the distribution of seismic intensities due to evaporitic intrusions along faults were also observed. Apart from seismological implications (unpredictable post-seismic deformation, possibly also in the far-field), these results deriving from regions at different levels of evaporitic evolution, may prove useful to understand patterns of mobilization of evaporites during periods of tectonic activity.

  17. Planets and satellites: tectonic twins

    NASA Astrophysics Data System (ADS)

    Kochemasov, G. G.

    2015-10-01

    There are only three solid planet-satellite pairs in the Solar system: Earth -Moon, Mars -Phobos, Pluto - Charon. For the first two pairs tectonic analogies were shown and explained by moving them in one circumsolar orbit. As it is known from the wave planetology [3, 4, 6], "orbits make structures". For the third pair the same was stated as a prediction based on this fundamental rule. Global tectonic forms of wave origin appear in cosmic bodies because they move in keplerian orbits with periodically changing accelerations. Warping bodies waves have a stationary character and obeying wave harmonics lengths. Starting from the fundamental 2πR-long wave 1 making the ubiquitous tectonic dichotomy (two-face appearance) warping wave lengths descend along harmonics. Very prominent along with the wave 1 are waves 2 responsible for tectonic sectoring superimposed on the wave 1 segments. Practically all bodies have traces of shorter waves making numerous polygons (rings) often confused with impact craters. Earth and the Moon moving in one circumsolar orbit both are distorted by wave 1, wave 2 and wave 4 features aligned along extent tectonic lines [4, 5]. At Earth they are: Pacific Ocean (2πR-structure) and Indian Ocean (πR-structure) from both ends with Malay Archipelago (πR/4-structure) in the middle. At Moon they are: Procellarum Ocean (2πR) and SPA Basin (πR) from ends and Mare Orientale (πR/4) in the middle. A regular disposition is surprising. Both Oceans and Basin occur on opposite hemispheres, lying in the middle both ring structures occur in the boundary between two hemispheres and are of the same relative size. These triads stretch along lines parallel to the equator (Earth) and with the angle about 30 degrees to it (Moon) indicating at a different orientation of the rotation axes in the ancient time [2]. On the whole, one could speak about a "lunar mould" of Earth [5] (Fig. 1-3). Another tectonic twin is the pair Mars -Phobos. Both bodies sharing one

  18. South Korea's renewed focus on space weather

    NASA Astrophysics Data System (ADS)

    Ahn, Byung-Ho

    2011-10-01

    Nearly 1000 years before European scientists David Fabricius and Galileo Galilei made historic observations of sunspots, royal astronomers in Korea were recording their observations of blemishes on the Sun. Sunspot records appeared as early as 640 C.E. in Korea [Yang et al., 1998], and records with statistically significant populations of data have been available since 1105 C.E. during the Goryeo dynasty (918-1392). The records are quite meticulous. For example, one entry dated 1151 in the annals of the Goryeo dynasty says, "There is a black spot in the sun as large as an egg" (Goryeo-Sa, 1451). At that time, sunspots were categorized according to size: plum, egg, peach, or pear. In Goryeo-Sa, various celestial phenomena such as solar eclipses, comets, novae, meteors, etc., were also recorded. Along with sunspots, aurorae were carefully described in several Korean chronicles, including Goryeo-Sa. Descriptions of aurorae, commonly referred to as "red energy," include their color, shape, motion, and distribution. For example, a description written in 1770 reads, "It spread across the sky like a piece of silk cloth and then dispersed" [Chanjipcheong, 1908; Park, 2008]. Applying a power spectrum analysis technique to all sunspot and aurora records during the Goryeo dynasty, Yang et al. [1998] and Lee et al. [2005] have shown 10.5-year and 97-year cycles for the sunspot records and 10-year and 87-year cycles for the aurora records.

  19. The treatment of tuberculosis in South Korea.

    PubMed

    Seung, K J; Bai, G H; Kim, S J; Lew, W J; Park, S K; Kim, J Y

    2003-10-01

    South Korea's complex system of tuberculosis control has never been fully described. The prevalence of tuberculosis has dropped dramatically since 1965, partly because of farsighted governmental policy that provided low-cost, accessible tuberculosis treatment to the entire population. Within the tuberculosis control system, public and private sector entities provide a wide variety of treatment options. The National Tuberculosis Program focuses on improving cure rates for new cases, while the private sector has taken more of a role in the treatment of drug-resistant tuberculosis and other types of complicated cases. There has been a decrease in drug-resistant tuberculosis since 1980 for multiple reasons, including increased cure rates from the introduction of rifampin-based regimens, improved nutrition and living standards, and the treatment of drug-resistant cases in the private sector. Multidrug-resistant tuberculosis, however, still poses a significant threat to public health. The limited outcomes data that exist in South Korea for multidrug-resistant tuberculosis treatment suggest that cure rates are low and failure and abandonment rates are high. New public health measures are needed to improve the control of multidrug-resistant tuberculosis.

  20. Sedimentation and tectonics in the southern Bida Basin, Nigeria: depositional response to varying tectonic context

    SciTech Connect

    Braide, S.P. )

    1990-05-01

    The Upper Cretaceous Bida basin of central Nigeria is sandwiched between the Precambrian schist belts of the Northern Nigerian massif and the West African craton. Of interest is the southern part of the basin, which developed in continental settings, because the facies architecture of the sedimentary fill suggests a close relation between sedimentation dynamics and basin margin tectonics. This relationship is significant to an understanding of the basin's origin, which has been controversial. A simple sag and rift origin has been suggested, and consequently dominated the negative thinking on the hydrocarbon prospects of the basin which were considered poor. This detailed study of the facies indicates rapid basin-wide changes from various alluvial fan facies through flood-basin and deltaic facies to lacustrine facies. Paleogeographic reconstruction suggests lacustrine environments were widespread and elongate. Lacustrine environments occurred at the basin's axis and close to the margins. This suggests the depocenter must have migrated during the basin's depositional history and subsided rapidly to accommodate the 3.5-km-thick sedimentary fill. Although distinguishing pull-apart basins from rift basins, based solely on sedimentologic grounds, may be difficult, the temporal migration of the depocenter, as well as the basin architecture of upward coarsening cyclicity, show a strong tectonic and structural overprint that suggests a tectonic framework for the Southern Bida basin similar in origin to a pull-apart basin.

  1. Global tectonics and space geodesy.

    PubMed

    Gordon, R G; Stein, S

    1992-04-17

    Much of the success of plate tectonics can be attributed to the near rigidity of tectonic plates and the availability of data that describe the rates and directions of motion across narrow plate boundaries \\m=~\\1 to 60 kilometers wide. Nonetheless, many plate boundaries in both continental and oceanic lithosphere are not narrow but are hundreds to thousands of kilometers wide. Wide plate boundary zones cover \\m=~\\15 percent of Earth's surface area. Space geodesy, which includes very long baseline radio interferometry, satellite laser ranging, and the global positioning system, is providing the accurate long-distance measurements needed to estimate the present motion across and within wide plate boundary zones. Space geodetic data show that plate velocities averaged over years are remarkably similar to velocities averaged over millions of years.

  2. Global tectonics and space geodesy

    NASA Technical Reports Server (NTRS)

    Gordon, Richard G.; Stein, Seth

    1992-01-01

    Much of the success of plate tectonics can be attributed to the near rigidity of tectonic plates and the availability of data that describe the rates and directions of motion across narrow plate boundaries of about 1 to 60 kilometers. Nonetheless, many plate boundaries in both continental and oceanic lithosphere are not narrow but are hundreds to thousands of kilometers wide. Wide plate boundary zones cover approximately 15 percent of earth's surface area. Space geodesy, which includes very long baseline radio interferometry, satellite laser ranging, and the global positioning system, provides the accurate long-distance measurements needed to estimate the present motion across and within wide plate boundary zones. Space geodetic data show that plate velocities averaged over years are remarkably similar to velocities avaraged over millions of years.

  3. Tectonics and composition of Venus

    NASA Technical Reports Server (NTRS)

    Anderson, D. L.

    1980-01-01

    The uncompressed density of Venus is a few percent less than the Earth. The high upper mantle temperature of Venus deepens the eclogite stability field and inserts a partial melt field. A thick basaltic crust is therefore likely. The anomalous density of Venus relative to the progression from Mercury to Mars may therefore have a tectonic rather than a cosmo-chemical explanation. There may be no need to invoke differences in composition or oxidization state.

  4. Earth's Decelerating Tectonic Plates (Invited)

    NASA Astrophysics Data System (ADS)

    Forte, A. M.; Moucha, R.; Rowley, D. B.; Quere, S.; Mitrovica, J. X.; Simmons, N. A.; Grand, S. P.

    2009-12-01

    We employ a recently developed convection model constrained by seismic, geodynamic and mineral physics data (Simmons et al., GJI 2009) to explore the impact of time-dependent changes in mantle buoyancy forces on tectonic plate accelerations. This plate-coupled mantle convection model incorporates a viscosity structure that reconciles both glacial isostatic adjustment and global convection-related data sets (Mitrovica & Forte, EPSL 2004) and it successfully reproduces present-day plate velocities, global surface gravity and topography data. This convection model predicts the recent deceleration of several major plates in the Pacific and Indo-Atlantic hemispheres. Independent verification of these predictions is a fundamental test of the plausibility of the buoyancy forces and rheological structure in the convection model. To this end, we consider marine magnetic anomaly and space geodetic constraints on tectonic plate motions to determine a new global map of present-day rates of change of plate velocities. This map shows that several major plates, such as the Pacific, Africa and Nazca plates are presently decelerating and that they contribute to a globally-averaged slowdown in tectonic plate speeds. These joint geologic-geodetic inferences of plate decelerations are consistent with those predicted by our tomography-based convection model.

  5. Episodic plate tectonics on Venus

    NASA Technical Reports Server (NTRS)

    Turcotte, Donald

    1992-01-01

    Studies of impact craters on Venus from the Magellan images have placed important constraints on surface volcanism. Some 840 impact craters have been identified with diameters ranging from 2 to 280 km. Correlations of this impact flux with craters on the Moon, Earth, and Mars indicate a mean surface age of 0.5 +/- 0.3 Ga. Another important observation is that 52 percent of the craters are slightly fractured and only 4.5 percent are embayed by lava flows. These observations led researchers to hypothesize that a pervasive resurfacing event occurred about 500 m.y. ago and that relatively little surface volcanism has occurred since. Other researchers have pointed out that a global resurfacing event that ceased about 500 MYBP is consistent with the results given by a recent study. These authors carried out a series of numerical calculations of mantle convection in Venus yielding thermal evolution results. Their model considered crustal recycling and gave rapid planetary cooling. They, in fact, suggested that prior to 500 MYBP plate tectonics was active in Venus and since 500 MYBP the lithosphere has stabilized and only hot-spot volcanism has reached the surface. We propose an alternative hypothesis for the inferred cessation of surface volcanism on Venus. We hypothesize that plate tectonics on Venus is episodic. Periods of rapid plate tectonics result in high rates of subduction that cool the interior resulting in more sluggish mantle convection.

  6. Assessment of trace metals in four bird species from Korea.

    PubMed

    Kim, Jungsoo; Oh, Jong-Min

    2013-08-01

    In birds, heavy metal concentrations are influenced by diet intake, migratory pattern, and residence time. In the present study, heavy metal concentrations (in microgram per gram dry weight) were measured in livers of four bird species from Korea. Iron concentrations were greater in Eurasian Woodcocks (Scolopax rusticola) than in Grey Herons (Ardea cinerea), Little Egrets (Egretta garzetta), and Schrenck's Bitterns (Ixobrychus eurhythmus). Copper concentrations in Grey Herons were significantly higher than in other species. Lead concentrations were greater in Schrenck's Bitterns and Eurasian Woodcocks than in Grey Herons and Little Egrets. Eurasian Woodcocks had higher cadmium concentrations than in other species. Zinc and manganese concentrations did not differ among species. Iron, zinc, manganese, and copper concentrations from this study were within the range of other Korean bird studies, and these concentrations were far below toxic levels. Cadmium and lead accumulation trends in each species were different, and the results might be associated with their migration pattern and residence time in Korea. Grey Herons, Little Egrets, and Schrenck's Bitterns are usually summer visitors, and Eurasian Woodcocks are passage migrants. But herons and egrets were collected in spring, autumn, and winter, but not during breeding season. They might be residents, so they could more reflect Korean cadmium and lead contaminations than Schrenck's Bitterns. However, Eurasian Woodcocks could more reflect habitats outside Korea because of their short staying time in Korea.

  7. North Korea: Terrorism List Removal

    DTIC Science & Technology

    2009-04-15

    Second- 28 Yi Sang-il and Chin Se-ku. Yongbyon nuclear facility can be disabled within...The White House, Roundtable Interview of the President by Foreign Print Media, August 30, 3007. 32 Choe Sang- hun and David E. Sanger, North Korea...2006 through the spring of 2007 to smuggle conventional arms, including machine guns , automatic rifles, and anti-tank rocket launchers, to the

  8. North Korea: Terrorism List Removal?

    DTIC Science & Technology

    2008-07-10

    and Chin Se-ku. Yongbyon nuclear facility can be disabled within a year. JongAng Ilbo (internet version), March 13, 2007. Korea’s nuclear programs and...the President by Foreign Print Media, August 30, 3007. 30 Choe Sang- hun and David E. Sanger, North Korea claims U.S. will remove sanctions...including machine guns , automatic rifles, and anti-tank rocket launchers, to the Tamil Tigers in Sri Lanka. The Sri Lankan navy intercepted and

  9. Preliminary Estimation of Postseismic Deformation Parameters from Continuous GPS Data in Korea Peninsula and Ieodo after the 2011 Tohoku-Oki MW9.0 Earthquake

    NASA Astrophysics Data System (ADS)

    Aris, W. A. W.; Musa, T. A.; Lee, H.; Choi, Y.; Yoon, H.

    2016-09-01

    This paper describes utilization of GPS data in Korea Peninsula and IEODO ocean research station for investigation of postseismic deformation characteristic after the 2011 Tohoku-oki Mw9.0 Earthquake. Analytical logarithmic and exponential functions were used to evaluate the postseismic deformation parameters. The results found that the data in Korea Peninsula and IEODO during periods of mid-2011 - mid-2014 are fit better using logarithmic function with deformation decay at 134.5 ±0.1 days than using the exponential function. The result also clearly indicates that further investigation into postseismic deformation over longer data span should be taken into account to explain tectonic deformation over the region.

  10. U.S.-South Korea Relations

    DTIC Science & Technology

    2013-04-26

    News , December 1, 2012. U.S.- South Korea Relations Congressional Research Service 7 • China’s rising influence in ...entered into force and will be eliminated completely in the fifth year of the agreement. South Korea also agreed to allow U.S.-based car manufacturers to...sell in South Korea up to 25,000 cars per year per manufacturer as long as they met U.S. safety and environmental standards. This

  11. An Early, Transient, Impact-driven Tectonic Regime in the Hadean?

    NASA Astrophysics Data System (ADS)

    O'Neill, C.; Marchi, S.; Zhang, S.

    2015-12-01

    The earliest preserved crust formed in a tectonic regime that different from present in several significant ways. Earth was still losing a significant fraction of its primordial heat, and heat production was declining more rapidly than in any period subsequently. Additionally, a waning impact flux provided an important thermal - and mechanical - forcing on the early Earth. These factors affect tectonics in a number of ways - internal velocities are faster, and internal viscosities lower due to hotter internal temperatures. Previous modelling of the tectonic evolution of the Earth under these conditions suggests that the early Earth may have exhibited periods of hot stagnant-lid convection - where vigorous internal convection - and volcanic activity - occurred under a tectonically quiescent lid. As the Earth cooled the planet would have transited into an episodic regime - characterised by periods of tectonic quiescence interspersed by extreme tectonic activity. Such scenarios explain a number of facets of the early Earth, including its observed slow mixing rates, inefficient cooling, and its paleomagnetic and tectonic history. Here we expand these models to incorporate the effects of major impacts. We find tectonic forcing due to impacts to be a major dynamic driver during the Hadean, with major return flow driving horizontal surface deformation, and transient subduction events. Such events may be reflected in the Hadean zircon record. Post this impact-dominated phase, models suggest an over-heated Earth may have then experienced a long phase of stagnant-lid convection, lasting till the meso-Archaean.

  12. Tectonic structure of East Antarctica

    NASA Astrophysics Data System (ADS)

    Leychenkov, German; Grikurov, Garrik; Golynsky, Alexander

    2013-04-01

    First overviews of tectonic structure of the Southern Continent were made by the pioneers of Antarctic earth science investigations almost 100 years ago. Despite rapidly advancing international geological studies under the Antarctic Treaty, the presentations of Antarctic tectonic structure remained largely speculative until the end of the past century when implementation of modern analytical and remote-sensing research technologies enabled compilation of more credible tectonic models of Antarctica. The East Antarctic bedrock consists mainly of the Precambrian crystalline complexes and the Paleozoic-Early Mesozoic platform units. Crystalline Shield is locally complicated by Neoproterozoic aulacogenes and Late Paleozoic to Mesozoic rifts. Shield assemblages reliably recognized in coastal outcrops indicate the predominant occurrence of Archean cratonic nuclei and Mesoproterozoic mobile belts. The undisturbed platform cover strata are exposed in East Antarctica mainly along its boundary with West Antarctica. Tectonic structure of ice-covered regions (more that 99% of the East Antarctic territory) is interpreted using mostly magnetic and bedrock topography data, but other geophysical and geological information (satellite, airborne and over-ice gravity; seismology; active seismics; erratics; detrital zircons dates; etc.) is also important. Archean cratons are geologically documented in western Dronning Maud Land, Enderby Land, Princess Elizabeth Land and in the southern Prince Charles Mts. Their distribution under the ice is marked by a specific magnetic pattern including low-amplitude mosaic and/or high-amplitude long-wavelength anomalies. The most extensive ancient craton being 1000 km across is believed to extend from the southern Prince Charles Mts. to the Gamburtsev Mts. Mesoproterozoic mobile belts are distinguished by elongated high-amplitude magnetic anomalies and are mapped along the costal area as the zone of 250-600 km wide. The Gamburtsev Mts. area is also

  13. Serious fungal infections in Korea.

    PubMed

    Huh, K; Ha, Y E; Denning, D W; Peck, K R

    2017-02-04

    Information on the incidence and prevalence of fungal infections is of critical value in public health policy. However, nationwide epidemiological data on fungal infections are scarce, due to a lack of surveillance and funding. The objective of this study was to estimate the disease burden of fungal infections in the Republic of Korea. An actuarial approach using a deterministic model was used for the estimation. Data on the number of populations at risk and the frequencies of fungal infections in those populations were obtained from national statistics reports and epidemiology papers. Approximately 1 million people were estimated to be affected by fungal infections every year. The burdens of candidemia (4.12 per 100,000), cryptococcal meningitis (0.09 per 100,000), and Pneumocystis pneumonia (0.51 per 100,000) in South Korea were estimated to be comparable to those in other countries. The prevalence of chronic pulmonary aspergillosis (22.4 per 100,000) was markedly high, probably due to the high burden of tuberculosis in Korea. The low burdens of allergic bronchopulmonary aspergillosis (56.9 per 100,000) and severe asthma with fungal sensitization (75.1 per 100,000) warrant further study. Oral candidiasis (539 per 100,000) was estimated to affect a much larger population than noted in previous studies. Our work provides valuable insight on the epidemiology of fungal infections; however, additional studies are needed.

  14. The United States-Republic of Korea Alliance: The Way Forward

    DTIC Science & Technology

    2012-03-13

    Korea in order to deter an attack by the Democratic Peoples ’ Republic of Korea. This paper examines the security alliance that exists between the...region: The Republic of Korea, the Democratic Peoples ’ Republic of Korea, the Peoples ’ Republic of China, Japan and the Russian Federation. This paper...of Korea (ROK), Alliance, South Korea, North Korea, Democratic Peoples ’ Republic of Korea (DPRK), United States Forces Korea (USFK), Korea Command

  15. Tectonic characterization of a potential high-level nuclear waste repository at Yucca Mountain, Nevada

    USGS Publications Warehouse

    Whitney, John W.; O'Leary, Dennis W.

    1993-01-01

    Tectonic characterization of a potential high-level nuclear waste repository at Yucca Mountain, Nevada, is needed to assess seismic and possible volcanic hazards that could affect the site during the preclosure (next 100 years) and the behavior of the hydrologic system during the postclosure (the following 10,000 years) periods. Tectonic characterization is based on assembling mapped geological structures in their chronological order of development and activity, and interpreting their dynamic interrelationships. Addition of mechanistic models and kinematic explanations for the identified tectonic processes provides one or more tectonic models having predictive power. Proper evaluation and application of tectonic models can aid in seismic design and help anticipate probable occurrence of future geologic events of significance to the repository and its design.

  16. Origin of Small Tectonic Plates

    NASA Astrophysics Data System (ADS)

    Mallard, C.; Coltice, N.; Seton, M.; Müller, D.; Tackley, P.

    2015-12-01

    The plate tectonic theory allowed to split the Earth surface into 6 (Le Pichon 1968) to 52 tectonic plates (Bird 2003). These plates are separated into two groups: the first of 7 large plates and the second of numerous smaller plates (Morra et al 2013). Previous studies using the reconstruction of the past 200 My, suggest that the size of large plates is driven by mantle flow. But the tools employed are descriptive (Morra et al 2013, Sornette and Pisarenko 2003), hence ignoring forces and physical principles within the lithosphere and the mantle. The processes at the origin of small plates remain unknown. We developed a new approach to explain the plate sizes. We demonstrate that the physics of convection drives it. We applied plate tectonics theory on 3D spherical convection models generating plate-like motions, which give access to a complete survey of data: velocities, viscosity and heat flow. Our data show that (1) the large plates depend on the dominating scale of the convective flow due to the initiation or the shutdown of subductions; (2) the smaller plates are generated thanks to large variability of regional stresses along subduction zone by slab pull and suction influenced by the geometry of trenches. Our results are consistent with the quick reorganizations of back-arc basins occuring synchronously with the modification of subduction zones geometry around the Pacific plate (Sdrolias et al 2004). Hence, we conclude that (1) the decreasing number of small plates in the plate reconstructions back in time is an artifact induced by their short lifetime, that is why they are artificially ignored; (2) the geometry of past trenches is simplified leading to an underestimation of the length of subduction zones.

  17. Continental margin tectonics - Forearc processes

    SciTech Connect

    Lundberg, N.; Reed, D.L. )

    1991-01-01

    Recent studies of convergent plate margins and the structural development of forearc terranes are summarized in a critical review of U.S. research from the period 1987-1990. Topics addressed include the geometry of accretionary prisms (Coulomb wedge taper and vertical motion in response to tectonic processes), offscraping vs underplating or subduction, the response to oblique convergence, fluids in forearc settings, the thermal framework and the effects of fluid advection, and serpentinite seamounts. Also included is a comprehensive bibliography for the period.

  18. Tectonic deformation in southern California

    NASA Technical Reports Server (NTRS)

    Jackson, David D.

    1993-01-01

    Our objectives were to use modem geodetic data, especially those derived from space techniques like Very Long Baseline Interferometry (VLBI), Satellite Laser Ranging (SLR), and the Global Positioning System (GPS) to infer crustal deformation in southern California and relate it to plate tectonics and earthquake hazard. To do this, we needed to collect some original data, write computer programs to determine positions of survey markers from geodetic observables, interpret time dependent positions in terms of velocity and earthquake caused episodic displacements, and construct a model to explain these velocities and displacements in terms of fault slip and plate movements.

  19. South Korea Powers Ahead with Globalization Plans

    ERIC Educational Resources Information Center

    McNeill, David

    2009-01-01

    For government officials in South Korea, it's a vision worth savoring: Within the next decade, South Korea becomes Southeast Asia's top higher-education destination, poaching thousands of Chinese, Indian, and Japanese students from American universities and overtaking rivals Singapore, Malaysia, and Hong Kong. The higher-education system's…

  20. Korea in the 21st Century.

    DTIC Science & Technology

    1996-02-01

    Amsden, Asia’s Next Giant: South Korea and Late Industralization (Oxford: Oxford University Press, 1989). 17 manage the absorption of North Korea by...is to use this new airport as a light industry and biotechnology hub with easy com- munications and transportation to and from China, Japan, Russia

  1. Divorce in Korea: Trends and Educational Differentials

    ERIC Educational Resources Information Center

    Park, Hyunjoon; Raymo, James M.

    2013-01-01

    The authors extend comparative research on educational differences in divorce by analyzing data from Korea. A primary motivation was to assess whether the theoretically unexpected negative educational gradient in divorce in Japan is also observed in Korea. Using vital statistics records for marriages and divorces registered between 1991 and 2006,…

  2. How much plutonium does North Korea have?

    SciTech Connect

    Albright, D.

    1994-09-01

    U.S. intelligence discovered in the 1980s that North Korea was building a small nuclear reactor. The reactor was described as a gas-cooled, graphite-moderated model similar to those Britian and France used to produce electric power as well as plutonium for nuclear weapons. When Western nations expressed concern about the reactor Russia pressed North Korea to sign the Non-Proliferation Treaty (NPT) which it did on December 12, 1985. However, North Korea stalled on signing the required safeguards agreement that allows the International Atomic Energy Agency (IAEA) to inspect nuclear facilities until January 1992. Inspections by the IAEA revealed discrepancies with the amounts of plutonium separated as declared by the North Koreans. The IAEA also received reports that two North Korean waste sites were hidden. By February 1993 the IAEA and the North Koreans has reached an impasse: North Koreas initial declarations of plutonium inventory could not be confirmed and North Korea refused to cooperate. At the least, North Korea admits to having separated 100 grams of plutonium. At the most, worst case estimate, they could have a total of 6 - 13 kilograms of separated plutonium. A first nuclear weapon can require up to 10 kilograms of weapon-grade plutonium. Any settlement needs to include a way to insure that the IAEA can verify North Korea`s past nuclear activities and determine the amount of plutonium that may have been separated in the past. 2 refs.

  3. International University Will Open in North Korea

    ERIC Educational Resources Information Center

    McNeill, David

    2007-01-01

    This article reports that construction is nearing completion on Pyongyang University of Science and Technology in North Korea, in which academics from around the world will teach the best of the country's graduate students. This will be North Korea's first international university and will let the world know that the capacity of their scientists…

  4. North Korea: Terrorism List Removal

    DTIC Science & Technology

    2008-11-06

    ct/rls/crt/2006/82736.htm] at p. 147. 28 Yi Sang-il and Chin Se-ku. Yongbyon nuclear facility can be disabled within a year. JongAng Ilbo (internet...Interview of the President by Foreign Print Media, August 30, 3007. 32 Choe Sang- hun and David E. Sanger, North Korea claims U.S. will remove sanctions...smuggle conventional arms, including machine guns , automatic rifles, and anti-tank rocket launchers, to the Tamil Tigers in Sri Lanka. The Sri Lankan

  5. The United States Air Force in Korea 1950-1953

    DTIC Science & Technology

    1983-01-01

    material which likely will be of limited interest to a general reader but which may be significant to the military planner and student. There was good reason...war, suggested valuable source material for research, and Mr. Wilbur W. Hoare, Jr., Historian of the Joint Chiefs of Staff, ensured that top-level...copyright material : To Mr. Beverly Smith, Jr., for information in "Why We Went to War in Korea," in The Saturday Evening Post, 10 November 1951. To

  6. Shanghanlun in Korea, 1610-1945

    PubMed Central

    Suh, Soyoung

    2015-01-01

    This article examines how Korean physicians of traditional medicine have utilized Zhang Ji’s 張 機 (150–219 CE) Shanghanlun 傷寒論 (Treatise on Cold Damage Disorders, just Treatise hereafter) from the 17th century to the early twentieth century. As one of the two most influential pillars of Chinese medicine, the Treatise, with its clinical implications, has inspired many scholars and practitioners in their pursuit of medical innovation. What, then, have been the Korean motivations in referring to the Treatise over the past few centuries? What does the Korean utilization and modification of the Chinese classic tell us about the desires, limits, and possibilities of pursuing medical innovations in Korea? By examining the ways in which major pre-modern Korean texts employed the Treatise, this article primarily aims to reveal patterns of (re)arranging the Treatise that formed an indigenous style of medicine. Under the growing sense of nationalist concern and colonial contestation in the early twentieth century, the Korean compilation of the Treatise began to depart from the earlier interpretations. A range of nationalist rhetoric and editorial designs reflect the Korean urgency in seeking resources to compete with Western medicine. The postcolonial consumption of the Treatise also reflects Korean strategies in navigating medical references from outside to meet their social and clinical agendas. The changing pattern of textual and professional utilization of the Treatise exemplifies how a significant Chinese text continues to be a living tradition in Korea by expanding the targeted audience and satisfying local demands. PMID:26778942

  7. Analysis of tectonic features in US southwest from Skylab photographs

    NASA Technical Reports Server (NTRS)

    Abdel-Gawad, M. (Principal Investigator); Tubbesing, L.

    1975-01-01

    The author has identified the following significant results. Skylab photographs were utilized to study faults and tectonic lines in selected areas of the U.S. Southwest. Emphasis was on elements of the Texas Zone in the Mojave Desert and the tectonic intersection in southern Nevada. Transverse faults believed to represent the continuation of the Texas Zone were found to be anomalous in strike. This suggests that the Mojave Desert block was rotated counterclockwise as a unit with the Sierra Nevada. Left-lateral strike-slip faults in Lake Mead area are interpreted as elements of the Wasatch tectonic zone; their anomalous trend indicates that the Lake Mead area has rotated clockwise with the Colorado Plateau. A tectonic model relating major fault zones to fragmentation and rotation of crustal blocks was developed. Detailed correlation of the high resolution S190B metric camera photographs with U-2 photographs and geologic maps demonstrates the feasibility of utilizing S190B photographs for the identification of geomorphic features associated with recent and active faults and for the assessment of seismic hazards.

  8. Tectonic models for Yucca Mountain, Nevada

    USGS Publications Warehouse

    O'Leary, D. W.

    2006-01-01

    Performance of a high-level nuclear waste repository at Yucca Mountain hinges partly on long-term structural stability of the mountain, its susceptibility to tectonic disruption that includes fault displacement, seismic ground motion, and igneous intrusion. Because of the uncertainty involved with long-term (10,000 yr minimum) prediction of tectonic events (e.g., earthquakes) and the incomplete understanding of the history of strain and its mechanisms in the Yucca Mountain region, a tectonic model is needed. A tectonic model should represent the structural assemblage of the mountain in its tectonic setting and account for that assemblage through a history of deformation in which all of the observed deformation features are linked in time and space. Four major types of tectonic models have been proposed for Yucca Mountain: a caldera model; simple shear (detachment fault) models; pure shear (planar fault) models; and lateral shear models. Most of the models seek to explain local features in the context of well-accepted regional deformation mechanisms. Evaluation of the models in light of site characterization shows that none of them completely accounts for all the known tectonic features of Yucca Mountain or is fully compatible with the deformation history. The Yucca Mountain project does not endorse a preferred tectonic model. However, most experts involved in the probabilistic volcanic hazards analysis and the probabilistic seismic hazards analysis preferred a planar fault type model. ?? 2007 Geological Society of America. All rights reserved.

  9. Plate Tectonic Cycle. K-6 Science Curriculum.

    ERIC Educational Resources Information Center

    Blueford, J. R.; And Others

    Plate Tectonics Cycle is one of the units of a K-6 unified science curriculum program. The unit consists of four organizing sub-themes: (1) volcanoes (covering formation, distribution, and major volcanic groups); (2) earthquakes (with investigations on wave movements, seismograms and sub-suface earth currents); (3) plate tectonics (providing maps…

  10. Magmatic-Tectonic Evolution of Tharsis

    NASA Technical Reports Server (NTRS)

    Anderson, R. C.; Dohm, J. M.

    2000-01-01

    The tectonic history of the western hemisphere region of Mars was dominated by the formation of the Tharsis rise. In this study, we identify local centers of tectonic activity and examine how each of the centers fit into the overall evolution of the Tharsis region.

  11. 78 FR 32356 - United States-Korea Free Trade Agreement

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-30

    ... 178 RIN 1515-AD86 United States-Korea Free Trade Agreement AGENCIES: U.S. Customs and Border... United States-Korea Free Trade Agreement entered into by the United States and the Republic of Korea.... SUPPLEMENTARY INFORMATION: Background On June 30, 2007, the United States and the Republic of Korea...

  12. Occupational Hearing Loss in Korea

    PubMed Central

    2010-01-01

    In this article, current status of noise exposure in workplaces, trend of workers with noise-induced hearing loss (NIHL), and prevalence of NIHL in workers by industry and job category in Korea were reviewed. In addition, trends of research on the audiological effects such as hearing loss from noise and occupational hearing loss from non-noise in Korea were addressed through reports in industrial audiology. Though noise exposure level has improved, noise still shows the highest rate of cases exceeding exposure limit among workplace hazards. NIHL is the most common occupational disease except work-related disease such as musculoskeletal disorders and cerebrovascular diseases, and NIHL prevalence is thought to be much higher than reported in official publications. Noise affecting hearing comes from various sources such as workplaces, military settings, areas with exposure to high noise, and specific noise sources. There is also occupational hearing loss by non-noise including chemicals such as organic solvents and heavy metals, barotrauma, and trauma due to welding spark. Noise affects daily life through audiological effects such as hearing loss and tinnitus, non-audiological physical effects (e.g., cardiovascular), and psychosocial and behavioral effects. Development of systematic and comprehensive hearing conservation programs for lowering the noise level in workplaces and preventing the NIHL, and preparation of technological, administrative system for its settlement at workplace are urgently needed. PMID:21258593

  13. Household Arthropod Allergens in Korea

    PubMed Central

    Jeong, Kyoung Yong

    2009-01-01

    Arthropods are important in human health, which can transmit pathogens to humans, parasitize, or produce important allergens. Allergy prevalence becomes higher in Korea recently as well as other developed countries in contrast to a decrease of infectious diseases. Allergic diseases caused by household arthropods have increased dramatically during the last few decades since human beings spend more their time for indoor activities in modernized life style. Household arthropods are one of the most common causes of allergic diseases. Biological characterization of household arthropods and researches on their allergens will provide better understanding of the pathogenesis of allergic diseases and suggest new therapeutic ways. Therefore, studies on arthropods of allergenic importance can be considered one of the major research areas in medical arthropodology and parasitology. Here, the biology of several household arthropods, including house dust mites and cockroaches, the 2 most well known arthropods living indoor together with humans worldwide, and characteristics of their allergens, especially the research activities on these allergens performed in Korea, are summarized. PMID:19885330

  14. Occupational hearing loss in Korea.

    PubMed

    Kim, Kyoo Sang

    2010-12-01

    In this article, current status of noise exposure in workplaces, trend of workers with noise-induced hearing loss (NIHL), and prevalence of NIHL in workers by industry and job category in Korea were reviewed. In addition, trends of research on the audiological effects such as hearing loss from noise and occupational hearing loss from non-noise in Korea were addressed through reports in industrial audiology. Though noise exposure level has improved, noise still shows the highest rate of cases exceeding exposure limit among workplace hazards. NIHL is the most common occupational disease except work-related disease such as musculoskeletal disorders and cerebrovascular diseases, and NIHL prevalence is thought to be much higher than reported in official publications. Noise affecting hearing comes from various sources such as workplaces, military settings, areas with exposure to high noise, and specific noise sources. There is also occupational hearing loss by non-noise including chemicals such as organic solvents and heavy metals, barotrauma, and trauma due to welding spark. Noise affects daily life through audiological effects such as hearing loss and tinnitus, non-audiological physical effects (e.g., cardiovascular), and psychosocial and behavioral effects. Development of systematic and comprehensive hearing conservation programs for lowering the noise level in workplaces and preventing the NIHL, and preparation of technological, administrative system for its settlement at workplace are urgently needed.

  15. Nutrition policy in South Korea.

    PubMed

    Park, Hye-Kyung

    2008-01-01

    Since 1970s, the economic and social development in South Korea, as well as dietary pattern, has undergone various changes. Concerns for the decreased nutrition quality and physical activities among Koreans, especially young population, call for a need of a holistic approach in national food and nutrition policy. The National Health Promotion Act of 1995 included national interventions and programs to deal with nutrition-related chronic diseases and obesity prevention. A nation-wide monitoring system, which includes nutrition and health examination survey, is being built and run by the Ministry of Health and Welfare and its affiliated organizations every three years. The Korea Food and Drug Administration (KFDA) is another key agency undertaking national food and nutrition policies. The KFDA recently promulgated the national strategic plans for improving food safety and nutrition, focusing on children. Nutrition labelling policy for processed food is managed by KFDA and various education programs are developed and disseminated to enhance the awareness of nutrition labelling. The agency also makes standards and regulates foods for special dietary uses and health functional food. The Rural Development Administration (RDA) is responsible for maintaining the food composition database. Finally, the National School Lunch Program is mainly governed by the Ministry of Education and Human Resources Development. The above central government agencies along with regional health centers are making efforts to promote the healthy eating habits in addition to constructing healthy environment by making laws and programs and by research and social marketing.

  16. Hotspot evolution and Venusian tectonic style

    NASA Technical Reports Server (NTRS)

    Mcgill, George E.

    1994-01-01

    Because hotspots represent an important manifestation of heat loss on Venus, their geological evolution is of fundamental importance for any attempt to understand Venusian tectonics. Eistla Regio is an approximately 7500-km-long, moderately elevated region inferred to overlie one or more large mantle upwellings or hotspots. It also contains many shield volcanoes and coronae believed due to the rise of thermal plumes in the mantle. Central Eistla Regio includes two large volcanoes, Sappho and Anala, and several coronae in close proximity. Detailed mapping in this region results in two conclusions of tectonic significance: (1) Sappho and Anala occur near the intersection of two major extensional deformation zones, and (2) the coronae are older than the large volcanoes. Several of the coronae occur as a chain along Guor Linea, one of the major extensional deformation zones. Stratigraphic relationships indicate that the coronae began forming very soon after the emplacement of the widespread regional plains materials. Thus Central Eistla Regio was the site of a swarm of plumes that first formed coronae and then later formed shield volcanoes. The expected result of such a swarm would be thermal thinning of the elastic lithosphere with time. However, model results, geological observations, and gravity data suggest that the change from coronae to shield volcanoes was accompanied by a thickening of the lithosphere with time. This thickening is interpreted to be the result of global cooling of the lithosphere following the most recent episode of near-global resurfacing. The global cooling must have occurred faster than local heating of the lithosphere due to the impingement of thermal plumes.

  17. Gravity and tectonic patterns of Mercury

    NASA Astrophysics Data System (ADS)

    Matsuyama, I.; Nimmo, F.

    2008-12-01

    We consider the effect of tidal deformation, spin-orbit resonance, non-zero eccentricity, despinning, and reorientation on the global-scale gravity, shape, and tectonic patterns of planetary bodies. Large variations of the gravity and shape coefficients from the synchronous rotation and zero eccentricity values, J2/C22=10/3 and (b-c)/(a-c)=1/4, arise due to non-synchronous rotation and non-zero eccentricity even in the absence of reorientation or despinning. Reorientation or despinning induce additional variations. As an illustration of this theory, we consider the specific example of Mercury. The large gravity coefficients estimated from the Mariner 10 flybys cannot be attributed to the Caloris basin alone since the required mass excess in this case would have caused Caloris to migrate to one of Mercury's hot poles. Similarly, a large remnant bulge due to a smaller semimajor axis and spin-orbit resonance can be dismissed since the required semimajor axis is unphysically small (< 0.1 AU). Reorientation of a large remnant bulge recording an epoch of faster rotation (without significant semimajor axis variations) can explain the large gravity coefficients. This requires initial rotation rates > 20 times the present value and a positive gravity anomaly associated with Caloris capable of driving 10-45° equatorward reorientation. The required gravity anomaly can be explained by infilling of the basin with material of thicknesses > 7 km, or an annulus of volcanic plains emplaced around the basin with annulus width ~ 1200 km and fill thicknesses > 2 km. The predicted tectonic pattern due to these despinning and reorientation scenarios and radial contraction is in good agreement with the observed lobate scarp pattern.

  18. Mapping Seafloor Tectonics from Space

    NASA Astrophysics Data System (ADS)

    Sandwell, D. T.; Smith, W. H.

    2005-12-01

    Our current understanding of the topography and tectonics of the ocean basins is largely derived from dense satellite altimeter measurements of the marine gravity field combined with sparse geophysical measurements from research vessels. First generation satellite altimetry was initiated in the 1970s by NASA with the Skylab and GEOS-3 missions, followed by the brief but highly successful Seasat mission of 1978. Seasat provided the first global view of the marine gravity field, well illustrated by Bill Haxby's maps of the early 1980s. It is difficult to express the excitement in the scientific community when the global signatures of the postulated ridges, transforms, and subduction zones were revealed. Moreover, Seasat proved that non-repeat orbit altimetry was the obvious way to map the ocean basins and the US Navy quickly developed Geosat in 1985 to finish the job. For 10 years the Geosat data remained classified until ESA's ERS-1 duplicated the secret information. The sudden availability of dense measurements from these second generation altimeters (Geosat and ERS-1) is perhaps the most important ocean science observation in the last two decades. These data provided not only a spectacular confirmation of plate tectonics but also partly revealed smaller-scale structures including thousands of seamounts, propagating rifts, ridge jumps, and global-scale variations in seafloor roughness. In addition, the dense gravity information was combined with sparse ship soundings to construct global bathymetry maps at ~10 km resolution - a great improvement over hand-drawn maps but still far worse than our current maps of Mars, Venus, and the Moon. While these data filled a huge gap in our understanding of the ocean basins, they also triggered a thirst for more. Third generation altimeters with improved range precision are on the horizon. The scientific rationale for a factor of 5 improvement in altimeter precision spans three broad areas of earth science: one, resolving the

  19. Toward a sustainable regional electricity system: The case of Kangwaon Province in Korea

    NASA Astrophysics Data System (ADS)

    Jung, Inwhan

    Korea's exceptional economic growth for the last three decades has been accompanied by a rapid growth in commercial energy use. While the world increased its total primary energy consumption by 1.7 percent annually during the period between 1971 and 1994, Korea expanded its consumption level by 8.5 percent during the same period. The first quarter of the twenty-first century will be a period when energy consumption in Korea escalates even further, particularly in electricity consumption. This projection raises potential conflicts between Korea's economic growth and Korea's participation in international efforts to reduce greenhouse gas (GHG) emissions (Noh, 1991). A sustainable energy system is likely to promote sustainable development. However, Korea's current electricity system mainly comprised of fossil fuels and nuclear power is unsustainable in the context of energy, environment, and economy (E3). As a means of addressing the problem, this study introduces the country's electricity system shaped by the actions of local regions. How a local region, such as Kangwon Province in Korea, might take steps to mitigate the problems associated with Korea's current electricity system? Reducing regional electricity requirements through end-use efficiency improvements in electric appliances, buildings, and industrial processes is fundamentally important. Decentralized and renewable-oriented electricity supply options are also important to the success of region-based sustainable electricity systems. This dissertation compares environmental and economic benefits between the conventional and sustainable electricity systems to meet electricity requirements in Kangwon Province in the year 2010. The results clearly indicate that the region-based sustainable electricity system gives significant benefits to the Province in terms of energy, economy, and environment. In the final chapter, policy guidelines are developed to implement region-based sustainable electricity plans.

  20. Horizontal deformation in South Korea from permanent GPS network data, 2000-2003

    NASA Astrophysics Data System (ADS)

    Hamdy, A. M.; Park, P.-H.; Lim, H.-C.

    2005-02-01

    Analysis of continuous GPS data 2000-2003 at 50 stations of the Korean GPS Network (KGN) suggests that the southern part of the Korean peninsula is tectonically more stable than other regions in the Eastern Asia. The average velocity was ~1.5 mm/yr and the average overall strain rate was around -0.3 × 10-9str/yr. The obtained velocity field indicates the presence of anticlockwise rotation of the whole region with respect to Daejeon station (DAEJ), in the central part of South Korea. It also showed that KM-OB (Kyonggi Massif and the Okchon Basin) and YM-TB (Yeongnam Massif and Taebaeksan Basin) have left-lateral shearing movements. Both movements were confirmed by the deformation analysis of the KGN horizontal velocity field using the infinitesimal plate theory. The results show that South Korea moves toward the WNW direction with a velocity of 0.9 mm/yr with a slow anticlockwise rotation. The strain field in South Korea indicates the existence of both compression and tension. The compression and extension axes have WSW-EWE and NNW-SSE directions, respectively.

  1. Burden of noncommunicable diseases and national strategies to control them in Korea.

    PubMed

    Khang, Young-Ho

    2013-07-01

    Noncommunicable diseases (NCDs) are the most important causes of premature mortality and disability-adjusted life years in Korea. NCDs are also the main contributor to socioeconomic inequalities in mortality and life expectancy. Reduction of NCDs and NCD inequalities would result in significant improvement in healthy life expectancy and health equity in Korea. Major NCD risk factors such as dietary risks (including salt intake), alcohol consumption, cigarette smoking, and high blood pressure were found to be the leading modifiable risk factors of disability-adjusted life years in Korea, based on the 2010 Global Burden of Disease Study. Several Korean studies have shown that these risk factors play an important role in creating socioeconomic inequalities in NCD mortality and total mortality. Current international discussions on NCD policies in the United Nations and the World Health Organization would provide better opportunities for developing aggressive population-wide policy measures in Korea. Considering the paucity of population-wide policies to control major NCD risk factors in Korea, rigorous population approaches such as taxation and regulation of unhealthy commodities as well as public education and mass campaigns should be further developed in Korea.

  2. Growth of a tectonic ridge

    SciTech Connect

    Fleming, R.W.; Messerich, J.A.; Johnson, A.M.

    1997-12-31

    The 28 June 1992 Landers, California, earthquake of M 7.6 created an impressive record of surface rupture and ground deformation. Fractures extend over a length of more than 80 km including zones of right-lateral shift, steps in the fault zones, fault intersections and vertical changes. Among the vertical changes was the growth of a tectonic ridge described here. In this paper the authors describe the Emerson fault zone and the Tortoise Hill ridge including the relations between the fault zone and the ridge. They present data on the horizontal deformation at several scales associated with activity within the ridge and belt of shear zones and show the differential vertical uplifts. And, they conclude with a discussion of potential models for the observed deformation.

  3. Tethys geology and tectonics revisited

    NASA Technical Reports Server (NTRS)

    Croft, Steven K.

    1991-01-01

    Tethys, a medium sized icy satellite of Saturn, was imaged by both Voyager 1 and 2 spacecraft at sufficiently high resolution to allow some geologic analysis. One fairly complete and several brief descriptions of Tethys' geology have been given. Partial results are given herein of a new analysis of Tethys' geology done as part of a comparative tectonic and cryovolcanic study of the saturnian satellites. A new geologic sketch map of Tethys' north polar area is given. This map is based on a sequence of images transformed to a polar stereographic projection at the same scale. The images present the same area under different illuminations, each of which brings out different features. A new global map is in progress.

  4. Discriminating Tectonic Tremor from Magmatic Processes in Observationally Challenging Environments

    NASA Astrophysics Data System (ADS)

    Brown, J. R.; Beroza, G. C.

    2011-12-01

    Deep tectonic tremor is a long-duration, low amplitude signal that has been shown to consist of low frequency earthquakes (LFEs) on the plate interface in subduction zones. Detecting LFEs from tremor-like signals in subduction settings can be challenging due to the combination of volcanic seismicity and sparse station geometry. This is particularly true for island arcs such as the Alaska-Aleutian subduction zone where the islands are small and noise levels are high. We have detected and located LFEs within tremor signals along the Alaska-Aleutian Arc in four locations: Kodiak Island, Alaska Peninsula, eastern Aleutians, and the Andreanof Islands. In all areas, the LFEs are located 10-40 km trenchward of the volcanic chain at depths ranging from 45-70 km. Location errors are significant (+/- 20 km in depth) due to sparse station geometry such that there is the possibility that the tremor could be associated with nearby volcanoes. Since most documented volcanic tremor is located in the shallow crust, it can often be discriminated from tectonic tremor simply based on location. However, deep volcanic tremor has been documented in Hawaii to depths of 40 km and could be more widespread. In the Aleutian arc, deep long period events (DLPs), which are thought to result from the movement of magma and volatiles, have been located as deep as 45 km and sometimes resemble tremor-like signals. The spectral character is another potential discriminant. We compare the cepstra (Fourier transform of the logarithmic power spectrum of a time series) of the tectonic tremor-like signals/LFEs and DLPs associated with volcanoes. Source characteristics of DLPs (non-shear slip) and tectonic tremor/LFEs (shear slip) are distinct and should be noticeable in the cepstral domain. This approach of using tremor locations and cepstral analysis could be useful for detecting and differentiating tectonic tremor from deep volcanic processes in other island arcs as well.

  5. Tectonics and ice sheet dynamics of West Antarctic margins

    NASA Astrophysics Data System (ADS)

    Gohl, Karsten

    2010-05-01

    An understanding of the glacial history of the Amundsen Sea Embayment (ASE) and Pine Island Bay (PIB) is essential for proposing models on the future development of the West Antarctic Ice Sheet. This requires an understanding of the tectonic history and knowledge of tectonic features such as lineaments, ridges, sills and basins, because basement morphology and inherited erosional features control the flow direction of ice-sheets and the influx of Circum-Polar Deep Water (CDW). This is an attempt to reconstruct the tectonic history with the aim to search for basement features and crustal boundaries which may be correlated to the flow and dynamics of the ice-sheet. The Amundsen Sea Embayment of West Antarctica is in a prominent location for a series of tectonic and magmatic events from Paleozoic to Cenozoic times. Seismic, magnetic and gravity data from the embayment and PIB reveal the crustal thickness and significant tectonic features. NE-SW trending magnetic and gravity anomalies and the thin crust indicate a former rift zone which was active during or in the run-up to the breakup process between Chatham Rise and West Antarctica before or at 90 Ma. NW-SE trending gravity and magnetic anomalies, following a prolongation of Peacock Sound, indicate the extensional southern boundary to the Bellingshausen Plate which was active between 79 and 61 Ma. It is likely that the prominent Pine Island Trough follows a structural boundary between the crustal blocks of Ellsworth Land and Marie Byrd Land. Data are shown from the ASE and PIB which can be interpreted in context with the reconstruction of the ice advance and retreat history in this area. Differences in the behaviour of the ice-sheet are shown to exist for the western and eastern parts of PIB due to basement structures affecting the inflow of CDW.

  6. Copycat Suicide Induced by Entertainment Celebrity Suicides in South Korea

    PubMed Central

    Jang, Soo Ah; Sung, Ji Min; Park, Jin Young

    2016-01-01

    Objective Throughout the past several years, there have been a number of entertainment celebrity suicides in South Korea. The aim of this study was to investigate the clustering of suicides following celebrities' suicides in South Korea from 2005 to 2008, particularly according to certain characteristics. Methods Seven celebrity suicides were examined and defined using the Korean Integrated Newspaper Database System (KINDS) and from these, we considered four affected periods occurring 28 days after each celebrity's suicide. A Poisson time-series autoregression model was used to estimate the relative risk of the total suicide number for each affected period from 2005 to 2008. Logistic regression analysis was performed to investigate whether there were specific increases in the numbers of suicides in subgroups matching each celebrity. Results There were significant increases in the risk of suicide during the affected periods. Remarkable increases were found in the subgroups matching each celebrity, especially in the group in which all factors (sex, age, and method) were similar. Conclusion This study provides confirmation that a significant copycat effect was induced by these celebrities' suicides, especially among people who identified more with the celebrities. This implies that countermeasures for upright media coverage of celebrity suicides should be discussed and practiced properly in South Korea. PMID:26766949

  7. Recommendations for Carotid Stenting in Korea

    PubMed Central

    Chang, Hyuk Won; Suh, Sang-il; Jeong, Hae Woong; Suh, Dae Chul

    2015-01-01

    Carotid artery angioplasty with stenting (CAS) is being performed in many hospitals in Korea. Most of the guidelines which are being used are similar, but the practical aspects such as techniques are different between hospitals. For example, usage of various protective devices, the oral antiplatelet regimen prior to procedure and placing of temporary pacemaker to prevent bradycardia are different between hospitals. In this article, we summarize and propose the guidelines for CAS which is currently being accepted in Korea. These guidelines may be helpful in providing protocol to neurointerventionalist who perform CAS and to standardize the process including reporting of CAS in the future comparative trials in Korea. PMID:25763292

  8. Korea`s choice of a new generation of nuclear plants

    SciTech Connect

    Redding, J.R.

    1994-12-31

    The ABWR and SBWR design, both under development at GE, provide the best platform for developing the next generation advanced plants. The ABWR, which is rapidly setting the standard for new nuclear reactor plants, is clearly the best choice to meet the present energy needs of Korea. And through a GE/Korea partnership to develop the plant of the next century, Korea will establish itself as a leader in innovative reactor technology.

  9. Tectonic ancestry of central Montana and its influence on inversion tectonics

    SciTech Connect

    Woodward, L.A.

    1996-06-01

    Inversion tectonics, where structurally low areas become structurally high, has profound implications for hydrocarbon exploration. Effective exploration depends on understanding structures, timing, and controls on tectonic inversion. In central Montana tectonic inversion occurred three times in Phanerozoic time and reflects Precambrian tectonic trends. Westerly striking, steep foliation in Archean crystalline rocks defines the tectonic grain in basement exposures. The Helena embayment of the Middle Proterozoic Belt Basin formed an east-trending aulacogen extending into the craton in central Montana. Westerly trending fault-blocks of probable Late Proterozoic age formed within the embayment. The trough was tectonically inverted in the Devonian, but was depressed in the Carboniferous, accumulating major thicknesses of Madison Group and Big Snowy Group strata. Tectonic inversion again occurred with rise of the {open_quotes}Belt island{close_quotes} in the Jurassic. The trough was reactivated with a thick accumulation of lower Lower Cretaceous strata. Laramide (Late Cretaceous-early Tertiary) deformation resulted in tectonic inversion with rise of the Little Belt, Big Snowy, and related uplifts. Reactivation with reverse and strike-slip movement occurred on synsedimentary Proterozoic westerly trending normal faults that bounded the Helena embayment. Subsidence was probably related to crustal extension, whereas tectonic inversion and rise is inferred to be caused by crustal shortening. West-northwesterly trending en echelon folds that cross central Montana suggest major left shift. The Precambrian structural framework and fabric of the region thus appear to have had major influence on tectonic features that were multiply reactivated in Phanerozoic time.

  10. Tectonic and neotectonic framework of the Yucca Mountain Region

    SciTech Connect

    Schweickert, R.A.

    1992-09-30

    Highlights of major research accomplishments concerned with the tectonics and neotectonics of the Yucca Mountain Region include: structural studies in Grapevine Mountains, Bullfrog Hills, and Bare Mountain; recognition of significance of pre-Middle Miocene normal and strike-slip faulting at Bare Mountain; compilation of map of quaternary faulting in Southern Amargosa Valley; and preliminary paleomagnetic analysis of Paleozoic and Cenozoic units at Bare Mountain.

  11. Origin of adakite-like plutons in southern Korea

    NASA Astrophysics Data System (ADS)

    Oh, Jeong-Im; Choi, Sung Hi; Yi, Keewook

    2016-10-01

    We present Sr-Nd-Pb isotopic compositions for two adakite-like intrusions in southern Korea (Jindong and Bongnae), including major and trace element concentrations, and the sensitive high-resolution ion microprobe (SHRIMP) zircon U-Pb age. Our aim is to constrain the origin and tectonomagmatic processes that gave rise to the plutons. A SHRIMP U-Pb zircon age of 88.7 ± 0.7 Ma was obtained from a Jindong granodiorite sample. The Jindong plutons belong to the medium-K calc-alkaline series, and have an overall enrichment in large ion lithophile elements (LILE), such as K, Rb, Ba, and Pb, and a relative depletion in high field strength elements, such as Nb, Ta, and Ti, compared with the neighboring elements in the primitive mantle-normalized multi-trace element variation diagram. It was found that (87Sr/86Sr)i = 0.70475-0.70596, (143Nd/144Nd)i = 0.512547-0.512604, [(εNd)i = + 0.4 to 2.2], and (206Pb/204Pb)i = 18.19-18.37, which fall within the field of the arc-type Cretaceous to Tertiary Bulguksa intrusive rocks in the Sr-Nd and Pb-Pb isotopic correlation diagrams. The elevated Sr/Y (17-40), but low La/Yb (3.7-8.8) ratios of the Jindong plutons, together with their coherent geochemical trends and U-shaped rare earth element (REE) patterns, indicate that they were not formed by slab melting, but by amphibole-dominated fractional crystallization of the Bulguksa-like arc magma. A SHRIMP U-Pb zircon age of 226.5 ± 2.5 Ma was obtained from a Bongnae tonalite sample. The Bongnae plutons belong to the shoshonitic series. Their trace element patterns resemble the Jindong samples, but are characterized by significantly negative U anomalies in mafic rocks. They also have elevated MgO, Ni, Co, Cr, Rb, Ba, Sr, and low Al2O3 and Na2O contents at a given SiO2 concentration compared with the Jindong plutons, and are typified by highly radiogenic Sr and unradiogenic Nd and Pb isotopic compositions: [(87Sr/86Sr)i = 0.71096-0.71290, (143Nd/144Nd)i = 0.511641-0.511681, (εNd)i = - 13

  12. Space Weather Services of Korea

    NASA Astrophysics Data System (ADS)

    Yoon, KiChang; Kim, Jae-Hun; Kim, Young Yun; Kwon, Yongki; Wi, Gwan-sik

    2016-07-01

    The Korean Space Weather Center (KSWC) of the National Radio Research Agency (RRA) is a government agency which is the official source of space weather information for Korean Government and the primary action agency of emergency measure to severe space weather condition. KSWC's main role is providing alerts, watches, and forecasts in order to minimize the space weather impacts on both of public and commercial sectors of satellites, aviation, communications, navigations, power grids, and etc. KSWC is also in charge of monitoring the space weather condition and conducting research and development for its main role of space weather operation in Korea. In this study, we will present KSWC's recent efforts on development of application-oriented space weather research products and services on user needs, and introduce new international collaborative projects, such as IPS-Driven Enlil model, DREAM model estimating electron in satellite orbit, global network of DSCOVR and STEREO satellites tracking, and ARMAS (Automated Radiation Measurement for Aviation Safety).

  13. Space Weather Services of Korea

    NASA Astrophysics Data System (ADS)

    Yoon, K.; Hong, S.; Park, S.; Kim, Y. Y.; Wi, G.

    2015-12-01

    The Korean Space Weather Center (KSWC) of the National Radio Research Agency (RRA) is a government agency which is the official source of space weather information for Korean Government and the primary action agency of emergency measure to severe space weather condition. KSWC's main role is providing alerts, watches, and forecasts in order to minimize the space weather impacts on both of public and commercial sectors of satellites, aviation, communications, navigations, power grids, and etc. KSWC is also in charge of monitoring the space weather condition and conducting research and development for its main role of space weather operation in Korea. In this study, we will present KSWC's recent efforts on development of application-oriented space weather research products and services on user needs, and introduce new international collaborative projects, such as IPS-Driven Enlil model, global network of DSCOVR and STEREO satellites tracking, and ARMAS (Automated Radiation Measurement for Aviation Safety).

  14. Tectonics and Volcanism of East Africa as Seen Using Remote Sensing Imagery

    NASA Technical Reports Server (NTRS)

    Hutt, Duncan John

    1996-01-01

    The East African Rift is the largest area of active continental geology. The tectonics of this area has been studied with remote sensing data, including AVHRR, Landsat MSS and TM, SPOT, and electronic still camera from Shuttle. Lineation trends have been compared to centers of volcanic and earthquake activity as well as the trends shown on existing geologic maps. Remote sensing data can be used effectively to reveal and analyze significant tectonic features in this area.

  15. Venus: Mantle convection, hotspots, and tectonics

    NASA Technical Reports Server (NTRS)

    Phillips, R. J.

    1989-01-01

    The putative paradigm that planets of the same size and mass have the same tectonic style led to the adaptation of the mechanisms of terrestrial plate tectonics as the a priori model of the way Venus should behave. Data acquired over the last decade by Pioneer Venus, Venera, and ground-based radar have modified this view sharply and have illuminated the lack of detailed understanding of the plate tectonic mechanism. For reference, terrestrial mechanisms are briefly reviewed. Venusian lithospheric divergence, hotspot model, and horizontal deformation theories are proposed and examined.

  16. Interdisciplinary Studies of Magma-Tectonic Interactions

    NASA Astrophysics Data System (ADS)

    LaFemina, Peter; Stix, John; Saballos, Armando

    2013-08-01

    The Pan-American Advanced Studies Institute (PASI) Magma-Tectonic Interactions in the Americas brought together researchers, postdoctoral fellows, and graduate students from every country in the Americas with active volcanoes and one participant from Iceland. Lecturers presented the latest geochemical and geophysical approaches to studying magma-tectonic interactions. Participants were introduced to the tectonics and volcanism of Nicaragua through a daylong field trip and given opportunities to collect and analyze their own data, including seismic, geodetic, and geochemical data, at the Cerro Negro volcano.

  17. Geographic Distribution of Urologists in Korea, 2007 to 2012.

    PubMed

    Song, Yun Seob; Shim, Sung Ryul; Jung, Insoo; Sun, Hwa Yeon; Song, Soo Hyun; Kwon, Soon-Sun; Ko, Young Myoung; Kim, Jae Heon

    2015-11-01

    The adequacy of the urologist work force in Korea has never been investigated. This study investigated the geographic distribution of urologists in Korea. County level data from the National Health Insurance Service and National Statistical Office was analyzed in this ecological study. Urologist density was defined by the number of urologists per 100,000 individuals. National patterns of urologist density were mapped graphically at the county level using GIS software. To control the time sequence, regression analysis with fitted line plot was conducted. The difference of distribution of urologist density was analyzed by ANCOVA. Urologists density showed an uneven distribution according to county characteristics (metropolitan cities vs. nonmetropolitan cities vs. rural areas; mean square=102.329, P<0.001) and also according to year (mean square=9.747, P=0.048). Regression analysis between metropolitan and non-metropolitan cities showed significant difference in the change of urologists per year (P=0.019). Metropolitan cities vs. rural areas and non-metropolitan cities vs. rural areas showed no differences. Among the factors, the presence of training hospitals was the affecting factor for the uneven distribution of urologist density (P<0.001). Uneven distribution of urologists in Korea likely originated from the relatively low urologist density in rural areas. However, considering the time sequencing data from 2007 to 2012, there was a difference between the increase of urologist density in metropolitan and non-metropolitan cities.

  18. Factors influencing computer literacy of Taiwan and South Korea nurses.

    PubMed

    Hsu, Hui-Mei; Hou, Ying-Hui; Chang, I-Chiu; Yen, David C

    2009-04-01

    Healthcare is experiencing a major transformation in its information technology base. Hospitals are adopting information technology (IT) to reduce costs and increase competitiveness. IT applications in healthcare are trending towards electronic patient records and even health records. Therefore, practices in nursing are also affected by IT. Many researchers have studied what computer literacy a nurse should possess, but have focused less on factors that actually impact computer literacy. The purposes of this study are to examine current computer literacy levels of nurses, and to indicate what variables influence their computer literacy. Taiwan and South Korea both implemented a national health insurance system, and used state-of-the art IT to provide higher volume and better quality of services. The data were collected from two case hospitals which are located in Taiwan and South Korea, respectively. By using a structured questionnaire, a total of 203 nurses responded; 104 from Taiwan and 99 from South Korea. The results revealed that personal innovativeness in IT, computer education, and age are significant factors that affected computer literacy levels. These factors serve as reference for administrators and executives in hospitals, or nursing educators seeking the data necessary to make decisions on curriculum.

  19. Serological Detection of Borrelia burgdorferi among Horses in Korea

    PubMed Central

    Lee, Seung-Hun; Yun, Sun-Hee; Choi, Eunsang; Park, Yong-Soo; Lee, Sang-Eun; Cho, Gil-Jae; Kwon, Oh-Deog; Kwak, Dongmi

    2016-01-01

    Lyme disease is a tick-borne zoonotic infectious disease caused by Borrelia burgdorferi. The present study assessed the infection status of B. burgdorferi among horses reared in Korea using ELISA and PCR. Between 2009 and 2013, blood samples were collected from 727 horses throughout Korea. Data for each animal including age, gender, breed, and region of sample collection were used for epidemiological analysis. Overall, 38 (5.2%; true prevalence: 5.5%) of 727 horses were seropositive by ELISA. There were statistically significant differences according to breed and region (P<0.001) whose differences might be attributed to the ecology of vector ticks and climate conditions. Using 2 nested PCR, none of the samples tested positive for B. burgdorferi. Thus, a positive ELISA result can indicate only that the tested horse was previously exposed to B. burgdorferi, with no certainty over the time of exposure. Since global warming is likely to increase the abundance of ticks in Korea, continuous monitoring of tick-borne diseases in Korean horses is needed. PMID:26951987

  20. Vulnerability to temperature-related mortality in Seoul, Korea

    NASA Astrophysics Data System (ADS)

    Son, Ji-Young; Lee, Jong-Tae; Anderson, G. Brooke; Bell, Michelle L.

    2011-07-01

    Studies indicate that the mortality effects of temperature may vary by population and region, although little is known about the vulnerability of subgroups to these risks in Korea. This study examined the relationship between temperature and cause-specific mortality for Seoul, Korea, for the period 2000-7, including whether some subgroups are particularly vulnerable with respect to sex, age, education and place of death. The authors applied time-series models allowing nonlinear relationships for heat- and cold-related mortality, and generated exposure-response curves. Both high and low ambient temperatures were associated with increased risk for daily mortality. Mortality risk was 10.2% (95% confidence interval 7.43, 13.0%) higher at the 90th percentile of daily mean temperatures (25 °C) compared to the 50th percentile (15 °C). Mortality risk was 12.2% (3.69, 21.3%) comparing the 10th (-1 °C) and 50th percentiles of temperature. Cardiovascular deaths showed a higher risk to cold, whereas respiratory deaths showed a higher risk to heat effect, although the differences were not statistically significant. Susceptible populations were identified such as females, the elderly, those with no education, and deaths occurring outside of a hospital for heat- and cold-related total mortality. Our findings provide supportive evidence of a temperature-mortality relationship in Korea and indicate that some subpopulations are particularly vulnerable.

  1. Temporal Trends of Hospitalized Patients with Heart Failure in Korea

    PubMed Central

    Youn, Jong-Chan; Ryu, Kyu-Hyung

    2017-01-01

    Heart failure (HF) is an important cardiovascular disease because of its increasing prevalence, significant morbidity, high mortality and rapidly expanding health care costs. The number of HF patients is increasing worldwide and Korea is no exception. Temporal trends of four representative Korean hospitalized HF registries–the Hallym HF study, the Korean Multicenter HF study, the Korean Heart Failure (KorHF) registry and the Korean Acute Heart Failure (KorAHF) registry showed mild survival improvement reflecting overall HF patient care development in Korea despite the increased severity of enrolled patients with higher incidence of multiple comorbidities. Moreover, device therapies such as implantable cardioverter defibrillator and cardiac resynchronization therapy and definitive treatment such as heart transplantation have been increasing in Korea as well. To prevent HF burden increase, it is essential to set up long term effective prevention strategies for better control of ischemic heart disease, hypertension and diabetes, which might be risk factors for HF development. Moreover, proper HF guidelines, performance measures, and performance improvement programs might be necessary to limit HF burden as well. PMID:28154584

  2. Serological Detection of Borrelia burgdorferi among Horses in Korea.

    PubMed

    Lee, Seung-Hun; Yun, Sun-Hee; Choi, Eunsang; Park, Yong-Soo; Lee, Sang-Eun; Cho, Gil-Jae; Kwon, Oh-Deog; Kwak, Dongmi

    2016-02-01

    Lyme disease is a tick-borne zoonotic infectious disease caused by Borrelia burgdorferi. The present study assessed the infection status of B. burgdorferi among horses reared in Korea using ELISA and PCR. Between 2009 and 2013, blood samples were collected from 727 horses throughout Korea. Data for each animal including age, gender, breed, and region of sample collection were used for epidemiological analysis. Overall, 38 (5.2%; true prevalence: 5.5%) of 727 horses were seropositive by ELISA. There were statistically significant differences according to breed and region (P<0.001) whose differences might be attributed to the ecology of vector ticks and climate conditions. Using 2 nested PCR, none of the samples tested positive for B. burgdorferi. Thus, a positive ELISA result can indicate only that the tested horse was previously exposed to B. burgdorferi, with no certainty over the time of exposure. Since global warming is likely to increase the abundance of ticks in Korea, continuous monitoring of tick-borne diseases in Korean horses is needed.

  3. Antiviral treatment of influenza in South Korea.

    PubMed

    Choe, Young June; Lee, Hyunju; Lee, Hoan Jong; Choi, Eun Hwa

    2015-06-01

    Antiviral therapy has an important role in the treatment and chemoprophylaxis of influenza. At present, two classes of antiviral agents, adamantanes and neuraminidase inhibitors, are available for the treatment and chemoprophylaxis of influenza in Korea. Because of the widespread resistance against adamantanes, neuraminidase inhibitors are mainly used. Because each country has a unique epidemiology of influenza, the proper use of antiviral agents should be determined based on local data. Decisions on the clinical practice in the treatment of influenza in South Korea are guided by the local surveillance data, practice guidelines, health insurance system and the resistance patterns of the circulating influenza viruses. This review highlights the role of antiviral agents in the treatment and outcome of influenza in Korea by providing comprehensive information of their clinical usage in Korea.

  4. Molecular epidemiology of norovirus in South Korea.

    PubMed

    Lee, Sung-Geun; Cho, Han-Gil; Paik, Soon-Young

    2015-02-01

    Norovirus is a major cause of viral gastroenteritis and a common cause of foodborne and waterborne outbreaks. Norovirus outbreaks are responsible for economic losses, most notably to the public health and food industry field. Norovirus has characteristics such as low infectious dose, prolonged shedding period, strong stability, great diversity, and frequent genome mutations. Besides these characteristics, they are known for rapid and extensive spread in closed settings such as hospitals, hotels, and schools. Norovirus is well known as a major agent of food-poisoning in diverse settings in South Korea. For these reasons, nationwide surveillance for norovirus is active in both clinical and environmental settings in South Korea. Recent studies have reported the emergence of variants and novel recombinants of norovirus. In this review, we summarized studies on the molecular epidemiology and nationwide surveillance of norovirus in South Korea. This review will provide information for vaccine development and prediction of new emerging variants of norovirus in South Korea.

  5. The dynamic evolution of rheumatology in Korea.

    PubMed

    Kim, Ho-Youn; Song, Yeong-Wook

    2016-03-01

    Rheumatology was first recognized as a distinct clinical specialty in Korea just 35 years ago. Young professors who were trained in rheumatology in the USA and afterwards returned to Korea contributed substantially to advances in rheumatology clinical practice, educational programmes and research activities. They also established the Korean Rheumatism Association, later renamed the Korean College of Rheumatology. These young rheumatologists had a major role not only in raising the level of clinical and scientific activities, but also in promoting academic exchanges around the Asia-Pacific region, the USA and Europe. Subsequently, Korea's rapid economic growth and high education level enabled rheumatology to advance rapidly. Today, continued efforts are required to raise the standard of clinical and basic research, to optimize clinical practice with regard to new biologic agents, to exploit personalized and targeted therapies for the rheumatic diseases, and to meet the medical demands of Korea's ageing society.

  6. Negotiations with North Korea: Lessons learned

    NASA Astrophysics Data System (ADS)

    Gallucci, Robert L.

    2014-05-01

    In this paper, I summarize the events leading to the negotiation of the Agreed Framework with North Korea. I also highlight the threats that result from the current situation, and some of the technical issues relevant to understanding events.

  7. Galapagos Tectonics and Evolution (Invited)

    NASA Astrophysics Data System (ADS)

    Hey, R. N.

    2010-12-01

    Galapagos is now considered one of the type-examples of hotspot-ridge interaction, although in the early years of plate tectonics it was generally thought that this interpretation was demonstrably wrong, with two influential groups insisting that non-hotspot models were required for this area. The key to understanding Galapagos tectonic evolution was the recognition that small ridge axis jumps toward the hotspot had occurred, producing complicated magnetic anomalies and asymmetric lithospheric accretion. My dissertation work, guided by Jason Morgan, showed that this simple modification to plate tectonic theory could resolve the seemingly compelling geometric arguments against the Cocos and Carnegie aseismic ridges being Galapagos hotspot tracks, and further that if Galapagos were a hotspot near Fernandina, fixed with respect to the Hawaii hotspot, there should be aseismic ridges on the Cocos and Nazca plates with the observed Cocos and Carnegie ridge geometry, both aseismic ridges forming when the hotspot was ridge-centered, but only the Carnegie ridge since the plate boundary migrated north of the hotspot. A great deal of subsequent research has shown that some areas are considerably more complicated than originally thought, but the following basic model still appears to hold. The Farallon plate split apart along the Grijalva scarp, possibly a preexisting Pacific-Farallon FZ that intersected the hotspot at this time (although alternative interpretations exist), probably in response to tensional stress caused by slab pull in different directions at the Mid-America and Peru-Chile trenches. This break-up allowed more orthogonal subduction of independent Cocos and Nazca plates beginning shortly after 25 Ma. The original Cocos-Nazca ridge trended E-NE, but soon reorganized into N-S spreading segments. The subsequent evolution involved substantial northward ridge migration and ridge jumps, mostly toward the Galapagos hotspot. Recent ridge jumps have occurred in

  8. Hearing Aid Use and Associated Factors in South Korea.

    PubMed

    Moon, Il Joon; Baek, Sun Young; Cho, Yang-Sun

    2015-10-01

    Despite the high prevalence of hearing impairment in the elderly, the rate of hearing aid use is still low. The objectives of this study were to report the nation-wide prevalence of hearing aid use in the Korean population and to determine the associated factors with hearing aid use utilizing a nationally representative data set.We obtained data from the 2010 to 2012 Korea National Health and Nutrition Examination Surveys, which were cross-sectional surveys of the civilian, noninstitutionalized population of the Republic of Korea at age ≥40 years (N = 12,709). A field survey team performed interviews as well as physical examinations. Hearing aid use was assessed using an interviewer-administered questionnaire and pure-tone audiometry was administered for all participants in a sound-attenuating booth. Prevalence of hearing aid acquisition and regular use were calculated in participants who reported perceived hearing loss and who have bilateral hearing thresholds exceeding the 40 dB hearing level. Multivariable analyses were used to examine the associated factors with hearing aid use.The prevalence of hearing aid acquisition and regular use was 17.4% and 12.6%, respectively, in South Korea. Increased hearing threshold (OR 1.05, 95% CI 1.03-1.07), severe perceived hearing loss (OR 10.73, 95% CI 4.52-25.46), annoying tinnitus (OR 3.30, 95% CI 1.61-6.74), balance problems (OR 0.39, 95% CI 0.18-0.86), and myopia (OR 0.30, 95% CI 0.12-0.76) were associated factors of regular use of hearing aids.The prevalence of hearing aid use in Korea is relatively low. Finding relevant factors of hearing aid use could provide further insight in setting up hearing-rehabilitation strategy for the elderly with significant hearing loss.

  9. Prevalence and incidence of rheumatoid arthritis in South Korea.

    PubMed

    Sung, Yoon-Kyoung; Cho, Soo-Kyung; Choi, Chan-Bum; Bae, Sang-Cheol

    2013-06-01

    Several studies of rheumatoid arthritis (RA) incidence and prevalence indicate that occurrence of the disease varies significantly among different populations. We aimed to estimate the prevalence and incidence of RA in South Korea. We used Korean National Health Insurance (NHI) claims data to estimate the prevalence of RA in 2007-2009 and the incidence of RA in 2008. On the basis of our previous validation study, the presence of RA was defined by the diagnostic code for RA with biologic or non-biologic disease-modifying anti-rheumatic drugs in the same claim in each year. To estimate the incidence of RA, we identified cases of RA in 2008 and set the 12-month period prior to 2008 as a disease-free period. Among the incident case of 2008, only patients who continued treatment in 2009 were defined as true incident case of RA in 2008. The corresponding prevalence estimates were 0.26 % (95 % CI 0.25-0.27) in 2006, 0.27 % (95 % CI 0.26-0.28) in 2007, and 0.27 % (95 % CI 0.26-0.28) in 2008. The incidence of RA in 2008 was estimated at 42/100,000 (95 % CI 29.3-54.7) in the general population of South Korea. Data gathered nationwide through the NHI yielded estimates of RA prevalence and incidence in South Korea. This study is the first report of nationwide prevalence and incidence of South Korea and those are comparable to values for other countries in Asia.

  10. Geomorphic Indices in the Assessment of Tectonic Activity in Forearc of the Active Mexican Subduction Zone

    NASA Astrophysics Data System (ADS)

    Gaidzik, K.; Ramirez-Herrera, M. T.

    2015-12-01

    Rapid development of GIS techniques and constant advancement of digital elevation models significantly improved the accuracy of extraction of information on active tectonics from landscape features. Numerous attempts were made to quantitatively evaluate recent tectonic activity using GIS and DEMs, and a set of geomorphic indices (GI), however these studies focused mainly on sub-basins or small-scale areal units. In forearc regions where crustal deformation is usually large-scale and do not concentrate only along one specific fault, an assessment of the complete basin is more accurate. We present here the first attempt to implement thirteen GI in the assessment of active tectonics of a forearc region of an active convergent margin using the entire river basins. The GIs were divided into groups: BTAI - basin geomorphic indices (reflecting areal erosion vs. tectonics) and STAI - stream geomorphic indices (reflecting vertical erosion vs. tectonics). We calculated selected indices for 9 large (> 450 km2) drainage basins. Then we categorized the obtained results of each index into three classes of relative tectonic activity: 1 - high, 2 - moderate, and 3 - low. Finally we averaged these classes for each basin to determine the tectonic activity level (TAI). The analysis for the case study area, the Guerrero sector at the Mexican subduction zone, revealed high tectonic activity in this area, particularly in its central and, to a lesser degree, eastern part. This pattern agrees with and is supported by interpretation of satellite images and DEM, and field observations. The results proved that the proposed approach indeed allows identification and recognition of areas witnessing recent tectonic deformation. Moreover, our results indicated that, even though no large earthquake has been recorded in this sector for more than 100 years, the area is highly active and may represent a seismic hazard for the region.

  11. Tectonic Subsidence Analysis of the Pearl River Mouth Basin, Northern South China Sea

    NASA Astrophysics Data System (ADS)

    Tang, X.; Huang, S. S. X. E. C.; Zhuang, W.; LIU, Z.; Duan, W.; Hu, S.

    2015-12-01

    The Pearl River Mouth Basin (PRMB hereafter) in the northern margin of the South China Sea has attracted great attention not only because of its special tectonic location but also for its abundant hydrocarbon resources. Tectonic evolution controls the petroleum geological condition of hydrocarbon-bearing basins. Efforts have been made to understand the tectonic evolution of this basin. However, many issues about the tectonic features and the evolution process of this basin, such as the age of the breakup unconformities and the anomalously accelerated subsidence during the post-rifting stage, remain controversial. Here we employ tectonic subsidence analysis of sedimentary basins, a technique of removing isostatic loading and compaction effects by back-stripping, to investigate the tectonic controls on the basin formation of the PRMB. We performed the analysis on 4 drill wells and 43 synthetic wells constructed based on recently acquired seismic profiles. The result shows that tectonic subsidence in the eastern sags of the PRMB began to decrease at ~30Ma while in the western sags the onset was ~23.8Ma. This suggests that the break-up time i.e. the end of rifting in the PRMB is earlier in the eastern sags than in the western sags. Abnormally accelerated tectonic subsidence occurred between 17.5-16.4Ma during the post-rifting stage, at an average subsidence rate as high as 301.9m/Ma. This phenomenon discriminates the PRMB from the category of classical Atlantic passive continental marginal basins, of which the tectonic subsidence during the post-rifting stage decays exponentially. The main objective of this paper is to provide insights into the geological and geodynamic evolution of the PRMB. The result bears significance to hydrocarbon exploration in this region.

  12. Exogenous model of global tectonics

    NASA Astrophysics Data System (ADS)

    Kalenda, Pavel; Wandrol, Ivo; Kopf, Tomáš; Frydrýšek, Karel; Neumann, Libor; Procházka, Václav; Ostřihanský, Lubor

    2014-05-01

    of the Science as a whole. References Berger, J. (1975): A Note on Thermoelastic Strains and Tilts, 1975, J. Geophys.Res., 80, pp. 274-277. Croll, J.G.A. (2006): From asphalt to the Arctic: new insights into thermo-mechanical ratcheting processes. III Int. Conf. On Computational Mechanics. Lisbon, Portugal, 5-8 June. Croll, J.G.A. (2007): A new hypothesis for Earth lithosphere evolution. New Concepts in Global Tectonics Newsletter, no. 45, December, 2007, 34-51. IPCC (2007): IPCC Fourth Assessment Report: Climate Change 2007 (AR4). http://www.ipcc.ch/publications_and_data/publications_and_data_reports.shtml Kalenda P. et al. (2012): Tilts, global tectonics and earthquake prediction. SWB, London, 247pp.

