Deformation caused by the 2011 eastern Japan great earthquake monitored using the GPS single-epoch precise point positioning technique

Crustal deformation can provide constraints for studying earthquake rupture and shock wave transmission for the Mw9.0 eastern Japan great earthquake. Using the single- epoch precise point positioning （PPP） method and the appropriate positioning flow, we process GPS data from six IGS （International GNSS Service） sites （e.g., MIZU, TSK2, USUD, MTKA, AIRA and KSMV） located in Japan and obtain the positioning results with centimeter scale precision. The displacement time series of the six sites are analyzed using the least squares spectral analysis method to estimate deformations caused by the Mw9.0 mainshock and the Mw7.9 aftershock, and the cumulative displacements after 1 day. Mainshock displacements at station MIZU, the nearest site to the mainshock in the North （N）, East （E）, and Up （U） directions, are -1.202 m, 2.180 m and -0.104 m, respectively, and the cumulative deformations after 1 day are -1.117 m, 2.071 m and -0.072 m, respectively. The displacements at station KSMV, the nearest site to the Mw7.9 aftershock in the N, E and U directions, are -0.032 m, 0.742 m and -0.345 m, respectively. The other sites obviously experienced eastern movements and subsidence. The deformation vectors indicate that the horizontal displacements caused by the earthquake point to the epicenter and rupture. Elastic bounds evidently took place at all sites. The results indicate that the crustal movements and earthquake were part of a megathrust caused by the Pacific Plate sinking under the North American Plate to the northeast of Japan island arc.

Maximum entropy spectral characteristics of seismic activity for great earthquakes in China

The maximum entropy spectral characteristics of seismicity in the seismic enhanced region of 11 great earthquakes is analysed in this paper to seek the difference of seismic period spectral structure between the normal and the abnormal stage of seismic activity in this paper. The results show that, during decades or even one hundred years before great earthquakes, only short periods with 6.5～24.3 years appear, and long ones disappear. Otherwise, long periods with 18.5～38.5 years exist chiefly within the normal stages. Decades years after great earthquakes, the period spectra of seismicity are generally about several or ten years. Then the characteristics of great earthquakes is explained physically by applying the strong body seismogenic model, so a method of studying and predicting great earthquakes is offered.

Hemorrhagic gastric and duodenal ulcers after the Great East Japan Earthquake Disaster

AIM:To elucidate the characteristics of hemorrhagic gastric/duodenal ulcers in a post-earthquake period within one medical district.METHODS:Hemorrhagic gastric/duodenal ulcers in the Iwate Prefectural Kamaishi Hospital during the 6-mo period after the Great East Japan Earthquake Disaster were reviewed retrospectively.The subjects were 27patients who visited our hospital with a chief complaint of hematemesis or hemorrhagic stool and were diagnosed as having hemorrhagic gastric/duodenal ulcers by upper gastrointestinal endoscopy during a 6-mo period starting on March 11,2011.This period was divided into two phases:the acute stress phase,comprising the first month after the earthquake disaster,and the chronic stress phase,from the second through the sixth month.The following items were analyzed according to these phases:age,sex,sites and number of ulcers,peptic ulcer history,status of Helicobacter pylori(H.pylori)infection,intake of non-steroidal anti-inflammatory drugs,and degree of impact of the earthquake disaster.RESULTS:In the acute stress phase from 10 d to 1mo after the disaster,the number of patients increased rapidly,with a nearly equal male-to-female ratio,and the rate of multiple ulcers was significantly higher than in the previous year(88.9%vs 25%,P<0.005).In the chronic stress phase starting 1 mo after the earthquake disaster,the number of patients decreased to a level similar to that of the previous year.There were more male patients during this period,and many patients tended to have a solitary ulcer.All patients with duodenal ulcers found in the acute stress phase were negative for serum H.pylori antibodies,and this was significantly different from the previous year’s positive rate of 75%(P<0.05).CONCLUSION:Severe stress caused by an earthquake disaster may have affected the characteristics of hemorrhagic gastric/duodenal ulcers.

