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Abstract. Anomalous emanation of radon ( 222 Rn) was observed preceding large earthquakes and is considered to be linked to preseismic electromagnetic phenomena (e.g. great changes of atmospheric electric field and ionospheric disturbances). Here we analyze atmospheric radon concentration and estimate changes of electrical conditions in atmosphere due to preseismic radon anomaly. The increase of radon emanation obeys crustal damage evolution, following a powerlaw of time-to-earthquake. Moreover, the radon emanation decreases the atmospheric electric field by 40%, besides influencing the maximum strength of atmospheric electric field by 10 4 -10 5 V/m enough to trigger ionospheric disturbances. These changes are within the ranges observed or explaining electromagnetic phenomena associated with large earthquakes.

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We use temperature-dependent viscous remanent magnetization to estimate the emplacement age of tsunamigenic coral boulders along the shorelines of Ishigaki Island, Japan. The boulders consist of the hermatypic coral Porites, and the time of their deposition by tsunamis has been established using radiocarbon dating. Recently deceased corals at reef edges around Ishigaki Island record the Earth's current magnetic fi eld (present Earth fi eld, PEF) as a remanence parallel to the fi eld in the skeleton. Since the time when the coral skeletons were emplaced on the shorelines as boulders by destructive tsunami waves, a new viscous magnetization was partially overprinted in the boulder parallel to the PEF. The results of thermal demagnetization indicated that the boulders were rotated at least once, and their emplacement ages determined from L. Néel's relaxation theory for single-domain magnetite agree well with the radiocarbon ages, although there are traces of multidomain magnetites. New application of Néel's theory to tsunamigenic coral boulders gives us an opportunity to ascertain the age and transportation mode of individual tsunamigenic coral boulders in this area.

The seismic ray theory in anisotropic inhomogeneous media is studied based on nonEuclidean geometry called Finsler geometry. For a two-dimensional ray path, the seismic wavefront in anisotropic media can be geometrically expressed by Finslerian parameters. By using elasticity constants of a real rock, the Finslerian parameters are estimated from a wavefront propagating in the rock. As a result, the anisotropic parameters indicate that the shape of wavefront is expressed not by a circle but by a convex curve called a superellipse. This deviation from the circle as an isotropic wavefront can be characterized by a roughness of wavefront. The roughness parameter of the real rock shows that the shape of the wavefront is expressed by a fractal curve. From an orthogonality of the wavefront and the ray, the seismic wavefront in anisotropic media relates to a fractal structure of the ray path.

Well-defined polystyrenes with terminal carboxy groups were synthesized by the reaction of living polystyryl anions with 4-bromo-l,l,l-trimethoxybutane, followed by treatment with 0.1 N HCl at first and then with 0.2 N LiOH. The polymers thus obtained were carefully analyzed by size-exclusion chromatography (SEC), acid-base titration using potassium methoxide, 'H and I3C NMR, IR, and thin-layer chromatography (TLC)-flame ionization detection (FID). The analytical results indicated that the polymers had terminal carboxy groups withhigh degrees (>95%) as well as predictable molecular weights and narrow molecular weight distributions (Mw/&ln C 1.1). Chromatographic separation by TLC based on Si02 and quantitative analysis by FID for polymers with terminal carboxy groups were discussed.