  13. Publication of the Korea-WHO Cooperation History - 70 Years of Working Together for Heath: World Health Organization and the Republic of Korea.

    PubMed

    Cho, Heeyeon; Lee, Dong Woo; Choe, Young June; Choe, Seung Ah; Park, No Yai

    2017-03-01

    The World Health Organization (WHO) have been in collaborative efforts with the Republic of Korea in keeping of and for better health for all for the past decades. From the control of parasites to building of community health system in rural places, the works has now resulted in healthier Korea than ever, and has transformed the role of engaging as the world leader in contribution of health and development. Seventy years of independence, war, and poverty, transforming from a recipient country of official development assistance to a significant donor to the global society, we have emphasized the importance of international cooperation and the role of WHO in the past years in Korea and neighboring countries. Looking back of the past is meaningful to diagnose the present problems, and to foresee the future of our world.

  14. Publication of the Korea-WHO Cooperation History — 70 Years of Working Together for Heath: World Health Organization and the Republic of Korea

    PubMed Central

    2017-01-01

    The World Health Organization (WHO) have been in collaborative efforts with the Republic of Korea in keeping of and for better health for all for the past decades. From the control of parasites to building of community health system in rural places, the works has now resulted in healthier Korea than ever, and has transformed the role of engaging as the world leader in contribution of health and development. Seventy years of independence, war, and poverty, transforming from a recipient country of official development assistance to a significant donor to the global society, we have emphasized the importance of international cooperation and the role of WHO in the past years in Korea and neighboring countries. Looking back of the past is meaningful to diagnose the present problems, and to foresee the future of our world. PMID:28145638

  15. U.S.-South Korea Relations

    DTIC Science & Technology

    2014-02-12

    led Trans- Pacific Partnership (TPP) free trade agreement negotiations. Strategic Cooperation and the U.S.-ROK Alliance Dealing with North Korea...78.49 yrs.; North Korea = 69.2 yrs.) Infant Mortality: 4.01 deaths/1,000 live births (U.S. = 6.00) Fertility Rate: 1.24 children born/woman...its “interest” in joining the twelve-nation Trans- Pacific Partnership (TPP) free trade agreement 3

  16. US Military Presence in a Unified Korea

    DTIC Science & Technology

    2003-04-07

    profiles/ap_mp_05.cfm ; Internet; accessed 11 March 2003; and World Almanac Education Group, Inc., The World Almanac and Book of Facts 2003 (New York...New York: World Almanac Books, 2003), 108, 771, 799, 801, 843. 15 Han Woo-Keun, The History of Korea (Seoul, Korea: The Eul-Yoo Publishing Company...January 2003. 37 World Almanac Education Group, Inc., The World Almanac and Book of Facts 2003 (New York, New York: World Almanac Books, 2003), 218. 38

  17. Regional Disease Vector Ecology Profile: The Koreas

    DTIC Science & Technology

    2015-01-01

    Regional Disease Vector Ecology Profile: The Koreas Published and Distributed by the Armed Forces Pest Management Board Information... Ecology Profile: The Koreas 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f...presumed to be higher in the absence of sophisticated programs to suppress vectors or limit disease transmission. Disease Vector Ecology Profiles

  18. An overview of biotechnology in Korea.

    PubMed

    Choi; Hahm; Rhee; Han

    1999-03-01

    During the 1980s and 1990s, Korea has invested heavily in biotechnology research and development, with the aim of becoming a leading nation in this field. It is important to understand the historical progress of this development in order to appreciate the current state of biotechology in Korea. However, it is equally important to know what research is currently being planned and carried out, and by whom.

  19. Significant release of shear energy of the North Korean nuclear test on February 12, 2013

    NASA Astrophysics Data System (ADS)

    Barth, Andreas

    2014-07-01

    On February 12, 2013 the Democratic People's Republic of Korea (DPRK) carried out an announced nuclear test, which was the third after tests conducted in 2006 and 2009. An important task in discriminating a man-made explosion and a natural tectonic earthquake is the analysis of seismic waveforms. To determine the isotropic and non-isotropic characteristics of the detonation source, I invert long-period seismic data for the full seismic moment tensor to match the observed seismic signals by synthetic waveforms based on a 3D Earth model. Here, I show that the inversion of long-period seismic data of the 2013 test reveals a clear explosive (isotropic) component combined with a significant release of shear energy by the double-couple part of the moment tensor. While the isotropic part of the nuclear test in 2009 was similar to that in 2013, the double-couple part was lower by a factor of 0.55 compared to the explosion in 2013. Moreover, the ratio of the isotropic seismic moments of the 2013 and 2009 nuclear tests is 1.4 ± 0.1 and lower than published estimations of the yield ratio, which indicates the importance of considering the release of shear energy. The determined orientation of the double-couple fault plane is parallel to the dominating geologic fault structures NNE-SSW to NE-SW, but the calculated normal faulting mechanism does not correspond to the general tectonic strike-slip regime. Thus, explanations for the enhanced release of shear energy might be induced dip-slip motion pre-stressed by the previous test or near source damaging effects due to a changed containment of the nuclear explosion.

  20. The interior of Venus and Tectonic implications

    NASA Technical Reports Server (NTRS)

    Phillips, R. J.; Malin, M. C.

    1983-01-01

    It is noted in the present consideration of the Venus lithosphere and its implications for plate tectonics that the major linear elevated regions of Venus, which are associated with Beta Regio and Aphrodite Terra, do not seem to have the shape required for sure interpretation as the divergent plate boundaries of seafloor spreading. Such tectonics instead appear to be confined to the median plains, and may not be resolvable in the Pioneer Venus altimetry data. The ratios of gravity anomalies to topographic heights indicate that surface load compensation occurs at depths greater than about 100 km under the western Aphrodite Terra and 400 km under Beta Regio, with at least some of this compensation probably being maintained by mantle convection. It is also found that the shape of Venus's hypsogram is very different from the ocean mode of the earth's hypsogram, and it is proposed that Venus tectonics resemble intraplate, basin-and-swell tectonics on earth.

  1. 77 FR 75975 - Large Residential Washers From the Republic of Korea: Final Affirmative Countervailing Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-26

    ... International Trade Administration Large Residential Washers From the Republic of Korea: Final Affirmative... the Republic of Korea (Korea). For information on the estimated subsidy rates, see the ``Suspension of... Washers From the Republic of Korea: Preliminary Affirmative Countervailing Duty Determination...

  2. Volcanological constraints of Archaean tectonics

    NASA Technical Reports Server (NTRS)

    Thurston, P. C.; Ayres, L. D.

    1986-01-01

    Volcanological and trace element geochemical data can be integrated to place some constraints upon the size, character and evolutionary history of Archean volcanic plumbing, and hence indirectly, Archean tectonics. The earliest volcanism in any greenhouse belt is almost universally tholeitic basalt. Archean mafic magma chambers were usually the site of low pressure fractionation of olivine, plagioclase and later Cpx + or - an oxide phase during evolution of tholeitic liquids. Several models suggest basalt becoming more contaminated by sial with time. Data in the Uchi Subprovince shows early felsic volcanics to have fractionated REE patterns followed by flat REE pattern rhyolites. This is interpreted as initial felsic liquids produced by melting of a garnetiferous mafic source followed by large scale melting of LIL-rich sial. Rare andesites in the Uchi Subprovince are produced by basalt fractionation, direct mantle melts and mixing of basaltic and tonalitic liquids. Composite dikes in the Abitibi Subprovince have a basaltic edge with a chill margin, a rhyolitic interior with no basalt-rhyolite chill margin and partially melted sialic inclusions. Ignimbrites in the Uchi and Abitibi Subprovinces have mafic pumice toward the top. Integration of these data suggest initial mantle-derived basaltic liquids pond in a sialic crust, fractionate and melt sial. The inirial melts low in heavy REE are melts of mafic material, subsequently melting of adjacent sial produces a chamber with a felsic upper part underlain by mafic magma.

  3. Tectonic blocks and molecular clocks

    PubMed Central

    2016-01-01

    Evolutionary timescales have mainly used fossils for calibrating molecular clocks, though fossils only really provide minimum clade age constraints. In their place, phylogenetic trees can be calibrated by precisely dated geological events that have shaped biogeography. However, tectonic episodes are protracted, their role in vicariance is rarely justified, the biogeography of living clades and their antecedents may differ, and the impact of such events is contingent on ecology. Biogeographic calibrations are no panacea for the shortcomings of fossil calibrations, but their associated uncertainties can be accommodated. We provide examples of how biogeographic calibrations based on geological data can be established for the fragmentation of the Pangaean supercontinent: (i) for the uplift of the Isthmus of Panama, (ii) the separation of New Zealand from Gondwana, and (iii) for the opening of the Atlantic Ocean. Biogeographic and fossil calibrations are complementary, not competing, approaches to constraining molecular clock analyses, providing alternative constraints on the age of clades that are vital to avoiding circularity in investigating the role of biogeographic mechanisms in shaping modern biodiversity. This article is part of the themed issue ‘Dating species divergences using rocks and clocks’. PMID:27325840

  4. Oligocene tectonics and sedimentation, California

    USGS Publications Warehouse

    Nilsen, T.H.

    1984-01-01

    During the Oligocene epoch, California was marked by extensive nonmarine sedimentation, in contrast to its pre-Oligocene and post-Oligocene depositional history. The Oligocene continental deposits are especially widespread in southern California and fill a number of small and generally partly restricted basins. Fluvial facies in many basins prograded over previously deposited lower Tertiary turbidites. Volcanism, from widespread centers, was associated with the nonmarine sedimentation. However, some basins remained marine and a few contain Oligocene turbidites and pelagic sediments deposited at bathyal depths. The Oligocene redbeds of California do not form a post-orogenic molasse sequence comparable to the Old Red Sandstone or Alpine molasse. They are synorogenic and record local uplift of basins and surrounding source areas. Late Cretaceous to contemporary orogenesis in California has been generally characterized by the formation of small restricted basins of variable depth adjacent to small upland areas in response to strike-slip faulting. Deposition of Oligocene redbeds was associated with climatic change from warm and humid to cold and semiarid, and a global lowering of sea level. Oligocene tectonism occurred during the transition from subduction of the Farallon Plate to initiation of the modern San Andreas transform system. However, the major influence that caused uplift, formation of fault-bounded basins, and extensive redbed deposition, especially in southern California, was the approach of the Pacific-Farallon spreading ridge to the western margin of California. ?? 1984.

  5. Mapping Tectonic Stress Using Earthquakes

    SciTech Connect

    Arnold, Richard; Townend, John; Vignaux, Tony

    2005-11-23

    An earthquakes occurs when the forces acting on a fault overcome its intrinsic strength and cause it to slip abruptly. Understanding more specifically why earthquakes occur at particular locations and times is complicated because in many cases we do not know what these forces actually are, or indeed what processes ultimately trigger slip. The goal of this study is to develop, test, and implement a Bayesian method of reliably determining tectonic stresses using the most abundant stress gauges available - earthquakes themselves.Existing algorithms produce reasonable estimates of the principal stress directions, but yield unreliable error bounds as a consequence of the generally weak constraint on stress imposed by any single earthquake, observational errors, and an unavoidable ambiguity between the fault normal and the slip vector.A statistical treatment of the problem can take into account observational errors, combine data from multiple earthquakes in a consistent manner, and provide realistic error bounds on the estimated principal stress directions.We have developed a realistic physical framework for modelling multiple earthquakes and show how the strong physical and geometrical constraints present in this problem allow inference to be made about the orientation of the principal axes of stress in the earth's crust.

  6. Tectonic and metallogenic model for northeast Asia

    USGS Publications Warehouse

    Parfenov, Leonid M.; Nokleberg, Warren J.; Berzin, Nikolai A.; Badarch, Gombosuren; Dril, Sergy I.; Gerel, Ochir; Goryachev, Nikolai A.; Khanchuk, Alexander I.; Kuz'min, Mikhail I.; Prokopiev, Andrei V.; Ratkin, Vladimir V.; Rodionov, Sergey M.; Scotese, Christopher R.; Shpikerman, Vladimir I.; Timofeev, Vladimir F.; Tomurtogoo, Onongin; Yan, Hongquan; Nokleberg, Warren J.

    2011-01-01

    This document describes the digital files in this report that contains a tectonic and metallogenic model for Northeast Asia. The report also contains background materials. This tectonic and metallogenic model and other materials on this report are derived from (1) an extensive USGS Professional Paper, 1765, on the metallogenesis and tectonics of Northeast Asia that is available on the Internet at http://pubs.usgs.gov/pp/1765/; and (2) the Russian Far East parts of an extensive USGS Professional Paper, 1697, on the metallogenesis and tectonics of the Russian Far East, Alaska, and the Canadian Cordillera that is available on the Internet at http://pubs.usgs.gov/pp/pp1697/. The major purpose of the tectonic and metallogenic model is to provide, in movie format, a colorful summary of the complex geology, tectonics, and metallogenesis of the region. To accomplish this goal four steps were taken: (1) 13 time-stage diagrams, from the late Neoproterozoic (850 Ma) through the present (0 Ma), were adapted, generalized, and transformed into color static time-stage diagrams; (2) the 13 time-stage diagrams were placed in a computer morphing program to produce the model; (3) the model was examined and each diagram was successively adapted to preceding and subsequent diagrams to match the size and surface expression of major geologic units; and (4) the final version of the model was produced in successive iterations of steps 2 and 3. The tectonic and metallogenic model and associated materials in this report are derived from a project on the major mineral deposits, metallogenesis, and tectonics of the Northeast Asia and from a preceding project on the metallogenesis and tectonics of the Russian Far East, Alaska, and the Canadian Cordillera. Both projects provide critical information on bedrock geology and geophysics, tectonics, major metalliferous mineral resources, metallogenic patterns, and crustal origin and evolution of mineralizing systems for this region. The major

  7. Tectonic map of the Arabian Peninsula

    USGS Publications Warehouse

    Brown, Glen F.

    1972-01-01

    This tectonic map of the Arabian peninsula, prepared for the Audi Arabian Ministry of Petroleum and Mineral Resource, is the first of a series of peninsular maps that attempt to show regional features. Much recent information resulting from detailed geologic mapping notably within the Arabian craton, from geophysical surveys, both airborne and oceanographic in adjacent seas, from deep exploratory drilling, and from photography from the Gemini and Apollo space programs, has been used in the tectonic evaluation.

  8. Tectonic History of the Terrestrial Planets

    NASA Technical Reports Server (NTRS)

    Solomon, Sean C.

    1993-01-01

    The topics covered include the following: patterns of deformation and volcanic flows associated with lithospheric loading by large volcanoes on Venus; aspects of modeling the tectonics of large volcanoes on the terrestrial planets; state of stress, faulting, and eruption characteristics of large volcanoes on Mars; origin and thermal evolution of Mars; geoid-to-topography ratios on Venus; a tectonic resurfacing model for Venus; the resurfacing controversy for Venus; and the deformation belts of Lavinia Planitia.

  9. Elysium Region, Mars: Characterization of tectonic features

    NASA Technical Reports Server (NTRS)

    Hall, J. L.; Solomon, S. C.; Head, J. W.; Mouginis-Mark, P. J.

    1984-01-01

    In this paper the tectonic features of the Elysium region are identified and characterized. Identification of features was made using USGS controlled photomosaics (Elysium quadrangle, and portions of Amenthes and Cebrenia quadrangles); Viking Orbiter photographic data were used in individual cases to assist in identification. The positions and orientations of tectonic features can then be used, in conjunction with estimates of the mass of the volcanic load obtained from gravity modelling, to constrain the thickness of the elastic lithosphere in the region.

  10. Tectonic microplates: laying it down on wax

    NASA Astrophysics Data System (ADS)

    Katz, R. R.; Bodenschatz, E.

    2008-12-01

    We present a wax analogue model of sea-floor spreading that produces rotating, growing microplates. Wax microplates are kinematically similar to sea-floor tectonic microplates in terms of spreading rate and growth rate. Furthermore, their spiral pseudofault geometry is quantitatively consistent with Schouten's oceanic microplate model. These results suggest that Schouten's edge-driven microplate model captures the kinematics of tectonic microplate evolution on Earth. We propose a theory for the formation of microplates.

  11. 78 FR 66785 - Korea Hydro and Nuclear Power Co., Ltd., and Korea Electric Power Corporation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-06

    ... APR1400 Standard Plant Design submitted by Korea Hydro and Nuclear Power Co., Ltd. (KHNP) and Korea... application for standard design certification of the APR1400 Standard Plant Design. The APR1400 stands for... advanced design features to enhance plant safety, economical efficiency, and convenience of operation...

  12. Exploring links between tectonics, catchment morphology and hydrographs across Europe

    NASA Astrophysics Data System (ADS)

    Vanmaercke, Matthias; Campforts, Benjamin; Van Ruyskensvelde, Glenn; Poesen, Jean

    2016-04-01

    A growing number of studies show that contemporary catchment sediment yields (SY, [t/km²/y]) are strongly correlated to patterns of seismic activity at regional to continental scales. Nonetheless, the mechanisms explaining these correlations are still poorly understood. Seismicity may increase SY by triggering landslides or weakening the surface lithology. On the other hand seismicity can be considered as a proxy for tectonic movements, while there is a growing consensus that tectonics exert an important influence on catchment morphology. This morphology influences the properties of runoff events (e.g. peak discharge, stream power). Given the large influence of large runoff events on annual SY, it is therefore possible that observed correlations between SY and seismicity are (at least partly) attributable to tectonic influences on catchment morphology. We test this hypothesis by investigating links between runoff hydrographs and patterns in catchment properties at a European scale using numerous catchment indices such as the slope, channel steepness, circularity, drainage length, river network topology, etc. From DEMs with a resolution of ca. 100m we randomly delineated over 5000 catchments across Europe with an area of 90 to 100 km². For each of these catchments, we simulated a runoff hydrograph, using a simple Hortonian runoff model that routes water through the catchment based on previously proposed flow velocity equations. We made abstraction of rainfall patterns, lithology, land use and all factors other than topography. Hence, the hydrographs only reflect the influence of the morphological properties of the catchments and allow for comparisons. First results show that, apart from average catchment slope, there are very few regional patterns in catchment morphological properties that may significantly affect hydrographs. In some tectonically active regions, channel slopes are slightly steeper compared to catchments with the same average catchment slope in

  13. Preliminary analysis of Venusian tectonics and evolution

    NASA Astrophysics Data System (ADS)

    Nikishin, A. M.

    1990-11-01

    Five stages in the evolution of Venus are discussed: accretion, segregation of early crust from magma ocean; volcanic reworking of early crust, development of tectonics of soft plastic plates with formation of tesserae in compression zones and plains in dilatation zones; formation of weakened planetary zones of dilatation saturated by mantel hot-spot structures against a backdrop of dispersed mantel hot-spot tectonics and plateau volcanism. The following subjects are discussed: types of structures and structural regions of Venus; tectonic structure of Venus and its interpretation; thickness and composition of Venusian crust; model of geological evolution of Venus; asymmetry of tectonic structure of Venus; and reasons for the great differences in the tectonics of the Earth and Venus. The tectonics of Venus differ from those of the Earth because Venus was always impoverished in terms of water, a highly important agent of magmatism and the main fluid involved in the fusion fo sialic rocks. Venusian volcanism therefore was less intense and a sialic crust is largely absent. The greenhouse effect on Venus causes increased plasticity of its lithosphere.

  14. Ridge push engine of plate tectonics

    NASA Astrophysics Data System (ADS)

    Swedan, N. H.

    2015-07-01

    Convection of the upper mantle drives the tectonic plates. This convection is a thermodynamic cycle that exchanges heat and mechanical work between mantle and tectonic plates. Thermodynamics and observations indicate that the energy of the geological activities resulting from plate tectonics is equal to the latent heat of melting, calculated at mantle's pressure, of the new ocean crust regenerated at midocean ridges. This energy varies with the temperature of ocean floor, which is correlated with surface temperature. The main objective of this manuscript is to demonstrate that plate tectonics is a thermodynamic engine and can be calculated as such. Unlike existing tectonic models, the thermodynamic model is very sensitive to variations of the temperature of ocean floor, which is correlated with surface temperature. Therefore, the observed increase of geological activities can be projected with surface temperature rise. Other objectives of the manuscript are to calculate the force that drives the tectonic plates, estimate the energy released, and validate the calculations based on experiments and observations. In addition to the scientific merit of projecting the geological activities, a good projection can have a broader impact at the societal and economical levels. Investment and insurance related decisions are affected by climate change, and our ability to project the geological activities is of paramount importance for the economy and public safety. This work can thus provide tools to assess the risks and hazards associated with the trend of geological activities with surface temperature rise.

  15. Spreading continents kick-started plate tectonics.

    PubMed

    Rey, Patrice F; Coltice, Nicolas; Flament, Nicolas

    2014-09-18

    Stresses acting on cold, thick and negatively buoyant oceanic lithosphere are thought to be crucial to the initiation of subduction and the operation of plate tectonics, which characterizes the present-day geodynamics of the Earth. Because the Earth's interior was hotter in the Archaean eon, the oceanic crust may have been thicker, thereby making the oceanic lithosphere more buoyant than at present, and whether subduction and plate tectonics occurred during this time is ambiguous, both in the geological record and in geodynamic models. Here we show that because the oceanic crust was thick and buoyant, early continents may have produced intra-lithospheric gravitational stresses large enough to drive their gravitational spreading, to initiate subduction at their margins and to trigger episodes of subduction. Our model predicts the co-occurrence of deep to progressively shallower mafic volcanics and arc magmatism within continents in a self-consistent geodynamic framework, explaining the enigmatic multimodal volcanism and tectonic record of Archaean cratons. Moreover, our model predicts a petrological stratification and tectonic structure of the sub-continental lithospheric mantle, two predictions that are consistent with xenolith and seismic studies, respectively, and consistent with the existence of a mid-lithospheric seismic discontinuity. The slow gravitational collapse of early continents could have kick-started transient episodes of plate tectonics until, as the Earth's interior cooled and oceanic lithosphere became heavier, plate tectonics became self-sustaining.

  16. House Dust Mite Allergy in Korea: The Most Important Inhalant Allergen in Current and Future

    PubMed Central

    Jeong, Kyoung Yong; Park, Jung-Won

    2012-01-01

    The house-dust mite (HDM), commonly found in human dwellings, is an important source of inhalant and contact allergens. In this report, the importance of HDM allergy in Korea and the characteristics of allergens from dust mite are reviewed with an emphasis on investigations performed in Korea. In Korea, Dermatophagoides farinae is the dominant species of HDM, followed by D. pteronyssinus. Tyrophagus putrescentiae is also found in Korea, but its role in respiratory allergic disease in Korea is controversial. The relatively low densities of mite populations and concentrations of mite major allergens in dust samples from Korean homes, compared to westernized countries, are thought to reflect not only different climatic conditions, but also cultural differences, such as the use of 'ondol' under-floor heating systems in Korean houses. HDM are found in more than 90% of Korean houses, and the level of exposure to HDM is clinically significant. About 40%-60% of Korean patients suffering from respiratory allergies, and more than 40% of patients suffering from atopic dermatitis, are sensitized to HDM. Mite allergens can be summarized according to their inherent auto-adjuvant activities and/or their binding affinities to the adjuvant-like substances: proteolytic enzymes, lipid binding proteins, chitin binding proteins, and allergens not associated with adjuvant-like activity. In general, allergens with a strong adjuvant-like activity or adjuvant-binding activity elicit potent IgE reactivity. In Korea, Der f 2 is the most potent allergen, followed by Der f 1. Immune responses are modulated by the properties of the allergen itself and by the adjuvant-like substances that are concomitantly administered with the antigens. Characterization of allergenic molecules and elucidation of mechanisms by which adjuvant-like molecules modulate allergic reactions, not only in Korea but also worldwide, will provide valuable information on allergic diseases, and are necessary for the

  17. A convective forecast experiment of global tectonics

    NASA Astrophysics Data System (ADS)

    Coltice, Nicolas; Giering, Ralf

    2016-04-01

    Modeling jointly the deep convective motions in the mantle and the deformation of the lithosphere in a self-consistent way is a long-standing quest, for which significant advances have been made in the late 1990's. The complexities used in lithospheric models are making their way into the models of mantle convection (density variations, pseudo-plasticity, elasticity, free surface), hence global models of mantle motions can now display tectonics at their surface, evolving self-consistantly and showing some of the most important properties of plate tectonics on Earth (boundaries, types of boundaries, plate sizes, seafloor spreading properties, continental drift). The goal of this work is to experiment the forecasting power of such convection models with plate-like behavior, being here StagYY (Tackley, 2008). We generate initial conditions for a 3D spherical model in the past (50Ma and younger), using models with imposed plate velocities from 200Ma. By doing this, we introduce errors in the initial conditions that propagate afterwards. From these initial conditions, we run the convection models free, without imposing any sort of motion, letting the self-organization take place. We compare the forecast to the present-day plate velocities and plate boundaries. To investigate the optimal parameterization, and also have a flavor of the sensitivity of the results to rheological parameters, we compute the derivatives of the misfit of the surface velocities relative to the yield stress, the magnitude of the viscosity jump at 660km and the properties of a weak crust. These derivates are computed thanks to the tangent linear model of StagYY, that is built through the automatic differentiation software TAF (Giering and Kaminski, 2003). References Tackley, P. J., Modeling compressible mantle convection with large viscosity contrasts in a three-dimensional spherical shell using the yin-yang grid, Phys. Earth Planet. Inter. 171, 7-18 (2008). Giering, R., Kaminski, T., Applying TAF

  18. Convection and plate tectonics on extrasolar planets

    NASA Astrophysics Data System (ADS)

    Sotin, C.; Grasset, O.; Schubert, G.

    2012-04-01

    The number of potential Earth-like exoplanets is still very limited compared to the overall number of detected exoplanets. But the different methods keep improving, giving hope for this number to increase significantly in the coming years. Based on the relationship between mass and radius, two of the easiest parameters that can be known for exoplanets, four categories of planets have been identified: (i) the gas giants including hot Jupiters, (ii) the icy giants that can be like their solar system cousins Uranus and Neptune or that can have lost their H2-He atmosphere and have become the so-called ocean planets, (iii) the Earth-like planets with a fraction of silicates and iron similar to that of the Earth, and (iv) the Mercury like planet that have a much larger fraction of iron. The hunt for exoplanets is very much focused on Earth-like planets because of the desire to find alien forms of life and the science goal to understand how life started and developed on Earth. One science question is whether heat transfer by subsolidus convection can lead to plate tectonics, a process that allows material to be recycled in the interior on timescales of hundreds of millions of years. Earth-like exoplanets may have conditions quite different from Earth. For example, COROT-7b is so close to its star that it is likely locked in synchronous orbit with one very hot hemisphere and one very cold hemisphere. It is also worth noting that among the three Earth-like planets of the solar system (Earth, Venus and Mars), only Earth is subject to plate tectonics at present time. Venus may have experienced plate tectonics before the resurfacing event that erased any clue that such a process existed. This study investigates some of the parameters that can influence the transition from stagnant-lid convection to mobile-lid convection. Numerical simulations of convective heat transfer have been performed in 3D spherical geometry in order to determine the stress field generated by convection

  19. Prevalence and Determinants of Diabetic Nephropathy in Korea: Korea National Health and Nutrition Examination Survey

    PubMed Central

    Ahn, Jae Hee; Yu, Ji Hee; Ko, Seung-Hyun; Kwon, Hyuk-Sang; Kim, Dae Jung; Kim, Jae Hyeon; Kim, Chul Sik; Song, Kee-Ho; Won, Jong Chul; Lim, Soo; Choi, Sung Hee; Han, Kyungdo; Cha, Bong-Yun

    2014-01-01

    Background Diabetic nephropathy is a leading cause of end stage renal disease and is associated with an increased risk of cardiovascular mortality. It manifests as albuminuria or impaired glomerular filtration rate (GFR), and the prevalence of diabetic nephropathy varies with ethnicity. The prevalence of diabetic nephropathy and its determinants in Korean adults have not previously been studied at the national level. This cross-sectional study was undertaken to ascertain the prevalence and determinants of albuminuria and chronic kidney disease (CKD) in Korean patients with diabetes. Methods The Korea National Health and Nutrition Examination Survey (KNHANES) V, conducted in 2011, was used to define albuminuria (n=4,652), and the dataset of KNHANES IV-V (2008-2011) was used to define CKD (n=21,521). Selected samples were weighted to represent the entire civilian population in Korea. Albuminuria was defined as a spot urine albumin/creatinine ratio >30 mg/g. CKD was defined as a GFR <60 mL/min/1.73 m2. Results Among subjects with diabetes, 26.7% had albuminuria, and 8.6% had CKD. Diabetes was associated with an approximate 2.5-fold increased risk of albuminuria, with virtually no difference between new-onset and previously diagnosed diabetes. Only systolic blood pressure was significantly associated with albuminuria, and old age, high serum triglyceride levels, and previous cardiovascular disease (CVD) were related with CKD in subjects with diabetes. Conclusion Korean subjects with diabetes had a higher prevalence of albuminuria and CKD than those without diabetes. Blood pressure was associated with albuminuria, and age, triglyceride level, and previous CVD were independent determinants of CKD in subjects with diabetes. PMID:24851205

  20. Tectonic development of Michigan basin

    SciTech Connect

    Prouty, C.E.

    1986-08-01

    The general form of the Michigan basin and surrounding frame structures - the Findlay, Kankakee, and Wisconsin arches - was inherited from the Precambrian. An ongoing study has provided new information on present basin configuration and the evolution of intrabasinal structures during the Paleozoic. This study involves: (1) isopach, structure contour, depocenter, and lithofacies map preparation; (2) diagenetic and epigenetic dolomitization processes and patterns; (3) Landsat imagery and lineament interpretation; (4) recognition of shearing mechanics and the resulting shear faulting and folding; and (5) the recognition of radial faults in contrast to shear faults. Monitoring of the above throughout the Paleozoic indicates that tectonic events within the basin were episodic in nature. Stresses are recognized as external and, through Fourier analysis of lineaments (shear faults), may be demonstrated as from the southeast, probably the Appalachian mobile belt. Shear faults are seated in Precambrian rocks, although they are probably not of that age. The faults occur with accompanying shear folds in rocks possibly as early as the Late Ordovician or Middle Silurian, but definitely by the Middle Devonian with the principal faulting and folding during the post-Osage Mississippian. Local shifting of the depocenter within the general Saginaw Bay area occurred during the early Paleozoic with a major shift westward to the present central basin position accompanied by the development of the present north-northwest ellipticity of the basin during the post-Osage, pre-Meramecian Mississippian. Barrier separation of the West Michigan Lagoon occurred in the Middle Ordovician and Middle and Late Devonian. Radial structures can be demonstrated in at least the Upper Silurian and Upper Devonian.

  1. Tectonic evolution of northwest Siberia

    SciTech Connect

    Natapov, L.P. )

    1993-09-01

    The ancient Siberian continent was split from early Pangen in early Riphean. The newly formed continent drifted from the southern to the northern hemisphere, reaching high altitudes only in the Late Paleozoic. Up to the Early Carboniferous, a typical passive margin of the Atlantic type, prograding to the ocean, developed along the present northern and eastern boundaries of this continent. In Upper Paleozoic, Triassic, and Jurassic, the carbonate sedimentation was replaced by the accumulation of thick terrigenous complexes along the northern and southern margins. Large submarine plains were formed by the merging of fans, while eustatic lowering of the ocean level enlarged the source area of detrital material. Distal facies, with time, were moving into the ocean. Rifting, penetrating inside the continent, conditioned for formation of large sedimentary basins. The development of the Sukhanskaya syneclise is associated with Riphean rifting, and Vilyuiskaya with Upper Devonian rifting. In the Upper Mesozoic, the covergent boundaries of lithospheric plates existed along the northern and eastern boundaries of the Siberian continent. As a result of the final collision of the continental margin with blocks of different nature (microcontinents, island arcs, etc.) transported by the Kula plate, and with chukchi and north Taimyr arctic blocks, Verkhoyansk and Taimyr fold belts appeared in the Upper Cretaceous. They were over-thrusted on clastic wedges, putting into shape the present-day structure of foredeeps. In the paper, principal attention is devoted to peculiarities of structure and development of sedimentary basins, formation of oil-producing complexes, and structures favorable for accumulation of hydrocarbons. All these features are analyzed at the background of this plate tectonic scenario.

  2. Prevalence of minimal hearing loss in South Korea

    PubMed Central

    Choi, Ji Eun; Ahn, Jungmin; Park, Hyun Woo; Baek, Sun-Young; Kim, Seonwoo; Moon, Il Joon

    2017-01-01

    This study evaluated the prevalence of minimal hearing loss (MHL) in South Korea based on the 2010 to 2012 Korea National Health and Nutrition Examination Survey. A total of 16,630 representative individuals (older than 12 years) who completed ear examinations and structured questionnaires were analyzed. Only participants who had normal tympanic membranes were included. MHL was categorized into the following three groups: 1) unilateral sensorineural hearing loss (USHL, pure-tone average (PTA) ≥ 15 dB in the affected ear), 2) bilateral sensorineural hearing loss (BSHL, 15 dB ≤ PTA < 40 dB in both ears), and 3) high-frequency sensorineural hearing loss (HFSHL, two or more high-frequency thresholds > 25 dB in either ear). To evaluate clinical symptoms, subjective hearing status, tinnitus, and quality of life of each MHL group were compared to those of normal-hearing listeners. The use of hearing aids (HAs) was also investigated in the MHL population. The prevalence of normal hearing and MHL were 58.4% and 37.4%, respectively. In univariate analyses, the prevalence of MHL increased with age. It was significantly increased in males. Regarding clinical symptoms, 13.0% and 92.1% of participants with MHL reported difficulties with hearing and annoying tinnitus, respectively. In multivariate analyses, these proportions were significantly higher in the MHL groups than in normal-hearing listeners. Participants with MHL also showed significantly lower Euro Qol-5D index scores than did normal-hearing listeners. Regarding hearing rehabilitation, among minimally hearing impaired participants with subjective hearing loss, only 0.47% of individuals used HAs. Our results reveal that MHL is common in South Korea. It is associated with significant subjective hearing loss, tinnitus, and poor quality of life. Therefore, clinicians need to pay attention to this special group and provide proper counselling and rehabilitative management. PMID:28196098

  3. Tsunami Run-up Heights at Imwon Port, Korea

    NASA Astrophysics Data System (ADS)

    Cho, Yong-Sik; Cho, Jeong-Seon

    2015-04-01

    surveyed again. The run-up heights for both 1983 and 1993 Tsunami events are computed along the Eastern Coastline of the Korean Peninsula. Finally, a tsunami hazard map is generated based on the computed and observed run-up heights. Significant information such as proper evacuation routes, shelters and hot lines are included in the map. Acknowledgements The research described in this publication was supported by the National Research Foundation of Korea (Reference No. 2010-0022337).

  4. Herpes zoster vaccine in Korea.

    PubMed

    Choi, Won Suk

    2013-07-01

    Herpes zoster and post-herpetic neuralgia deteriorate the quality of life because of severe pain and complications, and cause considerable social and economic burden of disease. In 2012, herpes zoster vaccine was released in Korea. The efficacy of herpes zoster vaccine is known to be 51.3-66.5% among the aged over 60 and 69.8-72.4% among adults between 50 and 59. It is also known that preventive efficacy is maintained for at least 5 years. Although there can be local reactions such as redness, pain and swelling at the site of injection and systemic reaction such as headache and eruption after herpes zoster vaccination, most of the adverse reactions are minor and disappear within days by themselves. As it is a live vaccine, persons with severe immune-suppression and pregnant women should not be vaccinated with the vaccine. Currently, Korean Society of Infectious Diseases recommended for the aged over 60 to be vaccinated with herpes zoster vaccine by subcutaneous route. In this article, clinical aspects and burden of disease of herpes zoster, efficacy and effects of herpes zoster vaccine, and herpes zoster vaccine recommendation by Korean Society of Infectious Diseases are discussed.

  5. Occupational respiratory cancer in Korea.

    PubMed

    Lee, Hye-Eun; Kim, Hyoung Ryoul

    2010-12-01

    Malignant mesothelioma and lung cancer are representative examples of occupational cancer. Lung cancer is the leading cause of cancer death, and the incidence of malignant mesothelioma is expected to increase sharply in the near future. Although information about lung carcinogen exposure is limited, it is estimated that the number of workers exposed to carcinogens has declined. The first official case of occupational cancer was malignant mesothelioma caused by asbestos exposure in the asbestos textile industry in 1992. Since then, compensation for occupational respiratory cancer has increased. The majority of compensated lung cancer was due to underlying pneumoconiosis. Other main causative agents of occupational lung cancer included asbestos, hexavalent chromium, and crystalline silica. Related jobs included welders, foundry workers, platers, plumbers, and vehicle maintenance workers. Compensated malignant mesotheliomas were associated with asbestos exposure. Epidemiologic studies conducted in Korea have indicated an elevated risk of lung cancer in pneumoconiosis patients, foundry workers, and asbestos textile workers. Occupational respiratory cancer has increased during the last 10 to 20 yr though carcinogen-exposed population has declined in the same period. More efforts to advance the systems for the investigation, prevention and management of occupational respiratory cancer are needed.

  6. Tectonic control of coastal onlap cycles, southwest Washington

    SciTech Connect

    Armentrout, J.M.

    1987-05-01

    Local coastal onlap and paleobiobathymetric curves for 14 sections define three Cenozoic depositional onlap-offlap cycles separated by regionally significant unconformities. A paleoclimatic curve for western Oregon and Washington, based on paleoecologic data sets, demonstrates that the local transgressions are coincident with cool climates and the regressions with warm climates, and are therefore not driven by glacioeustatic cycles. Comparison of the local coastal onlap and paleobiobathymetric curves with the global Cenozoic Cycle Chart (modified Exxon Sea Level Chart - May, 1986) further demonstrates the uniqueness of the western Washington curves. The global Cenozoic cycle Chart curve represents coastal onlap and sea level curves based on integration of both climate and tectonic variations. The non-parallel cycle pattern for southwest Washington suggests a unique tectonically forced system. Evidence derived from stratigraphic sequences, igneous rock geochemistry, radiometric dating, remnant magnetic patterns, sandstone provenance studies, and paleogeographic reconstructions is used to identify the tectonic events controlling the local depositional cycles. The principal events are (1) middle Eocene accretion of a seamount chain; (2) early-late Eocene westward relocation of subduction; (3) late Eocene onset of Cascade arc volcanism; (4) late-early Miocene plate readjustment due to back-arc extension in the Columbia River Plateau and Great Basin; and (5) late Pliocene to early Pleistocene northeast compression forced by continued subduction of remnants of the Kula Plate beneath North America.

  7. Revisiting Tectonic Corrections Applied to Pleistocene Sea-Level Highstands

    NASA Astrophysics Data System (ADS)

    Creveling, J. R.; Mitrovica, J. X.; Hay, C.; Austermann, J.; Kopp, R. E.

    2015-12-01

    The robustness of stratigraphic- and geomorphic-based inferences of Quaternary peak interglacial sea levels — and equivalent minimum continental ice volumes — depends on the accuracy with which highstand markers can be corrected for vertical tectonic displacement. For sites that preserve a Marine Isotope Stage (MIS) 5e sea-level highstand marker, the customary method for estimating tectonic uplift/subsidence rate computes the difference between the local elevation of the highstand marker and a reference eustatic (i.e., global mean) MIS 5e sea-level height, typically assumed to be +6 m, and then divides this height difference by the age of the highstand marker. This rate is then applied to correct the elevation of other observed sea-level markers at that site for tectonic displacement. Subtracting a reference eustatic value from a local MIS 5e highstand marker elevation introduces two potentially significant errors. First, the commonly adopted peak eustatic MIS 5e sea-level value (i.e., +6 m) is likely too low; recent studies concluded that MIS 5e peak eustatic sea level was ~6-9 m. Second, local peak MIS 5e sea level was not globally uniform, but instead characterized by significant departures from eustasy due to glacial isostatic adjustment (GIA) in response to successive glacial-interglacial cycles and excess polar ice-sheet melt relative to present day. We present numerical models of GIA that incorporate both of these effects in order to quantify the plausible range in error of previous tectonic corrections. We demonstrate that, even far from melting ice sheets, local peak MIS 5e sea level may have departed from eustasy by 2-4 m, or more. Thus, adopting an assumed reference eustatic value to estimate tectonic displacement, rather than a site-specific GIA signal, can introduce significant error in estimates of peak eustatic sea level (and minimum ice volumes) during Quaternary highstands (e.g., MIS 11, MIS 5c and MIS 5a).

