-Contains a single rift zone at the Cumbre Vieja volcanic center, numerous historical eruptions (Carracedo, 1994).

-Second and third rift zones formed a "Mercedes star" but ceased activity before 20 ka (Carracedo, 1994).

-Erupted melts are MORB-like in composition (Klugel et al., 2000).

-Geochemical analysis of 1949 eruption revealed no large magma reservoir within Cumbre Vieja, implying that magmas are stored in the upper mantle (Klugel et al., 2000).

Figure 1: Historic volcanism from Cumbre Vieja (Klugel et al., 2000).

-Two large calderas north of 1949 eruptive center are produced by a large scale detachment event and merge southward into the active rift center (Carracedo, 1994).

-1949 eruptions produced a ~3 km long fault zone that allowed the eastern flank to subside up to 4 m (Day et al., 1999).

-Extensive seismicity localized near fault zone and within erupting rift zone prior to and during eruption (Day et al., 1999).

-The major cause for concern over La Palma---what is the extent and stability of the fault/rift system of the Cumbre Vieja volcano?

Figure 2: Faulting along the active southern rift zone (Carracedo, 1994).