Continuous in situ measurements of volcanic gases with a diode-laser-based spectrometer: CO2 and H2O concentration and soil degassing at Vulcano (Aeolian islands: Italy)

Table 1 Mean values and standard deviations for CO₂ and H₂O concentrations and for their ratios, as measured for each site. The sites were labelled in the first column (see the text for details): measurement PLB1 to PLB3 were taken at different heigth from the ground level. All the remaining measurement were taken at ground level.

Site	T/°C	CO₂/ppm			H₂O/ppm			CO₂/H₂O
		Mean	(error)	st.dev.	mean	(error)	st.dev.	mean	(error)	st.dev.
Porto Levante Beach (2/8/04)
PLB1	26	769	(19)	240	39700	(400)	5600	0.0195	(5)	0.0058
PLB2	26	477	(13)	122	36200	(400)	3500	0.0132	(4)	0.0034
PLB3	26	450	(12)	115	34500	(400)	3600	0.0131	(3)	0.0032
Palizzi (26/8/04)
PAL1	26	384	(3)	40	25540	(80)	1140	0.0150	(1)	0.0016
PAL2	26	468	(3)	44	25830	(75)	1050	0.0182	(1)	0.0018
PAL3	24	564	(12)	120	23130	(75)	740	0.0244	(5)	0.0053
Fossa Grande (27/8/04)
FOG1	25	481	(24)	170	29000	(1000)	7500	0.0174	(12)	0.0090
FOG2	26	564	(15)	120	34300	(500)	3400	0.0165	(4)	0.0031
FOG3	29	541	(22)	200	35200	(2000)	19600	0.0195	(5)	0.0058
FOG4	26	505	(20)	173	30200	(900)	8000	0.0178	(3)	0.0074

ISSN: 1467-4866