Table 6.

Morphometric data concerning both bubbles and crystals of the selected samples collected during the 2002–2003 eruptive crisis

SampleSt51St57St55 and St61St62
Scoria June 2002Scoria December 2002Lava 2003Pumice April 2003
Total area analysed (mm2)230.16316.47542.811096.74
Bubbles
ϕba0.210.310.030.53
Average bubble distance (µm)323.59549.42500.03186.8
σ (standard deviation)0.040.380.080.04
Time of exsolution2 days7 days1 day15 hours
Crystals
ϕxxb0.380.450.380.07
Phenocrysts  Microlites
Nacc(mm−2)6.7×1034.3×1031.5×1044.1×104  2.4×104
Nvcd(mm−3)6.6×1044.3×1041.5×1057.3×105  1.4×1011
n° (L>0.80 mm)e (mm−4)6.5×1026.0×1013.7×102
n° (L<0.80 mm)e (mm−4)4.1×1042.8×1041.0×105
n°e (mm−4)1.3×104  3.4×108
Ld (L>0.80 mm)f0.1890.3430.2430.110  0.003
Ld (L<0.80 mm)f0.0980.0930.09
Nt (L>0.80 mm)g1.2×1022.1×1019.0×101
Nt (L<0.80 mm)g (mm−3)3.8×1032.6×1039.3×1021.4×103  9.4×105
R (L>0.80 mm)h0.750.730.95
R (L<0.80 mm)h0.990.990.990.98  0.92
  • aBubbles per unit area; brock crystallinity; careal number density per size class; dvolumetric number density; enumber density of crystal nuclei; fnumber-referenced dominant size; gnumber of crystal per unit volume; hlinear correlation coefficient; aand bmeasurements are directly determined from image analysis; all other parameters are determined from CSD plots.