共查询到20条相似文献，搜索用时 109 毫秒
1.
天灾研究中的当代物理新途径 总被引：2，自引：1，他引：1
应用当代物理学中的量子化方法，将日－地空间量子化。借天体分层结构特征，对地震震级公式及天体引潮力激起的孤波储能触发地震的原理作了探索性讨论。 相似文献
2.
近年来的天文观测发现了暗能量的存在，因而有必要讨论暗能量条件下的黑洞热力学。该文应用约化相空间量子化方法研究了被Quintessence包围的静态球对称黑洞的视界面积量子化问题，给出了面积谱。 相似文献
3.
如何选择照相机进行天体摄影河南读者蔡明来信问：在拍摄天体照片时，使用什么样的照相机？回答这个问题首先要搞清楚什么叫天体摄影。天体摄影主要是指拍摄太阳、月亮、行星，及星团星云等天体照片，清楚地记录下来它们的表面特征和物理现象。天体在底片上的成像大小可以... 相似文献
4.
5.
讨论有关天体测量中的测光问题，介绍一些地面天体测量仪器和空间天体测量望远镜的测光研究。给出一种测光资料的处理方法，并建议利用DCMT开展天文测光课题研究。 相似文献
6.
梅西耶天体观测马拉松朱晔华编译在一个夜晚观测１００个以上的Ｍ天体的活动，叫作“梅西耶天体马拉松”。１７８１年，法国天文学家查理斯·梅西耶（Ｃｈ·Ｍｅｓｓｉｅｒ）将他所观测到的星云状天体汇编成梅酉耶星表，表中包含１０３个星云、星团和星系类天体，后人又增... 相似文献
7.
近期大视场CCD成像观测表明，由年轻星激发的部分赫比格－哈罗（HH）天体的尺度范围超过1pc，比过去认识的HH天体的尺度大了一个量级。目前的观测已经发现pc尺度的HH天体有数十个，表明HH天体达到pc尺度是很普遍的，这将深刻地改变人们对年轻星与其周围环境作用的认识。综述评述了pc尺度HH天体的观测性质，讨论了巨HH天体对恒星形成的重大意义及其对周围星际介质的物理和化学影响。 相似文献
9.
10.
介绍了云南天文台天体测量工作的发展过程，论述了在空间时代地面光学基本天体测量的必要性和应具备的条件，并且叙述了在新的要求和条件下，地面光学基本天体测量工作应该发挥的作用和广阔的发展前景。 相似文献
11.
Gu Zhen-Nian 《Earth, Moon, and Planets》1996,74(1):35-47
The earthquake produces a global static displacement field due to the dislocation in the epicenter. This displacement field in turn changes the Earth's inertia tensor, hence exciting the variation of both polar motion and length of day. In general, large earthquake produces greater displacement field, which has greater effects upon the earth rotational properties. In spite of scientists efforts in the last decades, it is found that the polar motion and the length of day excited by earthquake are at least two orders of magnitude less than those derived from observation. In the future with high observational accuracy the effect of earthquake on polar motion and length of day would be observable.Using the fault plane parameters, the location of epicenter and the expression given by Dahlen as well as the step function, the accumulative change of the axial and equatorial moments of inertia of the Earth earthquake occurring in period of 1977–1994 is estimated in this paper. Results have shown that change of pole axis direction induced by single earthquake is independent of the magnitude of the earthquake, which is random, but large earthquake contributes most to the accumulative change of direction of polar drift. The earthquake tends to make the drift of rotational pole towards the direction of 130–150 E. This direction is roughly different to that inferred from observations. Accumulative changes of both the two equatorial principal moments and the axial moment of inertia of the Earth present the strongest non-randomness and secular behaviour. The change depends upon the slip angle of the fault movement in a large extent. 相似文献
12.
