 |
| Titel |
Probabilistic seismic hazard maps from seismicity patterns analysis: the Iberian Peninsula case |
| VerfasserIn |
A. Jiménez, A. M. Posadas, T. Hirata, J. M. García |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1561-8633
|
| Digitales Dokument |
URL |
| Erschienen |
In: Natural Hazards and Earth System Science ; 4, no. 3 ; Nr. 4, no. 3 (2004-06-10), S.407-416 |
| Datensatznummer |
250001692
|
| Publikation (Nr.) |
 copernicus.org/nhess-4-407-2004.pdf |
|
|
|
|
|
| Zusammenfassung |
| Earthquake prediction is a main topic in Seismology. Here, the goal is to
know the correlation between the seismicity at a certain place at a given
time with the seismicity at the same place, but at a following interval of
time. There are no ways for exact predictions, but one can wonder about the
causality relations between the seismic characteristics at a given time
interval and another in a region. In this paper, a new approach to this kind
of studies is presented. Tools which include cellular automata theory and
Shannon's entropy are used. First, the catalogue is divided into time
intervals, and the region into cells. The activity or inactivity of each
cell at a certain time is described using an energy criterion; thus a
pattern which evolves over time is given. The aim is to find the rules of
the stochastic cellular automaton which best fits the evolution of the
pattern. The neighborhood utilized is the cross template (CT). A grid search
is made to choose the best model, being the mutual information between the
different times the function to be maximized. This function depends on the
size of the cells β on and the interval of time τ which is considered for
studying the activity of a cell. With these β and τ, a set of probabilities
which characterizes the evolution rules is calculated, giving a
probabilistic approach to the spatiotemporal evolution of the region. The
sample catalogue for the Iberian Peninsula covers since 1970 till 2001. The
results point out that the seismic activity must be deduced not only from
the past activity at the same region but also from its surrounding activity.
The time and spatial highest interaction for the catalogue used are of
around 3.3 years and 290x165 km2, respectively; if a cell is inactive,
it will continue inactive with a high probability; an active cell has around
the 60% probability of continuing active in the future. The Probabilistic
Seismic Hazard Map obtained marks the main seismic active areas
(northwestern Africa) were the real seismicity has been occurred after the
date of the data set studied. Also, the Hurst exponent has been studied. The
value calculated is 0.48±0.02, which means that the process is
inherently unpredictable. This result can be related to the incapacity of
the cellular automaton obtained of predicting sudden changes. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|