Table 1. Sulfur dioxide and carbon dioxide fluxes measured at Crater Peak, Mount Spurr volcano, Alaska, 1991-1993

[d-m-y, day-month-year; t/d, metric tons/day; avg, average value; 
max, maximum value; min, minimum value; sd, standard deviation; 
n, number of SO2 determinations; BG, background; NM, not measured;
>, minimum value]

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  Date        SO2  SO2   SO2    SO2   SO2        CO2       CO2/SO2
              avg  max   min    sd     n                    (wt)
(d-m-y)           (t/d)        (t/d)            (t/d)
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22-07-91      BG   BG    BG      -     -          NM          -

===> Precursory seismic activity starts beneath Crater Peak, August 1991

21-08-91      BG   BG    BG      -     -          NM          -
29-08-91      BG   BG    BG      -     -          NM          -
03-09-91      85   97    72     18     2          NM          -
22-11-91      BG   BG    BG      -     -          NM          -
14-05-92      88   96    80     10     2          NM          -

===> Volcano-tectonic earthquakes peak, June 5, 1992

===> First volcanic tremor bursts, June 6, 1992

08-06-92      21   24    18      4     2          NM          -

===> Eruption, June 27, 1992

29-06-92       5   10     2      3     5          NM          -

===> Eruption, August 18, 1992

10-09-92      BG   BG    BG      -     -          NM          -

===> Volcanic tremor episodes, September 12-25, 1992

===> Eruption, September 16-17, 1992

21-09-92      23   38    10     12     5          NM          -
23-09-92      24   33    22      7     4          NM          -
24-09-92      79   92    72     11     3          NM          -
25-09-92     300  370   240     54     4      11,000         53
28-09-92     190  270   180     25     4      12,000         90
29-09-92     750  830   690     75     3       8,700         17

===> Volcanic tremor episode, October 2-5, 1992

02-10-92     450  450   450      0     2          NM          -
03-10-92     220  320   110    110     4       4,800         32
04-10-92     210  320   170     72     4       3,500         24
05-10-92     360  560   230    170     4       2,900         12
10-10-92     240  360   160    100     3          NM          -

===> Volcanic tremor episode, October 12, 1992

14-10-92      47   50    44      4     3       2,400         74
15-10-92      64   67    62      4     2          NM          -
16-10-92    >200    -     -      -     -      >2,000          -
19-10-92      BG   BG    BG      -     -          BG          -
23-10-92      24   26    22      3     2       2,100        127
29-10-92      BG   BG    BG      -     -          BG          -

===> Earthquake swarms, November 9, 1992
  
10-11-92      BG   BG    BG      -     -          BG          -
11-11-92      BG   BG    BG      -     -          BG          -
12-11-92      BG   BG    BG      -     -       1,100      infinite
13-11-92      BG   BG    BG      -     -       1,000      infinite
15-11-92      BG   BG    BG      -     -       1,000      infinite
08-12-92      BG   BG    BG      -     -      >1,000      infinite
11-12-92      BG   BG    BG      -     -        >500      infinite
15-12-92      BG   BG    BG      -     -       3,200      infinite
18-12-92      BG   BG    BG      -     -      >1,000      infinite

===> Swarm of small VT earthquakes, December 21-26, 1992

23-12-92      BG   BG    BG      -     -      >1,000      infinite
21-01-93      BG   BG    BG      -     -      >1,000      infinite
18-02-93      BG   BG    BG      -     -        >400      infinite

===> Seismicity at pre-August 1991 levels, April 1993

24-04-93      BG   BG    BG      -     -        >930      infinite
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