  8. Surface-wave potential for triggering tectonic (nonvolcanic) tremor

    USGS Publications Warehouse

    Hill, D.P.

    2010-01-01

    Source processes commonly posed to explain instances of remote dynamic triggering of tectonic (nonvolcanic) tremor by surface waves include frictional failure and various modes of fluid activation. The relative potential for Love- and Rayleigh-wave dynamic stresses to trigger tectonic tremor through failure on critically stressed thrust and vertical strike-slip faults under the Coulomb-Griffith failure criteria as a function of incidence angle is anticorrelated over the 15- to 30-km-depth range that hosts tectonic tremor. Love-wave potential is high for strike-parallel incidence on low-angle reverse faults and null for strike-normal incidence; the opposite holds for Rayleigh waves. Love-wave potential is high for both strike-parallel and strike-normal incidence on vertical, strike-slip faults and minimal for ~45?? incidence angles. The opposite holds for Rayleigh waves. This pattern is consistent with documented instances of tremor triggered by Love waves incident on the Cascadia mega-thrust and the San Andreas fault (SAF) in central California resulting from shear failure on weak faults (apparent friction, ????? 0.2). However, documented instances of tremor triggered by surface waves with strike-parallel incidence along the Nankai megathrust beneath Shikoku, Japan, is associated primarily with Rayleigh waves. This is consistent with the tremor bursts resulting from mixed-mode failure (crack opening and shear failure) facilitated by near-lithostatic ambient pore pressure, low differential stress, with a moderate friction coefficient (?? ~ 0.6) on the Nankai subduction interface. Rayleigh-wave dilatational stress is relatively weak at tectonic tremor source depths and seems unlikely to contribute significantly to the triggering process, except perhaps for an indirect role on the SAF in sustaining tremor into the Rayleigh-wave coda that was initially triggered by Love waves.

  9. Red Sea Kinematics in Relation to the Regional Tectonics Setting

    NASA Astrophysics Data System (ADS)

    Alotaibi, T.; Furlong, K. P.

    2015-12-01

    The Red sSea extensional system started approximately 22+3 Ma. Although, there is evidence that lithospheric weakening and associated incipient extension may have taken place since 30 Ma. There is oceanic crust found in the southern part of the rift, while the northern-most part still involves continental stretching. Meantime magnetic anomalies have been observed for the southern rift, the northern rift is characterized by several deeps where magnetic anomalies have been observed as well as an indication of the transition from continental to oceanic rifting. GPS stations along the Red Sea are consistent with kinematics implied from the magnetic anomalies - an opening rate in the southern part of ~ 15 mm/yr relative to Eurasia fixed while the opening rate in the is ~8 mm/yr. This significant decreasing of the opening rate towards the north implies complexity within the Red Sea extensional system.Our purpose here is to place the Red Sea extensional kinematics within the regional tectonics context by combining constraints on the rate or style of extension within the Red Sea with tectonic activities on the adjacent continental regions. To accomplish this, we will model the extensional kinematics through time by comparing recent kinematics based on the geophysical observations with ones that based on geological observations. In terms of present-day geophysical observations, we have GPS and magnetic anomalies data, and crustal and lithospheric thickness. Geological observations primarily come from stratigraphic and structural data sets.Our overall target is to construct a tectonic model that links the timing of the change in the style and extensional rate with the tectonic activities in Afar, Gulf of Aden, Zagros, Dead Sea fault and Anatolian region.

  10. Metal levels in livers of waterfowl from Korea.

    PubMed

    Kim, Jungsoo; Oh, Jong-Min

    2012-04-01

    This study presents concentrations of heavy metals (iron, zinc, manganese, copper, lead and cadmium) in livers of white-fronted geese (Anser albifrons), eurasian wigeons (Anas penelope), mallards (Anas platyrhynchos) and spot-billed ducks (Anas poecilorhyncha) from Korea in February 2006 and 2008. Iron concentrations were significantly lower in spot-billed ducks than in other species (ANOVA, p<0.001). Zinc concentrations were greater in white-fronted geese and spot-billed ducks than in eurasian wigeons and mallards (ANOVA, p<0.001). Manganese and copper concentrations in white-fronted geese were significantly higher than in other species (ANOVA, p<0.001). Cadmium concentrations were significantly higher in mallards and spot-billed ducks than in white-fronted geese (ANOVA, p=0.007). However, lead concentrations did not differ among species. Iron, zinc, manganese and copper concentrations from this study were within the range of other waterfowl studies. Therefore, we suggest that essential elements such as iron, zinc, manganese and copper are within normal range and are maintained there by normal homeostatic mechanism. Twenty individuals (29.0 percent) exceeded the threshold level for abnormal lead exposure (5 μg/g dry weight) in waterfowl in this study and it is a higher proportion than in herons, egrets and owls from Korea. We suggest that the result was attributed to ingestion of lead shot and sinkers. However, cadmium concentrations in waterfowl except one specimen were within the background concentrations for wild birds. In livers of four waterfowl species found in Korea, lead and cadmium concentrations were similar to previously reported in other geese and ducks; except for poisoning of lead shot or sinkers as shown in earlier studies.

  11. Overview of Asbestos Issues in Korea

    PubMed Central

    2009-01-01

    Asbestos is a carcinogen that causes diseases such as mesothelioma and lung cancer in humans. There was a sharp increase in the use of asbestos in Korea in the 1970s as Korea's economy developed rapidly, and asbestos was only recently banned from use. Despite the ban of its use, previously applied asbestos still causes many problems. A series of asbestos-related events that recently occurred in Korea have caused the general public to become concerned about asbestos. Therefore, it is necessary to take proper action to deal with asbestos-related events, such as mass outbreaks of mesothelioma among residents who lived near asbestos textile factories or asbestos mines. Although there have been no rapid increases in asbestos-related illnesses in Korea to date, such illnesses are expected to increase greatly due to the amount of asbestos used and long latency period. Decreasing the asbestos exposure level to levels as low as possible is the most important step in preventing asbestos-related illnesses in the next few decades. However, there is a lack of specialized facilities for the analysis of asbestos and experts to diagnose and treat asbestos-related illnesses in Korea; therefore, national-level concern and support are required. PMID:19543418

  12. Overview of asbestos issues in Korea.

    PubMed

    Kim, Hyoung Ryoul

    2009-06-01

    Asbestos is a carcinogen that causes diseases such as mesothelioma and lung cancer in humans. There was a sharp increase in the use of asbestos in Korea in the 1970s as Korea's economy developed rapidly, and asbestos was only recently banned from use. Despite the ban of its use, previously applied asbestos still causes many problems. A series of asbestos-related events that recently occurred in Korea have caused the general public to become concerned about asbestos. Therefore, it is necessary to take proper action to deal with asbestos-related events, such as mass outbreaks of mesothelioma among residents who lived near asbestos textile factories or asbestos mines. Although there have been no rapid increases in asbestos-related illnesses in Korea to date, such illnesses are expected to increase greatly due to the amount of asbestos used and long latency period. Decreasing the asbestos exposure level to levels as low as possible is the most important step in preventing asbestos-related illnesses in the next few decades. However, there is a lack of specialized facilities for the analysis of asbestos and experts to diagnose and treat asbestos-related illnesses in Korea; therefore, national-level concern and support are required.

  13. Plate tectonics on the early Earth: Limitations imposed by strength and buoyancy of subducted lithosphere

    NASA Astrophysics Data System (ADS)

    van Hunen, Jeroen; van den Berg, Arie P.

    2008-06-01

    The tectonic style and viability of modern plate tectonics in the early Earth is still debated. Field observations and theoretical arguments both in favor and against the uniformitarian view of plate tectonics back until the Archean continue to accumulate. Here, we present the first numerical modeling results that address for a hotter Earth the viability of subduction, one of the main requirements for plate tectonics. A hotter mantle has mainly two effects: 1) viscosity is lower, and 2) more melt is produced, which in a plate tectonic setting will lead to a thicker oceanic crust and harzburgite layer. Although compositional buoyancy resulting from these thick crust and harzburgite might be a serious limitation for subduction initiation, our modeling results show that eclogitization significantly relaxes this limitation for a developed, ongoing subduction process. Furthermore, the lower viscosity leads to more frequent slab breakoff, and sometimes to crustal separation from the mantle lithosphere. Unlike earlier propositions, not compositional buoyancy considerations, but this lithospheric weakness could be the principle limitation to the viability of plate tectonics in a hotter Earth. These results suggest a new explanation for the absence of ultrahigh-pressure metamorphism (UHPM) and blueschists in most of the Precambrian: early slabs were not too buoyant, but too weak to provide a mechanism for UHPM and exhumation.

  14. Korea-U.S. Relations: Issues for Congress

    DTIC Science & Technology

    2008-04-28

    foodgrains. South Korea followed a conciliation policy toward North Korea under the administrations of Kim Dae-jung and Roh Moo-hyun; but the...market. The regime has spent little of several billion dollars in foreign exchange earnings since 1998 to import food or medicines . The regime has...within North Korea. Key principles of this conciliation policy have been: the extension of South Korean economic and humanitarian aid to North Korea, the

  15. Strategic Partners: South Korea and the United States

    DTIC Science & Technology

    1989-01-01

    South Korea’s economic growth, has fallen off, forcing South Korea into new mar- kets. In 1984, the construction industry received a...are in - cluded in the calculation. Since the 1970s, South Korea and the United States have begun a new stage of extensive economic contact, although...The Japanese Outlook 78 The Korean Peninsula’s Future 80 6. US INTERESTS AND OPTIONS IN SOUTH KOREA 83 Carter Administration Korean Policy 83

  16. Tectonics of the Outer Planet Satellites

    NASA Technical Reports Server (NTRS)

    McKinnon, W. B.; Collins, G. C.; Moore, J. M.; Nimmo, F.; Pappalardo, R. T.; Prockter, L. M.; Schenk, P. M.

    2010-01-01

    Tectonic features on the satellites of the outer planets range from the familiar, such as clearly recognizable graben on many satellites, to the bizarre, such as the ubiquitous double ridges on Europa, the twisting sets of ridges on Triton, or the isolated giant mountains rising from Io's surface. All of the large and middle-sized outer planet satellites except Io are dominated by water ice near their surfaces. Though ice is a brittle material at the cold temperatures found in the outer solar system, the amount of energy it takes to bring it close to its melting point is lower than for a rocky body. Therefore, some unique features of icy satellite tectonics may be influenced by a near-surface ductile layer beneath the brittle surface material, and several of the icy satellites may possess subsurface oceans. Sources of stress to drive tectonism are commonly dominated by the tides that deform these satellites as they orbit their primary giant planets. On several satellites, the observed tectonic features may be the result of changes in their tidal figures, or motions of their solid surfaces with respect to their tidal figures. Other driving mechanisms for tectonics include volume changes due to ice or water phase changes in the interior, thermoelastic stress, deformation of the surface above rising diapirs of warm ice, and motion of subsurface material toward large impact basins as they fill in and relax. Most satellites exhibit evidence for extensional deformation, and some exhibit strike-slip faulting, whereas contractional tectonism appears to be rare. Io s surface is unique, exhibiting huge isolated mountains that may be blocks of crust tilting and foundering into the rapidly emptying interior as the surface is constantly buried by deposits from hyperactive volcanoes. Of the satellites, diminutive Enceladus is spectacularly active; its south polar terrain is a site of young tectonism, copious heat flow, and tall plumes venting into space. Europa's surface is

  17. Development of Source-Receptor matrix over South Korea in support of GAINS-Korea model

    NASA Astrophysics Data System (ADS)

    Choi, K. C.; Woo, J. H.; Kim, H. K.; Lee, Y. M.; Kim, Y.; Heyes, C.; Lee, J. B.; Song, C. K.; Han, J.

    2014-12-01

    A comprehensive and combined analysis of air pollution and climate change could reveal important synergies of emission control measures, which could be of high policy relevance. IIASA's GAINS model (The Greenhouse gas - Air pollution Interactions and Synergies) has been developed as a tool to identify emission control strategies that achieve given targets on air quality and greenhouse gas emissions at least costs. The GAINS-Korea Model, which is being jointly developed by Konkuk University and IIASA, should play an important role in understanding the impact of air quality improvements across the regions in Korea. Source-Receptor relationships (S-R) is an useful methodology in air pollution studies to determine the areas of origin of chemical compounds at receptor point, and thus be able to target actions to reduce pollutions. The GAINS model can assess the impact of emission reductions of sources on air quality in receptor regions based on S-R matrix, derived from chemical transport model. In order to develop S-R matrix for GAINS-Korea, the CAMx model with PSAT/OSAT tools was applied in this study. The coarse domain covers East Asia, and a nesting domain as main research area was used for Korea peninsula. To evaluate of S-R relationships, a modeling domain is divided into sixteen regions over South Korea with three outside of S. Korea countries (China, N. Korea and Japan) for estimating transboundary contributions. The results of our analysis will be presented at the conference.

  18. The tectonic and volcanic evolution of Venus: Catastrophic or gradual?

    NASA Technical Reports Server (NTRS)

    Solomon, Sean C.

    1993-01-01

    Radar imaging and altimetry data from the Magellan mission have yielded important new constraints on the tectonic and volcanic history of Venus and on its internal dynamics. The planet lacks global plate tectonics, but a number of chasm systems and corona moat structures have arcuate planforms, asymmetric topogrpahic profiles, and relief analogous to deep-sea trenches on Earth and may be products of limited lithospheric underthrusting or subduction. Several lines of evidence point to a crust and upper mantle stronger than would be predicted by simple extrapolation from Earth and the 450 K greater surface temperature; these include the unrelaxed depths of impact craters, apparently large values of elastic lithosphere thickness, and large ratios of gravity to topography. The density of impact craters indicates an averate crater retention age of about 500 My, but not more than 5% of the recognized craters have been volcanically embayed. This last observation has led to the proposal that Venus has been subjected to one or more global resurfacing events, the latest about 500 My ago, and that the volcanic flux during intervals between such events has been low. That more recent tectonic activity has been widespread, however, is indicated by the high relief and slopes of mountains, chasm walls, and plateau margins; the significant fraction (0.3) of impact craters deformed by younger faults; and the postformational vertical deformation of long channels. Interior dynamical scenarios advanced to account for episodic volcanic resurfacing include catastrophic overturn of a global lithosphere thickened by cooling or compositional buoyancy and strongly time-dependent mantle convective heat flux. Outgassing considerations and analogy with Earth and other terrestrial planets, however, suggests that such catastrophic models are unlikely. If the mantle of Venus cooled more efficiently than that of Earth because of, say, different boundary conditions, a different flow law, or a

  19. Wood Decay Fungi in South Korea: Polypores from Seoul

    PubMed Central

    Jang, Yeongseon; Jang, Seokyoon; Lee, Jaejung; Lee, Hwanhwi; Lee, Hanbyul; Lee, Young Min; Hong, Joo-Hyun; Min, Mihee; Lim, Young Woon; Kim, Changmu

    2014-01-01

    In Seoul, a majority of plant communities have undergone significant changes over the last few decades; however, how wood decay fungi have responded and adapted to the changes in vegetation remains unknown. Through an ongoing investigation of Korean indigenous fungi, ca. 300 specimens with poroid basidiocarp were collected in Seoul during 2008~2012. Morphological examination and molecular analysis using the internal transcribed spacer and nuclear large subunit ribosomal DNA region sequences helped identify 38 species belonging to 28 genera, 10 families, and 5 orders in this area. Among them, three polypores, Abundisporus pubertatis, Coriolopsis strumosa, and Perenniporia maackiae were found to be new to South Korea. PMID:25071382

  20. Iapetus: Tectonic structure and geologic history

    NASA Technical Reports Server (NTRS)

    Croft, Steven K.

    1991-01-01

    Many papers have been written about the surface of Iapetus, but most of these have discussed either the nature of the strongly contrasting light and dark materials or the cratering record. Little has been said about other geologic features on Iapetus, such as tectonic structures, which would provide constraints on Iapetus' thermal history. Most references have suggested that there is no conclusive evidence for any tectonic activity, even when thermal history studies indicate that there should be. However, a new study of Iapetus' surface involving the use of stereo pairs, an extensive tectonic network has been recognized. A few new observations concerning the craters and dark material were also made. Thus the geology and geologic history of Iapetus can be more fully outlined than before. The tectonic network is shown along with prominent craters and part of the dark material in the geologic/tectonic sketch map. The topology of crater rims and scarps are quite apparent and recognizable in the different image pairs. The heights and slopes of various features given are based on comparison with the depths of craters 50 to 100 km in diameter, which are assumed to have the same depths as craters of similar diameter on Rhea and Titania.

  1. Surface Geology and Tectonism on Enceladus

    NASA Astrophysics Data System (ADS)

    Helfenstein, P.; Thomas, P. C.; Veverka, J.; Porco, C.; Giese, B.; Wagner, R.; Roatsch, T.; Denk, T.; Neukum, G.; Turtle, E.

    2006-12-01

    Enceladus is remarkable not only for its active water-ice eruptions near the South Pole, but also because its surface geology preserves a system of large-scale tectonic patterns that record past, as well as present centers of tectonic deformation. The currently active South Polar Terrain (SPT) geological province defines a characteristic tectonic style, geometry, and size-scale: It is a crudely circular, kilometer-deep topographic depression that subtends ~70° in arc and is bounded by a circumpolar chain of south-facing arcuate scarps and kilometer- scale mountain belts (Porco et al.2006, Science 311 1393-1401). Nearer its center, ongoing water-ice eruptions emanate from a series of ~200-km-long quasi-parallel rifts, called "tiger stripes" that have an average spacing of 32 km. On the trailing side of Enceladus, the surface locations of ancient, now inactive tectonic provinces similar to the SPT are inferred from the similar geological patterns, geometry, and size- scales of two other tectonically disrupted regions; Sarandib Planitia (4°N, 298°W) and Diyar Planitia (0°N, 240°W).These regions may record the locations of ancient diapirs that have dissipated or perhaps the progressive migration of a single warm diapir to the South Pole of Enceladus as suggested by Nimmo and Pappalardo (2006, Nature 441, 614-616).

  2. The characteristics of drought occurrence in North Korea and its comparison with drought in South Korea

    NASA Astrophysics Data System (ADS)

    Lee, Bo-Ra; Oh, Su-Bin; Byun, Hi-Ryong

    2015-07-01

    The characteristics of the drought occurrence in North Korea over a period of 56 years (1952-2007) were analyzed by region, compared with those of South Korea, and graphed as a drought map for easy detection of the drought's history. To assess them, the Effective Drought Index (EDI), which was calculated from the daily precipitation data for 109 grids of the Korean Peninsula, was used. The daily precipitation data were extracted from the Asian Precipitation Highly Resolved Observational Data Integration towards Evaluation of Water Resources (APHRODITE). The characteristics of the drought occurrence in North Korea were summed up in the following five points. First, North Korea was divided into four drought sub-regions: the Northeastern region (G1), the Northern region (G2), the Central region (G3), and the Southern region (G4). Second, droughts occurred most frequently in G1 (28) and G4 (28 events) and least frequently in G3 (15 events). Third, in all sub-regions, short-term droughts lasting less than 100 days were the most frequent (53 % or higher) and the longest drought lasted 2,911 days (June 30, 1973 to June 20, 1981), which occurred in G3. Fourth, short-term droughts occurred mainly in spring, mid-term droughts (100-500 days) in spring and summer, and long-term droughts (over 500 days) in summer. Fifth, a dry period (monthly mean EDI <0) appeared in all sub-regions between 1973 and 1981 and between 1990 and 1993, and a strong negative precipitation anomaly appeared during each of these periods. When compared to the droughts in South Korea, those in North Korea were less frequent, but the mean duration was longer. Until 1979, droughts occurred almost at the same time in North Korea as South Korea, but beginning in 1980, the time differences between two regions became larger. Thus, the characteristics of the drought occurrence in North and South Korea differ.

  3. 77 FR 52758 - Large Power Transformers From Korea

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-30

    ... COMMISSION Large Power Transformers From Korea Determination On the basis of the record \\1\\ developed in the... the United States is materially injured, by reason of imports from Korea of large power transformers... power transformers from Korea were being sold at LTFV within the meaning of section 733(b) of the...

  4. 76 FR 54790 - Large Power Transformers From Korea

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-02

    ... COMMISSION Large Power Transformers From Korea Determination On the basis of the record \\1\\ developed in the... Korea of large power transformers, provided for in subheadings 8504.23.00 and 8504.90.95 of the... of large power transformers from Korea. Accordingly, effective July 14, 2011, the...

  5. 15 CFR 742.19 - Anti-terrorism: North Korea.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 15 Commerce and Foreign Trade 2 2012-01-01 2012-01-01 false Anti-terrorism: North Korea. 742.19...-CCL BASED CONTROLS § 742.19 Anti-terrorism: North Korea. (a) License Requirements. (1) All items on... anti-terrorism reasons require a license for export or reexport to North Korea. This includes all...

  6. 15 CFR 742.19 - Anti-terrorism: North Korea.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 15 Commerce and Foreign Trade 2 2013-01-01 2013-01-01 false Anti-terrorism: North Korea. 742.19...-CCL BASED CONTROLS § 742.19 Anti-terrorism: North Korea. (a) License Requirements. (1) All items on... anti-terrorism reasons require a license for export or reexport to North Korea. This includes all...

  7. 15 CFR 742.19 - Anti-terrorism: North Korea.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 2 2011-01-01 2011-01-01 false Anti-terrorism: North Korea. 742.19...-CCL BASED CONTROLS § 742.19 Anti-terrorism: North Korea. (a) License Requirements. (1) All items on... anti-terrorism reasons require a license for export or reexport to North Korea. This includes all...

  8. English Immersion and Educational Inequality in South Korea

    ERIC Educational Resources Information Center

    Jeon, Mihyon

    2012-01-01

    This article explores what immersion English education means in South Korea (henceforth Korea) and examines various related educational practices. The proposal for English immersion from the Presidential Transition Committee of the Lee administration in early 2008 has highlighted immersion education in Korea. Ironically, since the committee's…

  9. Korea: Balancing Economic Growth and Social Protection for Older Adults

    ERIC Educational Resources Information Center

    Yoon, Hyun-Sook

    2013-01-01

    Population aging in Korea is projected to be the most rapid among Organisation for Economic Co-operation and Development (OECD) countries between 2000 and 2050. However, social spending in Korea remains low, reflecting Korea's relatively young population, limited health and long-term care insurance coverage, and immaturity of its pension system.…

  10. Brain Korea 21 Phase II: A New Evaluation Model. Monograph

    ERIC Educational Resources Information Center

    Seong, Somi; Popper, Steven W.; Goldman, Charles A.; Evans, David K.

    2008-01-01

    In the late 1990s, the Korea Ministry of Education and Human Resources, in response to concern over the relatively low standing of the nation's universities and researchers, launched the Brain Korea 21 program BK21). BK21 seeks to make Korean research universities globally competitive and to produce more high-quality researchers in Korea. It…

  11. 77 FR 51569 - Large Residential Washers From Korea and Mexico

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-24

    ... COMMISSION Large Residential Washers From Korea and Mexico Scheduling of the final phase of countervailing... the United States is materially retarded, by reason of subsidized imports from Korea and less-than-fair-value imports from Korea and Mexico of large residential washers, provided for in subheading...

  12. 77 FR 9700 - Large Residential Washers From Korea and Mexico

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-17

    ... COMMISSION Large Residential Washers From Korea and Mexico Determinations On the basis of the record \\1... materially injured by reason of imports from Korea of large residential washers that are alleged to be sold in the United States at less than fair value (LTFV) and subsidized by the Government of Korea....

  13. 78 FR 10636 - Large Residential Washers From Korea and Mexico

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-14

    ... COMMISSION Large Residential Washers From Korea and Mexico Determinations On the basis of the record \\1...)) (the Act), that an industry in the United States is materially injured by reason of imports from Korea... subsidized by the Government of Korea and sold in the United States at less than fair value (LTFV)....

  14. 15 CFR 742.19 - Anti-terrorism: North Korea.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Anti-terrorism: North Korea. 742.19...-CCL BASED CONTROLS § 742.19 Anti-terrorism: North Korea. (a) License Requirements. (1) All items on... anti-terrorism reasons require a license for export or reexport to North Korea. This includes all...

  15. Recent meteorite falls in South Korea

    NASA Astrophysics Data System (ADS)

    Choi, Y.; Kim, M.; Byun, Y.; Yi, H.; Chang, S.; Choi, J.; Sohn, J.; Moon, H.; Park, J.

    2014-07-01

    In the evening of March 9, 2014, a fireball falling from north to south was observed in South Korea. Multiple explosions were heard and multiple videos recorded in cars from various places, suggesting that the fireball was separated into several pieces. Immediately thereafter, a series of discovery reports about meteorites from the southern part of South Korea followed and, as of today, three meteorites were confirmed and one meteorite, with a mass of about 20 kg, is pending. This discovery of a meteorite in South Korea occurs for the first time in 70 years. The overall trajectory of the fireball matches the area where meteorites were discovered. According to the preliminary analyses, the meteorite is an ordinary chondrite. The origin of the meteorite and its surface properties will be studied.

  16. Research and development for algae-based technologies in Korea: a review of algae biofuel production.

    PubMed

    Hong, Ji Won; Jo, Seung-Woo; Yoon, Ho-Sung

    2015-03-01

    This review covers recent research and development (R&D) activities in the field of algae-based biofuels in Korea. As South Korea's energy policy paradigm has focused on the development of green energies, the government has funded several algae biofuel R&D consortia and pilot projects. Three major programs have been launched since 2009, and significant efforts are now being made to ensure a sustainable supply of algae-based biofuels. If these R&D projects are executed as planned for the next 10 years, they will enable us to overcome many technical barriers in algae biofuel technologies and help Korea to become one of the leading countries in green energy by 2020.

  17. The Role of Ex-Vessel Neutron Dosimetry in Reactor Vessel Surveillance in South Korea

    NASA Astrophysics Data System (ADS)

    Kim, Byoung-Chul; Yoo, Choon Sung; Anderson, Stanwood L.; Fero, Arnold H.; Kim, Charles C.

    2009-08-01

    Korea Hydro and Nuclear Power (KHNP) is the sole nuclear utility in South Korea. KHNP operates 20 nuclear power plants. This fleet consists of 16 PWRs and four PHWRs. Of the PWRs, two are Westinghouse-design two-loop plants, four are Westinghouse-design three-loop plants, two are Framatome-design three-loop plants, and the remainder are the Korea Standard Nuclear Plant (KSNP), similar to CE-design plants where the reactor was supplied by CE and DOOSAN. In addition, KHNP has six new reactors under construction at the Shin-Kori and Shin-Wolsong sites. This large and diverse reactor fleet introduces significant challenges to the task of reactor vessel surveillance and of measuring the neutron exposure of the reactor vessel.

  18. Moving toward universal coverage of health insurance in Vietnam: barriers, facilitating factors, and lessons from Korea.

    PubMed

    Do, Ngan; Oh, Juhwan; Lee, Jin-Seok

    2014-07-01

    Vietnam has pursued universal health insurance coverage for two decades but has yet to fully achieve this goal. This paper investigates the barriers to achieve universal coverage and examines the validity of facilitating factors to shorten the transitional period in Vietnam. A comparative study of facilitating factors toward universal coverage of Vietnam and Korea reveals significant internal forces for Vietnam to further develop the National Health Insurance Program. Korea in 1977 and Vietnam in 2009 have common characteristics to be favorable of achieving universal coverage with similarities of level of income, highly qualified administrative ability, tradition of solidarity, and strong political leadership although there are differences in distribution of population and structure of the economy. From a comparative perspective, Vietnam can consider the experience of Korea in implementing the mandatory enrollment approach, household unit of eligibility, design of contribution and benefit scheme, and resource allocation to health insurance for sustainable government subsidy to achieve and sustain the universal coverage of health insurance.

  19. Tidal Power Exploitation in Korea

    NASA Astrophysics Data System (ADS)

    Choi, Byung Ho; Kim, Kyeong Ok; Choi, Jae Cheon

    The highest tides in South Korea are found along the northwest coast between latitudes 36-38 degrees and the number of possible sites for tidal range power barrages to create tidal basins is great due to irregular coastlines with numerous bays. At present Lake Sihwa tidal power plant is completed. The plant is consisted of 10 bulb type turbines with 8 sluice gates. The installed capacity of turbines and generators is 254MW and annual energy output expected is about 552.7 GWh taking flood flow generation scheme. Three other TPP projects are being progressed at Garolim Bay (20 turbines with 25.4MW capacity), Kangwha (28 turbines with 25.4MW capacity), Incheon (44 or 48 turbines with 30 MW capacity) and project features will be outlined here. The introduction of tidal barrages into four major TPP projects along the Kyeonggi bay will render wide range of potential impacts. Preliminary attempts were performed to quantify these impacts using 2 D hydrodynamic model demonstrating the changes in tidal amplitude and phase under mean tidal condition, associated changes in residual circulation (indicator for SPM and pollutant dispersion), bottom stress (indicator for bedload movement), and tidal front (positional indicator for bio-productivity) in both shelf scale and local context. Tidal regime modeling system for ocean tides in the seas bordering the Korean Peninsula is designed to cover an area that is broad in scope and size, yet provide a high degree of resolution in strong tidal current region including off southwestern tip of the Peninsula (Uldolmok , Jangjuk, Wando-Hoenggan), Daebang Sudo (Channel) and Kyeonggi Bay. With this simulation system, real tidal time simulation of extended springneap cycles was performed to estimate spatial distribution of tidal current power potentials in terms of power density, energy density and then extrapolated annual energy density.

  20. Sex preferences and fertility in South Korea during the year of the Horse.

    PubMed

    Lee, Jungmin; Paik, Myungho

    2006-05-01

    Since antiquity, people in several East Asian countries, such as China, Japan, and South Korea, have believed that a person is destined to possess specific characteristics according to the sign of the zodiac under which he or she was born. South Koreans, in particular, have traditionally considered that the year of the Horse bears inauspicious implications for the birth of daughters. Using monthly longitudinal data at the region level in South Korea between 1970 and 2003, we found that in the year of the Horse, the sex ratio at birth significantly increased while fertility decreased.

  1. Outdoor Air Pollution and Pterygium in Korea.

    PubMed

    Lee, Ki Woong; Choi, Yoon Hyeong; Hwang, Sung Ha; Paik, Hae Jung; Kim, Mee Kum; Wee, Won Ryang; Kim, Dong Hyun

    2017-01-01

    We investigated relationships between outdoor air pollution and pterygium in Korean adults. This study includes 23,276 adults in population-based cross-sectional data using the Korea National Health and Nutrition Examination Survey 2008-2011. Pterygium was assessed using slit lamp biomicroscopy. Air pollution data (humidity, particulate matter with aerodynamic diameter less than 10 μm [PM₁₀], ozone [O₃], nitrogen dioxide [NO₂], and sulfur dioxide levels [SO₂]) for 2 years preceding the ocular examinations were acquired. Associations of multiple air pollutants with pterygium or pterygium recurrence after surgery were examined using multivariate logistic models, after adjusting for several covariates. Distributed lag models were additionally used for estimating cumulative effects of air pollution on pterygium. None of air pollution factors was significantly associated with pterygium or pterygium recurrence (each P > 0.05). Distributed lag models also showed that air pollution factors were not associated with pterygium or pterygium recurrence in 0-to-2 year lags (each P > 0.05). However, primary pterygium showed a weak association with PM10 after adjusting for covariates (odds ratio [OR] 1.23; [per 5 μg/m³ PM₁₀ increase]; P = 0.023). Aging, male sex, and greater sun exposure were associated with pterygium, while higher education level and myopia were negatively associated with pterygium (each P ≤ 0.001). Male sex and myopia were negatively associated with pterygium recurrence (each P < 0.05). In conclusion, exposure to higher PM10 levels was associated with primary pterygium, although this study observed no significant association between air pollution and overall pterygium or pterygium recurrence in Korean adults.

  2. The history of vaccination and current vaccination policies in Korea

    PubMed Central

    2012-01-01

    There may be many reasons for the significant decrease in the incidence of the pediatric infectious diseases in modern Korea; this could be due to the improvement of sanitary facilities, significant growth of Korean economy, improvement of nutrition, development and dissemination of antibiotics and implantation of vaccination, and overall improvement of medical technology. The development of vaccination has been highlighted as a striking achievement of the modern medical sciences with new technologies in many fields of medicine. Since 1876, the method for vaccination has opened its new era by Suk-Young Jee, known as the Jenner in Korea who wrote a book about smallpox vaccination, and it led an opportunity to propagate the needs for the vaccination in Korea. There was a time when pediatric wards were full of patients with parasitic diseases and many vaccine-preventable diseases such as diphtheria, pertussis, Japanese B encephalitis, and poliomyelitis in 1950s-1960s. We do not see those infectious diseases that often any more in recent years. However, we still have patients with water-borne diseases and other communicable diseases related to increasing international travels. We just experienced the first pandemic influenza of the 21st century in 2009 and avian influenza is still a threat to humans in other parts of the world with an unpredictable potential of pandemicity. In addition, we have tough battles with emerging antibiotic resistance in many strains of bacteria and increased opportunistic infections due to improvement of medical technology involving more aggressive treatment modality and use of medical devices. Researches in many areas are under way and we hope that some of them may be preventable and decreased with a development of new vaccines in the future. PMID:23596573

  3. Continental origin of the Bibong eclogite, southwestern Gyeonggi massif, South Korea

    NASA Astrophysics Data System (ADS)

    Park, Seung-Ik; Kwon, Sanghoon; Kim, Sung Won; Yi, Keewook; Santosh, M.

    2014-12-01

    Eclogite is a high-pressure (HP) metamorphic rock that provides important information about the subduction of both continental and oceanic crusts. In this study we present SHRIMP zircon U-Pb isotopic data for a suite of the basement gneisses to investigate the origin of the Proterozoic Bibong eclogite in the Hongseong area, South Korea. Zircon grains from the basement felsic gneisses yielded Paleoproterozoic protolith ages ranging from ca. 2197 to 1880 Ma, and were intruded by syenite at ca. 750 Ma. A HP regional metamorphic event of Triassic age (ca. 255-227 Ma) is recorded in the zircon rims of the country rocks, which is also observed in the zircons from the eclogite. The contacts between the Bibong eclogite and its host rocks support an origin for the Proterozoic protoliths, indicating continental intrusions. The Hongseong area thus preserves evidence for the Triassic collision, indicating a tectonic linkage among the northeast Asian continents.

  4. Plate tectonic modelling: virtual reality with GMAP

    NASA Astrophysics Data System (ADS)

    Torsvik, Trond Helge; Smethurst, Mark Andrew

    1999-05-01

    Palaeogeographic reconstructions have been an integral part of global tectonic research since the advent of the plate tectonic paradigm, and GMAP is a state of the art computer program which performs all processing and plotting tasks associated with the generation of palaeogeographic reconstructions and plate tectonic modelling. GMAP is menu-driven and easy to use; the user is never far removed from the basic data from which palaeogeographic reconstructions are derived, and therefore has a sense of total control over the program's performance. GMAP can generate reconstructions based on known Euler rotation data poles or palaeomagnetic poles. The user is also free simply to move continents around on the screen, according to less tangible constraints. GMAP is supplied with a full range of continental outlines. It is also possible to import new continents via simple ASCII files. GMAP is in use at leading institutions world-wide, and has been the work-horse of the EUROPEAN GEOTRAVERSE and EUROPROBE projects.

  5. The tectonics of Venus: An overview

    NASA Technical Reports Server (NTRS)

    Solomon, Sean C.

    1992-01-01

    While the Pioneer Venus altimeter, Earth-based radar observatories, and the Venera 15-16 orbital imaging radars provided views of large-scale tectonic features on Venus at ever-increasing resolution, the radar images from Magellan constitute an improvement in resolution of at least an order of magnitude over the best previously available. A summary of early Magellan observations of tectonic features on Venus was published, but data available at that time were restricted to the first month of mapping and represented only about 15 percent of the surface of the planet. Magellan images and altimetry are now available for more than 95 percent of the Venus surface. Thus a more global perspective may be taken on the styles and distribution of lithospheric deformation on Venus and their implications for the tectonic history of the planet.

  6. Tectonics of Neyterkob corona on Venus

    NASA Technical Reports Server (NTRS)

    Kauhanen, K.

    1993-01-01

    Neyterkob double corona (50 deg N 202 deg) presents an area of corona-related interfering tectonic patterns which are formed in different phases of evolution of the corona and modified by regional stresses. Analyzing the patterns can reveal something about the coronal formation. Tectonic features form distinct units on topographic depressions, slopes, and volcanic flows extending over one radius of the corona. A remarkable amount of compressional features were found near the rim and related to interaction between adjacent coronae. Radial extension was mainly observed on a peculiar NE-SW trending high crossing the corona. Concentric fractures were found to the east partly connected to the lithospheric flexure. Tectonic features indicate movements of volcanic activity and modification of the area by more regional stresses.

  7. Practical Treatments for Constipation in Korea

    PubMed Central

    Park, Kyung-Sik; Park, Moo-In; Shin, Jeong-Eun; Jung, Kee-Wook; Kim, Seong-Eun; Lee, Tae-Hee; Koo, Hoon-Sup

    2012-01-01

    Constipation is a digestive symptom that is frequently seen in clinical practice. Its prevalence has been reported to be 2% to 20%, depending on geographical region. Despite the rapid development of medical science, systematic studies on constipation have been rarely conducted in Korea. Recently, guidelines on the diagnosis and treatment of functional gastrointestinal disorders, including constipation, were proposed by The Korean Society of Neurogastroenterology and Motility. These guidelines are expected to reflect the current situation regarding treatment of constipation in Korea. In this paper, practical constipation treatment methods that are in current use will be reviewed with reference to these recent guidelines. PMID:23019388

  8. North Korea: Economic Leverage and Policy Analysis

    DTIC Science & Technology

    2010-01-22

    humanitarian aid. Sources: Kim Myong Chol, “Kim Jong-il shifts to plan B,” Asia Tiimes, May 21, 2009, Online edition. “North Korea begins ‘Plan C...Asia Times, October 14, 2009, Online edition. Zhang Lianqui, “There is a Dangerous Component in the ‘Warm Winter’ of the DPRK Nuclear Issue, Huanqiu...Boycott Six-Party Talks ,” The Wall Street Journal, April 14, 2009, Online version. 7 Denis D. Gray, “North Korea turns to air smuggling,” Associated

  9. Development of microsatellite markers to genetically differentiate populations of Octopus minor from Korea and China.

    PubMed

    Kang, Jung-Ha; Kim, Yi-Kyung; Park, Jung-Youn; An, Chel-Min; Jun, Je-Chun

    2012-08-01

    Of the more than 300 octopus species, Octopus minor is one of the most popular and economically important species in Eastern Asia, including Korea, along with O. vulgaris, O. ocellatus, and O. aegina. We developed 19 microsatellite markers from Octopus minor and eight polymorphic markers were developed to analyze the genetic diversity and relationships among four octopus populations from Korea and three from China. The number of alleles per locus varied from 10 to 49, and allelic richness per locus ranged from 2 to 16.4 across all populations. The average allele number among the populations was 11.1, with a minimum of 8.3 and a maximum of 13.6. The mean allelic richness was 8.7 in all populations. The Hardy-Weinberg equilibrium (HWE) test revealed significant deviation in 19 of the 56 single-locus sites, and null alleles were presumed in five of eight loci. The pairwise F ( ST ) values between populations from Korea and China differed significantly in all pairwise comparisons. The genetic distances between the China and Korea samples ranged from 0.161 to 0.454. The genetic distances among the populations from Korea ranged from 0.033 to 0.090, with an average of 0.062; those among populations from China ranged from 0.191 to 0.316, with an average of 0.254. The populations from Korea and China formed clearly separated into clusters via an unweighted pair group method with arithmetic mean dendrogram. Furthermore, a population from muddy flats on the western coast of the Korean Peninsula and one from a rocky area on Jeju Island formed clearly separated subclusters. An assignment test based on the allele distribution discriminated between the Korean and Chinese origins with 96.9 % accuracy.

