Preliminary analysis of the shear-wave splitting observations from the Qiaojia seismic array

A total of 351 shear-wave splitting results at 25 stations were obtained from the seismic data recorded in period of January,2013 to December,2016,by a broadband seismic array deployed in the northern segment of Xiaojiang Fault Zone(n-XJFZ).Meanwhile,the stress field of the n-XJFZ was determined by inverting 140 focal mechanism solutions of the small earthquakes within the study area which were recorded in the same period.This determination confirmed a compressive stress in NW-SE orientation and an extensional stress in the NE-SW orientation,with little difference from those released by previous studies.The shear-wave splitting results show a spatial complexity in polarization orientation,different from one site to another.How-ever,the polarization orientations integrated for the subareas suggest that the fault trends seemingly played important roles.All the subareas bear two dominant orientations,N10°E and N90°E,both of which are different from the azimuths of the principal compressive stress,due to the fault distribution.The time delay averaged over the entire region is 4.56 ms/km,close to that of the upper boundary of the generally accepted interval worldwide but larger than those in most of the investigated regions in the Chinese mainland,which probably implies an alignment of more micro-cracks in the n-XJFZ.Interestingly,the 2014 Ms6.5 Ludian earthquake was found to have caused a variation in the time delays of the slow shear waves within the study area though its epicenter was outside.This earthquake resulted in an evident drop of the time delays remaining for 4 months,however,lifted a bit the time-delay level with respect to that prior to the earthquake.

The Character of Shear-wave Splitting in Marble in the Critical State of Rupture

This paper mainly observed and analyzed the character of shear-wave splitting in rock specimens while they were in the critical state of rupture. The rock specimens for study are made of Laizhou marble from Shandong, China. A series of records were obtained from two rock specimens when they were in the critical state of rupture. The result shows that, in the critical state just before rock rupture, there may be the phenomenon of rise and fall in the time delay of shear-wave splitting, even though the load was kept constant. That is to say, the time delay of shear-wave splitting may have a falling process before rock rupture.

Correlation of Surgical Times with Laparoscopic Live Donor Kidney Transplant Outcomes

Most studies revealed that ischemic time has substantial role in occurrence of delayed graft function (DGF) after deceased donor kidney transplantation. However, less is known about the potential impact of surgical times on early outcomes following live donor kidney transplantation. A retrospective cohort of 189 consecutive laparoscopic live donor kidney transplant (LDKT) recipients from January 2006 to August 2012 was analyzed to reveal the impact of pneumoperitoneum time (PT) and anastomosis time (AT) on donor and recipient length of hospital stay and early graft function (EGF). DGF was observed in 13 (6.8%) patients while slow graft function (SGF) was seen in 27 (14%) of the recipients. The median AT was 28 minutes (interquartile range 23, 35 minutes). AT was associated with DGF (Odds Ratio [OR] 1.044, per minute, 95% CI 1.007, 1.082, p = 0.018). Median recipient length of hospital stay was 8 (interquartile range 7, 11) days. Every 13.5 minutes of longer AT was associated with 1 extra day in hospital. The median PT was 180 minutes (interquartile range 144, 234 minutes). PT was associated with both DGF (OR 1.013 per minute, 95% CI 1.005, 1.021, p = 0.001) and SGF (OR 1.009 per minute, 95% CI 1.002, 1.016, p = 0.016). Every extra hour of PT was associated with 0.42 more days in hospital for the donor. Surgical times may be underestimated variables in dictating use of hospital resources. The effect of surgical times on long term hard outcomes entails further study.

Study on the S-wave Splitting Characteristics in the Longtan Reservoir Area,Guangxi,China

In this paper,the shear wave splitting features of the Longtan reservoir area are studied by adopting the traditional cross-correlation coefficient method and polarization analysis,using the data recorded by the seismic network founded by a project under the National Science and Technology Pillar Program from April 2009 to April 2010.We found that most of polarization directions at seismic stations are consistent with the direction of the overall regional stress field,but local structures and faults may control or influence the fast shear-wave polarization direction.The time-delay normalized to source-station path is between 10 to 25ms/km,and among them,the time-delay is about 10ms/km at the LIL and XIL sites,which are farther away from the dam.The water depth is relatively shallow and seismic activity relatively weak after water storage,indicating the effect of reservoir water penetration,or loading,on the state of cracks in the reservoir area.We also found that the delay time changes consistently with the water level at stations DPD and GAL.It may be related to crack expansion and water penetration caused by the reservoir impoundment.

On Shear Wave Splitting in the Zhangjiakou-Bohai Sea Seismic Belt

The Zhangjiakou-Bohai Sea seismic belt is an important seismic zone in North China. The direction of principal compressive stress is near EW in this region. According to digital seismic data from the Capital Region from September 2005 to September 2010,and using the SAM method,the spatial distribution of the crust anisotropy characteristics are studied and discussed in the middle-eastern part of the Zhangjiakou-Bohai Sea seismic belt. The principal polarization direction,which is near EW direction,is obvious in the middleeastern Zhangjiakou-Bohai Sea seismic belt. The spatial distribution of polarization direction crossing the Zhangjiakou-Bohai Sea seismic belt shows that there is little difference among the Yanshan uplift area,inside of the seismic zone and North China basin,and the principal polarization direction is near EW.