Correlation between lunar node tide and great earthquakes

This study selects six consecutive 18.6 years of global M≥7.0 earthquakes,calculates the lunar declination angle based on the time of the earthquakes,and divides the global earthquakes into 13 research regions according to the global plate distribution facts to explore the lunar infl uence of earthquakes.The relationship between the lunar declination angle and these earthquakes is analyzed.The analysis results show that when the moon advances to a certain interval of its declination angle,the earthquakes are concentrated in a certain research region,whereas other research regions are relatively calm,providing a scientifi c basis for medium and long-term earthquake predictions in each research region.The 18.6-year cycle is the lunar declination angle change cycle,and it is also the major nutation cycle of the earth’s motion and lunar node movement cycle.This is,in reality,the eff ect of the lunar node tide,which is worthy of further study.

Preliminary results for the rupture process of Jan.10, 2018, Mw7.6 earthquake at east of Great Swan Island, Honduras

At UTC 2018-01-10 02:51:31,an Mw7.6 earthquake occurred 44 km east of Great Swan Island,Honduras(location 17.469°N,83.520°W,depth 10 km,according to the United States Geological Survey).We carried out studies of the focal mechanism and rupture process of the earthquake,using seismic data from the IRIS data center.For the focal mechanism solution,a point source model was used to invert 26 far-field P-waveforms and 26 SHwaveforms with high S/N ratio and relatively even azimuth coverage(epicentral distance 30°<△<90°);then the result(Figure 1)was used to construct a finite fault model for rupture process inversion(Yao ZX and Ji C,1997;Wang WM et al.,2008),resulting in a preliminary model of the slip distribution of this earthquake(Figures 2–4).The calculated seismic moment is 2.41×10^20 N·m and the estimated earthquake magnitude Mw=7.5.The maximum slip is about 1900 cm.

Research on the Tectonic Environment and Seismogenic Mechanism of the 1927 Gulang Great Earthquake with M=8.0

In this paper, we discussed the seismotectonic environment of the deep-seated and shallowcrust and seismological and geological model caused the 1927 Gulang great earthquake, basedon the recent research concerning about the active fault, surface rupture, fault planesolution, seismic activity, as well as the deep geophysical exploration data analysis in theepicentral area.The result shows that the 1927 Gulang great earthquake was caused by NE-SW-strikingcompressional thrusting. It was a latest event occurred in the reverse fault-folding belt thatdeveloped along the intracrustal decollement.

Evaluation of the Long-Term Changes in Fatigue of Cancer Survivors Who Received Outpatient Chemotherapy in the Area Affected by the Great East Japan Earthquake

Objective: The aim of the study is to evaluate the long-term changes in fatigue of cancer patients receiving outpatient chemotherapy after a disaster such as the Great Earthquake. Methods: From 2012 to 2014, we measured subjective fatigue, autonomic function, and physical activity with reference to the criteria for chronic fatigue syndrome. Results: The participants were 13, 9 males (69.2%) and 4 females (30.8%). The most common cancer among the participants was lung cancer 4 patients (30.8%). In 2012, eight patients (61.6%) received anti-cancer drugs and three (23.0%) received the drug by intravenous drip and oral administration. Physical fatigue (p = 0.004), mental fatigue (p = 0.002), comprehensive fatigue (p = 0.012), and comprehensive evaluations (p = 0.032) were significantly different. Significant differences in the autonomic nervous function were observed during the three years from 2012 to 2014 (log LF [p = 0.017], log HF [p = 0.023] and log LF/HF [p = 0.039]). Similar to Subjective fatigue, Significant differences in physical activity were observed during the three years from 2012 to 2014 (DA [p = 0.042], TST [p = 0.037], SE [p = 0.018], AW [p = 0.023] and Naps [p = 0.014]). Conclusions: The participants fatigue worsened at one time, but showed improvement over time. In the event of an emergency such as a disaster, it is necessary to evaluate the physical and mental condition based on objective indicators of cancer patients receiving anti-cancer drug treatment and provide nursing support.

GIS as an Information Infrastructure for Recovery and Reconstruction after the Great East Japan Earthquake

This study considers the regional characteristics of the Tohoku region and the extent of the damage caused by the Great East Japan Earthquake and makes proposals for recovery and reconstruction of the areas affected by this disaster as well as for a reduction of the impact of natural disasters that may occur in the future with GIS （geographic information systems） as a social infrastructure positioned at the heart of the information infrastructure. Due to the fact that social media that used ICT （information and communication technology） was useful in the days directly after the disaster, it can be said that it is necessary to investigate the provision of an information infrastructure that uses ICT to reduce the impact of disasters. Therefore, this study proposes the construction of a geographical information database using GIS and the provision and sharing of information using social media GIS after discussion of the relationship between the development of the computerization of Japan and GIS as a valid example of using information systems for recovery and reconstruction after the Great East Japan Earthquake.

