January 29, 2001. Copyright 2001. Graphic News. All rights reserved.

RUMBLINGS BENEATH FUJI-SAN ALARM JAPANESE

LONDON, January 29, Graphic News: JAPANÕS government is stepping up its eruption emergency plans following rumblings deep under Mount Fuji, JapanÕs national icon and symbol of the countryÕs ancient stability.

Scientists usually record about 10 low-frequency earthquakes a year beneath Mount Fuji, but this rose to 133 in October, then jumped to 222 in November before falling back to 144 in December. Seismic activity has tapered off further in January.

Japan sits above the junction of at least three tectonic plates, making it one of the worldÕs most earthquake-prone countries, and is regularly jolted with tremors of varying strength.

Last year, one of the most seismically active in recent years, saw three volcanic eruptions and tens of thousands of related tremors.

But scientists say that the rumbling in Fuji-sanÕs pipework are not signs of an imminent eruption. These tremors are nine miles (14.4km) below the ground. Magma, or molten rock, working upward towards an eruption would cause tremors much closer to the surface.

ÒSeismic activity means there is a movement of magma down there,Ó said Shigeo Aramaki, a volcanologist at the University of Tokyo. ÒIt is a serious sign, but we don't know where it is moving or where it is going.Ó

Researchers have placed more than 1,000 high-intensity earthquake monitors around Japan and use global positioning system (GPS) satellites to predict tremors.

Plans to cope with a major disaster in the area, 93 miles (150km) west of Tokyo, which will be discussed at a meeting of volcanic experts on February 5, are expected to lead to more monitors and other measures, including a Òhazard map.Ó

Local officials have been criticized for failing to make risk studies of Mount Fuji -- at 12,387 feet (3,775 metres) the highest of the 86 active volcanoes on the Japanese archipelago -- for fear of frightening the 2.5 million tourists who visit the mountain annually.

Now JapanÕs Central Disaster Prevention Council has called for detailed disaster plans and a review of earthquake monitoring near the volcano.

A hazard map, based on data from past eruptions and on topographic contours, can accurately predict the path of flowing lava or superheated gas and mud that incinerates all in its way.

Combined with a rehearsed plan for evacuating people, a hazard map can save lives, scientists say, especially now that they are increasingly able to give at least a few daysÕ warning of eruptions.

Mount Fuji last erupted in 1707 and spewed ash for two weeks on Tokyo, then known as Edo. Since then, the sprawl of the worldÕs largest city has reached closer to the mountain, and spas and golf courses have been built around its slopes.

The volcano was iconized by the Japanese artist, Katsushika Hokusai, in his ÒThirty-six Views of Mount Fuji,Ó produced in the 1830s. Today the Shinkansen (bullet train) on the Tokyo-Osaka route gives travellers a stunning view of one of the most beautiful sights in Japan.
/ENDS
Sources: Reuters, Washington Post, japan-guide.com,