  10. Tectonic evolution of the Qinghai-Tibet Plateau

    NASA Astrophysics Data System (ADS)

    Pan, Guitang; Wang, Liquan; Li, Rongshe; Yuan, Sihua; Ji, Wenhua; Yin, Fuguang; Zhang, Wanping; Wang, Baodi

    2012-07-01

    The Qinghai-Tibet Plateau, composed of several continental slivers within the eastern Tethyan domain, is one of the pivotal sites to examine to better understand the theory of plate tectonics and the orogenic evolution on Earth. This plateau is generally inferred to be a collage of several continental blocks that rifted from Gondwanaland and subsequently accreted to the Asian continent. However, recent recognition of over twenty ophiolite mélange zones and their associated island arcs indicates that the traditional model of tectonic evolution requires revision. Based on 177 recently finished 1:250,000 scale geological maps and related studies, we summarize the main tectonic context of the Qinghai-Tibet Plateau and propose a new integrated model to account for the new findings. The complex orogen of the immense Qinghai-Tibet Plateau, consisting of multiple island arc-basin systems that developed at different stages while surrounded by the North China, Yangtze, Tarim, and Indian plates, is emphasized. The entire orogen, surrounded by suture zones that mark the locations of oceanic closure, is investigated by examining (I) the first-order tectonic units and ophiolitic mélanges (including arc-arc/continent collision zones) and (II) their internally enclosed blocks as the second-order tectonic units. Therefore, the Qinghai-Tibet Plateau is divided into three major orogenic systems, namely, from northeast to southwest, the Early Paleozoic Qinling-Qilianshan-Kunlunshan (Qin-Qi-Kun), the Late Paleozoic-Triassic Qiangtang-Sanjiang, and the Late Paleozoic to Cenozoic Gangdese-Himalaya orogenic systems, which are separated by the Kangxiwa-Muzitagh-Maqin-Mianxian and the Bangong-Shuanghu-Changning-Menglian sutures, respectively. We propose that the formation and evolution of the Qinghai-Tibet Plateau to have been intrinsically related to those of the eastern Tethys, recorded by the Longmu Co-Shuanghu ophiolite mélange zone, the Southern Qiangtang Paleozoic accretionary arc

  11. Subduction Drive of Plate Tectonics

    NASA Astrophysics Data System (ADS)

    Hamilton, W. B.

    2003-12-01

    Don Anderson emphasizes that plate tectonics is self-organizing and is driven by subduction, which rights the density inversion generated as oceanic lithosphere forms by cooling of asthenosphere from the top. The following synthesis owes much to many discussions with him. Hinge rollback is the key to kinematics, and, like the rest of actual plate behavior, is incompatible with bottom-up convection drive. Subduction hinges (which are under, not in front of, thin leading parts of arcs and overriding plates) roll back into subducting plates. The Pacific shrinks because bounding hinges roll back into it. Colliding arcs, increasing arc curvatures, back-arc spreading, and advance of small arcs into large plates also require rollback. Forearcs of overriding plates commonly bear basins which preclude shortening of thin plate fronts throughout periods recorded by basin strata (100 Ma for Cretaceous and Paleogene California). This requires subequal rates of advance and rollback, and control of both by subduction. Convergence rate is equal to rates of rollback and advance in many systems but is greater in others. Plate-related circulation probably is closed above 650 km. Despite the popularity of concepts of plumes from, and subduction into, lower mantle, there is no convincing evidence for, and much evidence against, penetration of the 650 in either direction. That barrier not only has a crossing-inhibiting negative Clapeyron slope but also is a compositional boundary between fractionated (not "primitive"), sluggish lower mantle and fertile, mobile upper mantle. Slabs sink more steeply than they dip. Slabs older than about 60 Ma when their subduction began sink to, and lie down on and depress, the 650-km discontinuity, and are overpassed, whereas younger slabs become neutrally buoyant in mid-upper mantle, into which they are mixed as they too are overpassed. Broadside-sinking old slabs push all upper mantle, from base of oceanic lithosphere down to the 650, back under

  12. Convective, intrusive geothermal plays: what about tectonics?

    NASA Astrophysics Data System (ADS)

    Santilano, A.; Manzella, A.; Gianelli, G.; Donato, A.; Gola, G.; Nardini, I.; Trumpy, E.; Botteghi, S.

    2015-09-01

    We revised the concept of convective, intrusive geothermal plays, considering that the tectonic setting is not, in our opinion, a discriminant parameter suitable for a classification. We analysed and compared four case studies: (i) Larderello (Italy), (ii) Mt Amiata (Italy), (iii) The Geysers (USA) and (iv) Kizildere (Turkey). The tectonic settings of these geothermal systems are different and a matter of debate, so it is hard to use this parameter, and the results of classification are ambiguous. We suggest a classification based on the age and nature of the heat source and the related hydrothermal circulation. Finally we propose to distinguish the convective geothermal plays as volcanic, young intrusive and amagmatic.

  13. Current microseismicity and generating faults in the Gyeongju area, southeastern Korea

    NASA Astrophysics Data System (ADS)

    Han, Minhui; Kim, Kwang-Hee; Son, Moon; Kang, Su Young

    2017-01-01

    A study of microseismicity in a 15 × 20 km2 subregion of Gyeongju, southeastern Korea, establishes a direct link between minor earthquakes and known fault structures. The study area has a complex history of tectonic deformation and has experienced large historic earthquakes, with small earthquakes recorded since the beginning of modern instrumental monitoring. From 5 years of continuously recorded local seismic data, 311 previously unidentified microearthquakes can be reliably located using the double-difference algorithm. These newly discovered events occur in linear streaks that can be spatially correlated with active faults, which could pose a serious hazard to nearby communities. At-risk infrastructure includes the largest industrial park in South Korea, nuclear power plants, and disposal facilities for radioactive waste. The current work suggests that the southern segment of the Yeonil Tectonic Line and segments of the Seokup and Waup Basin boundary faults are active. For areas with high rates of microseismic activity, reliably located hypocenters are spatially correlated with mapped faults; in less active areas, earthquake clusters tend to occur at fault intersections. Microearthquakes in stable continental regions are known to exist, but have been largely ignored in assessments of seismic hazard because their magnitudes are well below the detection thresholds of seismic networks. The total number of locatable microearthquakes could be dramatically increased by lowering the triggering thresholds of network detection algorithms. The present work offers an example of how microearthquakes can be reliably detected and located with advanced techniques. This could make it possible to create a new database to identify subsurface fault geometries and modes of fault movement, which could then be considered in the assessments of seismic hazard in regions where major earthquakes are rare.

  14. A Model of Quality of College Life (QCL) of Students in Korea

    ERIC Educational Resources Information Center

    Yu, Grace (Byung-Hee); Lee, Dong-Jin

    2008-01-01

    This study develops and tests a model of quality of college life (QCL) of students in Korea. In this study, QCL of students is conceptualized in terms of needs satisfaction and affect balance. It has been hypothesized that satisfaction with education services, administrative services, and facilities have a significant impact on QCL, which in turn…

  15. Learners' Acceptance of E-Learning in South Korea: Theories and Results

    ERIC Educational Resources Information Center

    Lee, Byoung-Chan; Yoon, Jeong-Ok; Lee, In

    2009-01-01

    One of the most significant changes in the field of education in this information age is the paradigm shift from teacher-centered to learner-centered education. Along with this paradigm shift, understanding of students' e-learning adoption behavior among various countries is urgently needed. South Korea's dense student population and high…

  16. Regional Scale Application of USLE and WEPP for Soil Erosion Assessment in Korea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Due to the geographical location of Korea in the Asian monsoon belt more than half of annual precipitation occurs during the summer season (May to September). This causes significant amounts of soil loss from croplands, which is directly linked to the deterioration of surface water quality. Therefor...

  17. Poultry vaccination directed evolution of H9N2 low pathogenicity avian influenza viruses in Korea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Significant economic losses in the poultry industries have resulted from H9N2 low pathogenic avian influenza virus infections across North Africa, the Middle East and Asia. The present study investigated the evolutionary dynamics of H9N2 viruses circulating in Korea from 1996 to 2012. Our analysis o...

  18. Approaches to Teaching about Korea in a World Cultures Social Studies Curriculum. A guide for Teachers.

    ERIC Educational Resources Information Center

    Lewis, Linda; Linton, Stephen

    Korea, a country of major significance within the East Asian culture sphere, is also a country of historical and contemporary importance to the United States. Divided in 1945 into two zones, the North and the South, the communist northern sector became a formidable economic and military power, while the phenomenal growth of the southern sector's…

  19. Preliminary publications book 2 from project on mineral resources, metallogenesis, and tectonics of northeast Asia

    USGS Publications Warehouse

    Nokleberg, Warren J.; Miller, Robert J.; Naumova, Vera V.; Khanchuk, Alexander I.; Parfenov, Leonid M.; Kuzmin, Mikhail I.; Bounaeva, Tatiana M.; Obolenskiy, Alexander A.; Rodionov, Sergey M.; Seminskiy, Zhan V.; Diggles, Michael F.

    2003-01-01

    This is the Web version of a CD-ROM publication. This report consists of summary major compilations and syntheses accomplished in the six-year project through April 2003 for the study on the Mineral Resources, Metallogenesis, and Tectonics of Northeast Asia (Eastern and Southern Siberia, Mongolia, Northeastern China, South Korea, and Japan). The major scientific goals and benefits of the project are to: (1) provide a comprehensive international data base on the mineral resources of the region that is the first, extensive knowledge available in English; (2) provide major new interpretations of the origin and crustal evolution of mineralizing systems and their host rocks, thereby enabling enhanced, broad-scale tectonic reconstructions and interpretations; and (3) promote trade and scientific and technical exchanges between the North America and Northeast Asia. Data from the project are providing sound scientific data and interpretations for commercial firms, governmental agencies, universities, and individuals that are developing new ventures and studies in the project area, and for land-use planning studies that deal with both mineral potential issues. Northeast Asia has vast potential for known and undiscovered mineral deposits; however, little information existed in English in the West until publication of products from this project. Consequently, data and interpretations from the project are providing basic knowledge for major scientific, commercial, national, and international endeavors by other interested individuals and groups.

  20. Global Search of Triggered Tectonic Tremor

    NASA Astrophysics Data System (ADS)

    Peng, Z.; Aiken, C.; Chao, K.; Gonzalez-Huizar, H.; Wang, B.; Ojha, L.; Yang, H.

    2013-05-01

    Deep tectonic tremor has been observed at major plate-boundary faults around the Pacific Rim. While regular or ambient tremor occurs spontaneously or accompanies slow-slip events, tremor could be also triggered by large distant earthquakes and solid earth tides. Because triggered tremor occurs on the same fault patches as ambient tremor and is relatively easy to identify, a systematic global search of triggered tremor could help to identify the physical mechanisms and necessary conditions for tremor generation. Here we conduct a global search of tremor triggered by large teleseismic earthquakes. We mainly focus on major faults with significant strain accumulations where no tremor has been reported before. These includes subduction zones in Central and South America, strike-slip faults around the Caribbean plate, the Queen Charlotte-Fairweather fault system and the Denali fault in the western Canada and Alaska, the Sumatra-Java subduction zone, the Himalaya frontal thrust faults, as well as major strike-slip faults around Tibet. In each region, we first compute the predicted dynamic stresses σd from global earthquakes with magnitude>=5.0 in the past 20 years, and select events with σd > 1 kPa. Next, we download seismic data recorded by stations from local or global seismic networks, and identify triggered tremor as a high-frequency non-impulsive signal that is in phase with the large-amplitude teleseismic waves. In cases where station distributions are dense enough, we also locate tremor based on the standard envelope cross-correlation techniques. Finally, we calculate the triggering potential for the Love and Rayleigh waves with the local fault orientation and surface-wave incident angles. So far we have found several new places that are capable of generating triggered tremor. We will summarize these observations and discuss their implications on physical mechanisms of tremor and remote triggering.

  1. Tectonic reconstructions for paleobathymetry in Drake Passage

    NASA Astrophysics Data System (ADS)

    Eagles, Graeme; Jokat, Wilfried

    2014-01-01

    A minimum-complexity tectonic reconstruction, based on published and new basin opening models, depicts how the Scotia Sea grew by Cenozoic plate divergence, dismembering a Jurassic sheared margin of Gondwana. Part of the Jurassic-early Cretaceous ocean that accreted to this margin forms the core of the Central Scotia Plate, the arc plate above a trench at the eastern end of the Scotia Sea, which migrated east away from the Antarctic and South American plates. A sequence of extensional basins opened on the western edge of the Central Scotia Plate at 50-30 Ma, decoupled from the South American Plate to the northwest by slow motion on a long transform fault. Succeeding the basins, seafloor spreading started around 30 Ma on the West Scotia Ridge, which propagated northwards in the 23-17 Ma period and ceased to operate at 6 Ma. The circuits of plate motions inside and outside the Scotia Arc are joined via rotations that describe Antarctic-Central Scotia plate motion in Powell Basin until 20 Ma, and along the South Scotia Ridge thereafter. The modelled relative motion at the northern edge of the Scotia Sea is thus constrained only by the plate circuit, but nonetheless resembles that known coarsely from the geological record of Tierra del Fuego. A paleobathymetric interpretation of nine time slices in the model shows Drake Passage developing as an intermediate-depth oceanographic gateway at 50-30 Ma, with deep flow possible afterwards. Initially, this deep flow would have been made tortuous by numerous intermediate and shallow barriers. A frontal pattern resembling that in the modern Scotia Sea would have awaited the clearance of significant barriers by continuing seafloor spreading in the Scotia Sea at ~ 18.5 Ma, at Shag Rocks Passage, and after 10 Ma southeast of South Georgia.

  2. Modeling orbital changes on tectonic time scales

    NASA Technical Reports Server (NTRS)

    Crowley, Thomas J.

    1992-01-01

    Geologic time series indicate significant 100 ka and 400 ka pre-Pleistocene climate fluctuations, prior to the time of such fluctuations in Pleistocene ice sheets. The origin of these fluctuations must therefore depend on phenomena other than the ice sheets. In a previous set of experiments, we tested the sensitivity of an energy balance model to orbital insolation forcing, specifically focusing on the filtering effect of the Earth's geography. We found that in equatorial areas, the twice-yearly passage of the sun across the equator interacts with the precession index to generate 100 ka and 400 ka power in our modeled time series. The effect is proportional to the magnitude of land in equatorial regions. We suggest that such changes may reflect monsoonal variations in the real climate system, and the subsequent wind and weathering changes may transfer some of this signal to the marine record. A comparison with observed fluctuations of Triassic lake levels is quite favorable. A number of problems remain to be studied or clarified: (1) the EBM experiments need to be followed up by a limited number of GCM experiments; (2) the sensitivity to secular changes in orbital forcing needs to be examined; (3) the possible modifying role of sedimentary processes on geologic time series warrants considerably more study; (4) the effect of tectonic changes on Earth's rotation rate needs to be studied; and (5) astronomers need to make explicit which of their predictions are robust and geologists and astronomers have to agree on which of the predictions are most testable in the geologic record.

  3. Significant Tsunami Events

    NASA Astrophysics Data System (ADS)

    Dunbar, P. K.; Furtney, M.; McLean, S. J.; Sweeney, A. D.

    2014-12-01

    Tsunamis have inflicted death and destruction on the coastlines of the world throughout history. The occurrence of tsunamis and the resulting effects have been collected and studied as far back as the second millennium B.C. The knowledge gained from cataloging and examining these events has led to significant changes in our understanding of tsunamis, tsunami sources, and methods to mitigate the effects of tsunamis. The most significant, not surprisingly, are often the most devastating, such as the 2011 Tohoku, Japan earthquake and tsunami. The goal of this poster is to give a brief overview of the occurrence of tsunamis and then focus specifically on several significant tsunamis. There are various criteria to determine the most significant tsunamis: the number of deaths, amount of damage, maximum runup height, had a major impact on tsunami science or policy, etc. As a result, descriptions will include some of the most costly (2011 Tohoku, Japan), the most deadly (2004 Sumatra, 1883 Krakatau), and the highest runup ever observed (1958 Lituya Bay, Alaska). The discovery of the Cascadia subduction zone as the source of the 1700 Japanese "Orphan" tsunami and a future tsunami threat to the U.S. northwest coast, contributed to the decision to form the U.S. National Tsunami Hazard Mitigation Program. The great Lisbon earthquake of 1755 marked the beginning of the modern era of seismology. Knowledge gained from the 1964 Alaska earthquake and tsunami helped confirm the theory of plate tectonics. The 1946 Alaska, 1952 Kuril Islands, 1960 Chile, 1964 Alaska, and the 2004 Banda Aceh, tsunamis all resulted in warning centers or systems being established.The data descriptions on this poster were extracted from NOAA's National Geophysical Data Center (NGDC) global historical tsunami database. Additional information about these tsunamis, as well as water level data can be found by accessing the NGDC website www.ngdc.noaa.gov/hazard/

  4. DNA barcoding of Orchidaceae in Korea.

    PubMed

    Kim, Hye Min; Oh, Sang-Hun; Bhandari, Gauri Shankar; Kim, Chan-Soo; Park, Chong-Wook

    2014-05-01

    Species of Orchidaceae are under severe threat of extinction mainly due to overcollection and habitat destruction; accurate identification of orchid species is critical in conservation biology and sustainable utilization of orchids as plant resources. We examined 647 sequences of the cpDNA regions rbcL, matK, atpF-atpH IGS, psbK-psbI IGS and trnH-psbA IGS from 89 orchid species (95 taxa) and four outgroup taxa to develop an efficient DNA barcode for Orchidaceae in Korea. The five cpDNA barcode regions were successfully amplified and sequenced for all chlorophyllous taxa, but the amplification and sequencing of the same regions in achlorophyllous taxa produced variable results. psbK-psbI IGS showed the highest mean interspecific K2P distance (0.1192), followed by matK (0.0803), atpF-atpH IGS (0.0648), trnH-psbA IGS (0.0460) and rbcL (0.0248). The degree of species resolution for individual barcode regions ranged from 60.5% (rbcL) to 83.5% (trnH-psbA IGS). The degree of species resolution was significantly enhanced in multiregion combinations of the five barcode regions. Of the 26 possible combinations of the five regions, six provided the highest degree of species resolution (98.8%). Among these, a combination of atpF-atpH IGS, psbK-psbI IGS and trnH-psbA IGS, which comprises the least number of DNA regions, is the best option for barcoding of the Korean orchid species.

  5. The Growing Relationship Between South Korea and China: Consequences for North Korea

    DTIC Science & Technology

    2006-03-01

    This change has accelerated the growth of both of their already booming economies . Beyond that, it has helped propel Beijing into a pivotal role of...South Korea and China normalized relations in 1992. This change has accelerated the growth of both of their already booming economies . Beyond that...and South Korea will provide an opportunity for Pyongyang to improve its economy , thereby strengthening its standing and legitimacy internationally

  6. Total atmospheric mercury deposition in forested areas in South Korea

    NASA Astrophysics Data System (ADS)

    Han, Jin-Su; Seo, Yong-Seok; Kim, Moon-Kyung; Holsen, Thomas M.; Yi, Seung-Muk

    2016-06-01

    In this study, mercury (Hg) was sampled weekly in dry and wet deposition and throughfall and monthly in litterfall, and as it was volatilized from soil from August 2008 to February 2010 to identify the factors influencing the amount of atmospheric Hg deposited to forested areas in a temperate deciduous forest in South Korea. For this location there was no significant correlation between the estimated monthly dry deposition flux (litterfall + throughfall - wet deposition) (6.7 µg m-2 yr-1) and directly measured dry deposition (9.9 µg m-2 yr-1) likely due primarily to Hg losses from the litterfall collector. Dry deposition fluxes in cold seasons (fall and winter) were lower than in warmer seasons (spring and summer). The volume-weighted mean (VWM) Hg concentrations in both precipitation and throughfall were highest in winter, likely due to increased scavenging by snow events. Since South Korea experiences abundant rainfall in summer, VWM Hg concentrations in summer were lower than in other seasons. Litterfall fluxes were highest in the late fall to early winter, when leaves were dropped from the trees (September to November). The cumulative annual Hg emission flux from soil was 6.8 µg m-2 yr-1. Based on these data, the yearly deposition fluxes of Hg calculated using two input approaches (wet deposition + dry deposition or throughfall + litterfall) were 6.8 and 3.6 µg m-2 yr-1, respectively. This is the first reported study which measured the amount of atmospheric Hg deposited to forested areas in South Korea, and thus our results provide useful information to compare against data related to Hg fate and transport in this part of the world.

  7. Tectonic motion site survey of the National Radio Astronomy Observatory, Green Bank, West Virginia

    NASA Technical Reports Server (NTRS)

    Webster, W. J., Jr.; Allenby, R. J.; Hutton, L. K.; Lowman, P. D., Jr.; Tiedemann, H. A.

    1979-01-01

    A geological and geophysical site survey was made of the area around the National Radio Astronomy Observatory (NRAO) to determine whether there are at present local tectonic movements that could introduce significant errors to Very Long Baseline Interferometry (VLBI) geodetic measurements. The site survey consisted of a literature search, photogeologic mapping with Landsat and Skylab photographs, a field reconnaissance, and installation of a seismometer at the NRAO. It is concluded that local tectonic movement will not contribute significantly to VLBI errors. It is recommended that similar site surveys be made of all locations used for VLBI or laser ranging.

  8. Prevalence of metabolic syndrome and its related factors among North Korean refugees in South Korea: a cross-sectional study

    PubMed Central

    Kim, Yoon Jung; Lee, Yo Han; Lee, Yun Jeong; Kim, Kyeong Jin; An, Jee Hyun; Kim, Nam Hoon; Kim, Hee Young; Choi, Dong Seop; Kim, Sin Gon

    2016-01-01

    Objectives To determine the prevalence of metabolic syndrome (MetS) and its related factors among North Korean refugees (NKR) in South Korea. Design Cross-sectional study conducted using a questionnaire and anthropometric and biochemical data on NKR in South Korea. Setting Seoul, South Korea. Participants A sample of NKR who voluntarily underwent medical examinations in Anam Hospital of Korea University, Seoul, South Korea (N=708, consisting of 161 males and 547 females). To compare the prevalence of MetS, 1416 age- and gender-matched individuals from the South Korean population (SKP, at a ratio of 1:2 to NKR) were randomly selected from the fifth Korean National Health and Nutrition Examination Survey. Main outcome measures The prevalence of MetS and its related factors among NKR in South Korea and comparison with its prevalence among the general SKP. Results The prevalence of MetS among male and female NKR in South Korea was 19.7% and 17.2%, respectively. Although obesity is more prevalent in South than in North Korea, we found no difference in the prevalence of MetS between the female NKR and SKP groups (17.2% vs 16.6%, respectively; p=0.830). As regards the males, the small sample size of the NKR group yielded insufficient evidence of any difference in MetS prevalence between the NKR and SKP groups (19.7% vs 26.2%, respectively; p=0.134). We found that excess weight gain (≥5%) in South Korea was significantly associated with MetS among NKR. Conclusions The prevalence of MetS among NKR did not differ from that in the SKP group despite the lower prevalence of obesity in NKR than in the general SKP. The fact that excess weight gain in South Korea was associated with the risk of MetS suggests that public health policy makers should focus on preventing excess weight gain in NKR during resettlement in South Korea. PMID:27251685

  9. High Toxoplasma gondii Seropositivity among Brain Tumor Patients in Korea

    PubMed Central

    Jung, Bong-Kwang; Song, Hyemi; Kim, Min-Jae; Cho, Jaeeun; Shin, Eun-Hee; Chai, Jong-Yil

    2016-01-01

    Toxoplasma gondii is an intracellular protozoan that can modulate the environment of the infected host. An unfavorable environment modulated by T. gondii in the brain includes tumor microenvironment. Literature has suggested that T. gondii infection is associated with development of brain tumors. However, in Korea, epidemiological data regarding this correlation have been scarce. In this study, in order to investigate the relationship between T. gondii infection and brain tumor development, we investigated the seroprevalence of T. gondii among 93 confirmed brain tumor patients (various histological types, including meningioma and astrocytoma) in Korea using ELISA. The results revealed that T. gondii seropositivity among brain tumor patients (18.3%) was significantly (P<0.05) higher compared with that of healthy controls (8.6%). The seropositivity of brain tumor patients showed a significant age-tendency, i.e., higher in younger age group, compared with age-matched healthy controls (P<0.05). In conclusion, this study supports the close relationship between T. gondii infection and incidence of brain tumors. PMID:27180580

  10. OUTLINE OF VOCATIONAL TRAINING IN KOREA.

    ERIC Educational Resources Information Center

    Australian Dept. of Labour and National Service, Perth.

    THE POPULATION OF THE REPUBLIC OF KOREA WAS 27,184,000 IN 1963. AGRICULTURAL AND INDUSTRIAL PRODUCTION, ADVERSELY AFFECTED BY THE KOREAN WAR, HAS RECEIVED EMPHASIS THROUGH EXPORT PROMOTION, TAX REFORM, AND A STABILIZATION PROGRAM. A 6-YEAR FREE COMPULSORY EDUCATION IS SUPPLEMENTED BY "CIVIC SCHOOLS" AND "HIGHER CIVIC SCHOOLS"…

  11. Ten Years of Infrasound Observation in Korea

    NASA Astrophysics Data System (ADS)

    Lee, Hee-Il; Che, Il-Young; Kim, Tae Sung

    2010-05-01

    Over the ten years after the installation of our first seismo-acoustic array station (CHNAR) in September 1999, Korea Institute of Geoscience and Mineral Resources (KIGAM) has been continuously observing infrasound with an infrasound array network, named KIN (Korean Infrasound Network) in Korea. This network consists of seven seismo-acoustic arrays (BRDAR, KMPAR, CHNAR, YAGAR, KSGAR, ULDAR and TJIAR). The aperture size of the smallest array (KMPAR and TJIAR) is about 300m and the largest is about 1.4km. The number of acoustic gauges are between 4 (TJIAR) and 18 (YAGAR), and 1 or 5 seismometers are collocated at the center of the acoustic array. All seismic and infrasonic signals of the arrays are digitized at 40 samples/sec and transmitted to KIGAM in real time. Many interesting infrasound signals associated with different kind of anthropogenic source as well as natural one are detected by KIN. Ten years of seismo-acoustic data are analyzed by using PMCC program, and identified more than five thousand of infrasonic events and catalogued in our infrasound database. This database is used to study characteristics of seasonally dependent propagation of the infrasound wave in local scale, as well as to better understand how atmospheric condition affects the detection ratio at a specific station throughout the year. It also played a valuable role in discriminating the anthropogenic events such as the second nuclear test on 25 May 2009 in North Korea, from natural earthquakes, which is important in estimating the seismicity in Korea.

  12. Security Cooperation and Deterrence in Korea

    DTIC Science & Technology

    2013-05-23

    5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) School of Advanced Military Studies 250 Gibbon Ave. Ft...Soviet Union’s 53 Finley, The US Military Experience 1871-1982, 42. 54 Ibid., 43-44. 55 Ibid., 6. 56 Alan R. Millett, The War for Korea, 1950-1951

  13. Korea targets leadership role in physics

    NASA Astrophysics Data System (ADS)

    Durrani, Matin

    2013-11-01

    The Republic of Korea has transformed itself over the last 50 years from a nation based primarily on agriculture to a hi-tech industrial powerhouse. But now the country is seeing the importance of investing in fundamental science too, as Matin Durrani reports.

  14. Telecommunications and Data Communication in Korea.

    ERIC Educational Resources Information Center

    Ahn, Moon-Suk

    All facilities of the Ministry of Communications of Korea, which monopolizes telecommunications services in the country, are listed and described. Both domestic facilities, including long-distance telephone and telegraph circuits, and international connections are included. Computer facilities are also listed. The nation's regulatory policies are…

  15. [Gregarines from South Korea (author's transl)].

    PubMed

    Théodoridés, J; Desportes, I; Jolivet, P

    1976-01-01

    Study of 14 species of Gregarines from terrestrial arthropods (Myriapoda and Insecta) of south Korea. Some of them (Ramicephalus ozakii, Gregarina monoducta, Hoplorhynchus ozakii, Stylocephalus bahli) are typically asiatic whereas the others were already described from identical or similar european hosts.

  16. Childhood Maltreatment in South Korea: Retrospective Study

    ERIC Educational Resources Information Center

    Lee, Yanghee; Kim, Sangwon

    2011-01-01

    Objective: This study explored the prevalence of childhood maltreatment in South Korea using the retrospective version of ICAST and the associations between perceptions of abuse experienced during childhood and recent interpersonal problems and depression. Methods: 539 young persons, aged 18-24 years, from various universities, work places, and…

  17. Crisis and Employment: The Case of Korea

    ERIC Educational Resources Information Center

    Cho, Dongchul; Shin, Sukha

    2012-01-01

    This paper examines Korea's employment dynamics and analyzes how adverse impacts could be mitigated during the recent economic crisis in comparison with the 1997 to 1998 Asian crisis. A clear lesson is that policies to mitigate adverse impacts of financial crisis on the macroeconomic level should be given priority for preserving employment. In…

  18. The Quality of Life in South Korea

    ERIC Educational Resources Information Center

    Park, Chong-Min

    2009-01-01

    The AsiaBarometer survey of 1,023 respondents shows Life in Korea is highly modernized and digitalized without being much globalized. Despite the modernization and digitalization of their lifestyles, ordinary citizens still prioritize materialistic values more than post-materialistic values, and they remain least satisfied in the material life…

  19. 75 FR 67912 - North Korea Sanctions Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-04

    ...] [Pages 67912-67918] [FR Doc No: 2010-27829] DEPARTMENT OF THE TREASURY Office of Foreign Assets Control 31 CFR Part 510 North Korea Sanctions Regulations AGENCY: Office of Foreign Assets Control, Treasury. ACTION: Final rule. SUMMARY: The Department of the Treasury's Office of Foreign Assets Control...

  20. Incidence of hip fractures in Korea.

    PubMed

    Lim, Soo; Koo, Bo Kyeong; Lee, Eun Jung; Park, Jin Ho; Kim, Myoung Hee; Shin, Kun Hong; Ha, Yong Chan; Cho, Nam Han; Shin, Chan Soo

    2008-01-01

    Osteoporosis is a major public health problem in both Western and Asian populations. Because the aged population in Korea is increasing, the number of osteoporotic fractures is thought to be also increasing. However, there has been no nationwide analysis of osteoporotic fractures in Korea. We analyzed the incidence and cost of hip fracture from 2001 to 2004 by using data from the Health Insurance Review Agency, Korea. In the over 50 years age group, the number of hip fractures in women increased from 250.9/100,000 persons in 2001 to 262.8/100,000 in 2004, a 4.7% increase. However, that in men decreased from 162.8/100,000 in 2001 to 137.5/100,000 in 2004, a 15.5% decrease. Direct medical care costs of hip fracture increased from $62,707,697 in 2001 to $65,200,035 in 2004, and the proportional cost of hip fractures in the national medical costs increased by 4.5% over 4 years (from 0.200% in 2001 to 0.209% in 2004). On analysis of the population-based data obtained from the whole country from 2001 to 2004, the incidence rate of hip fractures in women, not in men, and its cost have increased in Korea. The gender distribution of hip fractures underlines the need for aggressive intervention in osteoporosis in elderly women.

  1. English Textbooks in Japan and Korea

    ERIC Educational Resources Information Center

    Yuasa, Katsura

    2010-01-01

    English education in Japan and Korea are similar in some respects. Although both countries are not completely but mostly monolingual societies, where citizens do not need English in their daily life, they have begun to realize the importance of English as a tool for international communication, and as a result their English education is becoming…

  2. Paraquat prohibition and change in the suicide rate and methods in South Korea.

    PubMed

    Myung, Woojae; Lee, Geung-Hee; Won, Hong-Hee; Fava, Maurizio; Mischoulon, David; Nyer, Maren; Kim, Doh Kwan; Heo, Jung-Yoon; Jeon, Hong Jin

    2015-01-01

    The annual suicide rate in South Korea is the highest among the developed countries. Paraquat is a highly lethal herbicide, commonly used in South Korea as a means for suicide. We have studied the effect of the 2011 paraquat prohibition on the national suicide rate and method of suicide in South Korea. We obtained the monthly suicide rate from 2005 to 2013 in South Korea. In our analyses, we adjusted for the effects of celebrity suicides, and economic, meteorological, and seasonal factors on suicide rate. We employed change point analysis to determine the effect of paraquat prohibition on suicide rate over time, and the results were verified by structural change analysis, an alternative statistical method. After the paraquat prohibition period in South Korea, there was a significant reduction in the total suicide rate and suicide rate by poisoning with herbicides or fungicides in all age groups and in both genders. The estimated suicide rates during this period decreased by 10.0% and 46.1% for total suicides and suicides by poisoning of herbicides or fungicides, respectively. In addition, method substitution effect of paraquat prohibition was found in suicide by poisoning by carbon monoxide, which did not exceed the reduction in the suicide rate of poisoning with herbicides or fungicides. In South Korea, paraquat prohibition led to a lower rate of suicide by paraquat poisoning, as well as a reduction in the overall suicide rate. Paraquat prohibition should be considered as a national suicide prevention strategy in developing and developed countries alongside careful observation for method substitution effects.

  3. Isolation and genetic characterization of H5N2 influenza viruses from pigs in Korea.

    PubMed

    Lee, Jun Han; Pascua, Philippe Noriel Q; Song, Min-Suk; Baek, Yun Hee; Kim, Chul-Joong; Choi, Hwan-Woon; Sung, Moon-Hee; Webby, Richard J; Webster, Robert G; Poo, Haryoung; Choi, Young Ki

    2009-05-01

    Due to dual susceptibility to both human and avian influenza A viruses, pigs are believed to be effective intermediate hosts for the spread and production of new viruses with pandemic potential. In early 2008, two swine H5N2 viruses were isolated from our routine swine surveillance in Korea. The sequencing and phylogenetic analysis of surface proteins revealed that the Sw/Korea/C12/08 and Sw/Korea/C13/08 viruses were derived from avian influenza viruses of the Eurasian lineage. However, although the Sw/Korea/C12/08 isolate is an entirely avian-like virus, the Sw/Korea/C13/08 isolate is an avian-swine-like reassortant with the PB2, PA, NP, and M genes coming from a 2006 Korean swine H3N1-like virus. The molecular characterization of the two viruses indicated an absence of significant mutations that could be associated with virulence or binding affinity. However, animal experiments showed that the reassortant Sw/Korea/C13/08 virus was more adapted and was more readily transmitted than the purely avian-like virus in a swine experimental model but not in ferrets. Furthermore, seroprevalence in swine sera from 2006 to 2008 suggested that avian H5 viruses have been infecting swine since 2006. Although there are no known potential clinical implications of the avian-swine reassortant virus for pathogenicity in pigs or other species, including humans, at present, the efficient transmissibility of the swine-adapted H5N2 virus could facilitate virus spread and could be a potential model for pandemic, highly pathogenic avian influenza (e.g., H5N1 and H7N7) virus outbreaks or a pandemic strain itself.

  4. Initiation of plate tectonics from post-magma ocean thermo-chemical convection

    NASA Astrophysics Data System (ADS)

    Foley, B. J.; Bercovici, D. A.

    2013-12-01

    also the possibility of chemical differentiation which would lead to an initially unstable compositional density profile in the newly solidified mantle. We thus perform numerical models with an initially unstable temperature profile (approximating the silicate solidus) both with and without an initially unstable compositional density profile. All models show an initial overturn beneath a stagnant lid, followed by stagnant lid convection and the eventual onset of plate tectonic style convection. The timescale for initiating plate tectonics depends on the Rayleigh number, parameters for healing and damage, and on the degree of chemical differentiation during magma ocean solidification. Similar to the results of the scaling analysis, higher surface temperature retards the initiation of plate tectonics, due to the effects of lithospheric healing. Compositional buoyancy significantly reduces the timescale for initiating plate tectonics due to the increased negative buoyancy of the lithosphere (i.e. including both thermal and chemical buoyancy). Thus chemical differentiation during magma ocean solidification provides a significant boost to initiating plate tectonics in the Hadean Earth.

  5. Archean collisional tectonics in SW Montana

    SciTech Connect

    Mogk, D.; Rickmond, D.; Salt, K.; Clark, M.; Mueller, P.; Lafrenze, D.; Wooden, J.; Henry, D.

    1985-01-01

    The Archean continental crust of SW Montana evolved through alternating cycles of stable platform sedimentation followed by crustal thickening through collisional tectonics. The ancient sialic crust in the Beartooth Mountains served as the nucleus for accretion of younger terranes to the west. The oldest orogenic cycle recognized in the Beartooth Mountains involves a 3.4 Ga old supracrustal sequence which was metamorphosed in the granulite facies (T=700-800/sup 0/C, P=6Kb, 35/sup 0/C/Km); deep burial is interpreted as the result of collisional tectonic thickening. The second orogenic cycle is subduction related and has produced 2.8 Ga old andesites, 2.75 Ga old calc-alkaline intrusives, upper amphibolite grade metamorphism, transcurrent faulting (in the North Snowy Block and Yankee Jim canyon at 2.8 Ga) and nappe emplacement. In the central Beartooths post-orogenic granites intrude pelitic schists (T=600/sup 0/C, P=8Kb, 25/sup 0/C/Km). West of the Beartooths the basement consists of 2.75-2.70 Ga old, tectonically telescoped coarse clastics (Gallatin, Madison Ranges) and stable platform sequences (Gravelly, Tobacco Root, Ruby Ranges). Nappe formation and granulite-migmatite (700-750/sup 0/C) associations are common, suggesting deep burial through tectonic thickening. A later-kinematic mesozonal (8Kb) qtz diorite-granodiorite batholithic complex is present in the northern Madison Range. Quartzofeldspathic paragneisses in the westernmost Archean basement are derived from either a continental or island arc source.

  6. Laboratory plate tectonics: a new experiment.

    PubMed

    Gans, R F

    1976-03-26

    A "continent" made of a layer of hexagonally packed black polyethylene spheres floating in clear silicon oil breaks into subcontinents when illuminated by an ordinary incandescent light bulb. This experiment may be a useful model of plate tectonics driven by horizontal temperature gradients. Measurements of the spreading rate are made to establish the feasibility of this model.

  7. Plate Tectonics and Continental Drift: Classroom Ideas.

    ERIC Educational Resources Information Center

    Stout, Prentice K.

    1983-01-01

    Suggests various classroom studies related to plate tectonics and continental drift, including comments on and sources of resource materials useful in teaching the topics. A complete list of magazine articles on the topics from the Sawyer Marine Resource Collection may be obtained by contacting the author. (JN)

  8. Plate tectonics of the Mediterranean region.

    PubMed

    McKenzie, D P

    1970-04-18

    The seismicity and fault plane solutions in the Mediterranean area show that two small rapidly moving plates exist in the Eastern Mediterranean, and such plates may be a common feature of contracting ocean basins. The results show that the concepts of plate tectonics apply to instantaneous motions across continental plate boundaries.

  9. Cenozoic rift tectonics of the Japan Sea

    SciTech Connect

    Kimura, K.

    1988-08-01

    The Japan Sea is one of the back-arc basins in trench-arc systems bordering the western Pacific. Recent paleomagnetic works suggest the Japan Sea opened during early to middle Miocene. Radiometric and microfossil ages of the Cenozoic onland sequences in the Japanese Islands elucidate the rift tectonics of the Japan Sea. The rifting history is summarized as follows: nonmarine volcanic formations of prerift stage before 50 Ma, rift-onset unconformity at 40 Ma, nonmarine volcanic formations of synrift stage 20-33 Ma, breakup unconformity 19 Ma showing the opening of the Japan Sea, marine volcanic and sedimentary formations of synrift stage 14.5-18 Ma, beginning of regional subsidence 14.5 Ma corresponding to the end of the Japan Sea opening, marine sedimentary formations of postdrift stage after 14.5 Ma. Rifting is not limited to the synrift stage but is continued to the syndrift stage. Rifting led to a horst-and-graben structure. Thus, the Cenozoic onland sequences in the Japanese Islands are suited for a study of rift tectonics because the sequences were subaerially exposed by the late Miocene-Holocene island-arc tectonics. Rift tectonics cannot be studied as easily in most Atlantic-type passive margins.

  10. Tectonic evolution of the terrestrial planets.

    PubMed

    Head, J W; Solomon, S C

    1981-07-03

    The style and evolution of tectonics on the terrestrial planets differ substantially. The style is related to the thickness of the lithosphere and to whether the lithosphere is divided into distinct, mobile plates that can be recycled into the mantle, as on Earth, or is a single spherical shell, as on the moon, Mars, and Mercury. The evolution of a planetary lithosphere and the development of plate tectonics appear to be influenced by several factors, including planetary size, chemistry, and external and internal heat sources. Vertical tectonic movement due to lithospheric loading or uplift is similar on all of the terrestrial planets and is controlled by the local thickness and rheology of the lithosphere. The surface of Venus, although known only at low resolution, displays features both similar to those on Earth (mountain belts, high plateaus) and similar to those on the smaller planets (possible impact basins). Improved understanding of the tectonic evolution of Venus will permit an evaluation of the relative roles of planetary size and chemistry in determining evolutionary style.

