Ruapehu - IGNS - Science Alert Bulletin V95/28
2 October 1995 (Monday)
20.00 hours NZDT (UT +13)
Ruapehu Volcanic Activity
As of 20.00h the situation and volcano status is:
* Volcanic seismicity has remained at a low level (at or below
pre-eruption levels) through the day. Some volcanic tremor has been
recorded, but this was very weak and lasted for only a few minutes at a
time. No discrete volcanic earthquakes have been recorded since 01.00
hours on 30 September.
* Institute field parties and members of the public have observed
occasional pulses of white steam above the volcano. Similar pulses were
seen during an inspection visit on Wednesday September 20, and seen then
to reflect minor hydrothermal eruptions within the Crater Lake. No ash
has been ejected during these events today.
Conclusions and Alert status
Seismic information and eyewitness reports over the past 2-3 days are such
that we conclude that the volcano has reduced its level of activity below
the level appropriate for Alert Level 4. We thus advise that as from
20.00 hours on 2 October 1995, the Alert Level for Ruapehu is reduced from
Level 4 to Level 3. From the scientific perspective this change in Alert
Level has a number of implications and caveats; these are detailed on the
next page, and on an accompanying map.
Dr C J N Wilson, Programme Leader, Volcanology.
Ph: (07) 374 8211; Fax (07) 374 8199