Figure 1
From: Causes of volcanic unrest at Mt. Spurr in 2004–2005 inferred from repeated tomography
Topography of the study area (extracted from Global Multi-Resolution Topography, GMRT)28 and distribution of the seismic stations (red triangles). The limits of the horseshoe caldera are highlighted by the orange line. The summit of Mt. Spurr and Crater Peak are indicated by the dotted line.
