á Summary
o
Addresses the question: Do calderas preserve the
shape of underlying magma chambers?
o
Models a mobilized and locked magma bodies with
a shifting yield surface.
o
Performed a Monty Carlo simulation with several
free parameters.
o
Found that calderas can form from bot complete
and incomplete mobilizations.
o
Calculate the stress at the magma chamber
boundary
á Did
they make a good case?
o
Why donŐt they worry about mixing?
¤ Discussion
of the timescales involved and that mixing happens on much larger timescales
o
Question whether the Fish Canyon Tuff was a good
example site for full caldera collapse
¤ Perhaps
the Fish Canyon caldera fits into one of the bands seen in Fig 2
¤ Fish
Canyon is very well mixed. Paper
says the mixing happened prior to the event and is not a concern for the models
á Do you
think the choice of scope is appropriate? / Why did this work end up in a high
profile publication?
o
The yield stress component makes it unique and
opposed to models where the entire chamber is mobilized.
o
Challenges current thoughts using a dynamic
model
á Discussion
on why people think the whole magma chamber is evacuated in caldera collapse.
o
Discussion of what our current volcano model is.
á Why
does the magma chamber have the shape it does in the model?
o
As you increase in volume it I easier to add
mass laterally
á Why doesnŐt caldera collapse in a partial
ejection system remobilize the magma?
á Discussion
of Fig 2.
o
Model can say a lot but caution should be used
when interpreting it. Agree they
did a good job.
o
They donŐt get above 50% of the erupted volume
á How can
we account for sequential eruptions giving different chemical compositions?
á Discussion
of whether the need for strong country rock reflects reality of know sites
á Why
doesnŐt varying conduit change things?
o
Choked flow condition assumes flow at the sound
speed
o
Does this assumption make sense?
o
Model assumes isothermal conditions but model
parameters include temperature rates.
á How do
you decide how many runs to do in a Monty Carlo simulation?
á What is
Kolmogorov-Smirnov test?
á Feedback:
How do people feel about the format/style of the paper