  11. Appendix C: Summary of Major Metallogenic Belts in Northeast Asia (the Russian Far East, Yakutia, Siberia, Transbaikalia, Northern China, Mongolia, South Korea, and Japan)

    USGS Publications Warehouse

    Rodionov, Sergey M.; Obolenskiy, Alexander A.; Distanov, Elimir G.; Badarch, Gombosuren; Dejidmaa, Gunchin; Hwang, Duk-Hwan; Khanchuk, Alexander I.; Ogasawara, Masatsugu; Nokleberg, Warren J.; Parfenov, Leonid M.; Prokopiev, Andrei V.; Seminskiy, Zhan V.; Smelov, Alexander P.; Yan, Hongquan; Davydov, Yuriy V.V.; Fridovskiy, Valeriy Yu.; Gamyanin, Gennandiy N.; Gerel, Ochir; Kostin, Alexei V.; Letunov, Sergey A.; Li, Xujun; Nikitin, Valeriy M.; Ratkin, Vladimir V.; Shpikerman, Vladimir I.; Sudo, Sadahisa; Sotnikov, Vitaly I.; Spiridonov, Alexander V.; Stepanov, Vitaly A.; Sun, Fengyue; Sun, Jiapeng; Sun, Weizhi; Supletsov, Valeriy M.; Timofeev, Vladimir F.; Tyan, Oleg A.; Vetluzhskikh, Valeriy G.; Wakita, Koji; Yakovlev, Yakov V.; Zorina, Lydia M.

    2010-01-01

    The major purposes of this chapter are to provide (1) an overview of the regional geology, tectonics, and metallogenesis of Northeast Asia for readers who are unfamiliar with the region, (2) a general scientific introduction to the succeeding chapters of this volume, and (3) an overview of the methodology of metallogenic and tectonic analysis used in this study. We also describe how a high-quality metallogenic and tectonic analysis, including construction of an associated metallogenic-tectonic model will greatly benefit other mineral resource studies, including synthesis of mineral-deposit models; improve prediction of undiscovered mineral deposit as part of a quantitative mineral-resource-assessment studies; assist land-use and mineral-exploration planning; improve interpretations of the origins of host rocks, mineral deposits, and metallogenic belts, and suggest new research. Research on the metallogenesis and tectonics of such major regions as Northeast Asia (eastern Russia, Mongolia, northern China, South Korea, and Japan) and the Circum-North Pacific (the Russian Far East, Alaska, and the Canadian Cordillera) requires a complex methodology including (1) definitions of key terms, (2) compilation of a regional geologic base map that can be interpreted according to modern tectonic concepts and definitions, (3) compilation of a mineral-deposit database that enables a determination of mineral-deposit models and clarification of the relations of deposits to host rocks and tectonic origins, (4) synthesis of a series of mineral-deposit models that characterize the known mineral deposits and inferred undiscovered deposits in the region, (5) compilation of a series of metallogenic-belt belts constructed on the regional geologic base map, and (6) construction of a unified metallogenic and tectonic model. The summary of regional geology and metallogenesis presented here is based on publications of the major international collaborative studies of the metallogenesis and

  12. Tectonic asymmetry of the earth and other planets

    NASA Technical Reports Server (NTRS)

    Pushcharovskiy, Y. M.; Kozlov, V. V.; Sulidi-Kondratyev, Y. D.

    1978-01-01

    The structures of Earth, Mars, Venus, and the Moon are examined and compared. Global tectonic characteristics are presented for each. A comparison of the tectonics reveals the structural asymetry of these planets and the moon. Tectonic asymmetry information for the group is used to interpret certain aspects of the earth's geological past.

  13. Post-rift geodynamics of the Songliao Basin, NE China: Origin and significance of T11 (Coniacian) unconformity

    NASA Astrophysics Data System (ADS)

    Song, Ying; Ren, Jianye; Stepashko, Andrei A.; Li, Jianguo

    2014-11-01

    The T11 unconformity lies between the Qingshankou and Yaojia Formations in the post-rifting sequence of the Cretaceous Songliao Basin, NE China. It is intimately associated with petroleum reservoirs and considered to be a disconformity forming in the tectonic quiet stage. We present the interpretations from new seismic surveys and cored sections of the Cretaceous Continental Scientific Drilling borehole (CCSD-SK-1) in order to resolve the nature and origin of T11 unconformity. The T11 is often a low-angle unconformity with underlying Qingshankou Formation having been deformed and eroded prior to deposition of the Yaojia Formation. In the post-rift evolution of the basin it marks an abrupt change from a deep lake to shallow lake or subaerial environment, documented by reddening of the lacustrine mudstone, extinction of the ostracod assemblages and a great increase of coarse detrital inputs. The sharp change of depositional environment, the truncation of gentle folds and the cluster of volcanic and paleoearthquake activities, all happened simultaneously, immediately before the development of T11 unconformity, indicating a significant regional compressional uplift event in the basin. The timing of the T11 unconformity formation is within the interval 88-86.2 Ma. Correlations with coeval unconformities in other Cretaceous sedimentary basins in eastern Asia indicate that this compressional uplift coincided with an episode of global plate reorganization between the Eurasian and Paleo-Pacific plates that culminated at 88-87 Ma. During this short interval the northeast Asian margin, in eastern China, South Korea, Japan and Russian Far East experienced widespread violent volcanic and granite emplacement activity triggered by compression resulting from rapid and orthogonal slab subduction. The post-rift basin tectonic inversion occurred during T11 (Coniacian) time; thereafter the basin again evolved in an extension regime. Two subsidence phases in post-rift history took

  14. Tectonic evolution and paleogeography of Europe

    SciTech Connect

    Yilmaz, P.O.; Norton, I.O.; Chuchla, R.J. ); Leary, D.A. )

    1993-09-01

    The goal of this study was to use the tectonic framework of European craton to constrain our understanding of the sedimentary basins of Europe. An understanding of the amalgamation of the crustal blocks of Europe during the Caledonian, Hercynian, and Alpine orogenies was accomplished using an Evans and Sutherland system. Paleogeographic maps were ;made and integrated with the plate reconstruction with an eye toward how regional plate-scale events affect play elements in the basins. Europe is an artifact of Phanerozoic tectonic history, an amalgamation of crustal blocks without a precambrian nucleus of it own. This is in direct contrast of Africa, Asia, and North America. Multiple riftings and collisions created extremely complex mountain building during the Caledonian, Hercynian, Cimmerian, and Alpine orogenies. Basins are diverse, superimposed, and have long-lived tectonic histories with complex structuring and highly variable play elements. The Hercynian orogene set up the framework for northern European hydrocarbon systems. Its collapse set up the Apulian Mesozoic hydrocarbon system. Alpine deformation and tectonically related extension in turn set up the Neogene hydrocarbon systems of the Carpathians Pannonian basin and the Apennines. Eleven paleogeographic maps were completed at a scale of 1:5,000,000. There are four for the Paleozoic to show the Hercynian orogeny and its subsequent foredeeps, and four for the Mesozoic, showing Tethyan rifting and associated subsidence, as well as the Cimmerian orogenies and start of Alpine deformation. The three time slices in the Cenozoic show the Alpine orogene and its foredeeps and the tectonically related extensional basins.

  15. Tectonic Evolution of the Jurassic Pacific Plate

    NASA Astrophysics Data System (ADS)

    Nakanishi, M.; Ishihara, T.

    2015-12-01

    We present the tectonic evolution of the Jurassic Pacific plate based on magnetic anomly lineations and abyssal hills. The Pacific plate is the largest oceanic plate on Earth. It was born as a microplate aroud the Izanagi-Farallon-Phoenix triple junction about 192 Ma, Early Jurassic [Nakanishi et al., 1992]. The size of the Pacific plate at 190 Ma was nearly half that of the present Easter or Juan Fernandez microplates in the East Pacific Rise [Martinez et at, 1991; Larson et al., 1992]. The plate boundary surrounding the Pacific plate from Early Jurassic to Early Cretaceous involved the four triple junctions among Pacific, Izanagi, Farallon, and Phoenix plates. The major tectonic events as the formation of oceanic plateaus and microplates during the period occurred in the vicinity of the triple junctions [e.g., Nakanishi and Winterer, 1998; Nakanishi et al., 1999], implying that the study of the triple junctions is indispensable for understanding the tectonic evolution of the Pacific plate. Previous studies indicate instability of the configuration of the triple junctions from Late Jurassic to Early Cretaceous (155-125 Ma). On the other hand, the age of the birth of the Pacific plate was determined assuming that all triple junctions had kept their configurations for about 30 m.y. [Nakanishi et al., 1992] because of insufficient information of the tectonic history of the Pacific plate before Late Jurassic.Increase in the bathymetric and geomagnetic data over the past two decades enables us to reveal the tectonic evolution of the Pacific-Izanagi-Farallon triple junction before Late Jurassic. Our detailed identication of magnetic anomaly lineations exposes magnetic bights before anomaly M25. We found the curved abyssal hills originated near the triple junction, which trend is parallel to magnetic anomaly lineations. These results imply that the configuration of the Pacific-Izanagi-Farallon triple junction had been RRR before Late Jurassic.

  16. Reorientation and Tectonic Patterns of Enceladus

    NASA Astrophysics Data System (ADS)

    Matsuyama, Isamu; Nimmo, F.

    2007-10-01

    The global scale tectonic pattern on Enceladus has been interpreted as due to a rotation rate increase, although no mechanism for doing so is known (Porco et al. 2006). We consider an alternative explanation: reorientation of the rotation poles with respect to Enceladus’ surface. Geological observations of equatorial features that resemble the polar "tiger stripes” tectonic features support this scenario (Helfenstein et al. 2006) which is physically plausible, either due to the rise of a hot plume (Nimmo and Pappalardo 2006) or variations in ice shell thickness (Ojakangas and Stevenson 1989). We find solutions for the stresses associated with triaxial distortions due to reorientation and/or despinning of a tidally deformed satellite. Following the analysis of Melosh (1977), we then predict the tectonic pattern due to different geometries for the reorientation of the rotation and tidal axes, and rotation rate variations. The observed N-S trending fractures in the leading hemisphere, which appear to have formed in response to E-W trending extensional stresses, and the circumpolar south polar terrain boundary at 55° S latitude, which seems to have formed in response to N-S trending compressional stresses (Porco et al. 2006), is more easily explained by a large reorientation ( 90°) of the rotation axis, rather than by a rotation rate increase. If Enceladus has a subsurface Ocean, cooling ultimately leads to expansion due to the water-ice volume change (Nimmo 2004). The predicted tectonic pattern due to the combination of large reorientation and a small radius expansion ( 10-3 %) is also in good agreement with the observed tectonic features. The predicted normal faulting province in the trailing hemisphere and circumpolar thrust faulting province around the north pole have not been observed, perhaps because of contrasts between the mechanical nature of the northern and southern polar regions due to degree-one convection or other unknown processes.

  17. Structure and Particle Size Distribution of Non-tectonic Faults - Difference from Tectonic Faults

    NASA Astrophysics Data System (ADS)

    Yamasaki, S.; Chigira, M.

    2009-04-01

    Non-tectonic faults are commonly formed by mass movements but their structures and formative processes have been scarcely studied in spite of their importance in slope development and slope stability. We observed structures of non-tectonic faults and analyzed particle size distribution of the material from the shear zones of non-tectonic faults and compared these results with those of tectonic faults. We clarified the structures of non-tectonic faults in pelitic schist by observing X-ray computer tomography images and cross-sections of paraffin-impregnated core samples that have been recovered from the subsurface by the hybrid drilling technique. We identified structures at various stages of non-tectonic fault development. Shearing within black layers, which are rich in graphite, dominates at an incipient stage. Then, rotation, fracturing, and pulverization of rock proceed, forming breccias and fine fractions in a fracture zone. Fracture zone at an early stage have many open fractures, which indicates a low confining pressure during deformation. With the development of a fracture zone, open fractures decrease and fine fractions increase in amount. Finally shearing deformation would be dominated by cataclastic flow in fine fractions. This stage is at a mature stage, where the structure becomes very similar to that of tectonic faults so that it cannot be distinguished from a tectonic fault by structure only. However, particle size distribution could indicate the formative condition of fine fractions in a fracture zone. We sampled "gauge" from several mature fracture zones in two landslide sites of pelitic schist, and analyzed their particle size distributions from 20 nm to 1 mm by using a laser diffraction particle size analyzer. The ultra micro particles in the fracture zone of a non-tectonic fault can be assumed to be primary particles which are less affected by alteration, and their particle size distributions could reflect the conditions of fracturing. The

  18. 76 FR 76146 - Large Power Transformers From the Republic of Korea: Postponement of Preliminary Determination of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-06

    ... International Trade Administration Large Power Transformers From the Republic of Korea: Postponement of... transformers from the Republic of Korea (Korea). See Large Power Transformers from the Republic of Korea... petitioners to the Department, entitled ``Large Power Transformers from the Republic of Korea--...

  19. Trends in Suicide Methods and Rates among Older Adults in South Korea: A Comparison with Japan

    PubMed Central

    Park, Subin; Lee, Hochang Benjamin; Lee, Su Yeon; Lee, Go Eun; Ahn, Myung Hee; Yi, Ki Kyoung

    2016-01-01

    Objective Lethality of the chosen method during a suicide attempt is a strong risk factor for completion of suicide. We examined whether annual changes in the pattern of suicide methods is related to annual changes in suicide rates among older adults in South Korea and Japan. Methods We analyzed annual the World Health Organization data on rates and methods of suicide from 2000 to 2011 in South Korea and Japan. Results For Korean older adults, there was a significant positive correlation between suicide rate and the rate of hanging or the rate of jumping, and a significant negative correlation between suicide rate and the rate of poisoning. Among older adults in Japan, annual changes in the suicide rate and the pattern of suicide methods were less conspicuous, and no correlation was found between them. Conclusion The results of the present study suggest that the increasing use of lethal suicide methods has contributed to the rise in suicide rates among older adults in South Korea. Targeted efforts to reduce the social acceptability and accessibility of lethal suicide methods might lead to lower suicide rate among older adults in South Korea. PMID:27081378

  20. The alternative concept of global tectonics

    NASA Astrophysics Data System (ADS)

    Anokhin, Vladimir; Kholmyansky, Mikhael

    2016-04-01

    The existing plate tectonic paradigm becomes more questionable in relation to the new facts of the Earth. The most complete to date criticism of plate tectonics provisions contained in the article (Pratt, 2000). Authors can recall a few facts that contradict the idea of long-range movement of plates: - The absence of convection cells in the mantle, detected by seismic tomography; - The presence of long-lived deep regmatic network in the crust, not distorted by the movement of plates; - The inability of linking the global geometry of the of mutual long-distance movement of plates. All this gives reason to believe that correct, or at least a satisfactory concept of global tectonics are not exist now. After overcoming the usual inertia of thinking the plate paradigm in the foreseeable future will replace by different concept, more relevant as the observable facts of the Earth and the well-known physical laws. The authors suggest that currently accumulated sufficient volume of facts and theoretical ideas for the synthesis of a new general hypothesis of the structure and dynamics of the Earth. Analysis of the existing tectonic theory suggests that most of their provisions are mutually compatible. Obviously, plume tectonics perfectly compatible with any of classical models. It contradicts the only plate tectonics (movement of hot spots in principle not linked either with each other or with the general picture of the plate movements, the presence of mantle convection and mantle streams are mutually exclusive, and so on). The probable transfer of the heated material down up within the Earth may occur in various forms, the simplest of which (and, consequently, the most probable) are presented plumes. The existence in the mantle numerous large volumes of decompressed substances (detected seismic tomography), can be correlated with the bodies of plumes at different stages of uplift. Plumes who raise to the bottom of the lithosphere, to spread out to the sides and form a set

  1. LOWLID FORMATION AND PLATE TECTONICS ON EXOPLANETS

    NASA Astrophysics Data System (ADS)

    Stamenkovic, V.; Noack, L.; Breuer, D.

    2009-12-01

    The last years of astronomical observation have opened the doors to a universe filled with extrasolar planets. Detection techniques still only offer the possibility to detect mainly Super-Earths above five Earth masses. But detection techniques do steadily improve and are offering the possibility to detect even smaller planets. The observations show that planets seem to exist in many possible sizes just as the planets and moons of our own solar system do. It is only a natural question to ask if planetary mass has an influence on some key habitability factors such as on plate tectonics, allowing us to test which exoplanets might be more likely habitable than others, and allowing us to understand if plate tectonics on Earth is a stable or a critical, instable process that could easily be perturbed. Here we present results derived from 1D parameterized thermal evolution and 2D/3D computer models, showing how planetary mass influences the propensity of plate tectonics for planets with masses ranging from 0.1 to 10 Earth masses. Lately [2, 3] studied the effect of planetary mass on the ability to break plates and hence initiate plate tectonics - but both derived results contradictory to the other. We think that one of the reasons why both studies [2, 3] are not acceptable in their current form is partly due to an oversimplification. Both treated viscosity only temperature-dependent but neglected the effect pressure has on enlarging the viscosity in the deep mantle. More massive planets have therefore a stronger pressure-viscosity-coupling making convection at high pressures sluggish or even impossible. For planets larger than two Earth masses we observe that a conductive lid (termed low-lid) forms above the core-mantle boundary and thus reduces the effective convective part of the mantle when including a pressure-dependent term into the viscosity laws as shown in [1]. Moreover [2, 3] use time independent steady state models neglecting the fact that plate tectonics is a

  2. Infection status of dragonflies with Plagiorchis muris metacercariae in Korea.

    PubMed

    Hong, S J; Woo, H C; Lee, S U; Huh, S

    1999-06-01

    Plagiorchis muris has been found in both house and field rats as well as in humans. The infection status of the second intermediate hosts of P. muris is prerequisite in understanding their biological features in an ecosystem. Six species of dragonflies were caught in a wide range of areas in Korea; and they were Sympetrum darwinianum, S. eroticum, S. pedomontanum, S. infuscatum, Pantala flavoscens, Calopteryx atrata, and Orthetrum albistylum speciosum. The occurrence of P. muris metacercariae in dragonflies was nationwide with various infection rates. The metacercarial burden of P. muris in the surveyed areas was the highest in S. eroticum followed by S. darwinianum, S. pedomontanum, and C. atrata. The highest infection rate by P. muris metacercariae was found in S. darwinianum followed by S. eroticum. The metacercarial burden was particularly heavy in the dragonflies found in Hamyang-gun and Kosong-gun, Kyongsangnam-do. It is, therefore, likely that dragonflies play a significant role as the second intermediate host in the life cycle of P. muris in Korea.

  3. Infection status of dragonflies with Plagiorchis muris metacercariae in Korea

    PubMed Central

    Woo, Ho-Chun; Lee, Soo-Ung; Huh, Sun

    1999-01-01

    Plagiorchis muris has been found in both house and field rats as well as in humans. The infection status of the second intermediate hosts of P. muris is prerequisite in understanding their biological features in an ecosystem. Six species of dragonflies were caught in a wide range of areas in Korea; and they were Sympetrum darwinianum, S. eroticum, S. pedomontanum, S. infuscatum, Pantala flavoscens, Calopteryx atrata, and Orthetrum albistylum speciosum. The occurrence of P. muris metacercariae in dragonflies was nationwide with various infection rates. The metacercarial burden of P. muris in the surveyed areas was the highest in S. eroticum followed by S. darwinianum, S. pedomontanum, and C. atrata. The highest infection rate by P. muris metacercariae was found in S. darwinianum followed by S. eroticum. The metacercarial burden was particularly heavy in the dragonflies found in Hamyang-gun and Kosong-gun, Kyongsangnam-do. It is, therefore, likely that dragonflies play a significant role as the second intermediate host in the life cycle of P. muris in Korea. PMID:10388263

  4. Current Status of Bariatric and Metabolic Surgery in Korea

    PubMed Central

    2016-01-01

    Bariatric surgery is considered to be the most effective treatment modality in maintaining long-term weight reduction and improving obesity-related conditions in morbidly obese patients. In Korea, surgery for morbid obesity was laparoscopic sleeve gastrectomy first performed in 2003. Since 2003, the annual number of bariatric surgeries has markedly increased, including adjustable gastric banding (AGB), Roux-en-Y gastric bypass, sleeve gastrectomy, mini-gastric bypass, and others. In Korea, AGB is much more common than in others countries. A large proportion of doctors, the public, and government misunderstand the necessity and effectiveness of bariatric surgery, believing that bariatric surgery has an unacceptably high morbidity, and that it is not superior to non-surgical treatments to improve obesity and obesity-related diseases. The effectiveness, safety, and cost-effectiveness of bariatric surgery have been well demonstrated. The Korean Society of Metabolic and Bariatric Surgery recommend bariatric surgery confining to morbidly obese patients (body mass index ≥40 or >35 in the presence of significant comorbidities). PMID:27834081

  5. Job and life satisfaction of nonstandard workers in South Korea.

    PubMed

    Lee, Bokim

    2013-08-01

    Since the South Korean financial crisis of the late 1990s, the number of nonstandard workers in South Korea has increased rapidly. With such a drastic change, it has been difficult to establish national welfare systems (e.g., accident insurance or support for families with dependent children) for nonstandard workers and identify critical aspects of their health. To evaluate job and life satisfaction among nonstandard workers, this study used a representative sample of South Koreans. Using data from the 2008 Korean Labor and Income Panel Study, the sample size totaled 4,340 observations, of which 1,344 (31.0%) involved nonstandard workers. Significant differences in job and life satisfaction between nonstandard workers and standard workers were found. The results also indicate discrimination in the welfare and fringe benefit systems in South Korea. Occupational health nurses must address the physical and psychological health issues, personal problems, and everyday life concerns of nonstandard workers. Given that the employment status of nonstandard workers in companies is generally unstable, it is difficult for these workers to report poor working conditions to employers or other authorities. Accordingly, occupational health nurses should advocate for nonstandard workers by notifying employers of the many problems they face.

  6. Geochemistry of the early Cretaceous Gunbuk-Jindong granitoids in the Gyeongsang basin, South Korea

    NASA Astrophysics Data System (ADS)

    Wee, Soo-Meen

    2014-05-01

    The Gunbuk-Jindong granitoids are located in the southwestern part of the Gyeongsang Basin in South Korea. The granitoids consists of gabbro, quartz diorite, granodiorite and granite that are intruded into Cretaceous sedimentary rocks of the Jindong formation. Gunbuk granitoids exhibit relatively high Al2O3,MgO, Cr and Sr contents, high Sr/Y and La/Yb ratios, but low Y and Yb contents, similar to adakites produced by slab melting associated with ridge subduction. In contrast, the Jindong granitoids have low Sr and high Y contents and are typical of calc-alkaline I-type granitoids. The Rb-Sr isotopic age of 97.0±8.4Ma with an initial Sr ratio of 0.7046 recommend that the magma has mantle signature and intruded during Early Cretaceous. The geochemical and tectonic features reveal that adakite-like signatures of the Gunbuk granitoids were generated by the interaction of slab-derived adakitic melts(caused by the thermal effect of ridge subduction) and mantle peridotite. The Gunbuk granitoids have similar geochemical characteristics, paleotectonic environments and intrusion ages to those of the Shiraishino granodiorites of Kyushu Island and the Tamba granitoids of San'yo belt located on southwestern Japanese arc. Chondrite normalized REE patterns show generally enriched LREEs and slight negative to flat Eu anomalies. On the ANK vs. A/CNK and tectonic discrimination diagrams, parental magma type of the granites corresponds to I-type and volcanic arc granite(VAG). Interpretations of the chemical characteristics of the granitic rocks favor their emplacement in a compressional tectonic regime at continental margin during the subduction of the Izanagi plate beneath the northeastern part of the Eurasian plate.

  7. Geochemistry of the Early Cretaceous Gunbuk-Jindong granitoids in the Gyeongsang basin, South Korea

    NASA Astrophysics Data System (ADS)

    Wee, S. M.

    2013-12-01

    The Gunbuk-Jindong granitoids are located in the southwestern part of the Gyeongsang Basin in South Korea. The granitoids consists of gabbro, quartz diorite, granodiorite and granite that are intruded into Cretaceous sedimentary rocks of the Jindong formation. Gunbuk granitoids exhibit relatively high Al2O3, MgO, Cr and Sr contents, high Sr/Y and La/Yb ratios, but low Y and Yb contents, similar to adakites produced by slab melting associated with ridge subduction. In contrast, the Jindong granitoids have low Sr and high Y contents and are typical of calc-alkaline I-type granitoids. The Rb-Sr isotopic age of 97.0×8.4Ma with an initial Sr ratio of 0.7046 recommend that the magma has mantle signature and intruded during Early Cretaceous. The geochemical and tectonic features reveal that adakite-like signatures of the Gunbuk granitoids were generated by the interaction of slab-derived adakitic melts(caused by the thermal effect of ridge subduction) and mantle peridotite. The Gunbuk granitoids have similar geochemical characteristics, paleotectonic environments and intrusion ages to those of the Shiraishino granodiorites of Kyushu Island and the Tamba granitoids of San'yo belt located on southwestern Japanese arc. Chondrite normalized REE patterns show generally enriched LREEs and slight negative to flat Eu anomalies. On the ANK vs. A/CNK and tectonic discrimination diagrams, parental magma type of the granites corresponds to I-type and volcanic arc granite(VAG). Interpretations of the chemical characteristics of the granitic rocks favor their emplacement in a compressional tectonic regime at continental margin during the subduction of the Izanagi plate beneath the northeastern part of the Eurasian plate.

  8. Boninites: Characteristics and tectonic constraints, northeastern Appalachians

    USGS Publications Warehouse

    Kim, J.; Jacobi, R.D.

    2002-01-01

    Boninites are high Mg andesites that are thought to form in suprasubduction zone tectonic environments as primary melts from refractory mantle. Boninites provide a potential constraint on tectonic models for ancient terranes that contain boninites because the only unequivocal tectonic setting in which "modern" boninites have been recognized is a fore-arc setting. Tectonic models for "modern" boninite genesis include subduction initiation ("infant arc"), fore-arc spreading, and the forearc side of intra-arc rifting (spreading). These models can be differentiated by the relative age of the boninites and to a lesser degree, geochemistry. The distinctive geochemistry of boninites promotes their recognition in ancient terranes. As detailed in this report, several mafic terranes in the northeastern Appalachians contain boninites; these terranes were situated on both sides of Iapetus. The characteristics of these boninites can be used to constrain tectonic models of the evolution of the northeastern Appalachians. On the Laurentian side of Iapetus, "infant arc" boninites were not produced ubiquitously during the Cambrian subduction initiation, unless sampling problems or minimum age dates obscure a more widespread boninite "infant arc". The Cambrian subduction initiation on the Laurentian side was probably characterized by both "infant arc" boninitic arc construction (perhaps the >496 Ma Hawley Formation and the >488 Ma Betts Cove Ophiolite) and "normal" arc construction (Mt. Orford). This duality is consistent with the suggestion that the pre-collisional geometry of the Laurentian margin was complex. The Bay of Islands Complex and Thetford Mines ophiolite boninites are likely associated with forearc/intra-arc spreading during the protracted evolution of the Cambrian arc system. The relatively young boninites in the Bronson Hill Arc suggest that the Taconic continuous eastward subduction tectonic model is less tenable than other models. On the Gondwana side of Iapetus, the

  9. A Comparative Study of the Epidemiology of Human Leptospirosis in Korea and Japan between 2006 and 2012.

    PubMed

    Lee, Myeong-Jin; Miki, Shinichiro; Kitagawa, Masahiro; Lee, Won-Chang

    2016-05-20

    We undertook a comparative analysis of the epidemiology of reported human leptospirosis (HL) cases in Korea and Japan. Between 2006 and 2012, the cumulative incidence of HL in Korea was higher than that in Japan (1.26 vs. 0.14 per 100,000 population, respectively), and the total reported cases were 632 and 196, respectively. Significantly more men were infected than women in both Korea (63.0% men, P < 0.01) and Japan (87.8% men, P < 0.01). In both countries, the incidence was highest among those aged 40 years and older (60%), and peaked in autumn (78.5% cases in Korea, and 46.9% cases in Japan). However, Japan exhibited a significantly higher proportion of male cases, a younger age distribution, and less prominent seasonality. A significant difference was observed in the incidence of HL between the capital city and rural areas in Korea, but not in Japan. The differences in agricultural and forestry practices, and the efficacy or wastewater treatment infrastructure might influence the incidence level in rural areas in both countries. The differences between the 2 countries might be because of their unique geographical characteristics and variations in their levels of industrialization.

  10. Tectonic evaluation of the Nubian shield of Northeastern Sudan using thematic mapper imagery

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Bechtel is nearing completion of a one-year program that uses digitally enhanced LANDSAT Thematic Mapper (TM) data to compile the first comprehensive regional tectonic map of the Proterozoic Nubian Shield exposed in the northern Red Sea Hills of northeastern Sudan. The status of significant objectives of this study are given. Pertinent published and unpublished geologic literature and maps of the northern Red Sea Hills to establish the geologic framework of the region were reviewed. Thematic mapper imagery for optimal base-map enhancements was processed. Photo mosaics of enhanced images to serve as base maps for compilation of geologic information were completed. Interpretation of TM imagery to define and delineate structural and lithogologic provinces was completed. Geologic information (petrologic, and radiometric data) was compiled from the literature review onto base-map overlays. Evaluation of the tectonic evolution of the Nubian Shield based on the image interpretation and the compiled tectonic maps is continuing.

  11. Magnetic anomalies in East Antarctica: a window on major tectonic provinces and their boundaries

    USGS Publications Warehouse

    Golynsky, A.V.

    2007-01-01

    An analysis of aeromagnetic data compiled within the Antarctic Digital Magnetic Anomaly Project (ADMAP) yields significant new insight into major tectonic provinces of East Antarctica. Several previously unknown crustal blocks are imaged in the deep interior of the continent, which are interpreted as cratonic nuclei. These cratons are fringed by a large and continuous orogenic belt between Coats Land and Princess Elizabeth Land, with possible branches in the deeper interior of East Antarctica. Most of the crustal provinces and boundaries identified in this study are only in part exposed. More detailed analyses of these crustal provinces and their tectonic boundaries would require systematic acquisition of additional high-resolution magnetic data, because at present the ADMAP database is largely inadequate to address many remaining questions regarding Antarctica’s tectonic evolution.

  12. Tectonic-sedimentary evolution of the eastern Brazilian marginal basins: Implications in their petroleum systems

    SciTech Connect

    Francisco, N.F.; Azambuja, N.C.; Mello, M.R. )

    1993-02-01

    A geological survey of eastern Brazilian marginal basins using sedimentological, tectonic and geochemical data has been carried out. The almost 4000 km long set of basins can be classified as component of a typical divergent, mature Atlantic-continental margin. Based on their tectonic-sedimentary sequence, they can be linked to a single evolutionary history, which can be divided in three main stages: pre-rift, rift, and drift. The integration of all data allowed the characterization of two major petroleum systems that represent about 90% of the known Brazilian hydrocarbons reserves: (1) the rift (Early Cretaceous) and the drift (Late Cretaceous-Paleogene). With respect to the oil-in-place volume and production, the most significant one is the drift system associated with the siliciclastic deep water turbidites reservoirs deposited in bathyal environments. Such reservoirs are clearly controlled by a favorable relationship of stratigraphic and tectonic settings.

  13. Investigation into the regional wrench tectonics of inner East Anatolia (Turkey) using potential field data

    NASA Astrophysics Data System (ADS)

    Büyüksaraç, Aydın

    2007-01-01

    The residual aeromagnetic and gravity anomalies of inner East Anatolia, surveyed by the Mineral Research and Exploration (MTA) of Turkey, display complexities. Some faults, which are known and new lineaments, are drawn from maxspot map derived from the location of the horizontal gradient of gravity anomalies. Tectonic lineaments of inner East Anatolia exhibit similarities to the direction of East Anatolian Fault Zone. Anticlockwise rotation, approximately -30°, defined from disorientations of aeromagnetic anomalies. The lineaments obtained from maxspots map produced from the gravity anomalies and disoriented aeromagnetic anomalies are in-line with the mobilistic system revealed by the palaeomagnetic data. These Alpine age continental rotations caused westward wrenching of the global lithosphere and led to significant tectonic reactivation and deformations. GPS measurements, current tectonic knowledge and the results of the evaluation of potential field data were combined in a base map to demonstrate similarities.

  14. The tectonic setting of the Seychelles, Mascarene and Amirante Plateaus in the Western Equatorial Indian Ocean

    NASA Technical Reports Server (NTRS)

    Mart, Y.

    1988-01-01

    A system of marine plateaus occurs in the western equatorial Indian Ocean, forming an arcuate series of wide and shallow banks with small islands in places. The oceanic basins that surround the Seychelles - Amirante region are of various ages and reflect a complex seafloor spreading pattern. The structural analysis of the Seychelle - Amirante - Mascarene region reflects the tectonic evolution of the western equatorial Indian Ocean. It is suggested that due to the seafloor spreading during a tectonic stage, the Seychelles continental block drifted southwestwards to collide with the oceanic crust of the Mascarene Basin, forming an elongated folded structure at first, and then a subduction zone. The morphological similarity, the lithological variability and the different origin of the Seychelles Bank, the Mascarene Plateau and the Amirante Arc emphasizes the significant convergent effects of various plate tectonic processes on the development of marine plateaus.

  15. Data System for Structural Geology and Tectonics

    NASA Astrophysics Data System (ADS)

    Newman, Julie; Walker, J. Douglas; Tikoff, Basil; Good, Jessica; Michels, Zachary; Ash, Jason; Andrew, Joseph; Williams, Randolph

    2016-04-01

    We are prototyping a Data System for Structural Geology and Tectonics (SG&T) data that is platform independent (from mobile device to desktop) to enable collection and sharing of data from field to laboratory settings. The goals of this effort, funded by US National Science Foundation, are to enable recording and sharing data within the geoscience community, to encourage interdisciplinary research, and to facilitate the investigation of scientific questions that cannot currently be addressed. The development of the Data System emphasizes community input in order to build a system that encompasses the needs of researchers, in terms of data and usability. SG&T data is complex for a variety of reasons, including the wide range of temporal and spatial scales (many orders of magnitude each), the complex three-dimensional geometry of some geological structures, inherent spatial nature of the data, and the difficulty of making temporal inferences from spatial observations. To successfully implement the development of a SG&T data system, we must simultaneously solve three problems: 1) How to digitize SG&T data; 2) How to design a software system that is applicable; and 3) How to construct a very flexible user interface. To address the first problem, we introduce the "Spot" concept, which allows tracking of hierarchical and spatial relations between structures at all scales, and will link map scale, mesoscale, and laboratory scale data. A Spot is an observation or relationship with an area of significance. A Spot can be a single measurement, an aggregate of individual measurements, or even relationships between numerous other Spots. We address the second problem of software design through the use of a graph database to better preserve the myriad of potentially complex relationships. In order to construct a flexible user interface that follows a natural workflow and that serves the needs of the community, we are engaging the SG&T community in order to utilize the expertise

  16. Relations between tectonic tremor and metamorphic processes

    NASA Astrophysics Data System (ADS)

    Fagereng, A.; Diener, J. F.

    2011-12-01

    Tectonic tremor appears to require low effective stress conditions, and is therefore commonly inferred to correlate with zones of high fluid pressure. In subduction settings, tremor generally occurs near the down-dip end of the interseismically locked zone of the subduction thrust interface. We calculate the stable mineral assemblages in the subducting slab, and find that slab dehydration is not continuous, but rather restricted to a few reactions localized in pressure-temperature space. Along geothermal gradients applicable to Shikoku and Cascadia, our calculations indicate that localized voluminous water release from the breakdown of lawsonite and chlorite+glaucophane respectively, occurs near the tremor source region at the down-dip limit of the locked zone. The shape of the pressure-temperature path for the subducting slab prevents fluid release at depths above and below where these dehydration reactions occur. It therefore appears that tremor in these locations correlate with site-specific metamorphic dehydration reactions. Tremor is also observed along the deep extension of the central San Andreas Fault. We calculate the stable mineral assemblages in basalt and greywacke, representing main components of the Franciscan Complex melange rocks forming the protolith of San Andreas fault rocks. From thermal models and surface heat flow data it is apparent that the tremor source region is cooling and experiencing retrograde metamorphic conditions. Several mineralogical transitions occur at the temperature-depth conditions of tremor on the deep San Andreas, and during retrograde metamorphism these reactions lead to localized, significant removal of free water from the fault zone and an associated volume decrease. Contrary to subduction-related tremor, tremor on the San Andreas fault is therefore not linked to fluid production within the fault zone; rather it might be related to volume change and/or fault zone weakening that occurs as phyllosilicates replace more

  17. Ambient tectonic stress as fragile geological feature

    NASA Astrophysics Data System (ADS)

    Sleep, Norman H.

    2014-09-01

    seismic waves produce frictional failure within shallow pervasively cracked rocks. Distributed failure preferentially relaxes ambient tectonic stresses, providing a fragility measure of past strong shaking. Relaxation of the regional fault-normal compression appears to have occurred within granite from 768 m down to ˜1000-1600 m depth at the Pilot Hole near Parkfield, California. Subsequent movements on the main fault have imposed strike-slip stress within the relaxed region. Peak ground velocities of ˜2 m s-1 are inferred for infrequent (few 1000 yr recurrence) past earthquakes from stress relaxation within the granite and from the variation of S wave velocity with depth in the overlying sandstone. Conversely, frequent strong shaking in slowly deforming regions relaxes shallow ambient tectonic stress. This situation is expected beneath Whittier Narrows, where strong Love waves from numerous San Andreas events repeatedly produced nonlinear behavior.

  18. Plate tectonics drive tropical reef biodiversity dynamics

    NASA Astrophysics Data System (ADS)

    Leprieur, Fabien; Descombes, Patrice; Gaboriau, Théo; Cowman, Peter F.; Parravicini, Valeriano; Kulbicki, Michel; Melián, Carlos J.; de Santana, Charles N.; Heine, Christian; Mouillot, David; Bellwood, David R.; Pellissier, Loïc

    2016-05-01

    The Cretaceous breakup of Gondwana strongly modified the global distribution of shallow tropical seas reshaping the geographic configuration of marine basins. However, the links between tropical reef availability, plate tectonic processes and marine biodiversity distribution patterns are still unknown. Here, we show that a spatial diversification model constrained by absolute plate motions for the past 140 million years predicts the emergence and movement of diversity hotspots on tropical reefs. The spatial dynamics of tropical reefs explains marine fauna diversification in the Tethyan Ocean during the Cretaceous and early Cenozoic, and identifies an eastward movement of ancestral marine lineages towards the Indo-Australian Archipelago in the Miocene. A mechanistic model based only on habitat-driven diversification and dispersal yields realistic predictions of current biodiversity patterns for both corals and fishes. As in terrestrial systems, we demonstrate that plate tectonics played a major role in driving tropical marine shallow reef biodiversity dynamics.

  19. Plate tectonics drive tropical reef biodiversity dynamics.

    PubMed

    Leprieur, Fabien; Descombes, Patrice; Gaboriau, Théo; Cowman, Peter F; Parravicini, Valeriano; Kulbicki, Michel; Melián, Carlos J; de Santana, Charles N; Heine, Christian; Mouillot, David; Bellwood, David R; Pellissier, Loïc

    2016-05-06

    The Cretaceous breakup of Gondwana strongly modified the global distribution of shallow tropical seas reshaping the geographic configuration of marine basins. However, the links between tropical reef availability, plate tectonic processes and marine biodiversity distribution patterns are still unknown. Here, we show that a spatial diversification model constrained by absolute plate motions for the past 140 million years predicts the emergence and movement of diversity hotspots on tropical reefs. The spatial dynamics of tropical reefs explains marine fauna diversification in the Tethyan Ocean during the Cretaceous and early Cenozoic, and identifies an eastward movement of ancestral marine lineages towards the Indo-Australian Archipelago in the Miocene. A mechanistic model based only on habitat-driven diversification and dispersal yields realistic predictions of current biodiversity patterns for both corals and fishes. As in terrestrial systems, we demonstrate that plate tectonics played a major role in driving tropical marine shallow reef biodiversity dynamics.

  20. Transverse tectonic boundaries near Kodiak Island, Alaska.

    USGS Publications Warehouse

    Fisher, M.A.; Bruns, T.R.; Von Huene, R.

