Ruapehu - IGNS - Science Alert Bulletin V95/05

27 April 1995
Ruapehu Crater Lake
On 13 March the temperature of Crater Lake receded below 47-C, thus
enabling data to be obtained via the ARGOS satellite recording system.
From then until about 15 April, the lake temperature was declining,
reaching a low of 35-C.  Thereafter a slow rise commenced.  On 24 - 25
April a rapid rise in lake temperature occurred, accompanied by an
increase in volcanic tremor and acoustic noise output.  As of 27 April the
lake temperature has exceeded 47-C.
Based on the above information we recommend the Alert Level be raised back
to 2, and also recommend restrictions on access to Crater Lake basin are
B F Houghton
Acting Volcanology Programme Leader
Contact (07) 374 8211