|
National Volcano Early
Warning System (NVEWS)
The National Volcano
Early Warning System or NVEWS was developed by the USGS
allows for a systematic assessment of various hazards
and risks of a specific volcano. The hazards are
assessed and then compared to the amount of monitoring
present at the volcano. This is used to determine
whether or not a volcano has adequate monitoring
relative to its threat level. NVEWS was developed
for volcanoes in the US and its territories, but it can
still be applied to other volcanoes around the world.6
This is how Semeru is
rated on the NVEWS system...
Hazard Factors:
Volcano type: 1
Maximum VEI: 1
Explosive activity past
500 yrs: 1
Major explosive activity:
0
Eruption recurrence: 4
PFs: 1
Lava Flows: 0
Lahars: 1
Tsunami: 0
Hydrothermal explosion
potential: 0
Sector Collapse: 0
Primary lahar: 0
Seismic unrest: 1
Ground deformation: 0
Fumarolic/magmatic
degassing: 1
Sum= 11
Exposure:
Log 10 of VPI 30km: 6
Log 10 of population
downstream or downslope: 6
Fatalities: 1
Evacuations: 1
Local aviation exposure:
2
Regional aviation
exposure: 4
Power infrastructure: 1
Transportation
Infrastructure: 1
Major development: 1
Volcano is part of
island: 0
Sum= 23
Relative Threat
Ranking: 11 x 23 = 253
Monitoring Required: 4
Actual Level of
Monitoring: 1
Using the NVEWS model, Semeru should have a monitoring
level of 4. A monitoring level of 4 requires the
monitors to be able to track detailed changes in
real-time and to develop, test, and apply models of
ongoing and expected activity.6 From
the data available it is clear that Semeru does not have
the nescessary amount of monitoring, and only meets the
monitoring requirements of level 1. The only
monitoring on Semeru is seismic monitoring and some
satellite monitoring that is not even controlled by the
local officials. The amount of seismic monitoring
at Semeru is unclear, but it is most likely limited
based on the usual standards of volcanic monitoring in
Indonesia. Semeru has no monitoring of gas levels,
ground deformation, hydrologic activity, or any of the
other more advanced (expensive) monitoring equipment.
|