Horizontal crustal movement in Chinese mainland before and after the great Kunlun Mountain M=8.1 earthquake in 2001

The continuous GPS observation at the fiducial stations in the Crustal Movement Observation Network of China (CMONOC) recorded the crustal movement of Chinese mainland before and after the great Kunlun Mountain earthquake of M=8.1 on November 14, 2001, especially the horizontal crustal movement in the western part of China. Based on the datum defined by a group of stable stations with small mutual horizontal displacements for a few years, the time series of horizontal displacements at fiducial stations were obtained. Significant anomalous horizontal displacements had appeared at the fiducial stations in the western part of China since early November 2000 and several earthquakes with the magnitudes about 6.0 had occurred in Yunnan and Sichuan Provinces. The northward components of the horizontal displacement at the fiducial stations in west China had decreased signifi-cantly and even changed in the opposite sense since mid April 2001. After the earthquake, the northward dis-placements still decreased and there were significant westward displacements. The process of the crustal move-ment in the western part of Chinese mainland (in reference to east China) suggests that the main force source for this earthquake came from the northward pushing of the Indian plate. The great earthquake released a large amount of energy, as a result, the action applied by the Indian plate to Chinese mainland diminished significantly and after the great earthquake, the seismic activity in Chinese mainland decreased considerably until the end of 2002.

The Verification of the Resonance Prediction Method for Great Earthquake Motion and its Prediction

More than 200 great (strong) earthquakes are examined in this thesis on the basis of the method for prediction of movement resonance of great earthquakes; and through the table of about 20 disastrous or representative earthquakes among them, it is proved that there is still room for breakthrough in the prediction of great (strong) earthquakes. At the end of 1996, I predicted that there would be a great earthquake with magnitude between 7.5 and 8.4 and a series of great earthquakes in Japan Trench in the following 1 or 2 years, and later this prediction was realized. Further study on this method resulted in the formula of epicentre prediction. Recently I also worked out that we can reduce the time of great earthquake prediction and epicentre prediction through the study of the early earthquakes with magnitude ≥≥of M 4. Written predictions on 7 earthquakes with magnitude of M 6 between January, 1998 to September 10, 1998 are proved successful in varying degrees, which will solve the —‘poser set by some authorities in international earthquake research field Short-time ’earthquake prediction is impossible on the basis of contemporary scientific technology.

Wave separation for the great Sumatra-Andaman earthquake with regional seismic array

We analyzed the seismic waveforms from the December 26, 2004 Sumatra-Andaman earthquake recorded at broadband seismic stations in western Europe. Previous studies involving of the beam-forming technique and high frequency analysis suggest that the earthquake ruptured with a duration of around 500 s. This very long duration makes P wave overlap with later arrivals such as PP wave, which follows P in about 200 s. Since P waves are crucial for modeling earthquake processes, we propose an iterative method to separate P and PP waveforms. The separated P waveform confirms a second large energy release around 300 s after the initial rupture. The iterative signal separation technique is particularly useful for mixed signals that are not independent and the number of recording stations far exceeds number of mixed signal sources.

Seismicity anomalies before the great earthquake of M_S=8.1 in the Kunlun Pass and its significance to earthquake prediction

A great earthquake of MS=8.1 took place in the west of Kunlun Pass on November 14, 2001. The epicenter is lo-cated at 36.2N and 90.9E. The analysis shows that some main precursory seismic patterns appear before the great earthquake, e.g., seismic gap, seismic band, increased activity, seismicity quiet and swarm activity. The evolution of the seismic patterns before the earthquake of MS=8.1 exhibits a course very similar to that found for earthquake cases with MS7. The difference is that anomalous seismicity before the earthquake of MS=8.1 involves in the lar-ger area coverage and higher seismic magnitude. This provides an evidence for recognizing precursor and fore-casting of very large earthquake. Finally, we review the rough prediction of the great earthquake and discuss some problems related to the prediction of great earthquakes.

