How much volcanic material is produced every year?
Here's a few estimates.
Andesite and Dacite Volcanoes
Augustine (1976): 11.6 m3/sec
Usu (1910): 3.5 m3/sec
Bezymianny (1955-1957): 1.8 m3/sec
Santorini (1866-1870): 0.7 m3/sec
Mount St. Helens (1980-present): 0.5 m3/sec
Colima (1975-1976): 0.05 m3/sec
From Table 4.2 of Cas and Wright (1987).
The eruption rates for 14 composite cones ranged from 0.5 km3/1,000 years to 27.5 km3/1,000 years.
The current eruption rate of basalt at Kilauea is about 0.1 cubic km per year. That's high relative to the entire volcanic chain which was created by rates of <0.01 to 0.06 cubic km per year over the last 70 million years. High rates occurred 18, 48, and 58 million years ago. The lowest rates were from about 30-36 million years ago.
The eruption rates for the Puu Oo lava fountains ranged from 17 to 367 m3/sec (0.05 to 1.15 cubic km per year).
The Laki and Grimsvotn eruptions (1783-1785) had an average rate of 2,300 m3/sec (7.25 cubic km per year).
Nyamuragira (1901-1977): 0.4 m3/sec.
Vesuvio (1750-1900): 1.9 m3/sec.
Kilauea (1952-1971): 3.5 m3/sec.
Merapi (1890-1992): 0.04 m3/sec.
From Table 2 in Siswowidjoyo and others (1995).
Monogenetic Volcanic Fields
Michoacan-Guanajuato field: 0.8 km3/1,000 years.
Area near Paricutin: 1.2 km3/1,000 years.
Sources of Information:
Volcanic Successions Modern and Ancient; 1987; Cas, R.A.F., and Wright, J.V.; Allen & Unwin; London, UK; 528 p. del Marmol, M. and Marsh, B., 1994, Merapi volcano, central Java: source rocks and prediction of the eruptive behavior of the volcano: AGU abstracts, p. 731.
Hasenaka, T., and Carmichael, I.S.E., 1985, The cinder cones at Michoacan-Guanajuato, Central Mexico: their age, volume, and distribiution, and magma discharge rate: Journal of Volcanology and Geothermal Research, v. 25, p. 105-124.
Hasenaka, T., 1994, Size, distribution, and magma output rate for shield volcanoes of the Michoacan-Guanajuato volcanic field, Central Mexico: Journal of Volcanology and Geothermal Research, v. 63, p. 13-31.
Parfitt, E.A., Wilson, L., and Neal, C.A., 1995, Factors influencing the height of Hawaiian lava fountains: implications for the use of fountain height as an indicator of magma gas content: Bull. Volcanology, v. 57, p. 440-450.
Purbawinata, M.A., Ratdomopurbo, A., Sinulingga, I.K., Sumarti, S., Suharno, 1996, Merapi volcano a guide book: Volcanological Survey of Indonesia, Bandung, 64 p.
Siswowidjoyo, S., Suryo, I., and Yokoyama, I., 1995, Magma eruption rates of Merapi volcano, central Java, Indonesia during one century (1890-1992): Bull. Of Volcanology, v. 55, p. 233-263.
Shaw, H.R., 1987, Uniqueness of volcanic systems: in Decker, R.W., Wright, T.L., and Stauffer, P.H., (eds.), Volcanism in Hawaii, U.S. Geological Survey Professional Paper 1350, v. 1, p. 1357-1394. Thordarson, Th, and Self, S., 1993, The Laki (Skaftar Fires) and Grimsvotn eruptions in 1783-1785: Bull. Of Volcanology, v. 55, p. 233-263.