Preliminary Spreadsheet of Eruption Source 

Parameters for Volcanoes of the World 

By Larry G. Mastin, Marianne Guffanti, John W. Ewert, and Jessica Spiegel 

Version 1.2 

Open-File Report 2009-1133 

U.S. Department of the Interior 

U.S. Geological Survey 
2 

U.S. Department of the Interior

KEN SALAZAR, Secretary 

U.S. Geological Survey

Suzette M. Kimball, Acting Director 

U.S. Geological Survey, Reston, Virginia: 2009 

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Suggested reference: 

Mastin, L.G., Guffanti, M., Ewert, J.E., and Spiegel, J., 2009, Preliminary spreadsheet of eruption source 

parameters for volcanoes of the world: U.S. Geological Survey Open-File Report 2009-1133, v. 1.2, 25 p. 

Available at http://pubs.usgs.gov/of/2009/1133/
Introduction 

Volcanic eruptions that spew tephra into the atmosphere pose a hazard to jet 

aircraft. For this reason, the International Civil Aviation Organization (ICAO) has 

designated nine Volcanic Ash and Aviation Centers (VAACs) around the world whose 

purpose is to track ash clouds from eruptions and notify aircraft so that they may avoid 

these ash clouds. During eruptions, VAACs and their collaborators run volcanic-ashtransport-and-dispersion (VATD) models that forecast the location and movement of ash 

clouds. These models require as input parameters the plume height H, the mass-eruption 

rate M , duration D, erupted volume V (in cubic kilometers of bubble-free or “dense rock 

equivalent” [DRE] magma), and the mass fraction of erupted tephra with a particle size 

smaller than 63 μm (m63). Some parameters, such as mass-eruption rate and mass 

fraction of fine debris, are not obtainable by direct observation; others, such as plume 

height or duration, are obtainable from observations but may be unavailable in the early 

hours of an eruption when VATD models are being initiated. For this reason, ash-cloud 

modelers need to have at their disposal source parameters for a particular volcano that are 

based on its recent eruptive history and represent the most likely anticipated eruption. 

They also need source parameters that encompass the range of uncertainty in eruption 

size or characteristics. 

In spring of 2007, a workshop was held at the U.S. Geological Survey (USGS) 

Cascades Volcano Observatory to derive a protocol for assigning eruption source 

parameters to ash-cloud models during eruptions. The protocol derived from this effort 

was published by Mastin and others (in press), along with a world map displaying the 

assigned eruption type for each of the world’s volcanoes. Their report, however, did not 

include the assigned eruption types in tabular form. Therefore, this Open-File Report 

presents that table in the form of an Excel spreadsheet. These assignments are 

preliminary and will be modified to follow upcoming recommendations by the 

volcanological and aviation communities. 

Assigned Eruption types and Source Parameters 

To assign eruption source parameters to the world’s volcanoes, we collected 

published data from well-documented eruptions and used those data to derive 11 types of 

volcanic eruptions, as listed in table 1. Associated with each eruption type are values of 

the eruption source parameters—plume height, eruption rate, erupted volume, duration, 

and mass fraction of fine tephra. We then assigned one of these eruption types to each of 

the world’s volcanoes, as described below. 

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Table 1. Guidelines used to assign eruption types to the world’s volcanoes. 

[The symbol H indicates characteristic plume height of recent historical eruptions. We assume that the most likely 

future eruption will resemble past recent eruptions. If both plume height and volcanic explosivity index (VEI) are 

available, the plume height that characterizes most eruptions at this volcano in recent decades is used to assign an 

eruption type. Otherwise, the VEI that characterizes most of the recent eruptions is used to assign an eruption type. 

Eruption type S8 (elutriated ash column) is assigned to a volcano only during an eruption on the basis of whether 

large-scale pyroclastic flows are being produced, not on the basis of historical activity.] 

Type Magma type Historical eruption 

characteristics 

M0 Insufficient historical 

data to characterize 

M1 H5 km or VEI2 

M2 H=5-8 km or VEI=3 

M3 

Basalt or other 

mafic 

>8 km or VEI4 

S0 Insufficient historical 

data to characterize 

S1 H6 km or VEI2 

S2 H=6-12 km or VEI=3 

S3 H12 km or VEI  4 

S8 Major pyroclastic flows, 

with an elutriated column 

rising primarily above 

the flows. 

S9 

Andesite, dacite, 

rhyolite, or other 

explosive 

composition 

Active lava dome is 

present 

U0 All magma types Submarine vent with a 

water depth 50 m 

The assigned eruption type for each volcano is based on its historical behavior (or 

lack thereof), using the guidelines summarized in Mastin and others (in press) and 

recapitulated here and in table 2. At volcanoes where the magma type of recent eruptions 

is known, we assign an eruption type “M” (mafic; for example, basalt or similar lowviscosity magma) or “S” (silicic; for example, andesite, dacite, rhyolite, or other higherviscosity magma). For a given eruption size as measured by plume height or erupted 

volume, mafic and silicic eruptions typically display somewhat different durations and 

grain-size distributions and so are assigned slightly different source parameters in the 

classification scheme. If the magma type is unknown or inaccessible, we assign it on the 

basis of the type of volcanic feature in the Smithsonian Institution database (Siebert and 

Simkin, 2002-9). For example, shield volcanoes, fissure vents, cinder cones, and maars 

are considered mafic; whereas stratovolcanoes, lava domes, pumice cones, calderas, 

complex volcanoes, explosion craters, and bimodal volcanic fields are considered silicic. 

