Iwate-san, Honshu, Japan
- This photo shows the Amphitheater and
Yakushi-dake central cone of east Iwate Volcano viewed from the east.
- Iwate-san is located in Iwate Prefecture
on the northeast end of Japan's main island, Honshu. The volcano started
to show signs of reawakening around March, when high levels of seismic
activity became apparent. Since then, tilting and other changes in the
mountain's geometry have been observed, and earthquake activity has
been steadily rising. The first "Volcanic Advisory," a fairly
high-level notice to alert the public to danger, was issued on April
29. A second was issued on June 24, following low-frequency quakes and
long volcanic tremors, as well as earthquake swarms.
- July 10, 1998
- The evening television news reported
that a third Volcanic Advisory was issued today (July 10) in the wake
of several perceptible earthquakes and a large-amplitude tremor followed
by a volcanic quake this morning. Today's movements are the largest
observed so far.
- Scientists say that the frequency of
earthquakes is still increasing and distension of the mountain along
a N-S baseline through the summit crater is continuing. Though no surface
phenomenon indicative of an eruption has been observed, local newspapers
report that steam explosions on the mountain's west side are feared,
and authorities have begun work on hazard maps for the area. Several
local villages also decided not to open the mountain to climbers, which
they normally do on July 1, and local media report that additional seismometers,
tilt meters, and other observation equipment are being put into place
to help scientists and authorities get a better hold on the mountains
activity.
|