Application of SASHA for Portugal cases: mainland Portugal

Carvalho A. (LNEC), Albarello D. (Un. Siena), Meroni F. (INGV) and Zonno G. (INGV)

Elements used for a preliminary application evaluate the Seismic Hazard of Portugal using SASHA2.0.3

• seismic catalog with Intensity Io

• attenuation parameters

• SASHA2.0.3 program code

• At the moment, local seismic histories have not been considered

Using SASHA2.0.3• completeness is accounted for

during hazard computations• no effect of uncertain

seismotectonic zoning• evetual clustering is accounted

for and no aftershock removal is required

Hazard Mapping Based on Macroseismic Data Considering the influence of Geological Conditions

By M.L. Sousa and C.S. Oliveira

Natural Hazards 14: 2007-225, 1997

Lisboa 1755

Distribution of seismic seismicity around Mainland Portugal, Lower Tagus Valley and Algarve

Seismic catalogue

Seismic catalog SHARE

The seismic catalog from the European project SHARE has been considered

converted the Mw into intensity Io using the published relationship

Only Moment Magnitude Mw >= 5.5

Only more about 100 events

Completed the SHARE catalog with the Events used for attenuation parameters that were NOT in the SHARE catalog

Seismic catalog SHARE finding the intensity I0

Used the SCR relationship to evaluate Io from Mw

by courtesy Varini et al., 2013

3°General Meeting UPStrat-MAFA

Attenuation distributions

by courtesy Varini et al., 2013

3°General Meeting UPStrat-MAFA

Attenuation distributions

by courtesy Varini et al., 2013

3°General Meeting UPStrat-MAFA

by courtesy Varini et al., 2013

3°General Meeting UPStrat-MAFA

Example of seismic catalog input for SASHA2.0.3

Previous results by Sousa and Oliveira, 2007

Basic Cornell approach

Hazard evaluation Portugal by SASHA2.0.3

20 y Average Return Time 50 y Average Return Time

Hazard evaluation Portugal by SASHA2.0.3

95 y Average Return Time Previous estimates (Sousa and Oliveira, 2007)

Hazard evaluation Portugal by SASHA2.0.3

475 y Average Return Time Previous estimates (Sousa and Oliveira, 2007)

Hazard evaluation Portugal by SASHA2.0.3

475 y Average Return Time Previous estimates (Sousa 2006)

Comparison with previous results

Results using the Cornell approach

Comparison with SASHA outcomes

10 100 1000 100004

5

6

7

8

9

10

Hazard evaluation Portugal by SASHA2.0.3

475 y Average Return Time Previous estimates (Sousa and Oliveira, 2007)

Deggregation

The use of the SASHA code provides hazard estimates for Portugal that are significantly different from the ones provided by the standard Cornell-McGuire approach

These differences also relies on the different use of available information (seismic history, seismotectonic zoning)

The ones here illustrated just represent a first preliminary application of SASHA code: local seismic histories will be considered along with a more accurate revision of available apicentral information

Conclusions (very preliminary)