For volcanoes with enough well-described historical eruptions to discern a trend, we 

assign future eruption type based on plume height of observed eruptions (where 

available) or on the characteristic eruption size as listed in the Smithsonian Institution 

database, using the volcanic explosivity index (VEI) of Newhall and Self (1982). For 

volcanoes that erupted many times in the past century, we give particular weight to 

eruptions in the past few decades in assigning an eruption type. Volcanoes with no welldescribed historical activity are assigned default type M0 or S0, and volcanoes whose 

vents lie more than 50 m below the ocean surface are assigned type U0, which is assumed 

to produce no eruptive plume. 

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Table 2. Eruption types and source parameters assigned to each eruption type 

[The mass eruption rate, M , erupted volume V, and mass fraction of fine ash m63 for each eruption type are based 

on mapping and characterization of the tephra-fall deposits at the example eruptions given in column 2. Plume height 

H and eruption duration D are from historical accounts. Types M1, M2, M3, S1, S2, S3, S8, S9, and U0 are assigned 

to each eruption. Type “M”, or mafic types, include basaltic and ultramafic magmas; type “S”, or silicic types, includ

andesite, dacite, rhyolite, and others, such as phonolite, that can produce high ash columns. Submarine eruptions that 

occur beneath at least 50-m water depth are assigned type “U0”.] 

e 

Eruption type Example 

(Date as M/D/Y) 

H, km 

above 

vent

D 

hr 

M

kg/s 

V 

km3

m63

Mafic, standard (M0) Cerro Negro, Nicaragua, 4/9-13/1992 7 60 1105 0.01 0.05 

 Small (M1) Mount Etna, Italy, 7/19-24/2001 2 100 5103 0.001 0.02 

 Medium (M2) Cerro Negro, Nicaragua, 4/9-13/1992 7 60 1105 0.01 0.05 

 Large (M3) Fuego, Guatemala, 10/14/1974 10 5 1106 0.17 0.1 

Silicic, standard (S0) Mount Spurr, USA, 8/18/1992 11 3 4106 0.015 0.4 

 Small (S1) Mount Ruapehu, New Zealand, 

6/17/1996 

5 12 2105 0.003 0.1 

 Medium (S2) Mount Spurr, USA, 8/18/1992 11 3 4106 0.015 0.4 

 Large (S3) Mount St. Helens, USA, 5/18/1980 15 8 1107 0.15 0.5 

 Co-ignimbrite 

 cloud (S8) 

Mount St. Helens, USA, 5/18/1980 

(pre-9 AM) 

25 0.5 1108 0.05 0.5 

 Brief (S9) Soufrière Hills, Montserrat 

(composite) 

10 0.01 3106 0.0003 0.6 

Submarine (U0) None 0 -- -- -- 

Format of the Spreadsheet 

Columns A through O in table 3 are the original columns in the Smithsonian 

Institution database. (To save space in the PDF version, columns B through G, J, and O 

are omitted). Column P is the eruption type, which uses the labels M0, M1, S0, etc. 

defined in table 1. Volcanoes with historical activity are highlighted in gray. 

Uncertainty in Assigned Eruption Source Parameters 

These assignments represent our best assessment of the type and size of future 

eruptions, but actual eruptions will vary from these predictions. To account for the 

possible range of values, modelers should consider running multiple scenarios, such as 

the following: 

1. Run forecasts for eruption types M1, M2, and M3 or for eruption types S1, S2, 

and S3 simultaneously, depending on the volcano's magma type. 

2. For type S9 volcanoes, run models S1, S2, S3, and S9. 

3. For type U0 volcanoes, run models for eruption types M1 and M2. 

As observations are acquired during an eruption, some scenarios can be eliminated, and 

others refined. 

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Future Revisions 

The assigned eruption source parameters listed in column P of table 3 are 

preliminary. Assignments will change as we obtain input from colleagues with expertise 

in each geographic region, and as volcanic activity unfolds. The version number at the 

time of writing is given on the title page. The eruption types listed in table 1 may also be 

modified to incorporate more realistic or robust models, or to consider uncertainty. A 

workshop at the U.S. Geological Survey’s Cascades Volcano Observatory in September 

2009 will identify possible improvements to this scheme. Major changes, if they are 

undertaken, would be described in a new document and spreadsheet by the Eruption 

Source Parameters Workgroup (headed by the authors of this report). Changes in the 

assigned eruption type of individual volcanoes would also be made by the workgroup, in 

consultation with experts on that volcano. 

References Cited 

Mastin, L.G., Guffanti, M., Servranckx, R., Webley, P., Barsotti, S., Dean, K., Denlinger, 

R., Durant, A., Ewert, J.W., Neri, A., Rose, W.I., Schneider, D., Siebert, L., 

Stunder, B., Swanson, G., Tupper, A., Volentik, A., and Waythomas, C.F., in 

press, A multidisciplinary effort to assign realistic source parameters to models of 

volcanic ash-cloud transport and dispersion during eruptions: Journal of 

Volcanology and Geothermal Research. 

Newhall, C.G., and Self, S., 1982, The volcanic explosivity index (VEI): an estimate of 

explosive magnitude for historical volcanism: Journal of Geophysical Research, 

v. 87, p. 1231-1238. 

Siebert, L., and Simkin, T., 2002-9, Volcanoes of the World: an Illustrated Catalog of 

Holocene Volcanoes and their Eruptions, Smithsonian Institution, Global 

Volcanism Program Digital Information Series, GVP-3 

[http://www.volcano.si.edu/world/summary.xls]. 

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