335 research outputs found
Trace parameters for Teichmuller space of genus 2 surfaces and mapping class group
We obtain a representation of the mapping class group of genus 2 surface in terms of a coordinate system of the Teichmuller space defined by trace functions
Deep Investigations of Outer-Rise Tsunami Characteristics Using Well-Mapped Normal Faults Along the Japan Trench
To assess the risk of tsunamis from outer-rise earthquakes, we carried out tsunami simulations using 33 simple rectangular fault models with 60° dip angles based on marine seismic observations and surveys of the Japan Trench. The largest tsunami resulting from these models, produced by a Mw 8.7 normal-faulting event on a fault 332 km long, had a maximum height of 27.0 m. We tested variations of the predictions due to the uncertainties in the assumed parameters. Because the actual dip angles of the Japan Trench outer-rise faults range from 45° to 75°, we calculated tsunamis from earthquakes on fault models with 45°, 60°, and 75° dip angles. We also tested a compound fault model with 75° dip in the upper half and 45° dip in the lower half. Rake angles were varied by ±15°. We also tested models consisting of small subfaults with dimensions of about 60 km, models using other earthquake scaling laws, models with heterogeneous slips, and models incorporating dispersive tsunami effects. Predicted tsunami heights changed by 10–15% for heterogeneous slips, up to 10% for varying dip angles, about 5–10% from considering tsunami dispersion, about 2% from varying rake angles, and about 1% from using the model with small subfaults. The use of different earthquake scaling laws changed predicted tsunami heights by about 50% on average for the 33 fault models. We emphasize that the earthquake scaling law used in tsunami predictions for outer-rise earthquakes should be chosen with great care
Spatial variations of incoming sediments at the northeastern Japan arc and their implications for megathrust earthquakes
The nature of incoming sediments is a key controlling factor for the occurrence of megathrust earthquakes in subduction zones. In the 2011 Mw 9 Tohoku earthquake (offshore Japan), smectite-rich clay minerals transported by the subducting oceanic plate played a critical role in the development of giant interplate coseismic slip near the trench. Recently, we conducted intensive controlled-source seismic surveys at the northwestern part of the Pacific plate to investigate the nature of the incoming oceanic plate. Our seismic reflection data reveal that the thickness of the sediment layer between the seafloor and the acoustic basement is a few hundred meters in most areas, but there are a few areas where the sediments appear to be extremely thin. Our wide-angle seismic data suggest that the acoustic basement in these thin-sediment areas is not the top of the oceanic crust, but instead a magmatic intrusion within the sediments associated with recent volcanic activity. This means that the lower part of the sediments, including the smectite-rich pelagic red-brown clay layer, has been heavily disturbed and thermally metamorphosed in these places. The giant coseismic slip of the 2011 Tohoku earthquake stopped in the vicinity of a thin-sediment area that is just beginning to subduct. Based on these observations, we propose that post-spreading volcanic activity on the oceanic plate prior to subduction is a factor that can shape the size and distribution of interplate earthquakes after subduction through its disturbance and thermal metamorphism of the local sediment layer
Knowledge-based development of a nitrate-free synthesis route for Cu/ZnO methanol synthesis catalysts via formate precursors
Angiopoietin-1 Gene Therapy Attenuates Hypertension and Target Organ Damage in Nitric Oxide Synthase Inhibited Spontaneously Hypertensive Rats
Clinical Incidence of Sacroiliac Joint Arthritis and Pain after Sacropelvic Fixation for Spinal Deformity
∙ The authors have no financial conflicts of interest. © Copyright: Yonsei University College of Medicine 2012 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial Licens
Antiphospholipid Antibodies in Patients with Myasthenia Gravis
We measured antiphospholipid antibodies in sera from 94 patients with myasthenia gravis (MG). We found lgG aCL in 14/94 (14.9 % )lgM aCL in 6/94 (6.4 %) and LA in 4/56 (7.1 %) patients with MG. As a whole 21 of 94 (22.3 % ) patients with MG had some aPL. There was no correlation between the presence of aPL and the severity of MGthe presence of hyperplasia of thymustiter of the antiacetylcholine receptor antibodies or anti-single stranded DNA antibodies. Though the percentage of malignant thymoma with aPL were higher than that of malignant thymoma without aPLwe thought that aPL were not the specific antibody in malignant thymoma. In MGaPL did not play as the aCL syndrome and seemed to be non-specific antibodies
The Radio to Infrared Emission of Very High Redshift Gamma-Ray Bursts: Probing Early Star Formation through Molecular and Atomic Absorption Lines
We evaluate the broadband afterglow emission of very high redshift gamma-ray
bursts (GRBs) using standard relativistic blastwave models with both forward
and reverse shock components. For a broad range of parameters, a generic
property for GRBs at redshifts 5--30 is that the emission peaks in the
millimeter to far-infrared bands with milli-Jansky flux levels, first at a few
hours after the burst due to the reverse shock, and then again for several days
afterwards with somewhat lower flux due to the forward shock. The radio,
submillimeter and infrared continuum emission should be readily detectable out
to z \ga 30 by the Atacama Large Millimeter Array (ALMA), Extended Very Large
Array (EVLA), Square Kilometer Array (SKA) and other facilities. For relatively
bright bursts, spectroscopic measurements of molecular and atomic absorption
lines due to ambient protostellar gas may be possible. Utilizing models of
primordial protostellar clouds, we show that under certain conditions,
appreciable absorption may be caused by HD rotational transitions even in
metal-free environments. After sufficient metal enrichment, absorption from CO
rotational transitions and [OI] fine-structure transitions can also become
strong. With appropriate observing strategies in combination with optical
telescopes, ALMA and/or SKA may be able to detect such lines, offering a unique
probe of physical conditions in individual Pop III and early Pop II star
forming regions. We also remark on potential near-infrared absorption features
due to electronic transitions of H.Comment: MNRAS, in press; 16 pages, 11 figure
- …