1,404 research outputs found

    Sedimentary record of coseismic subsidence in Hersek coastal lagoon (Izmit Bay, Turkey) and the late Holocene activity of the North Anatolian Fault

    Get PDF
    This research was funded by the European Union in the framework of the REL.I.E.F. (Reliable Information on Earthquake Faulting) project (EVG1‐CT‐2002‐00069). Copyright @ 2011 American Geophysical Union.The late Holocene activity of a restraining bend of the northern strand of the North Anatolian Fault in Izmit Bay was investigated by a sedimentological, geochemical, and paleoecological analysis of sediment cores from Hersek coastal lagoon, NW Turkey. The sediment cores show a succession of sedimentary sequences composed of three units separated by gradual transitions. The first unit is composed of a thin layer of shell debris-rich sediment in abrupt contact with the underlying organic-rich deposits. This unit is over-lain by a thick foraminifera-rich mud deposit, and the sequences are capped by an organic-rich mud unit. These sequences are interpreted as silting up, shallowing upward deposits, typical of a lagoon becoming isolated from the sea. We suggest that they represent the sedimentary signature of coseismic subsidence, which was caused by reverse slip at the Hersek bend, and tsunamis in Izmit Bay. Our radiocarbon-dated paleoseismological record indicates (1) the atypical collapse of the hanging wall during the 740 earthquake and (2) subsidence of the footwall during the 987, 1509, and 1719 earthquakes. This study contributes to the understanding of the dynamics of restraining bends, and it highlights the potential of coastal sediments for reconstructing past earthquakes and tsunamis in regions dominated by strike-slip deformations.This article is available through the Brunel Open Access Publishing Fun

    Public Relations Work to Increase Attainability Relating to EMail-Communication

    Full text link
    The mere allotment of an e-mail address does in no way ensure answering quotas, which could be called sufficient to dependably hand out important information via roundmail. A loss of accessibility through e-mail addresses already provided by the university can be due to various technical problems and personal deficiencies of motivation. Students in particular often use external providers and are often also not on familiar terms with the use of consistent personal e-mail archives, POP-accounts, Web-Mail-Portals and the use of forewarding functions. Special email-courses are being offered within regular further training for staff and students

    EMail-Verteiler zur Distribution digitaler Informationen im Zentrum fĂŒr ZMK-MĂŒnster

    Full text link
    Auf der Basis verschiedener in HTML-Seiten integrierter PHP-Scripte können EMails an vordefinierte Zielgruppen, z.B. an alle Studenten, an alle Mitarbeiter einer Poliklinik oder auch an eine manuell selektierbare individuelle Liste von Personen geschickt werden. Der PHP-Server des Apache-Webserves sorgt fĂŒr eine augenblickliche, schnelle Distribution ohne AbhĂ€ngigkeit von Mail-Servern der UniversitĂ€t, persönlichen Providern oder lokalen EMail-Programmen. Digitale Verteiler sind herkömmlichen 'Snail-Mail'-Verteilern in Geschwindigkeit und QualitĂ€t weit ĂŒberlegen und werden diese vermutlich bald vollstĂ€ndig ersetzen können

    Extraktionskonzept bei multiplen vorzeitigen Milchzahnverlusten und horizontaler Verlagerung eines Eckzahnes

    Full text link
    Eine 9-jĂ€hrige Patientin stellte sich mit multiplen StĂŒtzzoneneinbrĂŒchen durch kariesbedingte vorzeitige Milchzahnverluste, einem vollretinierten, horizontal verlagerten Zahn 33, Mittellinienverschiebung sowie einem Unterkieferengstand zur kieferorthopĂ€dischen Beratung vor. Initial wurde im Ober- und Unterkiefer durch das Tragen aktiver Platten ein Fortschreiten der StĂŒtzzoneneinbrĂŒche verhindert, Milchzahnextraktionen durchgefĂŒhrt und auf den verzögerten Durchbruch der PrĂ€molaren gewartet. Im Alter von 10 Jahren wurden die ZĂ€hne 14, 24 und 44 extrahiert, sowie die operative Entfernung des verlagerten Zahnes 33 durchgefĂŒhrt. In einer knapp 2-jĂ€hrigen Multibracket-Therapie wurden die ZĂ€hne 44, 45, 46 mesialisiert und Zahn 44 an Eckzahnposition im 4. Quadranten eingestellt. Die verbleibenden ExtraktionslĂŒcken wurden geschlossen und die Oberkiefermitte eingestellt