    1981-01-01

    Transverse tectonic boundaries exist at the NE and SW ends of the Kodiak islands, so that the Aleutian arc-trench system is longitudinally segmented in this area. Evidence for the transverse boundaries includes alignments of such geologic features as offset volcanic lineations, terminations of structural trends, and boundaries of discrete zones of earthquake aftershock sequences. The boundaries appear to be broad zones of disruption that began to form during the late Miocene or Pliocene. Although oceanic fracture zones and seamount chains intersect the continental margin near the boundaries, subduction of these features probably did not cause the tectonic boundaries. The fracture zones and seamount chains have swept northeastward along the margin, at least since the late Pliocene, because of the direction of convergence of the Pacific and N American plates. -Authors

  1. Plate tectonics drive tropical reef biodiversity dynamics

    PubMed Central

    Leprieur, Fabien; Descombes, Patrice; Gaboriau, Théo; Cowman, Peter F.; Parravicini, Valeriano; Kulbicki, Michel; Melián, Carlos J.; de Santana, Charles N.; Heine, Christian; Mouillot, David; Bellwood, David R.; Pellissier, Loïc

    2016-01-01

    The Cretaceous breakup of Gondwana strongly modified the global distribution of shallow tropical seas reshaping the geographic configuration of marine basins. However, the links between tropical reef availability, plate tectonic processes and marine biodiversity distribution patterns are still unknown. Here, we show that a spatial diversification model constrained by absolute plate motions for the past 140 million years predicts the emergence and movement of diversity hotspots on tropical reefs. The spatial dynamics of tropical reefs explains marine fauna diversification in the Tethyan Ocean during the Cretaceous and early Cenozoic, and identifies an eastward movement of ancestral marine lineages towards the Indo-Australian Archipelago in the Miocene. A mechanistic model based only on habitat-driven diversification and dispersal yields realistic predictions of current biodiversity patterns for both corals and fishes. As in terrestrial systems, we demonstrate that plate tectonics played a major role in driving tropical marine shallow reef biodiversity dynamics. PMID:27151103

  2. Global Cretaceous plate tectonics and paleogeography

    SciTech Connect

    Barron, E.J.; Beeson, D.; Chen, P.; Dingle, R.V.; Frakes, L.A; Funnell, B.M.; Kauffman, E.G.; Petri, S.; Reyment, R.A.; Riccardi, A.C.

    1985-01-01

    The International Geologic Correlation Program (IGCP) Project 191, The Cretaceous Paleoclimatic Atlas Project has compiled 89 Cretaceous paleogeographic maps representing ten regions or continents. The map resolution varies from stage by stage (e.g. North America, Europe, USSR, Australia) to four maps (e.g. China, Southern South America) to a compilation of localities (Antarctica). The paleogeography is plotted here on global plate tectonic reconstructions for each stage. The reconstructions include continental positions and latitude. In addition, the oceanic plates are reconstructed including bathymetry based on a thermal age-depth relationship. The compiled paleogeography and plate tectonic base maps represent the most comprehensive framework for plotting and analyzing sedimentologic, geochemical and paleontologic data with respect to geography and latitude for the Cretaceous time period.

  3. Achievements in and Challenges of Tuberculosis Control in South Korea.

    PubMed

    Kim, Ji Han; Yim, Jae-Joon

    2015-11-01

    After the Korean War (1950-1953), nearly 6.5% of South Korea's population had active tuberculosis (TB). In response, South Korea implemented the National Tuberculosis Program in 1962. From 1965 to 1995, the prevalence of bacteriologically confirmed pulmonary TB in South Korea decreased from 940 to 219 cases per 100,000 population. Astounding economic growth might have contributed to this result; however, TB incidence in South Korea remains the highest among high-income countries. The rate of decrease in TB incidence seems to have slowed over the past 15 years. A demographic shift toward an older population, many of whom have latent TB and various concurrent conditions, is challenging TB control efforts in South Korea. The increasing number of immigrants also plays a part in the prolonged battle against TB. A historical review of TB in South Korea provides an opportunity to understand national TB control efforts that are applicable to other parts of the world.

  4. Plate Tectonics, Geographical Information System, paleogeography

    SciTech Connect

    Moore, Thomas L.; Scotese, Christopher

    2002-05-24

    The PaleoX.framwork is a dynamically linked/loaded framework for Cocoa applications. The primary goal of this library is to standardize several elements used for working with paleogeographic data. This includes objects designed to organize information for tectonic plates, including maps, rotation objects, plate names, and designations. In addition, PaleoX provides object-oriented solutions for handling standard paleogeographic file formats from the PALEOMAP Project.

  5. Mars plate tectonics (1) :An Earth prospective

    NASA Astrophysics Data System (ADS)

    Maruyama, S.; Dohm, J.; Baker, V.

    2001-12-01

    We hypothesize the existence of plate tectonism during the embryonic development of Mars, which resulted in the proposed Tharsis superplume (GSA, 2001). Similar to the major influence of superplume on the history of the Earth, we envision the Tharsis superplume to have dominated the geological and climatological history of Mars. Early Noachian plate tectonism is collectively explained by an array of prominent structures and features revealed through Viking-based geological investigations and through the recently acquired high-resolution topographic, imaginary, and geophysical coverage of the Mars Global Surveyor mission. These include: (1) highland-lowland boundary, (2) the Thaumasia highlands mountain range, (3) circular domes among distinct structures of similar trends (e.g., southwest margin of the Thaumasia highland mountain range), interpreted to be andesitic domes associated with subduction zone magma, (e.g., silicic-rich provenances that source andesitic materials to northern plains), and (4) geophysical anomalies such as those identified in the northern plain and regions located to the east-southeast of Hellas basin, interpreted to be the dead spreading centers and probably accreted terrains, respectively. Martian plate tectonism is thought to have continued after the core was frozen, resulting in the death of dynamo, because Mars potential temperature of mantle is expected to be higher than 1500° C, if 34% S-bearing Fe-Ni alloy core was consolidated. In this case, no magnetic stripes would remain in the northern lowland, whereas the proposed southern highland supercontinent that formed during the dynamo would have yielded strong magnetic signatures. For examples EW-trending narrow units with strong remanent magnetism in the southern highland may be accreted oceanic lithosphere. Moreover, the Archean hydrothermal system deposits located along the mid-oceanic ridges on the Earth suggest that the large amounts of carbonate and sulfate are expected to have

  6. Tectonic contrasts between Venus and the earth

    NASA Technical Reports Server (NTRS)

    Kaula, W. M.

    1984-01-01

    The long-wave features of the gravity field of Venus differ from those of the earth's field not only in their strong positive correlation with topography, but also in their gentler spectral slope. These properties are inconsistent with generation of the gravity field by plate tectonics or by processes at great depths; they are consistent with generation by a mantle convective system supporting the broad features in topography with an effective compensation depth of about 450 km.

  7. Acculturation and changes in dietary behavior and anthropometric measures among Chinese international students in South Korea

    PubMed Central

    Lee, Jounghee; Gao, Ran-Ran

    2015-01-01

    BACKGROUND/OBJECTIVES International students face dissimilar food environments, which could lead to changes in dietary behaviors and anthropometric characteristics between before and after migration. We sought to examine the risk factors, including dietary behaviors, acculturation, and demographic characteristics, related to overweight subjects residing in South Korea. SUBJECTS/METHODS We conducted a cross-sectional study, collecting data from 142 Chinese international students (63 males, 79 females) in 2013. RESULTS The mean age of the subjects was 25.4 years, and almost half of them immigrated to South Korea to earn a master's degree or doctoral degree (n = 70, 49.3%). Chinese international students showed an increase in skipping meals and eating speed, but a decrease in the frequency of fruit and vegetable consumption in South Korea compared to when they lived in China. We found a statistically significant increase in weight (69.4 → 73.9 kg) and BMI (22.4 → 23.8 kg/m2) for male subjects (P < 0.001) but no change for female subjects. We also found that overweight subjects were more likely to be highly acculturated and male compared with normal-weight subjects. CONCLUSION Among Chinese international students living in South Korea, male and more highly acculturated subjects are more vulnerable to weight gain. This study provides useful information to design tailored nutrition intervention programs for Chinese international students. PMID:26060543

  8. Analyzing the success of the volume-based waste fee system in South Korea.

    PubMed

    Park, Seejeen; Lah, T J

    2015-09-01

    For more than a decade, South Korea has been ranked first among the OECD (Organization for Economic Cooperation and Development) members in their municipal solid waste (MSW) recycling rate. One of the major contributing factors for its outstanding MSW recycling performance is the volume-based waste fee (VWF) system implemented in 1995. Despite the perceived success of VWF, there has been few research conducted that has sought to demonstrate the success of the policy in an empirical manner. Research conducted currently on VWF in South Korea tends to have limitations in empirical approaches and identifying the intervention effect of VWF on recycling performance. This study attempts to empirically test whether the adoption of VWF positively affected recycling performance in Korea over time. The findings suggest that although there was a dramatic increase of the recycling rate with the introduction of VWF in 1995, Korea's MSW recycling performance settled back again and showed the constant pace after the intervention. No significant differences in recycling rate were found between before and after 1995 period. In conclusion, implications and suggestions for both research and practice are proposed.

  9. Long-term care services expenditure projection in South Korea from 2015 to 2050.

    PubMed

    Kim, Nayoung

    2015-01-01

    South Korea has been undergoing significant change in its population structure over the past three decades. Within 10 years, South Korean baby-boomers will reach the age of 65 years and accelerate this change. This trend in population structure is crucial, because an aging population may increase medical demand, especially that for long-term care (LTC) services, which would create a financial burden on society. This study estimates total LTC expenditure in South Korea from 2015 to 2050 by modifying the method proposed by the UK Personal Social Science Research Unit, the seminal study on projecting costs of LTC services. Using population data from the projections of the Korean Statistical Information Service, I stratify the projected population by gender and age, using the groups 65-69, 70-74, 75-79 and 80 or over and divide LTC services into two categories, namely facility and home care. South Korea's total LTC expenditure is predicted to continuously increase and then reach 4.2% of GDP in 2050. Expenditure on LTC services for women is higher than that for men. Moreover, the increase in total expenditure is dramatic after 2040 for home-based services but is constant for facility services. This study shows that the presence of baby-boomers heavily influences LTC expenditure in South Korea.

  10. Mapping South Korea's Paddy Rice During 2001-2015 Based on Landsat Images

    NASA Astrophysics Data System (ADS)

    Huang, Y.; Ryu, Y.; Jiang, C.

    2015-12-01

    Agricultural land use change substantially affects terrestrial water and carbon cycles, and it is also significant for food security. Rice is an important food crop in South Korea, and its planting area has changed over the past years due to climate change and social development. However, the paddy rice maps in South Korea with high spatial, temporal resolutions and quality are still unavailable. In this study, annual paddy rice planting areas in South Korea during 2001-2015 were extracted using the phenology-based and artificial neural networks(ANN)-based method according to the availability of Landsat images. Three types of vegetation indices, Normalized Difference Vegetation Index(NDVI), Normalized Difference Water Index (NDWI) and Land Surface Water Index (LSWI), were calculated for both methods. For the phenology-based method, we calculated difference and ratio of the vegetation indices from the Landsat images before and after the inundating/transplanting phase, and set the extraction thresholds for rice paddy using the training samples. For the ANN-based method, using the vegetation indices of the Landsat image after inundation, slope and soil type data of the training samples as input, an ANN was established for rice paddy identification. The resultant maps of paddy rice were evaluated using validation samples and agricultural statistics. Finally, we analyzed the spatial and temporal patterns of South Korea's rice paddy during 2001-2015, and investigated the possible reasons.

  11. Metalimnobia crane flies (Diptera: Limoniidae) from Korea.

    PubMed

    Podenas, Sigitas; Byun, Hye-Woo

    2016-06-30

    Korean species of the crane fly genus Metalimnobia Matsumura, 1911 (Diptera: Limoniidae), are taxonomically revised. Metalimnobia (Metalimnobia) channpayna new species, is described and figured, M. (M.) bifasciata (Schrank, 1781), M. (M.) quadrinotata (Meigen, 1818) and M. (M.) zetterstedti (Tjeder, 1968) are listed for the first time in Korea, new information for previously known species, M. (M.) quadrimaculata (Linnaeus, 1760) is added. Identification key for all Korean Metalimnobia species is given. Wings, male and female terminalia are illustrated for all species.

  12. North Korea: Back on the Terrorism List

    DTIC Science & Technology

    2010-05-24

    42 Yi Sang-il and Chin Se-ku. Yongbyon nuclear facility can be disabled within a year. JongAng Ilbo (internet version), March 13, 2007. 43...Print Media, August 30, 3007. 46 Choe Sang- hun and David E. Sanger, North Korea claims U.S. will remove sanctions, International Herald Tribune...attempts in late 2006 through the spring of 2007 to smuggle conventional arms, including machine guns , automatic rifles, and anti-tank rocket launchers

  13. Occupational Burden of Cancer in Korea

    PubMed Central

    Lee, Hye-Eun; Kang, Seong-Kyu

    2010-01-01

    Objectives The extent of the occupational cancer burden has rarely been estimated in Korea. The aim of this study is to provide an estimation of the population attributable fraction (PAF) of occupational cancer in Korea. Methods Nine kinds of Group 1 carcinogens addressed by the International Agency for Research on Cancer (IARC) and 7 kinds of cancer were selected for the target carcinogens and diseases, respectively. The prevalence of carcinogen-exposed workers was estimated and correction factors were applied so that the value would be representative of the total population. Data on relative risk (RR) were taken from IARC reports and were compared with the RRs from the studies on Korean workers. The PAF was estimated according to Levin's formula. Results The proportion of the general Korean population exposed to carcinogens was 9.7%. The PAF of total cancer was 1.1% for incident cancer cases and 1.7% for cancer deaths. The PAFs of lung cancer and leukemia were 7.0% and 4.%, respectively. With the RRs reported from Korean studies, the PAF for lung cancer and leukemia were 3.7% and 3.4%, respectively. Conclusion The PAF in this study (1.1%) was lower than that reported in previous studies (2-4%) from developed countries. Considering that only 9 of the 29 kinds of Group 1 carcinogens were included in this study, the PAF might be underestimated. However, because the process of industrialization in Korea differs from that which occurred in other developed countries, 1.1% of the PAF might be appropriate for Korea. PMID:22953164

  14. ROK Military Policy Recommendations Toward North Korea

    DTIC Science & Technology

    2012-03-22

    though the South Korean Navy won the battle in the Yellow Sea, Kim Dae-Jung fired the fleet commander, Admiral Park Jung- seung , because North Korea...during the administration of President Kim Dae-jung and continued for 10 years through the Roh Moo-hyun Administration. This unilateral policy was based...changed during the administration of President Kim Dae-jung and continued for 10 years through the Roh Moo-hyun Administration. This unilateral policy

  15. Tritium production, recovery and application in Korea.

    PubMed

    Son, Soon-Hwan; Lee, Sook-Kyung; Kim, Kwang-Sin

    2009-01-01

    Four CANDU reactors have been operating at the site of Wolsong Nuclear Power Generation in Korea. The Wolsong tritium removal facility was constructed to reduce the tritium levels in heavy water systems. This facility was designed to process 100kg/h of tritiated heavy water feed and to produce 99% pure T(2). This recovered tritium will be made available for commercial applications. The initial phases on the tritium applications are made to establish the infrastructure and the tritium controls.

  16. China and North Korea: A Peculiar Relationship

    DTIC Science & Technology

    2011-03-01

    prevent North Korea from provoking a war. 80 “Singapore’s Lee calls N. Koreans ‘ psychopathic ...Singapores-Lee-calls-NKoreans- psychopathic ---WikiLeaks. 44 Before continuing, let us clarify the term “collapse.” As Samuel Kim states, “The...Singapore’s Lee calls N. Koreans ‘ psychopathic ’—WikiLeaks,” Agence France-Press, November 30, 2010. Accessed January 12, 2011. http

  17. Green Chemistry at the present in Korea

    PubMed Central

    Lee, Seung-Kyu; Park, Hyeon-Soo

    2015-01-01

    Objectives Despite the great contribution made by chemical substances to the development of modern civilization, their indiscriminate use has caused various kinds of damage to the global environment and human beings. Accordingly, the major developed countries and international society have tried to ensure the safe use of chemicals and a reduction in the use of hazardous chemicals through the establishment of the United Nations Environment Programme and various international agreements. In this reason, we tried to introduce about Green Chemistry progress at the present in worldwide and Korea. Methods We checked and analyzed relative journals, reports using keyword as like Green Chemistry, alternative chemicals, eco-friendly etc. and major country’s government homepage search. Results Green Chemistry theory, which argues for the reduction or removal of harmfulness in chemicals throughout their entire life-cycle, has been spreading, and major developed countries, such as the US and Denmark, have developed and operate programs to provide reliable chemical information to help replace hazardous chemicals. Korea has also been conducting studies as like eco-innovation project. Through this project the “Alternative Chemical Search program,” has been developed, distributed, and operated since 2011 to provide reliable information to small and medium-sized businesses that have difficulties collecting information to ensure conformity to international regulations. The program provides information that includes the regulations of major countries and Korea, information on 340 alternative chemicals, 70 application cases, and 1:1 consulting. Conclusions The Alternative Chemical Search program is expected to contribute to the establishment of response systems for regulation of Korean small and medium-sized businesses, and it also will be used to provide basic data for Korean hazardous chemical regulation, together with the Act on the Registration and Evaluation, etc. of

  18. U.S.- South Korea Relations

    DTIC Science & Technology

    2016-03-28

    2015 joint statement on North Korea says, “The United States will continue to strongly support [President Park’s] vision of a peacefully unified Korean...around the year 2020 . 51 The city of Dongducheon, where those soldiers are based, has protested this decision and withdrawn some cooperation with the...munitions, and ISR (intelligence, surveillance, and reconnaissance) assets. Reportedly, the Opcon transfer may not occur until 2020 or later. 67

  19. North Korea: Economic Leverage and Policy Analysis

    DTIC Science & Technology

    2009-06-04

    plan B,” Asia Tiimes, May 21, 2009, Online edition. 2 The extent that Pyongyang has...Mother Jones, Vol. 28, No. 3, May 1, 2003. p. 52. 42 Food and Agriculture Organization. Food Security Statistics. Online at http://www.fao.org...for Military.” People’s Daily Online , April 12, 2005. 64 Asia: The deal that wasn’t; North Korea. The Economist. London: September 24, 2005. p. 81

  20. Carboniferous sedimentation and tectonics in southern Morocco

    SciTech Connect

    Harris, J.P.; Crossley, R.; Aktas, G.; Matthews, S.J.; Boudda, A.

    1988-08-01

    The Carboniferous rocks of southern Morocco record the gradual change from the extensional tectonic style of the early Paleozoic to a compressional regime. During the Tournaisian and early Visean, northwest compression formed a rising anticline in the Anti-Atlas, which provided sediments to shallow marine basins formed in the flanking synclines. During the late Visean, tectonic activity increased markedly, and northward-downthrowing normal/oblique slip faulting formed submarine fault scarps. Turbidity currents and debris flows together with giant exotic blocks were shed northward from these scarps. The turbidity currents were deflected eastward to flow down the axes of these small easterly plunging marine basins. A late Visean phase of minor folding with locally developed cleavage and quartz veining closed these basins. The folded sequences are unconformably overlain by uppermost Visean fluvial sediments deposited from northward and eastward-flowing rivers. During the Pennsylvanian, collisional tectonics recorded in the Moroccan Meseta to the north were probably responsible for thrust faulting and the formation of a high-angle cleavage. Thick (up to 4.5 km) sandstones and conglomerates with red mudstones, paleosols, and coals are preserved on the fringes of the area. These were deposited by southeast-flowing rivers and are interpreted as the eroded remnants of a syn-postorogenic molasse deposited in a major foredeep south of the main orogen.

  1. Andean tectonics: Implications for Satellite Geodesy

    NASA Astrophysics Data System (ADS)

    Allenby, R. J.

    1984-09-01

    Current knowledge and theories of large scale Andean tectonics as they relate to site planning for the NASA Crustal Dynamics Program's proposed high precision geodetic measurements of relative motions between the Nazca and South American plates are summarized. The Nazca Plate and its eastern margin, the Peru-Chile Trench, is considered a prototype plate marked by rapid motion, strong seismicity and well defined boundaries. Tectonic activity across the Andes results from the Nazca Plate subducting under the South American plate in a series of discrete platelets with different widths and dip angles. This in turn, is reflected in the tectonic complexity of the Andes which are a multitutde of orogenic belts superimposed on each other since the Precambrian. Sites for Crustal Dynamics Program measurements are being located to investigate both interplate and extraplate motions. Observing operations have already been initiated at Arequipa, Peru and Easter Island, Santiago and Cerro Tololo, Chile. Sites under consideration include Iquique, Chile; Oruro and Santa Cruz, Bolivia; Cuzco, Lima, Huancayo and Bayovar, Peru; and Quito and the Galapagos Islands, Ecuador. Based on scientific considerations, Santa Cruz, Huancayo (or Lima), Quito and the Galapagos Islands should be replaced by Isla San Felix, Chile; Brazilia or Petrolina, Brazil; and Guayaquil, Ecuador. If resources permit, additional important sites would be Buenaventura and Villavicencio or Puerto La Concordia, Colombia; and Mendoza and Cordoba, Argentina.

  2. Tectonic map of Indonesia: A progress report

    USGS Publications Warehouse

    Hamilton, Warren Bell

    1970-01-01

    Orogeny, volcanism, and seismicity are now intensely active in Indonesia. Many Dutch tectonists--Brouwer, Umbgrove, van Bemifielen, Smit4Sibinga, Vening Meinesz, Westerveld, and others--recognized that this complex cluster of islands represents an early stage in the evolution of orogenic belts. Not until Indonesia is understood can we comprehend the Alps. This report summarizes some aspects of work to date on the Tectonic Map of Indonesia. The preparation of this map is a joint project of the Geological Survey of Indonesia and the United States Geological Survey, sponsored by the Government of Indonesia and the United States Agency for International Development. The Tectonic Map of Indonesia will be published at a scale of 1:5,000,000. Adjacent regions in other countries will be included to provide a broader context. The map limits presently envisaged are the parallels of 12° N. and 15° S., and the meridians of 91° and 148° E. Tectonic features will be shown in many colors and patterns. Bathymetry is being newly compiled, and will be shown with contours and shades of blue. Figure 1 shows the islands of Indonesia.

  3. Hot-spot tectonics on Io

    NASA Technical Reports Server (NTRS)

    Mcewen, A. S.

    1985-01-01

    The thesis is that extensional tectonics and low-angle detachment faults probably occur on Io in association with the hot spots. These processes may occur on a much shorter timescale on Ion than on Earth, so that Io could be a natural laboratory for the study of thermotectonics. Furthermore, studies of heat and detachment in crustal extension on Earth and the other terresrial planets (especially Venus and Mars) may provide analogs to processes on Io. The geology of Io is dominated by volcanism and hot spots, most likely the result of tidal heating. Hot spots cover 1 to 2% of Io's surface, radiating at temperatures typically from 200 to 400 K, and occasionally up to 700K. Heat loss from the largest hot spots on Io, such as Loki Patera, is about 300 times the heat loss from Yellowstone, so a tremendous quantity of energy is available for volcanic and tectonic work. Active volcanism on Io results in a resurfacing rate as high as 10 cm per year, yet many structural features are apparent on the surface. Therefore, the tectonics must be highly active.

  4. A palaeomagnetic perspective of Precambrian tectonic styles

    NASA Technical Reports Server (NTRS)

    Schmidt, P. W.; Embleton, B. J. J.

    1986-01-01

    The considerable success derived from palaeomagnetic studies of Phanerozoic rocks with respect to the tectonic styles of continental drift and plate tectonics, etc., have not been repeated by the many palaeomagnetic studies of Precambrian rocks. There are 30 years of research with results covering the major continents for Precambrian times that overlap considerably yet there is no concensus. There is good evidence that the usual assumptions employed by palaeomagnetism are valid for the Precambrian. The exisence of magnetic reversals during the Precambrian, for instance, is difficult to explain except in terms of a geomagnetic field that was predominantly dipolar in nature. It is a small concession to extend this notion of the Precambrian geomagnetic field to include its alignment with the Earth's spin axis and the other virtues of an axial geocentric dipole that characterize the recent geomagnetic field. In terms of greenstone terranes it is obvious that tectonic models postulated to explain these observations are paramount in understanding Precambrian geology. What relevance the current geographical relationships of continents have with their Precambrian relationships remains a paradox, but it would seem that the ensialic model for the development of greenstone terranes is favored by the Precambrian palaeomagnetic data.

  5. Andean tectonics: Implications for Satellite Geodesy

    NASA Technical Reports Server (NTRS)

    Allenby, R. J.

    1984-01-01

    Current knowledge and theories of large scale Andean tectonics as they relate to site planning for the NASA Crustal Dynamics Program's proposed high precision geodetic measurements of relative motions between the Nazca and South American plates are summarized. The Nazca Plate and its eastern margin, the Peru-Chile Trench, is considered a prototype plate marked by rapid motion, strong seismicity and well defined boundaries. Tectonic activity across the Andes results from the Nazca Plate subducting under the South American plate in a series of discrete platelets with different widths and dip angles. This in turn, is reflected in the tectonic complexity of the Andes which are a multitutde of orogenic belts superimposed on each other since the Precambrian. Sites for Crustal Dynamics Program measurements are being located to investigate both interplate and extraplate motions. Observing operations have already been initiated at Arequipa, Peru and Easter Island, Santiago and Cerro Tololo, Chile. Sites under consideration include Iquique, Chile; Oruro and Santa Cruz, Bolivia; Cuzco, Lima, Huancayo and Bayovar, Peru; and Quito and the Galapagos Islands, Ecuador. Based on scientific considerations, Santa Cruz, Huancayo (or Lima), Quito and the Galapagos Islands should be replaced by Isla San Felix, Chile; Brazilia or Petrolina, Brazil; and Guayaquil, Ecuador. If resources permit, additional important sites would be Buenaventura and Villavicencio or Puerto La Concordia, Colombia; and Mendoza and Cordoba, Argentina.

  6. Criminal Sovereignty: Understanding North Korea’s Illicit International Activities

    DTIC Science & Technology

    2010-03-01

    authorities in Myanmar who believed that local insurgent groups were intent on trading heroin for the arms.21 North Korea has also used its diplomatic...represent another strategic dimension of threats emanating from North Korea . While most of the world is focused on the country’s nuclear weapons and...incident, groups in Myanmar do not earn their profits from street sales, but from the middleman that has been, in certain instances, North Korea . Acting

  7. Current Issues Concerning Korea’s Anti-Terrorism Programs

    DTIC Science & Technology

    2011-06-10

    members on a state visit to Rangoon, Burma . In 1987 North Korea shot down a Korean Air Lines commercial flight.9 Besides the North Korean threat, South...arrivals of North Korean defectors ................................................37 Figure 4. Anti-terrorism-related organizations in Korea after 9.11...study will determine whether current Korean anti-terrorism programs effectively address all terrorist threats, including threats from North Korea

  8. Korea-U.S. Relations: Issues for Congress

    DTIC Science & Technology

    2008-07-25

    Bush Administration in 2008 committed 500,000 tons of foodgrains.. South Korea followed a conciliation policy toward North Korea under the...dollars in foreign exchange earnings since 1998 to import food or medicines . The regime has not adopted agricultural reforms similar to those of... conciliation policy were: the extension of South Korean economic and humanitarian aid to North Korea, the promotion of North-South economic relations

  9. United States National Interests in the Republic of Korea.

    DTIC Science & Technology

    1986-06-01

    South Korea by the United States. 41 During the war, the United Nations set up the Civilian Relief Agency to provide medicine, food , and shelter to...Japanese coast. Their mission was to escort and protect vessels carrying food , oil and other resources to Japan along two sea lanes, one connecting...Sales credits to South Korea for FY 87 to $230 mlllion.l II Security Assistance to the Republic of Korea has been instrumental in perserving peace In the

  10. North Korea’s Nuclear Weapons Development and Diplomacy

    DTIC Science & Technology

    2009-03-30

    between 30 and 50 kilograms, enough for five to eight atomic weapons. After North Korea tested a nuclear device in October 2006, the six party talks...the plutonium reprocessing plant produced enough weapons grade plutonium for the production of several atomic bombs. North Korea tested an atomic...produces and tests atomic bombs, and the locations where North Korea stores plutonium and atomic bombs. The declaration also reportedly contains no

  11. Military Armistice in Korea: A Case Study for Strategic Leaders

    DTIC Science & Technology

    2007-11-02

    negotiation the questions of the withdrawal of all foreign forces from Korea , the peaceful settlement of the Korean question, etc.5 Both sides did meet in...invasion]."𔃺 The Republic of Korea faced an insurgency and guerilla warfare that followed the Maoist model and culminated in the North Korean Army...the United States through a proxy. 12 . The first year of the war saw four major shifts in momentum. First, the DPRK (or North Korea ) thrust its Korean

  12. The Chinese Intervention in Korea: An Analysis of Warning

    DTIC Science & Technology

    1985-12-19

    precepts to Korea as early as 1936 when he wrote, "If the Koreans wish to break away from the claims of Japanese [read American] imperi- alism, we will... Korea . Both actions .Vcre preceded by the White Paper and Secretary of State Dean Acheson’s public statements that delineated an American defensive ...predictably denounced the American action in Korea , but did so in a manner that indicated little concern over Korean events. What shocked and incensed

  13. Defense Industry and Its Impacts on Economic Growth in Korea

    DTIC Science & Technology

    1992-06-01

    is likely in Korea . Some argue that the Korean economy would have developed much faster without the burden of the defense spending. We could have...industry to the civilian industry in Korea . The intent of this study is to determine how much impact and influence the Korean defense industry has had...in Korea based on 1987 data. Dr. Dong J. Hwang studied the future of the Korean defense industry. But none of these authors studied the defense

  14. The Future of United States Forces in Korea

    DTIC Science & Technology

    1993-03-22

    Kwak, The Reduction of US Forces in Korea in the Inter- Korean Peace Process: The Korean Journal of Defense Analysis, Vol. II No. 2 Winter 1990, pp... Korean Peace Process: The Korean Journal of Defense Analysis, Vol. II No. 2 Winter 1990. 11. Levin, Norman D., and Richard L. Sneider, " Korea in...group with 500 officers and enlisted personnel. After the Korean war broke out in June 1950, the United States sent its troops to Korea in July under

  15. Log-centric Airbase-opening Strategies in Korea

    DTIC Science & Technology

    2007-01-01

    is becoming politically less viable.”4 In the Korean theater of operations (KTO), Republic of Korea (ROK) and U.S. plan- ners, from Combined Forces...in the Korean War. —Lieutenant General Walton H. Walker, Commander, 8th U.S. Army, Korea , 19501 South Korean military members participate with U.S...pallet buildup and cargo loading Supplies are loaded onto Korean C–130 at Hickam Air Base, Hawaii Republic of Korea air force security advisor speaks

  16. A theoretical model for fluvial channel response time during time-dependent climatic and tectonic forcing and its inverse applications

    NASA Astrophysics Data System (ADS)

    Goren, Liran

    2016-10-01

    The fluvial response time dictates the duration of fluvial channel adjustment in response to changing climatic and tectonic conditions. However, when these conditions vary continuously, the channel cannot equilibrate and the response time is not well defined. Here I develop an analytical solution to the linear stream power model of fluvial incision that predicts the channel topography as a function of time-dependent climatic and tectonic conditions. From this solution, a general definition of the fluvial response time emerges: the duration over which the tectonic history needs to be known to evaluate channel topography. This new definition is used in linear inversion schemes for inferring climatic or tectonic histories from river long profiles. The analytic solution further reveals that high-frequency climatic oscillations, such as Milankovitch cycles, are not expected to leave significant fingerprints on the long profiles of fluvially incised detachment-limited rivers.

  17. The Ecology of Medical Care in Korea.

    PubMed

    Kim, Yong Soo; Choi, Yong Jun

    2016-11-01

    This study aimed to describe the ecology of medical care in Korea. Using the yearly data of 2012 derived from the Korea Health Panel, we estimated the numbers of people per 1,000 residents aged 18 and over who had any health problem and/or any medical care at a variety of care settings, such as clinics, hospitals, and tertiary hospitals, in an average month. There was a total of 11,518 persons in the study population. While the number of those who had any health problem in an average month was estimated to be 939 per 1,000 persons, the estimated numbers of ambulatory care users were 333 at clinics, 101 at hospital outpatient departments, 35 at tertiary hospital outpatient departments, and 38 for Korean Oriental medical providers. The number of people who used emergency care at least once was 7 per 1,000 persons in an average month. The numbers of people hospitalized in clinics and hospitals were 3 and 8, respectively, while 3 persons were admitted to tertiary hospitals. There was a gap between the number of people experiencing any health problem and that of those having any medical care, and primary care comprised a large share of people's medical care experiences. It was noteworthy that more patients received ambulatory care at tertiary hospitals in Korea than in other countries. We hope that discussion about care delivery system reform and further studies will be encouraged.

  18. Prevalence of primary immunodeficiency in Korea.

    PubMed

    Rhim, Jung Woo; Kim, Kyung Hyo; Kim, Dong Soo; Kim, Bong Seong; Kim, Jung Soo; Kim, Chang Hwi; Kim, Hwang Min; Park, Hee Ju; Pai, Ki Soo; Son, Byong Kwan; Shin, Kyung Sue; Oh, Moo Young; Woo, Young Jong; Yoo, Young; Lee, Kun Soo; Lee, Kyung Yil; Lee, Chong Guk; Lee, Joon Sung; Chung, Eun Hee; Choi, Eun Hwa; Hahn, Youn Soo; Park, Hyun Young; Kim, Joong Gon

    2012-07-01

    This study represents the first epidemiological study based on the national registry of primary immunodeficiencies (PID) in Korea. Patient data were collected from 23 major hospitals. A total of 152 patients with PID (under 19 yr of age), who were observed from 2001 to 2005, have been entered in this registry. The period prevalence of PID in Korea in 2005 is 11.25 per million children. The following frequencies were found: antibody deficiencies, 53.3% (n = 81), phagocytic disorders, 28.9% (n = 44); combined immunodeficiencies, 13.2% (n = 20); and T cell deficiencies, 4.6% (n = 7). Congenital agammaglobulinemia (n = 21) and selective IgA deficiency (n = 21) were the most frequently reported antibody deficiency. Other reported deficiencies were common variable immunodeficiencies (n = 16), X-linked agammaglobulinemia (n = 15), IgG subclass deficiency (n = 4). Phagocytic disorder was mostly chronic granulomatous disease. A small number of patients with Wiskott-Aldrich syndrome, hyper-IgE syndrome, and severe combined immunodeficiency were also registered. Overall, the most common first manifestation was pneumonia. This study provides data that permit a more accurate estimation PID patients in Korea.

  19. [Becoming medical doctors in colonial Korea: focusing on the faculty of medical colleges in early north Korea].

    PubMed

    Kim, Geun Bae

    2014-12-01

    This paper traces how Koreans of north area became medical doctors in colonial Korea. Most of the past research have focused only on the well-known medical doctors, or even when they discussed a great number of doctors, many research tended to only pay attention to the explicit final results of those doctors. This research, on the other hand, includes ordinary medical doctors as well as the renowed ones, and adjusts the focus to the lifetime period of their growth and activities. As a result, the misunderstanding and obscurity about the Korean medical doctors of north area during this period have been cleared. The new characteristics of the Korean medical doctors of this period have been found, along with their embodiment of historical significance. At the time, Koreans had to get through a number of qualifications in order to become doctors. First is the unique background of origin in which the family held interest in the modern education and was capable of supporting it financially. Second is the long-term status of education that the education from elementary to high school was completed without interruption. Third is the academic qualification that among various institutions of higher education, medical science was chosen as a major. Fourth is the condition of career in which as the career as a doctor had consistently continued. Thus, in oder to become a modern medical doctor, Koreans had to properly complete these multiple steps of process. The group of Korean medical doctors in north area, which was formed after getting through these series of process, possessed a number of characteristics. Firstly, as the upper-middle classes constituted the majority of medical doctors in Korea, the societal status of doctors rose and the foundation for the career as a doctor to be persisted as the family occupation settled. Secondly, the research career and academic degree became the principal method to escape from the discrimination and hierarchy existed between doctors. A

  20. Plate tectonics from VLBI and SLR global data

    NASA Technical Reports Server (NTRS)

    Harrison, Christopher G. A.; Robaudo, Stefano

    1992-01-01

    This study is based on data derived from fifteen years of observations of the SLR (side-looking radar) network and six years of the VLBI (very long baseline interferometry) network. In order to use all available information VLBI and SLR global data sets were combined in a least squares fashion to calculate station horizontal velocities. All significant data pertaining to a single site contribute to the station horizontal motion. The only constraint on the solution is that no vertical motion is allowed. This restriction does not greatly affect the precision of the overall solution given the fact that the expected vertical motion for most stations, even those experiencing post glacial uplift, is well under 1 cm/yr. Since the average baseline is under 4,000 km, only a small fraction of the station vertical velocity is translated into baseline rates so that the error introduced in the solution by restricting up-down station movement is minimal. As a reference, station velocities were then compared to the ones predicted by the NUVEL-1 geological model of DeMets et al. (1990). The focus of the study is on analyzing these discrepancies for global plate tectonics as well as regional tectonic settings. The method used also allows us not only to derive horizontal motion for individual stations but also to calculate Euler vectors for those plates that have enough stations located on the stable interior like North America, Pacific, Eurasia, and Australia.

  1. On the Origin of Plate Tectonics

    NASA Astrophysics Data System (ADS)

    Bercovici, D.

    2014-12-01

    The emergence of plate tectonics was Earth's defining moment. How and when platetectonics started is shrouded in mystery because of the paucity of observations in theArchean as well the challenge of understanding how plates are generated. The damage theoryof lithospheric weakening by grain-reduction provides a physical framework for plategeneration. This model builds on grain-scale processes to elucidate planetary-scaletectonics, and is consistent with lab and field observations of polycrystalline rocks andlithospheric shear zones. The grain-damage model accounts for the evolution of damage andhealing (by grain growth) at various planetary conditions, hence predicts plate boundaryformation and longevity, and how they depend on surface environment. For example, the onset of prototectonics is predicted to require clement conditions tokeep healing from erasing weak zones; conversely, cool conditions possibly requiredtectonics to draw down primordial CO2. Thus whether tectonics preceded a cool climate (andwater) or vice versa is immaterial as they likely needed each other or neither wouldexist. Sparse evidence that prototectonics co-initiated with liquid water hints at thelink between tectonics, water and surface conditions. The establishment of wide-spread plate tectonics started between >4Ga and 2.7Ga, and mayhave taken over a billion years to develop. Under Earth-like conditions, combininggrain-damage with intermittent Archean protosubduction produces persistent weak zones thataccumulate to yield well developed plates within 1Gyrs. In contrast, Venus' hottersurface conditions promotes healing and prohibits weak zone accumulation, which explainswhy plate tectonics failed to spread on our sister planet. Damage and weak-zone inheritance may also influence plate evolution and reorganization inthe modern era. Changes in plate direction, such as reflected in the Emperor-Hawaiianbend, leave weak zones misaligned with plate motion, causing oblique plate boundaries

  2. Tectonic Framework of the Kachchh Rift Basin

    NASA Astrophysics Data System (ADS)

    Talwani, P.; Gangopadhyay, A. K.

