Ruapehu - IGNS - Volcano Alert System

We split each level into two parts; one for freqently active cones and the other for reawakening sytems. Would appreciate any comments on our approach.

Comments to: Brad Scott B.scott@gns.cri.nz

Scientific Alert Levels

___________________________________________________________________________
|Scientific                                                               |
|Alert    Phenomena Observed                Scientific Interpretation     |
|Level                                           (Volcano Status)         |
|*************************************************************************|
|0  Typical background surface             Usual dormant, intra-eruption  |
|   activity;seismicity,                   or quiescent state.            |
|   deformation and heat					          |
|   flow at low levels.       						  |
|*************************************************************************|
|1  Departure from typical                 Minor phreatic activity.	  |
|   background surface activity. 				   	  |
|- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -|
|   Apparent seismic, geodetic,            Signs of volcano unrest.	  |
|   thermal or other unrest                No significant eruption threat.|
|   indicators.								  |
|*************************************************************************|
|2  Increase from low level of             Significant change in level or |
|   eruptive activity, accompanied         style of ongoing eruptive      |
|   by changes to monitored                activity.		          |
|   indicators.							          |
|- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -|
|   Increase in seismicity,deformation,     Indications of intrusive	  |
|   heat flow and/or other unrest           processes.  Local eruption    |
|   indicators.                             threat.			  |
|									  |
|*************************************************************************|
|3  Increased vigour of ongoing             Significant local eruption in |
|   activity and monitored indicators.      progress. 			  |
|-------------------------------------------------------------------------|
|   Commencement of minor eruptions         Increasing intrusive trends   |
|   at reawakening vent(s).  Relatively     indicate real possibility of  |
|   high and increasing trends shown by     hazardous eruptions.          |
|   unrest indicators.					 	 	  |
|									  |
|*************************************************************************|
|4  Significant change to ongoing           Hazardous local eruption in   |
|   activity and monitored indicators.      progress.			  |
|-------------------------------------------------------------------------|
|   Establishment of magmatic activity      Large scale eruption now      |
|   at reawakening vent(s), with            appears imminent.		  |
|   acceleration of unrest indicators.  				  |
|									  |
|*************************************************************************|
| 5  Hazardous large volcanic eruption      Destruction within the        |
|    in progress.                           Permanent Danger (red) Zone.  |
|                                           Significant risk over wider   |
|                                           areas.			  |
|*************************************************************************|

Note: The frequently active cone volcanoes (White, Ngauruhoe, Ruapehu) require definitions different from all other volcano systems, hence the subdivisions of Stages 1,2, 3 and 4. The upper portion relates to the frequently active volcanoes, while the lower to the other systems (Auckland, Taranaki, Taupo, Okataina etc).