    Correlations of Heavy Quarks Produced at Large Hadron Collider

    Full text link
    We study the correlations of heavy quarks produced in relativistic heavy ion collisions and find them to be quite sensitive to the effects of the medium and the production mechanisms. In order to put this on a quantitative footing, as a first step, we analyze the azimuthal, transverse momentum, and rapidity correlations of heavy quark-anti quark (QQ‟Q\overline{Q}) pairs in pppp collisions at O\cal{O}(αs3\alpha_{s}^{3}). This sets the stage for the identification and study of medium modification of similar correlations in relativistic collision of heavy nuclei at the Large Hadron Collider. Next we study the additional production of charm quarks in heavy ion collisions due to multiple scatterings, {\it viz.}, jet-jet collisions, jet-thermal collisions, and thermal interactions. We find that these give rise to azimuthal correlations which are quite different from those arising from prompt initial production at leading order and at next to leading order.Comment: 26 pages, 15 figures. Three new figures added, comparison to experimental data included, abstract and discussion expande

    Quantitative reconstruction of precipitation changes on the NE Tibetan Plateau since the Last Glacial Maximum – extending the concept of pollen source area to pollen-based climate reconstructions from large lakes

    Get PDF
    Pollen records from large lakes have been used for quantitative palaeoclimate reconstruction, but the influences that lake size (as a result of species-specific variations in pollen dispersal patterns that smaller pollen grains are more easily transported to lake centre) and taphonomy have on these climatic signals have not previously been systematically investigated. We introduce the concept of pollen source area to pollen-based climate calibration using the north-eastern Tibetan Plateau as our study area. We present a pollen data set collected from large lakes in the arid to semi-arid region of central Asia. The influences that lake size and the inferred pollen source areas have on pollen compositions have been investigated through comparisons with pollen assemblages in neighbouring lakes of various sizes. Modern pollen samples collected from different parts of Lake Donggi Cona (in the north-eastern part of the Tibetan Plateau) reveal variations in pollen assemblages within this large lake, which are interpreted in terms of the species-specific dispersal and depositional patterns for different types of pollen, and in terms of fluvial input components. We have estimated the pollen source area for each lake individually and used this information to infer modern climate data with which to then develop a modern calibration data set, using both the multivariate regression tree (MRT) and weighted-averaging partial least squares (WA-PLS) approaches. Fossil pollen data from Lake Donggi Cona have been used to reconstruct the climate history of the north-eastern part of the Tibetan Plateau since the Last Glacial Maximum (LGM). The mean annual precipitation was quantitatively reconstructed using WA-PLS: extremely dry conditions are found to have dominated the LGM, with annual precipitation of around 100 mm, which is only 32% of present-day precipitation. A gradually increasing trend in moisture conditions during the Late Glacial is terminated by an abrupt reversion to a dry phase that lasts for about 1000 yr and coincides with "Heinrich event 1" in the North Atlantic region. Subsequent periods corresponding to the BĂžlling/AllerĂžd interstadial, with annual precipitation (<i>P</i><sub>ann</sub>) of about 350 mm, and the Younger Dryas event (about 270 mm <i>P</i><sub>ann</sub>) are followed by moist conditions in the early Holocene, with annual precipitation of up to 400 mm. A drier trend after 9 cal. ka BP is followed by a second wet phase in the middle Holocene, lasting until 4.5 cal. ka BP. Relatively steady conditions with only slight fluctuations then dominate the late Holocene, resulting in the present climatic conditions. The climate changes since the LGM have been primarily driven by deglaciation and fluctuations in the intensity of the Asian summer monsoon that resulted from changes in the Northern Hemisphere summer solar insolation, as well as from changes in the North Atlantic climate through variations in the circulation patterns and intensity of the westerlies

    Parity Violation in Proton-Proton Scattering at 221 MeV

    Full text link
    TRIUMF experiment 497 has measured the parity violating longitudinal analyzing power, A_z, in pp elastic scattering at 221.3 MeV incident proton energy. This paper includes details of the corrections, some of magnitude comparable to A_z itself, required to arrive at the final result. The largest correction was for the effects of first moments of transverse polarization. The addition of the result, A_z=(0.84 \pm 0.29 (stat.) \pm 0.17 (syst.)) \times 10^{-7}, to the pp parity violation experimental data base greatly improves the experimental constraints on the weak meson-nucleon coupling constants h^{pp}_\rho and h^{pp}_\omega, and has implications for the interpretation of electron parity violation experiments.Comment: 17 pages RevTeX, 14 PostScript figures. Revised version with additions suggested by Phys. Rev.
    • 

    corecore