    2001-05-01

    Evaluation of available geological data has allowed us to determine the tectonic framework of the Kachchh rift basin (KRB), the host to the 1819 Kachchh (MW 7.8), 1956 Anjar ( M 6.0) and the recent January 26, 2001 Bhachau (MW 7.6) earthquakes. The ~ 500 km x 200 km east-west trending KRB was formed during the Mesozoic following the break-up of Gondwanaland. It is bounded to the north and south by the Nagar Parkar and Kathiawar faults which separate it from the Precambrian granitic rocks of the Indian craton. The eastern border is the Radanpur-Barmer arch (defined by an elongate belt of gravity highs) which separates it from the early Cretaceous Cambay rift basin. KRB extends ~ 150 km offshore to its western boundary, the continental shelf. Following India's collision with Eurasia, starting ~ 50 MY ago, there was a stress reversal, from an extensional to the (currently N-S) compressional regime. Various geological observations attest to continuous tectonic activity within the KRB. Mesozoic sediments were uplifted and folded and then intruded by Deccan trap basalt flows in late Cretaceous. Other evidence of continuous tectonic activity include seismically induced soft sediment deformation features in the Upper Jurassic Katrol formation on the Kachchh Mainland and in the Holocene sequences in the Great Rann. Pleistocene faulting in the fluvial sequence along the Mahi River (in the bordering Cambay rift) and minor uplift during late Quaternary at Nal Sarovar, prehistoric and historic seismicity associated with surface deformation further attest to ongoing tectonic activity. KRB has responded to N-S compressional stress regime by the formation of east-west trending folds associated with Allah Bund, Kachchh Mainland, Banni, Vigodi, Katrol Hills and Wagad faults. The Allah Bund, Katrol Hill and Kachchh Mainland faults were associated with the 1819, 1956 and 2001 earthquakes. Northeast trending Median High, Bhuj fault and Rajkot-Lathi lineament cut across the east

  3. Crustal Magnetic Field Anomalies and Global Tectonics

    NASA Astrophysics Data System (ADS)

    Storetvedt, Karsten

    2014-05-01

    A wide variety of evidence suggests that the ruling isochron (geomagnetic polarity versus age) hypothesis of marine magnetic lineations has no merit - undermining therefore one of the central tenets of plate tectonics. Instead, variable induction by the ambient geomagnetic field is likely to be the principal agent for mega-scale crustal magnetic features - in both oceanic and continental settings. This revitalizes the fault-controlled susceptibility-contrast model of marine magnetic lineations, originally proposed in the late 1960s. Thus, the marine magnetic 'striping' may be ascribed to tectonic shearing and related, but variable, disintegration of the original iron-oxide mineralogy, having developed primarily along one of the two pan-global sets of orthogonal fractures and faults. In this way, fault zones (having the more advanced mineral alteration) would be characterized by relatively low susceptibility, while more moderately affected crustal sections (located between principal fault zones) would be likely to have less altered oxide mineralogy and therefore higher magnetic susceptibility. On this basis, induction by the present geomagnetic field is likely to produce oscillating magnetic field anomalies with axis along the principal shear grain. The modus operandi of the alternative magneto-tectonic interpretation is inertia-driven wrenching of the global Alpine age palaeo-lithosphere - triggered by changes in Earth's rotation. Increasing sub-crustal loss to the upper mantle during the Upper Mesozoic had left the ensuing Alpine Earth in a tectonically unstable state. Thus, sub-crustal eclogitization and associated gravity-driven delamination to the upper mantle led to a certain degree of planetary acceleration which in turn gave rise to latitude-dependent, westward inertial wrenching of the global palaeo-lithosphere. During this process, 1) the thin and mechanically fragile oceanic crust were deformed into a new type of broad fold belts, and 2) the continents

  4. Interdisciplinary approach to exploit the tectonic memory in the continental crust of collisional belts.

    NASA Astrophysics Data System (ADS)

    Gosso, G.; Marotta, A. M.; Rebay, G.; Regorda, A.; Roda, M.; Spalla, M. I.; Zanoni, D.; Zucali, M.

    2015-12-01

    Collisional belts result by thoroughly competing thermo-mechanical disaggregation and coupling within both continental and oceanic lithospheric slices, during construction of tectono-metamorphic architectures. In multiply reworked metamorphics, tectonic units may be contoured nowadays on the base of coherent thermo-baric and structural time-sequences rather than simply relying on lithologic affinities. Sequences of equilibrium assemblages and related fabric imprints are an approach that appears as a more reliable procedure, that enables to define tectonic units as the volume of crustal slices that underwent corresponding variations during the dynamics of an active margin and takes into account a history of physical imprints. The dimensions of these tectonic units may have varied over time and must be reconstructed combining the tracers of structural and metamorphic changes of basement rocks, since such kind of tectono-metamorphic units (TMUs) is a realistic configuration of the discrete portions of orogenic crust that experienced a coherent sequence of metamorphic and textural variations. Their translational trajectories, and bulk shape changes during deformation, cannot simply be derived from the analysis of the geometries and kinematics of tectonic units, but are to be obtained by adding the reconstruction of quantitative P-T-d-t paths making full use of fossil mineral equilibria. The joint TMU field-and-laboratory definition is an investigation procedure that bears a distinct thermo-tectonic connotation, that, through modelling, offers the opportunity to test the physical compatibilities of plate-scale interconnected variables, such as density, viscosity, and heat transfer, with respect to what current interpretative geologic histories may imply. Comparison between predictions from numerical modelling and natural data obtained by this analytical approach can help to solve ambiguities on geodynamic significance of structural and thermal signatures, also as a

  5. New Radar Altimeter Missions are Providing a Dramatically Sharper Image of Global Marine Tectonics

    NASA Astrophysics Data System (ADS)

    Sandwell, D. T.; Müller, D.; Garcia, E.; Matthews, K. J.; Smith, W. H. F.; Zaron, E.; Zhang, S.; Bassett, D.; Francis, R.

    2015-12-01

    Marine gravity, derived from satellite radar altimetry, is a powerful tool for mapping tectonic structures, especially in the deep ocean basins where the topography remains unmapped by ships or is buried by thick sediment. The ability to infer seafloor tectonics from space was first demonstrated in 1978 using Seasat altimeter data but the spatial coverage was incomplete because of the short three-month lifetime of the satellite. Most ocean altimeters have repeat ground tracks with spacings of hundreds of kilometers so they do not resolve tectonic structures. Adequate altimeter coverage became available in 1995 when the United States Navy declassified the Geosat radar altimeter data and the ERS-1 altimeter completed a 1-year mapping phase. These mid-1990's altimeter-derived images of the ocean basins remained static for 15 years because there were no new non-repeat altimeter missions. This situation changed dramatically in 2010 when CryoSat-2, with its advanced radar altimeter, was launched into a non-repeat orbit and continues to collect data until perhaps 2020. In addition the Jason-1 altimeter was placed into a 14-month geodetic phase at the end of its lifetime. More recently the 1.5 times higher precision measurements from the AltiKa altimeter aboard the SARAL spacecraft began to drift away from its 35-day repeat trackline. The Chinese HY-2 altimeter is scheduled to begin a dense mapping phase in early 2016. Moreover in 2020 we may enjoy significantly higher resolution maps of the ocean basins from the planned SWOT altimeter mission with its advanced swath mapping ability. All of this new data will provide a much sharper image of the tectonics of the deep ocean basins and continental margins. During this talk we will tour of the new tectonic structures revealed by CryoSat-2 and Jason-1 and speculate on the tectonic views of the ocean basins in 2020 and beyond.

  6. Possible salt tectonics in Ariadnes Colles ?

    NASA Astrophysics Data System (ADS)

    Wendt, L.; Gasselt, S. V.; Neukum, G.

    2008-09-01

    Location Ariadnes Colles and the chaotic terrains Atlantis Chaos, Gorgonum Chaos and a further, unnamed chaotic terrain centred at 37°S, 164.4°W form individual provinces of hummocky terrain located at the deepest parts of Eridania Basin, the putative source region of Ma'adim Vallis [1,2,3,4]. The location was recently proposed as a MSL landing site [5]. Previous studies The individual knobs within Ariadnes Colles range between flat-topped mesas of up to 10 km in width and 200 m of relief down to small cone-shaped hills of only a few hundred meters in width [2] (Fig.1). Although classified as chaotic terrain, this area differs significantly from the chaotic terrains found elsewhere on Mars. The hills consist of a light-toned, indurated material [3, 5] covered by dark rock [1]. Howard and Moore [3] noted that the smaller knobs exhibit a more rounded top, are lower in elevation and are found close to the borders of the knob field, whereas the more mesa-like hills are concentrated towards its centre. They also noted that the light-toned hill tops are dissected by linear features they interpreted as joints. The mineralogy of this region is very diverse. Preliminary results based on CRISM data are consistent with the presence of phyllosilicates, sulphates and/or hydrated silica and pyroxene [5]. New obserations Our investigations using HRSC imagery confirm this overall pattern. The smaller hills consist exclusively of light-toned material and are covered only partly by a thin veneer of dust (Fig. 2). Their bases are angular or irregularly shaped and their tops are rounded to peaked, but never exhibit a mesa-like flat top. In contrast, the much larger mesas are always built up by basaltic material, which is superimposed on the bright knobs. Figure 3 shows a HiRISE image of one of the lighttoned knobs. It can be clearly seen that the light-toned material rises from beneath the inter-knob lava which covered it prior to erosion. It has been eroded and forms a scarp near

  7. The Psychological Problems of North Korean Adolescent Refugees Living in South Korea

    PubMed Central

    Lee, Young Mun; Shin, Ok Ja

    2012-01-01

    Objective As the number of North Korean adolescent refugees drastically increased in South Korea, there is a growing interest in them. Our study was conducted to evaluate the mental health of the North Korean adolescent refugees residing in South Korea. Methods The subjects of this study were 102 North Korean adolescent refugees in Hangyeore middle and high School, the public educational institution for the North Korean adolescent refugees residing in South Korea, and 766 general adolescents in the same region. The Korean version of Child Behavior Check List (K-CBCL) standardized in South Korea was employed as the mental health evaluation tool. Results The adolescent refugees group showed a significantly different score with that of the normal control group in the K-CBCL subscales for sociality (t=29.67, p=0.000), academic performance (t=17.79, p=0.000), total social function (t=35.52, p=0.000), social withdrawal (t=18.01, p=0.000), somatic symptoms (t=28.85, p=0.000), depression/anxiety (t=13.08, p=0.000), thought problems (t=6.24, p=0.013), attention problems (t=4.14, p=0.042), internalized problems (t=26.54, p=0.000) and total problems (t=5.23, p=0.022). Conclusion The mental health of the North Korean adolescent refugees was severe particularly in internalized problems when compared with that of the general adolescents in South Korea. This result indicates the need for interest in not only the behavior of the North Korean adolescent refugees but also their emotional problem. PMID:22993519

  8. Symbiosis of Steel, Energy, and CO2 Evolution in Korea

    NASA Astrophysics Data System (ADS)

    Lee, Hyunjoung; Matsuura, Hiroyuki; Sohn, Il

    2016-09-01

    This study looks at the energy intensity of the steel industry and the greenhouse gas intensity involved with the production of steel. Using several sources of steel production data and the corresponding energy sources used provides a time-series analysis of the greenhouse gas (GHG) and energy intensity from 1990 to 2014. The impact of the steel economy with the gross domestic product (GDP) provides indirect importance of the general manufacturing sector within Korea and in particular the steel industry. Beyond 2008, the shift in excess materials production and significant increase in total imports have led to an imbalance in the Korean steel market and continue to inhibit the growth of the domestic steel market. The forecast of the GHG and energy intensity along with the steel production up to 2030 is provided using the auto regressive integrated moving average analysis.

  9. Glacial reorganization of topography in a tectonically active mountain range

    NASA Astrophysics Data System (ADS)

    Adams, Byron; Ehlers, Todd

    2016-04-01

    Tests of the interactions between tectonic and climate forcing on Earth's topography often focus on the concept of steady-state whereby processes of rock deformation and erosion are opposing and equal. However, when conditions change such as the climate or tectonic rock uplift, then surface processes act to restore the balance between rock deformation and erosion by adjusting topography. Most examples of canonical steady-state mountain ranges lie within the northern hemisphere, which underwent a radical change in the Quaternary due to the onset of widespread glaciation. The activity of glaciers changed erosion rates and topography in many of these mountain ranges, which likely violates steady-state assumptions. With new topographic analysis, and existing patterns of climate and rock uplift, we explore a mountain range previously considered to be in steady-state, the Olympic Mountains, USA. The details of our analysis suggest the dominant topographic signal in the Olympic Mountains is a spatial, and likely temporal, variation in erosional efficiency dictated by orographic precipitation, and Pleistocene glacier ELA patterns, and not tectonic rock uplift rates. Alpine glaciers drastically altered the relief structure of the Olympic Mountains. The details of these relief changes are recorded in channel profiles as overdeepenings, reduced slopes, and associated knickpoints. We find the position of these relief changes within the orogen is dependent on the position of the Pleistocene ELA. While alpine glaciers overdeepened valleys in regions near the Pleistocene ELA (which has a tendency to increase relief), headward erosion of west and north flowing glacier systems captured significant area from opposing systems and caused drainage divide lowering. This divide lowering reduced relief throughout the range. We demonstrate similar topographic effects recorded in the basin hypsometries of other Cenozoic mountain ranges around the world. The significant glacial overprint on

  10. Lasting mantle scars lead to perennial plate tectonics

    PubMed Central

    Heron, Philip J.; Pysklywec, Russell N.; Stephenson, Randell

    2016-01-01

    Mid-ocean ridges, transform faults, subduction and continental collisions form the conventional theory of plate tectonics to explain non-rigid behaviour at plate boundaries. However, the theory does not explain directly the processes involved in intraplate deformation and seismicity. Recently, damage structures in the lithosphere have been linked to the origin of plate tectonics. Despite seismological imaging suggesting that inherited mantle lithosphere heterogeneities are ubiquitous, their plate tectonic role is rarely considered. Here we show that deep lithospheric anomalies can dominate shallow geological features in activating tectonics in plate interiors. In numerical experiments, we found that structures frozen into the mantle lithosphere through plate tectonic processes can behave as quasi-plate boundaries reactivated under far-field compressional forcing. Intraplate locations where proto-lithospheric plates have been scarred by earlier suturing could be regions where latent plate boundaries remain, and where plate tectonics processes are expressed as a ‘perennial' phenomenon. PMID:27282541

  11. Lasting mantle scars lead to perennial plate tectonics.

    PubMed

    Heron, Philip J; Pysklywec, Russell N; Stephenson, Randell

    2016-06-10

    Mid-ocean ridges, transform faults, subduction and continental collisions form the conventional theory of plate tectonics to explain non-rigid behaviour at plate boundaries. However, the theory does not explain directly the processes involved in intraplate deformation and seismicity. Recently, damage structures in the lithosphere have been linked to the origin of plate tectonics. Despite seismological imaging suggesting that inherited mantle lithosphere heterogeneities are ubiquitous, their plate tectonic role is rarely considered. Here we show that deep lithospheric anomalies can dominate shallow geological features in activating tectonics in plate interiors. In numerical experiments, we found that structures frozen into the mantle lithosphere through plate tectonic processes can behave as quasi-plate boundaries reactivated under far-field compressional forcing. Intraplate locations where proto-lithospheric plates have been scarred by earlier suturing could be regions where latent plate boundaries remain, and where plate tectonics processes are expressed as a 'perennial' phenomenon.

  12. Lasting mantle scars lead to perennial plate tectonics

    NASA Astrophysics Data System (ADS)

    Heron, Philip J.; Pysklywec, Russell N.; Stephenson, Randell

    2016-06-01

    Mid-ocean ridges, transform faults, subduction and continental collisions form the conventional theory of plate tectonics to explain non-rigid behaviour at plate boundaries. However, the theory does not explain directly the processes involved in intraplate deformation and seismicity. Recently, damage structures in the lithosphere have been linked to the origin of plate tectonics. Despite seismological imaging suggesting that inherited mantle lithosphere heterogeneities are ubiquitous, their plate tectonic role is rarely considered. Here we show that deep lithospheric anomalies can dominate shallow geological features in activating tectonics in plate interiors. In numerical experiments, we found that structures frozen into the mantle lithosphere through plate tectonic processes can behave as quasi-plate boundaries reactivated under far-field compressional forcing. Intraplate locations where proto-lithospheric plates have been scarred by earlier suturing could be regions where latent plate boundaries remain, and where plate tectonics processes are expressed as a `perennial' phenomenon.

  13. Geologic control of knickpoints in eastern part of Korea

    NASA Astrophysics Data System (ADS)

    Kim, Jong Yeon

    2010-05-01

    A knickpoint (KP) is a steepened reach in the fluvial longitudinal profile, often coinciding with the sharply defined descents of waterfalls or cascades that separate graded reaches. Despite the overall simplicity of this concept, there is confusion in definitions of a KP due to differences in the scales of research. For basin-scale research, KPs are generally steepened reaches sometimes described as ‘knickzones'(e.g., Zaprowski et al., 2001; Wolkowinski and Granger, 2004), whereas at the reach scale, KPs coincide with waterfalls and bedrock steps, regardless of their spatial dimensions. Here, the term is used in former, basin-scale sense. Bedrock KPs may originate from relative base-level fall (e.g., sea-level fall [Mosley, 1984; Yodis and Kesel, 1993] and/or surface uplift [Seeber and Gornitz, 1983; Humphrey and Konrad, 2000], lithological and structural controls (Pohn, 1983; Miller, 1991; Alexandrowicz, 1994), and changes in tributary inputs and discharge and sediment supply (Penck, 1925; von Engeln, 1940; Hasbargen and Paola, 2000). Recent work has also proposed that bedrock river KPs can initiated with base-level fall and migrate headward follow the tributaries (Crosby and Whipple, 2006). The origins of KPs can be different by the geomorphic setting of the drainage basin area. Especially the role of lithologic boundaries and faulting can be regarded as primary cause of KP formation. To find the role of lithologic control of KP distribution in Korea, longitudinal profiles of 12 streams, higher than 4th order in Horton-Strahler system, are analyzed. Longitudinal profiles are extracted from 1:25,000 Map Series (Korea National Geographic Institute) and the lithologic boundaries and fault lines are drawn based on the information from KIGAM's 1:50,000 Geological map series. Most of KPs are found near of lithologic boundaries or fault lines, however there are some KPs found upstream of large tributary input. However, physical strength of each lithologies have not

  14. Comparative study on the epidemiological aspects of enterohemorrhagic Escherichia coli infections between Korea and Japan, 2006 to 2010

    PubMed Central

    Lee, Won-Chang; Kwon, Young Hwan

    2016-01-01

    Background/Aims: To compare the epidemiological aspects of enterohemorrhagic Escherichia coli (EHEC) between Korea and Japan by analyzing the current state of EHEC infection outbreaks and related risk factors. Methods: We investigated the epidemiological aspects of EHEC infection cases between Korea and Japan from 2006 to 2010. The following factors were analyzed: national prevalence rate (PR), regional prevalence rate, epidemic aspects (i.e., Cases related to gender), male to female morbidity ratio, age, and seasonal distribution. Results: In total, there were 254 cases of EHEC with an average PR of 0.11 per 100,000 populations in Korea from 2006 to 2010. During the same period in Japan, there were 20,883 cases of EHEC with an average PR of 3.26 per 100,000 populations. The PR in Japan was significantly higher than that in Korea (p < 0.01). In both countries, more females than males had EHEC infections, with the highest incidence of infections (> 50%) observed for individuals younger than 9 years. EHEC is an emerging zoonosis and may be caused by consumption of raw or undercooked meat products from ruminants. Conclusions: This study provides a quantitative analysis of the epidemiological aspects and risk factors of EHEC infections in Korea and Japan and will provide insight on effective future strategies to reduce these infections. PMID:26886212

  15. Seismic images of modern convergent margin tectonic structure

    SciTech Connect

    Von Huene, R.; Miller, J.

    1986-07-01

    An atlas of 14 seismic sections shows major tectonic features across various convergent margins. All sections are at the same scale and have been processed to a research level. Such processing produces clear images of sediment accretion from below. Most margins show sediment subduction. The results of tectonic erosion are seen in midslope areas as buttresses against which the accretion complex is stacked. The images of structures indicating tectonic erosion are about as common as the images of structure indicating accretion.

  16. Tectonics of China: Continental scale cataclastic flow

    NASA Astrophysics Data System (ADS)

    Gallagher, John J., Jr.

    Stratigraphic, structural, and earthquake evidence indicates that cataclastic flow, that is, flow by brittle mechanisms (e.g., fracture and slip), was dominant in China from late Paleozoic. This process has operated over a range of scales including the continental scale. China is made up of large brittle basement elements immersed in ductile zones which are analogous to porphyroclasts (large, often brittle fragments) surrounded by fluxion (foliation or flow) structures in cataclastic rocks, respectively. This basement fabric for China is seen on Landsat imagery and on tectonic maps and is comparable to cataclastic rock fabrics seen in fault zones, on outcrops, and in thin sections. Brittle basement elements are broken into two or more large rigid blocks, and the dimensions of elements and blocks are within 1 order of magnitude of each other. Ductile zones are made up of fragments which are many orders of magnitude smaller than the ductile zones. Rigid blocks and fragments are identified, and their dimensions are measured through earthquake, fault, and fracture patterns. Rigid basement blocks are surrounded by earthquakes. The sedimentary rocks over the basement faults at the block boundaries seem to be affected by fault movements because they are characterized by facies changes, thickness changes, high-angle faults, and forced folds. Ductile basement zones are earthquake prone, and deformation of the ductile basement affects the overlying sedimentary rocks, as is demonstrated by unconformities and by a wide variety of structures. Thrust faults, buckle folds, and strike slip faults are common in and adjacent to western ductile zones. Structures are most intensely developed where ductile zones abut brittle elements. Both brittle elements and ductile zones are rifted and cut by strike slip faults in eastern China. The mechanical fabric of China and the boundary conditions acting on China are now and always have been determined by its plate tectonic history. This

  17. Plate tectonic models derived from multiple data sources: Examples from the Arctic

    NASA Astrophysics Data System (ADS)

    Webb, Peter; Masterton, Sheona; Eue, Dorothea

    2013-04-01

    hypotheses exist for the formation of the North American Cordillera; including the accretion of a series of allochthonous and parautochthonous terranes to ancestral North America in a prolonged orogeny, the formation of a ribbon continent in the Panthalassa Ocean which eventually accreted to North America or the accretion of two superterranes migrating northwards from significantly south of their present day position. To some degree, Russian Arctic tectonics mirrors the North American counterpart, with the Arctic Alaska and Chukotka terranes thought to be of similar or contiguous origin. The Verkhoyansk fold and thrust belt is formed during the collision of a micro-continent with the Siberian Craton and a series of arcs and back arcs accrete on the Pacific side of the craton. We demonstrate the construction of the plate model using the techniques described above to assess the validity of hypotheses and the origin of exotic Arctic terranes.

  18. Punctuated tectonic evolution of the earth

    NASA Astrophysics Data System (ADS)

    Davies, Geoffrey F.

    1995-12-01

    The potential of a phase transformation barrier to cause mantle layering has been incorporated into calculations of the thermal evolution of the earth's mantle based on parameterised convection theory. A range of possible behaviors is demonstrated, depending on parameter values, including episodic layering, long-term layering or no layering. Novel findings are 1-2 Ga phases that might correspond with major tectonic eras, and that early mantle overturns may have caused global magmatic and tectonic convulsions. For the more plausible parameter values, the models are initially layered, but typically the layering becomes unstable and breaks down episodically via mantle overturns. Subsequently the models evolve into whole-mantle convection due to the increasing ability of subducted plates to penetrate the phase barrier as the mantle cools, consistent with geophysical evidence against strong layering of the present mantle. The early layering-overturn cycles may occur on timescales of a few hundred million years. The overturns replace cooler upper mantle material with hotter lower mantle material, and would cause global convulsions that potentially correspond with episodes of crust formation. Such models permit plate tectonics to operate in the Archean between overturns, though the early crust may record mainly the effects of overturns, which could generate, aggregate and/or rework large volumes of mafic crust in a short time. They would help to explain present degrees of depletion of the mantle in incompatible elements as well as strong upper mantle depletion in the early Archean. The early convulsions may have controlled the composition of the atmosphere and frustrated the development of life.

  19. Tectonic classification of Cenozoic Iberian foreland basins

    NASA Astrophysics Data System (ADS)

    De Vicente, G.; Cloetingh, S.; Van Wees, J. D.; Cunha, P. P.

    2011-04-01

    The Iberian microcontinent stands out because of its intense Alpine intraplate deformation. This is reflected in a large number of Cenozoic basins of very different sizes. Most of the contacts between topographic highs and basins are thrust or strike-slip faults. All these basins seem to have undergone a common sedimentary evolution, comprising four stages: initiation of sedimentation, intense syn-tectonic infilling, change from endorheic to exorheic drainage, and accelerated erosion related to fluvial incision. This simple evolutionary model shows a migration from East to West, in which basins are still tectonically active at the Atlantic margin of Iberia. This common evolution is also found in a series of geometrical characteristics, such as the ratio r of length of strike-slip fault and length of thrust fault, that are very similar in both types of basin border settings. Thrust-related basins are mainly associated with segmented pop-downs, whereas the main basins have the characteristics of open-ramp basins. Strike-slip related basins are mostly transpressive structures, although small pull-apart basins are usual along the Vilariça and Messejana faults. For basin areas larger than 100-1000 km 2, a constant r value of 0.6 is found (including the Ebro, Duero, Madrid, Lower Tagus and Badajoz basins). Within the Iberian microcontinent, the total amount of Cenozoic contractional deformation was distributed between strike-slip and thrust faults with an r ratio close to 0.6. However, for small basins this parameter seems to depend on the type of fault, range or deformation belt (pure strike-slip, transtension, transpression, and pop-up) independently of its local tectonic development.

  20. Carbonate clumped isotope thermometry in continental tectonics

    NASA Astrophysics Data System (ADS)

    Huntington, Katharine W.; Lechler, Alex R.

    2015-04-01

    Reconstructing the thermal history of minerals and fluids in continental environments is a cornerstone of tectonics research. Paleotemperature constraints from carbonate clumped isotope thermometry have provided important tests of geodynamic, structural, topographic and basin evolution models. The thermometer is based on the 13C-18O bond ordering in carbonates (mass-47 anomaly, Δ47) and provides estimates of the carbonate formation temperature independent of the δ18O value of the water from which the carbonate grew; Δ47 is measured simultaneously with conventional measurements of carbonate δ13C and δ18O values, which together constrain the isotopic composition of the parent water. Depending on the geologic setting of carbonate growth, this information can help constrain paleoenvironmental conditions or basin temperatures and fluid sources. This review examines how clumped isotope thermometry can shed new light on problems in continental tectonics, focusing on paleoaltimetry, basin evolution and structural diagenesis applications. Paleoaltimetry is inherently difficult, and the precision in carbonate growth temperature estimates is at the limit of what is useful for quantitative paleoelevation reconstruction. Nevertheless, clumped isotope analyses have enabled workers to address previously intractable problems and in many settings offer the best chance of understanding topographic change from the geologic record. The portion of the shallow crust residing at temperatures up to ca. 200 °C is important as host to economic resources and records of tectonics and climate, and clumped isotope thermometry is one of the few proxies that can access this critical range with sensitivity to temperature alone. Only a handful of studies to date have used clumped isotopes to investigate diagenesis and other sub-surface processes using carbonate crystallization temperatures or the sensitivity of Δ47 values to a sample's thermal history. However, the thermometer is

  1. Dynamics of positional warfare malaria: Finland and Korea compared

    PubMed Central

    Huldén, Lena; Huldén, Larry

    2008-01-01

    Background A sudden outbreak of vivax malaria among Finnish troops in SE-Finland and along the front line in Hanko peninsula in the southwest occurred in 1941 during World War II. The common explanation has been an invasion of infective Anopheles mosquitoes from the Russian troops crossing the front line between Finland and Soviet Union. A revised explanation is presented based on recent studies of Finnish malaria. Methods The exact start of the epidemic and the phenology of malaria cases among the Finnish soldiers were reanalyzed. The results were compared with the declining malaria in Finland. A comparison with a corresponding situation starting in the 1990's in Korea was performed. Results and discussion The malaria cases occurred in July in 1941 when it was by far too early for infective mosquitoes to be present. The first Anopheles mosquitoes hatched at about the same time as the first malaria cases were observed among the Finnish soldiers. It takes about 3 – 6 weeks for the completion of the sporogony in Finland. The new explanation is that soldiers in war conditions were suddenly exposed to uninfected mosquitoes and those who still were carriers of hypnozoites developed relapses triggered by these mosquitoes. It is estimated that about 0.5% of the Finnish population still were carriers of hypnozoites in the 1940's. A corresponding outbreak of vivax malaria in Korea in the 1990's is similarly interpreted as relapses from activated hypnozoites among Korean soldiers. The significance of the mosquito induced relapses is emphasized by two benefits for the Plasmodium. There is a synchronous increase of gametocytes when new mosquitoes emerge. It also enables meiotic recombination between different strains of the Plasmodium. Conclusion The malaria peak during the positional warfare in the 1940's was a short outbreak during the last phase of declining indigenous malaria in Finland. The activation of hypnozoites among a large number of soldiers and subsequent

  2. Interdecadal variation of Korea affecting tropical cyclone intensity

    NASA Astrophysics Data System (ADS)

    Choi, Ki-Seon; Cha, Yu-Mi; Kang, Sung-Dae; Kim, Hae-Dong

    2015-05-01

    This study analyzed a time series of average central pressure of tropical cyclone (TC) that affected Korea in summer season from 1965 to 2012. To determine whether climate regime shift exists in this time series, statistical change-point analysis was applied to this time series. The result showed that significant climate regime shift existed in 1989, that is, TC intensity from 1965 to 1988 (6588) was weaker than that from 1989 to 2012 (8912). Therefore, an average difference between former and latter periods was analyzed to study large-scale environments, which caused such difference. While TC genesis frequency showed a tendency that TCs in the 6588 period were originated from the northwest quadrant in the tropical and subtropical western North Pacific, TCs in the 8912 period were originated from the southeast quadrant. Thus, it was judged that TCs in the 6588 were generated at a higher latitude followed by moving to Korea, so their strength was weaker than those of TCs of 8912 due to lack of time to acquire sufficient energy from the sea. For TC passage frequency, TCs in the 6588 period showed a tendency to move a short distance from the sea far away from the southeast in Japan to the sea far away from the northeast in Japan or toward the East China Sea. On the other hand, TCs in the 8912 period moved a longer distance from the sea far away from the Philippines via Japan to the eastern sea of Kamchatka Peninsular or toward the east region in China. As such, an average difference of intensity between the former period and the latter period over the 500-hPa streamline was analyzed to determine why the intensity of TCs in the 6588 period was weaker than that of TCs in the 8912 period. As a result, anomalous cold northerlies from anomalous cyclones based on the northern territory of Japan were predominant, while these anomalous flows were originated from the tropical and subtropical western Pacific followed by moving to Korea, thereby affecting the weakening of the TC

  3. From tectons to luminescent supramolecular ionic liquid crystals.

    PubMed

    Dechambenoit, Pierre; Ferlay, Sylvie; Donnio, Bertrand; Guillon, Daniel; Hosseini, Mir Wais

    2011-01-14

    New phosphorescent and room-temperature liquid-crystalline materials were obtained by combining dicyanometallate anions with dicationic bisamidinium based tectons bearing four peripheral lipophilic pyrogallate moieties.

  4. Volcanism/tectonics working group summary

    SciTech Connect

    Kovach, L.A.; Young, S.R.

    1995-09-01

    This article is a summary of the proceedings of a group discussion which took place at the Workshop on the Role of Natural Analogs in Geologic Disposal of High-Level Nuclear Waste in San Antonio, Texas on July 22-25, 1991. The working group concentrated on the subject of the impacts of earthquakes, fault rupture, and volcanic eruption on the underground repository disposal of high-level radioactive wastes. The tectonics and seismic history of the Yucca Mountain site in Nevada is discussed and geologic analogs to that site are described.

  5. Tectonic Uplift and Eastern Africa Aridification

    NASA Astrophysics Data System (ADS)

    Sepulchre, Pierre; Ramstein, Gilles; Fluteau, Frédéric; Schuster, Mathieu; Tiercelin, Jean-Jacques; Brunet, Michel

    2006-09-01

    The history of Eastern African hominids has been linked to a progressive increase of open grassland during the past 8 million years. This trend was explained by global climatic processes, which do not account for the massive uplift of eastern African topography that occurred during this period. Atmosphere and biosphere simulations quantify the role played by these tectonic events. The reduced topographic barrier before 8 million years ago permitted a zonal circulation with associated moisture transport and strong precipitation. Our results suggest that the uplift itself led to a drastic reorganization of atmospheric circulation, engendering the strong aridification and paleoenvironmental changes suggested by the data.

  6. Plate tectonic history of the Arctic

    NASA Technical Reports Server (NTRS)

    Burke, K.

    1984-01-01

    Tectonic development of the Arctic Ocean is outlined, and geological maps are provided for the Arctic during the mid-Cenozoic, later Cretaceous, late Jurassic, early Cretaceous, early Jurassic and late Devonian. It is concluded that Arctic basin history is moulded by the events of the following intervals: (1) continental collision and immediately subsequent rifting and ocean formation in the Devonian, and continental rifting ocean formation, rapid rotation of microcontinents, and another episode of collision in the latest Jurassic and Cretaceous. It is noted that Cenozoic Arctic basin formation is a smaller scale event superimposed on the late Mesozoic ocean basin.

  7. The Tectonics and Evolution of Venus

    NASA Technical Reports Server (NTRS)

    Kaula, William M.

    1997-01-01

    This shift corresponded to a focusing of research on Venus. Some work included comparison with other planets. Venus research is being continued. The research can be summarized under five headings: (1) Planet formation; (2) Thermal and Compositional Evolution; (3) Tectonic structures and processes; (4) Determination and interpretation of gravity; and (5) Analyses of Ishtar Terra. Thirty-four publications were produced. References to publications supporting the summary are by year and letter: e.g., (1990 c,d) for the emphasis on the terminal phases in formation studies.

  8. Global Tectonics of Enceladus: Numerical Model

    NASA Astrophysics Data System (ADS)

    Czechowski, Leszek

    2016-10-01

    Introduction: Enceladus, a satellite of Saturn, is the smallest celestial body in the Solar System where volcanic and tectonic activities are observed. Every second, the mass of 200 kg is ejected into space from the South Polar Terrain (SPT) - [1]. The loss of matter from the body's interior should lead to global compression of the crust. Typical effects of compression are: thrust faults, folding and subduction. However, such forms are not dominant on Enceladus. We propose here special tectonic process that could explain this paradox. Our hypotheses states that the mass loss from SPT is the main driving mechanism of the following tectonic processes: subsidence of SPT, flow in the mantle and motion of adjacent tectonic plates. The hypotheses is presented in [2], [3] and[4].We suggest that the loss of the volatiles results in a void, an instability, and motion of solid matter to fill the void. The motion is presented at the Fig.1 and includes:Subsidence of the 'lithosphere' of SPT.Flow of the matter in the mantle.Motion of plates adjacent to SPT towards the active regionMethods and results: The numerical model of processes presented is developed. It is based on the equations of continuous media..If emerging void is being filled by the subsidence of SPT only, then the velocity of subsidence is 0.05 mmyr-1. However, numerical calculations indicate that all three types of motion are usually important. The role of a given motion depends on the viscosity distribution. Generally, for most of the models the subsidence is 0.02 mmyr-1, but mantle flow and plates' motion also play a role in filling the void. The preliminary results of the numerical model indicate also that the velocity of adjacent plates could be 0.02 mmyr-1 for the Newtonian rheology.Note that in our model the reduction of the crust area is not a result of compression but it is a result of the plate sinking. Therefore the compressional surface features do not have to be dominant. The SPT does not have to be

  9. Global organization of tectonic deformation on Venus

    NASA Technical Reports Server (NTRS)

    Bilotti, Frank; Connors, Chris; Suppe, John

    1993-01-01

    The geographic organization of surface deformation on Venus as on Earth is a key to understanding the global tectonic system. To date we have mapped the distribution of three unambiguous tectonic land forms on Venus: (1) linear foldbelts analogous to those at plate margins of the Earth; (2) linear rift zones, analogous to continental rifts on the Earth; and (3) distributed plains deformation in the form of wrinkle ridges and extensional faults and fractures. The linear foldbelts are the dominant structural style in the Northern Hemisphere; ninety percent of the planet's foldbelts lie above the equator. In contrast, compressive deformation in the Southern Hemisphere is dominated by two large, sweeping patterns of wrinkle ridges. The two hemispheres are divided by an equatorial region that is largely covered by rift zones and several large tessera blocks. A tectonic model of generally poleward convergence of the Northern Hemisphere explains the distribution of foldbelts and rift zones. In our model, a northern hemispherical plate (or system of plates) moves poleward and deforms along discrete, predominately longitudinal bands. We recognize four types of foldbelts based on their relationships to other large-scale tectonic features on Venus. There are foldbelts that lie within the low plains, foldbelts associated with coronae, novae and chasmata, foldbelts that lie at the margins of poly-deformed tessera plateaus, and the folded mountain belts around Lakshmi Planum. We see a geometric increase in the area of fold belts when normalized to percent area at a given latitude. This increase is consistent with our model of poleward convergence. Also, the orientations of most foldbelts are either approximately north-south or parallel to lines of latitude in the northern hemisphere. This observation is also consistent with the model in that the longitudinal bands are the result of the decreasing area of the sphere as the plate moves poleward and the latitudinal belts are the

  10. Tectonic history of the terrestrial planets

    NASA Technical Reports Server (NTRS)

    Solomon, Sean C.

    1990-01-01

    It is impossible in a single brief summary to convey the full range of research results that have come from this project over the last 13 years. The sweep of subjects covered ranges widely over the broad areas of the thermal and tectonic evolution of the terrestrial planets. A full list of all publications supported by this grant is presented. The list includes 48 published journal articles, 2 papers currently in press, 3 chapters of books, 4 M.I.T. theses, 1 technical report, and 107 published abstracts and extended abstracts. All of these publications were submitted separately to NASA at the time of publication or submission.

  11. Sexual Violence among Men in the Military in South Korea

    ERIC Educational Resources Information Center

    Kwon, Insook; Lee, Dong-Ok; Kim, Elli; Kim, Hyun-Young

    2007-01-01

    This research is about sexual violence among men in the military in South Korea. The authors investigated the frequencies, causes, and circumstances surrounding sexual violence and looked for characteristic features of sexual violence among men in the military in South Korea. They found a high frequency of physical sexual violence and a high level…

  12. 76 FR 54791 - Polyethylene Terephthalate (PET) Film From Korea

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-02

    ... COMMISSION Polyethylene Terephthalate (PET) Film From Korea Determination On the basis of the record \\1... antidumping duty order on polyethylene terephthalate (PET) film from Korea would not be likely to lead to... contained in USITC Publication 4254 (August 2011), entitled Polyethylene Terephthalate (PET) Film from...

  13. The Beginnings of Modern Education in Korea, 1883-1910

    ERIC Educational Resources Information Center

    Dittrich, Klaus

    2014-01-01

    Korea opened up to foreign intercourse in 1876, when the country concluded its first international treaty with Japan. Similar treaties with European and American nations followed during the 1880s. The period until 1910, when Korea was annexed to the Japanese Empire, saw manifold attempts to reform as well as resistance to these reforms. Against…

  14. Promoting E-Learning for Human Resource Development in Korea.

    ERIC Educational Resources Information Center

    Lee, Soo-Kyoung

    In Korea, e-learning is becoming increasingly prevalent and spreading into various aspects of human resources development. Korea's Ministry of Education and Human Resources Development (MOEHRD) and Ministry of Labor (MOL) have been especially active in establishing the legal basis and institutional framework to make e-learning a reality.…

  15. Japanese Higher Education Policy in Korea (1910-1945).

    ERIC Educational Resources Information Center

    Lee, Jeong-Kyu

    2002-01-01

    Examines the impact of Japanese nationalistic thought on the administrative systems and structures of colonial and modern higher education in Korea and analyzes Japanese educational policy in Korea in the colonial period (1910-1945). Identifies beneficial and negative impacts of the Japanese colonial education system. (SLD)

  16. Integrating Standardization into Engineering Education: The Case of Forerunner Korea

    ERIC Educational Resources Information Center

    Choi, Dong Geun; de Vries, Henk J.

    2013-01-01

    The Republic of Korea is a forerunner in integrating the topic of standardization into engineering education at the academic level. This study investigates developments and evolutions in the planning and operating of the University Education Promotion on Standardization (UEPS) in Korea. This paper examines why the Korean government initiated the…

  17. An Ecological Understanding of Youth Suicide in South Korea

    ERIC Educational Resources Information Center

    Lee, Seung-yeon; Hong, Jun Sung; Espelage, Dorothy L.

    2010-01-01

    This article reviews risk factors for youth suicide in South Korea (hereafter referred to as Korea), based on the ecological systems theory. Although youth suicide is a major concern for Korean society, understanding of this phenomenon has been limited since most of the empirical studies address personal characteristics without much consideration…

  18. South Korea: Language Policy and Planning in the Making

    ERIC Educational Resources Information Center

    Song, Jae Jung

    2012-01-01

    This monograph discusses South Korea's language situation in a language policy and planning context. This monograph consists of four parts. Part 1 presents a genetic, typological and sociolinguistic description of South Korea's national language, and an overview of minority languages, including English as well as other languages, recently…

  19. Motivations and Experiences of Expatriate Educators in South Korea

    ERIC Educational Resources Information Center

    Oliver, Nicolette

    2009-01-01

    This research is a qualitative case study of native English instructors at the Gyeonggi-do Institute for Foreign Language Education (GIFLE) in South Korea. A literature review of issues regarding expatriate educators is included. The guiding questions for this study include why these instructors chose to become educators, move to South Korea, and…

  20. English Education and Teacher Education in South Korea

    ERIC Educational Resources Information Center

    Jo, Seongja

    2008-01-01

    The spread of the English language is a global phenomenon, but it has a particular resonance in South Korea, where English is second only to Korean as a common language. The paper examines the current educational context in South Korea and the policy and practice issues that arise within this context regarding teacher education in English as a…