Hi Don - I think the Caldera wall is somewhat south of the resurgent dome - I don't think I understand how the caldera wall could erode even - due to the stream into Crowley lake? due to more faulting? Are you talking above ground or underground? Do you have any references to the caldera wall eroding? Are you talking about its floor? A collapse under the magma chamber?

One thing I'm sure of that could cause a problem is if a quake should strike on the fault that occurs along the south moat that causes Mammoth Mountain to get sqeezed (there's a strike-slip fault there) - now that could cause a nice explosion on the mountain but not of the caldera itself.

Canie