HEAT AND MASS
DISCHARGE AT THE
YELLOWSTONE CALDERA
The Yellowstone Caldera formed
640,000 years ago when >1000 km3
of rhyolitic magma erupted catastrophically,
creating deposits of the
Lava Creek Tuff (Christiansen 2001).
The elliptical caldera measures about
80 50 km (FIG. 1) and is the site
of thousands of annual earthquakes
and abundant ground-surface displacements
(Smith and Braile 1994;
Christiansen et al. 2007). Uplift/subsidence
(bradyseismic) cycles
focused on the resurgent domes
(FIG.1) can last decades, with tens of
centimeters of net change
(Dzurisin et al. 1990; Smith and
Braile 1994; Wicks et al. 2006). Since
the caldera formed, it has partly