Tilt change recorded by broadband seismometer prior to small phreatic explosion of Meakan-dake volcano, Hokkaido, Japan

Characterization of sapoviruses detected in Hokkaido, Japan.

Prediction of ground motion and dynamic stress change in Baekdusan (Changbaishan) volcano caused by a North Korean nuclear explosion.

Strong ground motions induce large dynamic stress changes that may disturb the magma chamber of a volcano, thus accelerating the volcanic activity. An underground nuclear explosion test near an active volcano constitutes a direct treat to the volcano. This study examined the dynamic stress changes of the magma chamber of Baekdusan (Changbaishan) that can be induced by hypothetical North Korean ...

Laser-Interferometric Broadband Seismometer for Epicenter Location Estimation

In this paper, we suggest a seismic signal measurement system that uses a laser interferometer. The heterodyne laser interferometer is used as a seismometer due to its high accuracy and robustness. Seismic data measured by the laser interferometer is used to analyze crucial earthquake characteristics. To measure P-S time more precisely, the short time Fourier transform and instantaneous frequen...

An Amateur Vertical Component Broadband Seismometer (Model MkXX)

A vertical component broadband (BB) seismometer, based on design ideas from numerous sources, was developed and fabricated by an amateur instrument builder in a home workshop using commonly available materials. The seismometer had a flat velocity response between 0.017-4 Hz, and sensitive enough to detect teleseismic events of magnitude 5.5 and greater from most places on earth.

Age and growth of marbled sole Pleuronectoes yokohomae in Kikonai Bay, Hokkaido, Japan

Age and growth of marbled sole Pleuronectes yokohamae werer estimated from growth increments in otolith. The samples were collected with commercial set nets and an experimental bottom trawl net in Kikonai Bay and the nearby waters, southern coast of Hokkaido, from May 1994 to July 1995. Monthly changes in the percentage occurrence of oltoliths with translucent edge in one band and the marginal ...