Auxiliary material for
Regional controls on volcano seismicity along the Aleutian arc
Helena Buurman1, Christopher J. Nye2, Michael E. West3 and Cheryl Cameron2
1
Geophysical Institute, University of Alaska Fairbanks, 903 Koyukuk Drive, Fairbanks, AK,
99775-7320, USA.
2
Alaska Volcano Observatory, Alaska Division of Geological and Geophysical Surveys, 3354
College Road, Fairbanks, AK, 99709, USA.
3
Alaska Earthquake Information Center, Geophysical Institute, University of Alaska Fairbanks,
903 Koyukuk Drive, Fairbanks, AK, 99775-7320, USA.
G-Cubed, 2013
Introduction
These materials include the earthquake catalogues used in this study, the assembled geochemical
data and a number of figures that result from these data but which are not directly relevant to the
outcomes in our study. The earthquake catalogues for each volcano are shown both as map
locations and plotted as a function of time in Appendix A, which also include supplemental
information on each volcano (such as location, elevation, etc). These data are published annually
by the Alaska Volcano Observatory as part of its volcano monitoring mission in Alaska. Data
outages and episodes of unrest have been defined by the authors and are described in the
manuscript. The geochemical data used in the study are listed in table Appendix C, and include
references to the publications from which the data are derived. The remaining figures Appendix
B, Appendix D, Appendix E, Appendix F, Appendix G and Appendix H contain notable
relationships between the data used in this study.
1. Appendix A presents the earthquake catalogues for each monitored volcano. Each
catalogue is displayed in a map view centred on the volcano’s summit (yellow triangle),
with volcanic earthquakes coloured according to depth and regional earthquakes shown
as grey circles. The extent of each catalog, which encompasses 90% of the earthquake
activity below the edifice, is indicated by a black circle. For closely-spaced peaks, the
catalogs are truncated in order to avoid overlap. Seismic stations are shown as black
squares and all Holocene vents associated with the volcano are shown as purple
diamonds. The catalogues are also displayed using depth as a function of time, where
volcanic earthquakes are shown as coloured circles (coloured as a function of depth) and
regional earthquakes are shown as grey circles. Grey bars represent data outages, yellow
bars indicate episodes of seismic unrest and red bars indicate eruptive episodes. The
cumulative earthquake rate is superimposed as a black line.
2. Appendix B shows the spread of seismicity below each volcano plotted as a function of
the elevation for each monitored volcano.
3. Appendix C shows the distribution of cumulative earthquake magnitudes per year of data
within 3 km depth bins below each volcano, for earthquake catalogues of radius 5 (Figure
1), 10 (Figure 2) and 15 (Figure 3) km centered on each volcano.
4. Appendix E is a map view of the Aleutian arc that shows available moment tensor
solutions in the upper 30 km of the crust between 1976 and 2012. Moment tensors are
grouped into thrust (blue circles), normal (green circles) and strike-slip (red circles).
5. Appendix F shows the distribution of cumulative earthquake magnitudes per year of data
within 3 km depth bins below each volcano, using only earthquakes that were recorded
outside of episodes of seismic or eruptive unrest.
6. Appendix G shows the distribution of cumulative earthquake magnitudes per year of data
within 3 km depth bins below each volcano, for volcanoes with a minimum of 5 (Figure
1), 6 (Figure 2) and 7 (Figure 3) seismic stations.
7. Appendix H shows the distribution of cumulative earthquake magnitudes per year of data
within 3 km depth bins below each volcano, using 1 year (Figure 1), 3 years (Figure 2)
and 5 years of data (Figure 3).
8. Appendix I shows the distribution of cumulative earthquake magnitudes per year of data
within 3 km depth bins below each volcano, using only earthquakes with magnitudes
greater than the arc-wide magnitude of completeness (1.4).
9. Appendix D shows the median whole-rock weight % SiO2 data derived from published
analyses.
9.1 Column “volcano”, volcano name
9.2 Column “Median weight % SiO2”, median whole-rock weight % SiO2 calculated
from published data
9.3 Column “Abbreviated references”, Authors and publication year for the published
analyses
9.4 Column “Full references”, Full references for each publication used to derive the
median SiO2 values used in this study.