On July 28, 1976, a major earthquake (M=7.9) occurred in the Tangshan region of China. After the earthquake, it was found that astronomical time-latitude anomalies were observed preceeding the occurrence of the earthquake. These observations had been obtained on the Astrolabe of the Beijing Astronomical Observatory and the VZT of Tianjin Latitide Station, which are just located around the epicentre. The anomalies were in the analyses of the time and latitude residuals, and there are more examples verifying these phenomena. However, all those examples were found in post-earthquake analyses. In this paper we discuss the possibility of earthquake prediction and forecast from the rediduals of astronomical time-latitude. For example, series of the five-day means are analyzed. The observations were supposed to be terminated two weeks before the earthquake, and the data are then analyzed a year backward. After removing their averages, the standard deviations are calculated of these series are calculation. Eight earthquakes were chosen as the events to be examined, (see Table). Most of the related instruments obtained excellent observations. The results are shown in the Figure. It is evident that abnormal peaks of RT and RF appeared before each earthquake. Thus we may conclude the followings:
- Under the normal observation conditions, one high predision instruments could inform about a major earthquake a few weeks or a few days before it occurrs.
- The astronomical observations are seriously affected by the weather and observers and so they are some what uncertain.
13.
汶川地震前后的气象异常 总被引：1，自引：0，他引：1
有研究认为局地气象异常与地震之间存在着一定的相关性,那么震惊中外的汶川大地震前后有没有气象异常呢？应用NCEP再分析资料,以1988—2007年20年间局地气象要素的平均值和标准偏差为基准,通过构建气象异常指数对2008年5月12日汶川发生的大地震前后的日平均气温、日最高气温、日最低气温、日平均降水强度和日平均气压等5项气象要素指标的异常状况进行了分析,结果表明在地震前2个月的时间内有异常状况出现,并且其变化幅度和持续时间都比较长,在地震过后这些异常并未立即消失;从5项气象要素异常空间分异来看,汶川是气象异常的中心地带,表征了汶川地震与局地气象之间存在着一定的相关性。尽管气象异常是否是地震发生的必然前兆尚待进一步考证,但出现在汶川特大地震前后的气象异常再次给我们一个提示,即气象异常与地震的关系值得深入研究。 相似文献
14.
Stjepan Selak 《Astrophysics and Space Science》1979,61(2):517-519
In this paper the irregularities of the dilatation function, in terms of which the occurrence of the gravitational field was interpreted by Selak (1978), were taken to be a cause of the earthquake phenomena. On this basis we attempted to support an empirical relation of Tsubokawa (stated by Rikitake, 1972) expressing the way in which the time-interval of anomalous land deformation depends on the magnitude of the earthquake. Besides this, we suggest a way in which the earthquake prediction could be performed. 相似文献
15.
Earthquakes are one of the most destructive and harmful natural disasters, especially in recent years, the 2008/5/12 Wenchuan M7.9 earthquake, the 2011/3/11 Tohoku M9.0 earthquake and the 2012/4/11 Sumatra M8.6 earthquake have caused a significant impact to the human life. In this paper, we make a study of the temporal and spatial distribution of the Global Positioning System Total Electron Content (GPS TEC) anomalies prior to the three strong earthquakes by the method of statistical analysis. Our results show that the pre-earthquake ionospheric anomalies are mainly positive anomalies and take the shape of a double-crest structure with a trough near the epicenter. The ionospheric anomalies do not coincide with the vertical projection of the epicenter of the subsequent earthquake, but mainly localize in the near-epicenter region and corresponding ionospheric anomalies are also simultaneously observed in the magnetic conjugate region prior to the three earthquakes. In addition, the amplitude and scale-size of the ionospheric ΔTEC are different with the magnitude of the earthquake, and the horizontal scale-size of the greatest anomalies before the Tohoku M9.0 earthquake is ～30° in longitude and ～10° in latitude, with the maximum amplitude of TEC disturbances reaching ～20 TECu relative to the background. The peak of anomaly enhancement usually occurs in the afternoon to sunset (i.e. between 14:00 and 18:00 local time) which lasts for approximate 2 hours. Possible causes of these anomalies are discussed, and after eliminating the effect of solar activities and magnetic storms it can be concluded that the detected obvious and regular anomalous behavior in TEC within just a few days before the earthquakes is related with the forthcoming earthquakes with high probability. 相似文献
16.
17.
