The best understood basaltic volcano in the world ( Tilling
and Dvorak, 1993) has entered its thirteenth year of more-or-less
continuous lava effusion, forming an extensive pahoehoe flow field
that has attained a volume of about 1 km
, with a magma supply
rate of 0.09 km
/year ( Dvorak and Dzurisin, 1993). The
lava flow field has grown considerably in area over the past four
years and in 1990-1991 overran the village of Kalapana ( Mattox
et al., 1993), all the while sending lava into the sea and causing
air pollution by the generation of a boundary layer acid aerosol.
Documentation of the growth of pahoehoe flows by internal injection
of lava and inflation of lava sheets or plateaus ( Hon et al.,
1994) is providing new insight into lava emplacement
characteristics. Steady-state, long-term (decades to centuries)
persistent activity, as featured by volcanoes such as Kilauea and
Stromboli, has been attributed to endogenous growth by considerably
greater amounts of intrusive magma than erupted material (
Giberti et al., 1992; Francis et al., 1993).
The ongoing eruption at Pu'u O'o and nearby vents has permitted the development of several new methodologies for studying thermal properties of lava flows using field, airborne, and satellite-based remote sensing devices. By using a field spectroradiometer, Flynn and Mouginis-Mark (1992) and Flynn et al. (1993) have been able to determine the temperature distribution on an active lava flow and the Kupaianaha lava lake. These techniques have been extended using Landsat thematic mapper observations ( Flynn et al., 1994) to provide an image of the total thermal energy coming from a lava flow. Other techniques, most notably the remote identification of near-surface (within 5 meters) active lava tubes ( Realmuto et al., 1992), have also been developed at Kilauea and may be important in future hazard assessment of ongoing eruptions.