%0 Journal Article %T Characteristic Changes of Scale Invariance of Seismicity Prior to Large Earthquakes: A Constructive Review %A Qiang Li %A Gui-Ming Xu %J International Journal of Geophysics %D 2013 %I Hindawi Publishing Corporation %R 10.1155/2013/391637 %X Recently, research on the characteristic changes of scale invariance of seismicity before large earthquakes has received considerable attention. However, in some circumstances, it is not easy to obtain these characteristic changes because the features of seismicity in different regions are various. In this paper, we firstly introduced some important research developments of the characteristic changes of scale invariance of seismicity before large earthquakes, which are of particular importance to the researchers in earthquake forecasting and seismic activity. We secondly discussed the strengths and weaknesses of different scale invariance methods such as the local scaling property, the multifractal spectrum, the Hurst exponent analysis, and the correlation dimension. We finally came up with a constructive suggestion for the research strategy in this topic. Our suggestion is that when people try to obtain the precursory information before large earthquakes or to study the fractal property of seismicity by means of the previous scale invariance methods, the strengths and weaknesses of these methods have to be taken into consideration for the purpose of increasing research efficiency. If they do not consider the strengths and weaknesses of these methods, the efficiency of their research might greatly decrease. 1. Introduction It is a well-known fact that the natural seismic system and the rock fracture system in laboratory have the properties of scale invariance [1¨C13]. Study on the characteristic changes of scale invariance of seismicity before large ruptures has been an intriguing subject to geophysicists recently. So far, great progresses have been made in this topic. For instance, analysis results of the temporal and spatial multifractal characteristic of seismicity indicate that there are anomalous changes of the singularity spectrum and generalized dimension spectrum before some large earthquakes [14¨C20]; study results of the earthquakes [21, 22], rock mechanics experiments [23, 24], and rock burst [25] indicate that the there are anomalous variations in the dimension of fractal objects prior to the major ruptures; research by Li and Xu [26] indicates that there is the possible correlation between the featuring change of the local scaling property and the process of seismogeny; a study by Zhao and Wang [27] shows that the Hurst exponent for the sequence of the interval time between earthquakes decreases prior to some large inland earthquakes. In addition, some study results proposed that the decrease of fractal dimension and Hurst exponent, as well %U http://www.hindawi.com/journals/ijge/2013/391637/