Dealing with moon theory and tidal dynamics and checking lists of earthquake data one can take the following two observations: 1) The first extreme proxigean spring tide in the new millennium happened on 2005 January 10, in new moon phase, and half a synodic month earlier, when the Moon was full on 2004 December 26, the Christmas Tsunami was triggered in the Indian Ocean. The next extreme tide in new moon phase will occur after one Saros cycle, on 2023 January 21. 2) The second observation is connected with the lunar evection anomaly. The time between the Whitsun Quake in China on 2008 May 12 and the Christmas Tsunami amounts to 1233 days. On the other hand, three lunar evectional cycles take 3 × Ue = 3 × 411.8 = 1235 days. These observations hint at lunisolar structures in the earthquake distribution. In the present treatise we will reveal such structures by composing lunisolar ephemerides and earthquake Tables. In particular, we use Student's t‐test and show that there is a significant relationship between the beat period Ue and the earthquake statistics (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
18.
Possible Ionospheric Electromagnetic Perturbations Induced by the Ms7.1 Yushu Earthquake 总被引：1，自引：0，他引：1
Zeren Zhima Shen Xuhui Zhang Xuemin Cao Jinbin Huang Jianping Ouyang Xinyan Liu Jing Bingqing Lu 《Earth, Moon, and Planets》2012,108(3-4):231-241
The power spectrum density (PSD) of magnetic field in the ELF/VLF band recorded by the experiment IMSC onboard the DEMETER satellite were used to study the Ms7.1 Yushu earthquake taking place on April 13, 2010 in China. The results indicate that possible ionospheric electromagnetic perturbations occurring 4?days before the earthquake in the frequency range [370–897?Hz]. Along the orbit 30880_up, which passed over the epicenter area on 9 April, enhanced PSD value of magnetic field at 410?Hz was detected both over the epicentral area and its conjugate point in the southern hemisphere. While on revisited orbits during other days (before and after the earthquake) the magnetic field spectra remained at a relatively low level. In order to be sure that the electromagnetic disturbances were induced by this Yushu earthquake, relative variations of the magnetic field in the ELF/VLF range [370–897?Hz] were calculated and compared with the normal background during 3?years (2007, 2008 and 2009) in the time interval from Jan. 1st to Apr. 30 and in the area [23°N–43°N, 86°E–106°E]. The results show that the normal level of magnetic field in this area is relatively low (~10?7?nT2/Hz), but a large increase occurred from Apr. 1st to Apr. 14 which exceeds 5σb. After the earthquake, the magnetic field in the ELF/VLF range gradually decreased. In order to exclude the influence of geomagnetic field activity, we selected only the data recorded during magnetically quiet local night-times. In addition, artificial noises were also removed from the dataset used in the present paper. Therefore the observed perturbations were independent of geomagnetic field disturbances, and might be attributed to seismic activity. 相似文献
19.
John P. Bagby 《Earth, Moon, and Planets》1973,6(3-4):398-404
The rate of release of earthquake energy over the past 65 yr is compared to the relationship of the longitude of perigee of the Moon to the Earth's longitude of perihelion. Certain perculiar phase and local hour angle relationships, of the Moon to earthquake epicenters, are also presented. Finally, the clustering of epicenters near the longitudes of Neptune and Uranus is examined. 相似文献
20.
Jyh-Woei Lin 《Astrophysics and Space Science》2012,341(2):251-258
Nonlinear principal component analysis (NLPCA) is implemented to analyze the spatial pattern of total electron content (TEC) anomalies 3 hours after Japan’s Tohoku earthquake that occurred at 05:46:23 on 11 March, 2011 (UTC) (M w =9). A geomagnetic storm was in progress at the time of the earthquake. NLPCA and TEC data processing were conducted on the global ionospheric map (GIM) for the time between 08:30 to 09:30 UTC, about 3 hours after this devastating earthquake and ensuing tsunami. Analysis results show stark earthquake-associated TEC anomalies that are widespread, and appear to have been induced by two acoustic gravity waves due to strong shaking (vertical acoustic wave) and the generation of the tsunami (horizontal Rayleigh mode gravity wave). The TEC anomalies roughly fit the initial mainshock and movement of the tsunami. Observation of the earthquake-associated TEC anomalies does not appear to be affected by a contemporaneous geomagnetic storm. 相似文献