caa a22 4500 475813553 CHVBK 20180406123804.0 cr unu---uuuuu 170329e20000401xx s 000 0 eng 10.1007/PL00001108 doi (NATIONALLICENCE)springer-10.1007/PL00001108 Spatial Distribution of Aftershocks and the Fractal Structure of Active Fault Systems [Elektronische Daten] [K. Nanjo, H. Nagahama] —The relationship between the fractal dimensions of aftershock spatial distribution and of pre-existing fracture systems is examined. Fourteen main shocks occurring in Japan were followed by aftershocks, and the aftershocks occurred in swarms around the main shock. Epicentral distributions of the aftershocks exhibit fractal properties, and the fractal dimensions are estimated by using correlation integral. Observable pre-existing active fault systems in the fourteen aftershock regions have fractal structures, and the fractal dimensions are estimated by using the box-counting method. The estimated fractal dimensions derive positive correlation, showing independence from the main-shock magnitude. The correlation shows that aftershock distributions become less clustered with increasing fractal dimensions of the active fault system. That is, the clusters of the aftershocks are constrained under the fractal properties of the pre-existing active fault systems. If the fractal dimension of the active fault system is the upper limit value of the fractal dimension of the actual fracture geometries of rocks, then the clustering aftershocks manifest completely random and unpredictable distribution. Birkhäuser Verlag Basel,, 2000 Key Words: Aftershock, active fault system, fractal, fractal dimension, spatial distribution nationallicence Nanjo K. Institute of Geology and Paleontology, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan, e-mail: nanjo@dges.tohoku.ac.jp, JP aut Nagahama H. Institute of Geology and Paleontology, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan, e-mail: nanjo@dges.tohoku.ac.jp, JP aut https://doi.org/10.1007/PL00001108 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/PL00001108 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Nanjo K. Institute of Geology and Paleontology, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan, e-mail: nanjo@dges.tohoku.ac.jp, JP aut NATIONALLICENCE 700 1- Nagahama H. Institute of Geology and Paleontology, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan, e-mail: nanjo@dges.tohoku.ac.jp, JP aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer