Geoscience Reference
In-Depth Information
In the case of Kibedani geyser, a spouting mode and a pause mode are
alternately observed. Drawing a graph of time variation of a position of the
interface between the lump of water in the hole and atmosphere about the
former mode, we can see that time taken for the position of the interface
to reach a peak from the ground is shorter than one to turn back to the
ground from the peak.
For reproducing these characteristic time variation of a position of the
interface by the dynamical model, we additionally improved the modified
dynamical model. That is, we considered that during spouting a part of
gas under the lump of water was left out to atmosphere and added effects
of release of gas there in proportion to length of the lump of water in a
vertical direction to the former modified dynamical model. This addition-
ally improved dynamical model enabled reproduction of characteristic time
variation of a position of the interface similar to one of a spouting mode of
Kibedani geyser and estimation of parameters under it.
On the other hand, a pause mode among two modes of Kibedani geyser
cannot be reproduced by the dynamical model. However, it can be explained
by a mathematical model (a static model).
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Therefore, a chain of dynamics
of Kibedani geyser's spouting can be expressed completely by a combined
model combining the additionally improved modified dynamical model with
the mathematical model. In this combined model the mathematical model
or the dynamical model can have independent parameters, respectively.
From this characteristics, if a value of a parameter of one model, which
is decided as results of numerical simulation agrees with those of obser-
vation, is different from one of the other model, the value is regarded as
unrealistic one. Therefore, concerning common parameters to both models
equal value has to be had in each model. In this sense, this combined model
can be considered to connote a role as verification of estimated values of
parameters.
In this presentation, we will introduce this combined model and report
estimation of parameters under Kibedani geyser based on comparison
between results of simulation of this combined model and those of observa-
tion of Kibedani geyser.
2. Characteristics of Spouting Dynamics of Periodic
Bubbling Spring
As stated above, a position of the interface between the lump of water in
the hole and atmosphere of periodic bubbling spring generally varies with
