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Assessment of Volcanic Eruptions - John Seach
A. General Description
Volcano name, Latitude, Longitude, Country or region, Were there precursory phenomena?, Eruption start (day, month, year), Eruption end (day, month, year), Is the eruption continuing?
B. Sequence of the eruption.
Give the date, site of event, and character of the event.
central eruption, flank eruption, fissure eruption, explosions, nuee ardente, lava flow, crater lake eruption, lava lake, lava dome extrusion, lava spine extrusion, phreatic explosions, mud eruption, mud flow, subglacial eruption, island formation, tsunami, fumarole field, destruction of arable land, casualties.
C. Precursary phenomena
1) Felt shocks
Frequency per day, months or days before eruption, maximum intensity I to XII, distance from vent.
2) Unfelt shocks
Frequency per day, S-P duration/ sec, max ground amplitude (um or um/s at ... km from vent)'
3) Micro-tremors
Duration (total days or hours), period (sec), max amplitude (um or um/s at ... km from vent).
4) Changes in gas emission
None, moderate, significant.
5) ground changes
Fissures or landslides.
6) tilt
Outwards, inwards, none
amount (u radian)
distance from vent
time before eruption
7) Magnetic changes
Amount (gamma, or sec of arc), time before eruption.
8) Any other precursary phenomena
D. Instrumental Observations
seismograph, GPS measurements, satellite images, tiltmeter, Infrared, aerial observations.
E. Eruption details.
Vertical explosion, magmatic, phreatomagmatic, phreatic, type of ejectile, height of eruption column above vent (max and average km), Average mass of 10 largest ejectiles (... kg at ... km from source), area covered by deposit (sq km), mean thickness of deposits (m), mean thickness of deposit (m), distance and direction from vent, volume.