Ruapehu - IGNS - Science Alert Bulletin V95/09

12 September 1995
Ruapehu Crater Lake
 
UPDATE
 
Volcanic tremor and acoustic noise from Crater Lake was particularly
strong May - June and was followed by eruptions in June and July.  A
particularly large event on 29 June destroyed monitoring equipment
installed in the lake and telemetry equipment on the lake shore.  The 29
June eruption was probably the largest since 1988 from Crater Lake.
 
Observations since June have shown that the lake is consistently cooling
and seismic activity is lower, although results from chemical analyses of
the lake water indicate fresh lava is still available to the crater lake
system.  All available indications are that the recent heating episode and
associated eruptions is now over and the volcano has returned to a lower
level of activity.  However, the present state of the volcano does not
preclude further activity with little or no warning.
 
ALERT STATUS
 
In terms of the revised (August 1995) Volcano Alert system, we advise the
Alert Status for Mt Ruapehu be reduced down to Level 1.
 
For further information contact
Dr C J N Wilson, Programme Leader
Mr B J Scott, Manager Volcano Surveillance
Ph:  07 374 8211;   Fax: 07 374 8199