Large aftershocks triggering by Coulomb failure stress following the 2001 MS=8.1 great Kunlun earthquake

The great Kunlun earthquake occurred on Nov. 14, 2001 in Qinghai Province, China. Five large aftershocks with magnitude larger than 5.0 occurred near the Kunlun fault after main shock. Calculations of the change in Coulomb failure stress reveal that 4 of 5 large aftershocks occurred in areas with Dsf >0 (10-2~10-1 MPa) and one aftershock occurred in an area with Dsf =-0.56 MPa. It is concluded that the permanent fault displacement due to the main shock is the main cause of activity of large aftershocks, but not the whole cause.

Great Guam earthquake(M_(sz)=8.1)and time changes in geomagnetic transfer functions

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Seismic Design of Offshore Wind Turbine Withstands Great East Japan Earthquake and Tsunami

Japan＇s first open sea offshore wind farm, Kamisu offshore windfarm Phase l, was stricken by an earthquake of intensity 6 on the Japanese seismic scale and a five-meter-high tsunami during the Great East Japan Earthquake on March 11,2011. The wind farm resumed operation on March 14 after checks revealed no damage to the system, even though the wind farm was temporarily forced to stop due to the grid failure caused by the earthquake. Wind turbines require a precise seismic design especially in an earthquake-prone country such as Japan. Wind power Kamisu Phase 2 was built one year after the earthquake based on the experience of Kamisu Phase 1. This paper presents the seismic design of offshore wind turbines and the situation during the earthquake and tsunami.

New energy policy and low-carbon society in Japan after the Great East Japan Earthquake

The Great East Japan Earthquake in March 2011 devastated the eastern region of Japan.Due to the resulting nuclear accident,Japanese Cabinet decided to revise its energy policies.The Energy and Environment Council in National Policy Unit published options on the nation's scenarios for energy and economy in 2030.We estimated the economic impacts of the options to national economy and households in 2030.Finally,we clarified significant factors to establish a secure,affluent and low-carbon society based on the energy scenarios.

Re-Estimation of a Plausible Model of the Earthquake Fault as the Source of the 1771 Great Meiwa Tsunami Based on the Assessment of the Run-Up Height by Okinawa Prefecture, Japan

Plausible parameters of the earthquake fault which caused the 1771 Great Meiwa Tsunami were re-estimated by comparing the result of the tsunami run-up height by the numerical simulation by Okinawa Prefectural Government and those by 1) run-up height derived from previous field works, and 2) a historical record describing the run-up height in Miyako District. The re-estimation shows that the length of the fault off Miyako and Yaeyama districts is 300 km or more. However, the slip of the fault is 20 m off Yaeyama and 8 - 14 m off Miyako.

Consumer Reaction to the Great East Japan Earthquake

Following the Great East Japan Earthquake in March 2011, the demand for bottled water increased sharply. In this paper, the authors analyze who purchased more bottled water after the earthquake using Quick Purchase Report data. The results are as follows： first, consumers who before the earthquake tended to purchase less bottled water tended to increase the volume purchased after the earthquake; second, the motives for purchasing bottled water after the earthquake differed between consumers in the Tokyo and Osaka metropolitan districts.

Characteristics of Tsunami Damage to the Tide Walls in Iwate Prefecture from the Great East Japan Earthquake

This research paper describes the tsunami damage to tide walls observed using aerial photographs and field investigations at 13 locations along the coast of Iwate Prefecture, where significant tsunami damage occurred as a result of the Great East Japan Earthquake. This paper also summarizes the characteristics of the damage. The tide walls in Iwate Prefecture were constructed on a ria （hilly type） coast, this geographical feature of lwate being different from that of the other disaster areas, primarily Miyagi and Fukushima Prefectures. The results of our investigations show that all the devastated tide walls suffered from overflow before being damaged. In particular, the sloping and vertical type tide walls with slope protection were damaged by scouring of the infill sand or back fill soil due to the overflow of the tsunami. In the case of vertical type tide walls without slope protection, damage was caused by scouring of the back fill soil.

Xu Ping: From the Earthquake Zone to the Great Hall of the People

The young lady who once received a lot of help from society,today is committed to do what she can to contribute to the community.“This is the fifth year I have come to Beijing to attend the annual session of the National People’s Congress(NPC),but I’m just as thrilled today as I was the first time,”said Xu Ping.A 25-year-old young woman from a village which was heavily damaged in the massive Wen-chuan earthquake in 2008.