Statistical Seismology Science Gateway - Science Gateways for Distributed Computing Infrastructures - page 164

cate to access
a European DCI, such as the Turkish Grid. Alternatively, for relatively short
runs and trial purposes only, a user can directly run SFFs on the local cluster
“

To execute the SSF workflows, users need to submit a valid certi

Pomegranate ” , even when the user holds no certi cate.

12.3.2 SSS-Gateway Work fl ows

SSS-Gateway includes a total of eight workflows; one workflow for each of the
seven SSFs and additionally one wrapper workflow for the advanced service level.
All the workflows, except the one for SSF6, are designed as simple workflows that
contain a single node with one or more input ports and a single output port .Asan
example, the SSF3 workflow is shown in Fig. 12.3 . On the other hand, the SSF6
workflow is designed as a typical parameter sweep work fl ow , as depicted in
Fig. 12.3 , containing three nodes that perform the following tasks:

The generator job SSF6-Distribute prepares speci

￿ c parameter sets for branches

included in the logic-tree analysis.

The parametric job SSF6-Execute performs calculations for each generated
parameter set.

￿

The collector job SSF6-Combine produces the final output of the workflow by
means of processing the results obtained for each branch.

￿

SSF1 work fl ow combines different earthquake catalogs to obtain a more reliable
integrated earthquake catalog and also analyzes the produced catalog for com-
pleteness by using Stepp

s method (Stepp 1972). Fore- and aftershock elimination
is also conducted by determining time and space windows (Deniz 2009). The
workflow allows an arbitrary number of earthquake catalogs to be used as input and
also provides the option to download catalogs from a number of prede

'

ned sources.
Furthermore, it is possible to specify different parameters for combining (such as
location bounds, date range, etc.) and for producing completeness results.
Both SSF2 and SSF3 work fl ows estimate input parameters of the Gutenberg-
Richter magnitude

frequency relation (Gutenberg 1944) for different probabilistic
seismic hazard analysis (PSHA) models and additionally estimate parameters of

-

Fig. 12.3 SSF3 ( left ) and SSF6 ( right ) workflows